The life of a cancer patient is complicated by a litany of physical, psychological, social and spiritual factors leading to anxiety, fatigue, depression and several other unpleasant emotional issues. Nausea and vomiting, insomnia and pain also contribute greatly to the overall discomfort. These symptoms often result in a significant reduction in the quality of life. A host of non-pharmacological therapeutic interventions have been tried to alleviate this associated physical and emotional issues in cancer patients, with limited success. Yoga therapy has increasingly demonstrated evidence based benefits in alleviating many of these cancer-related symptoms and in greatly improving the quality of life of these patients.

Keywords: yoga; cancer; anxiety; depression; fatigue; nausea and vomiting; cancer pain; quality of life

Yoga evolved over thousands of years in India. The ancient sages developed this practice as an integrative physical, psychological and spiritual regimen with the ultimate aim at establishing a ‘union’ with the ‘Source’. This Eastern discipline in now popular in the West in a non-spiritual/non-religious format, comprising mainly of asanas (physical postures), pranayama (breathing exercises) and dhyana (meditation), with an emphasis on achieving and maintaining optimal health (both external and internal). It is estimated that in 2016, almost 36 million Americans practiced yoga.¹ Yoga practices trigger several neuro endocrine and hemodynamic changes that beneficially modify the initiation and/or progression of several human disease processes. These diseases include neurological, psychological, orthopedic, cardiovascular and pulmonary ailments. The positive impact of yoga on many other health conditions is also being investigated and scientific data is gradually accumulating. Favorable results have also been noted in alleviating some of the ancillary symptoms experienced by patients with cancer.² However, despite the increasing number of evidence based studies attesting to the beneficial effects of yoga as a complementary modality in cancer patients³ and the popularity of complementary therapeutic modalities in these patients,⁴ most oncologists are still not, proactively, recommending yoga therapy to their cancer patients.⁵

This article objectively scrutinizes the published studies and presents a brief review of the evidence based data attesting to the ameliorating properties of yoga, when used in patients struggling with several cancer related symptoms.

A comprehensive search of ‘yoga and cancer’ and several cancer and yoga related topics was carried out using PubMed (Medline) and PMC (PubMed Central) database of the US National Library of Medicine; National Institutes of Health. Other contemporary and complementary medicine databases were also queried and relevant publications were reviewed. Additional studies were identified by searching bibliographies of reviews and were also consulted, if relevant.

Search under ‘yoga and cancer’ revealed 339 citations dating back to 1975 on PubMed. PMC revealed 2,736 full length articles. Other queries revealed: ‘cancer and anxiety’: PubMed:12,694, PMC:87,583; ‘cancer and depression’: PubMed:19,680, PMC:57,853; ‘cancer and pain’: PubMed:90,082, PMC:170,754; ‘cancer and nausea and vomiting’, PubMed:13,458, PMC:29,948; ‘cancer and fatigue’, PubMed: 16,246, PMC: 48,097; ‘cancer and insomnia’: PubMed:1,394, PMC:11,803; ‘cancer and quality of life’: PubMed:64,004, PMC:202,092. Results of similar queries involving yoga were as follows: ’yoga and anxiety’: PubMed:539, PMC: 3344; ‘yoga and depression’: PubMed:514. PMC:3667; ‘yoga and pain’: PubMed:562, PMC:3579; ‘yoga and nausea/vomiting’: PubMed:10, PMC:329; ‘yoga and fatigue’: PubMed:206, PMC:1892; ‘yoga and insomnia’: PubMed:66, PMC:870; and ‘yoga and quality of life’: PubMed:626, PMC:4178.

Yoga Interventions used in Studies: There is no standardized approach in conducting yoga for clinical studies. This lack of uniformity stems from several factors. Firstly, there are several yoga styles - Anusara, Ashtanga, Bikram, Iyengar, Jivamukti, Kripalu, Sivananda, Sudarshan kriya yoga, Tibetan Yoga, Vinyasa yoga etc. Secondly, there are hundreds of commonly performed yoga poses, several versions of breathing exercises and many approaches to attain meditation/relaxation. Most clinical studies appear to utilize all three commonly performed formats of yoga - asanas (postures), pranayama (breathing exercises) and dhyana (meditation). The total time duration prescribed for the yoga practice varied from 60-90minutes, with a minimum participation of three times a week. Self-practice at home was allowed/encouraged in some studies. The study duration varied from 6weeks to 12weeks. Most study individuals participated for a minimum of 18 sessions of yoga. A typical session consisted of several yoga poses such as sun salutations, seated or reclining postures, standing poses, twists, transition poses; inversion etc. The duration of posture hold varied from 20 seconds to 5minutes. Breathing exercises included several techniques, such as ujjayi (ocean breath), bhastrika (bellows breath), nadi shodhana (alternate nostril breathing), etc. Meditation and deep relaxation was achieved using different approaches such as mantra changing, imagery, lying with the eyes closed in savasana (corpse pose) etc. The duration of each modality varied from 20-40minutes. Most yoga sessions were conducted by certified yoga instructors

Cancer is a major public health problem worldwide. According to the American Cancer Society, it is estimated that in 2017, there will be 688,780 new cancer cases diagnosed and 600,920 cancer deaths in the US.⁶ It continues to be the second leading cause of death in the USA.⁶ The statistics are equally dismal for the entire world - in 2012, there were 14.1 million new cases of cancer diagnosed and 32.6 million people were living with cancer.⁷ In 2015, available data indicates that cancer caused 8.8 million deaths and was the second leading cause of death, globally.⁸ It is estimated that in 2030, new cancer cases will increase to almost 21.7million and cancer deaths to 13million, around the world.⁹ The period encompassing the diagnosis of cancer, its treatment and the post treatment rehabilitation, is often associated with a significant disruption in a patient’s life. This entire period may be complicated by a litany of distressing factors and these include anxiety, stress and depression.¹⁰ Fatigue and insomnia also contribute greatly to the overall discomfort.^11,12 Pain, both acute and chronic, is also common during this stage.^13–16 Chemotherapy may further bring disturbing nausea and vomiting.¹⁷ These symptoms, unfortunately, often occurring concomitantly and result in a significant reduction in the quality of life of these patients.^18–20 A host of non-pharmacological therapeutic interventions have been tried in order to alleviate the cancer and its treatment related noxious symptoms, with limited success.^21–25 Yoga therapy has been demonstrating an increasing potential benefit in improving these cancer-related physical and emotional issues and greatly improving the quality of life of these patients.^26,27

Anxiety

Symptoms of anxiety are part of everyone's life and are common in the general population,²⁸ but pathological anxiety is significantly more common^29,30 and often under-diagnosed in cancer patients.³¹ Significant anxiety may affect from 2% to 14% of patients with advanced cancer.^32–34 Its presence is associated with a subjective increase in other symptoms²⁹ and experiencing decreased physical functioning.³⁵ Anxiety also results in a poorer quality of life in these patients.³⁶ Survival time is decreased.³⁷

Yoga has beneficial effects in the complementary treatment of anxiety.³⁸ Meditation helps decrease anxiety in the cancer patients.^39,40 Yoga exercise also helps ameliorate cancer related anxiety.^41–43 Though the available data is positive, clinical studies in cancer patients remain limited.

Depression

According to current diagnostic criteria,⁴⁴ major depression is characterized by five or more of the following symptoms being present concurrently for at least two weeks:

1. Depressed mood,
2. Loss of interest in previously pleasurable activities
3. Feelings of inappropriate guilt or worthlessness
4. Recurrent thoughts of death or suicide
5. Psychomotor slowing or agitation
6. Disturbance of appetite
7. Disturbance of sleep
8. disturbance of energy and
9. Impaired concentration

One of the five symptoms must include depressed mood or diminished interest in previously pleasurable activities. It is a common ailment globally and carries the heaviest burden of disability among mental and behavioral disorders.⁴⁵ Major depression has a high rate of co-occurrence with other medical conditions.⁴⁶

Depression is common in cancer patients,⁴⁷ with prevalence rates of 13% to 40%.^48,49 These rates are much higher than that seen in the general population.⁵⁰ About 20% to 30% of breast cancer patients experience severe depression.⁵¹ Depressed cancer patients have a decreased quality of life.⁵² The negative effect on mortality has also been documented.^53,54 Unfortunately, despite the availability of excellent therapeutic pharmaceuticals for this ailment, antidepressant therapy is often associated with non-efficacy, drug resistance⁵⁵ polypharmacy⁵⁶ non-compliance, relapses and a high cost.^57–59

Several studies have provided persuasive evidence attesting to the benefits of yoga therapy in patients with depression.^60–63 Attenuation of depression has also been noted in patients with cancer, especially breast cancer, in several clinical trials.^64–66 A recent Cochrane meta-analysis of 23 studies involving 2166 participants concluded that moderate quality evidence exists in supporting the use of yoga for a therapeutic reduction in depression, anxiety and fatigue, when compared with other psychosocial/educational interventions, in patients with breast cancer.⁶⁷ Reduction of depression has also been noted in other cancers.⁶⁸ Interestingly, emotional benefits have also been seen in cancer caregivers with yoga therapy.⁶⁹

Pain

Pain in cancer is common⁷⁰ and often the most feared symptom.⁷¹ Pain may be due to the cancer itself, or its treatments, which may include surgery, chemotherapy and radiotherapy.⁷² It is estimated that up to 20% of cancer patients are unable to find pain relief with conventional treatment.⁷³ When the malignant disease is advanced, almost 70% of patients may be unable to get rid of the pain.⁷⁴ Complementary therapies are often resorted to by these patients.^75,76 Some studies have demonstrated benefits of yoga in pain reduction in these patients.^77,78 Further studies are however needed for a better evidence based analysis and practical recommendations.

Nausea and vomiting

Nausea and vomiting in most animals is a protective function that serves to expel potential harmful substances from the gastrointestinal tract prior to their absorption and/or to prevent indigestible material from entering the gut.⁷⁹ In humans, nausea and vomiting is also seen in many physiological conditions, such as pregnancy⁸⁰ and motion sickness.⁸¹ However, nausea and vomiting may accompany and often alerts humans to many disease processes, especially those involving the gastro-intestinal tract.⁸² Nausea and vomiting is also a common side effect of cancer chemotherapy⁸³ and can be very distressing.^84–88 It remains one of the most difficult of all side effects to treat in these patients.^89,90 It greatly reduces their quality of life.⁹¹ Its appearance may also lead to a dangerous refusal to continue essential cancer treatment.⁹²

Yoga therapy has also been studied in these patients, as a complementary modality. A small study in 2007, reported a significant decrease in post-chemotherapy-induced nausea frequency, nausea severity and intensity of anticipatory nausea and vomiting in patients practicing yoga when compared with the non-yoga control group.⁹³ However, a recent 8-week study did not demonstrate a benefit stemming from the practice of yoga in ameliorating symptoms of nausea and vomiting related to cancer chemotherapy.⁹⁴

Fatigue

Patients with cancer frequently experience significant fatigue.^95,96 The prevalence rates may be as high as 75% in these patients.⁹⁷ Besides the cancer,⁹⁸ treatment with chemotherapy and radiotherapy is often associated with fatigue and this further reduces the patient’s quality of life.^99–101 In one study, a quarter of the cancer patients experienced severe fatigue during a six month follow up, during palliative treatment.¹⁰² Fatigue in cancer patients is also quite persistent and up to one third of them may experience it for up to 10 years after the cancer diagnosis.¹⁰³ Cancer-related fatigue is the most important cause of a decreased quality of life in these patients.¹⁰⁴ It’s presence also appears to prognosticate a reduced survival.¹⁰⁵

Physical exercise has been suggested to combat this often stubborn and persistent symptom.¹⁰⁶ Yoga has also been successfully tried. Besides incorporating exercise, yoga diminishes many adverse psychological emotions in cancer patients, further attenuating the feelings of fatigue.¹⁰⁷ Many participants also experience improved sleep patterns.¹⁰⁸ A Cochrane review, after performing a meta-analysis of 23 studies involving 2166 participants, concluded that yoga practice presented a moderate-quality evidence in reducing fatigue and sleep disturbances when compared with no therapy in cancer patients.¹⁰⁹

Insomnia

Insomnia means poor-quality or inadequate sleep. It is characterized by one or more of the following problems: difficulty falling asleep, difficulty maintaining sleep, waking up too early in the morning or sleep that is not refreshing.¹¹⁰ Sleep disturbances are common in the general population.^111,112 Pharmacological agents are commonly prescribed to help improve sleep quality and/or duration.¹¹³ Lifestyle interventions and cognitive behavioral therapies are also commonly used.¹¹⁴ Insomnia adversely affects the quality of life in many patients.¹¹⁵ Yoga therapy, including mindfulness, has been helpful in the complementary management of sleep.^116,117

Poor quality of sleep is extremely common in cancer patients,^118,119 but often ignored.¹²⁰ The causes are multifactorial and include cancer related symptoms, treatment side effects and a host of associated emotional factors.^121–123 The positive benefits of yoga in establishing better sleep in cancer patients has been reported in some studies.^124,125 A recent trial involving 410 patients demonstrated that the group participating in yoga noticed an improvement in several sleep parameters, including reduction in post-intervention medication use, when compared with standard care participants.¹²⁶ Yoga appears to play a beneficial role in the management of sleep disturbances in cancer patients.

Quality of life

The World Health Organization defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.¹²⁷ Quality of life (QOL) or health - is an individual’s perceived physical and mental health and can be measured by several means, including self-reported questionnaires,^128–130 such as the Health-related quality of life (HRQOL),¹³¹ SF-36,¹³² EuroQol¹³³ and WHOQOL.¹³⁴ Quality of life is becoming an important consideration and its improvement, one of the therapeutic goals, in the treatment of many diseases, including cancer.¹³⁵

Quality of life in cancer, is the physical, emotional, social and functional well-being and perceived symptom burden, from a patient’s point of view.¹³⁶ Cancer diagnosis, treatment and survival greatly affect the QOL in these patients.¹³⁷ Several demographic risk factors also are related to cancer-related QOL.¹³⁸ QOL also appears to prognosticate survival in many cancers.^139–141 Yoga can improve the quality of life in cancer patients.^5,142 Several studies have shown that women with breast cancer realize a marked improvement in quality of life scores and emotional well-being with yoga therapy.^143–146 The beneficial effect of yoga on the quality of life has also been noted in other cancers.^147–149

Due to the small number of studies, often with limited participants, no causal relationship between yoga and cancer connected pain alleviation, or yoga and cancer related nausea and vomiting relief, can be made. However, evidence based data clearly demonstrates that yoga therapy is a safe and acceptable adjunctive therapeutic intervention in cancer patients with many other disturbing ancillary symptoms. Larger and more robust studies have demonstrated that most cancer patients experience a decrease in fatigue and become more physically active, with yoga therapy. There is also a measurable improvement in their psychological wellbeing, especially with a clinically relevant reduction in depression. The overall quality of life is also significantly improved. Because of the small sample size of studies and a lack of a standardized yoga study protocol, the role of individual yoga interventions in alleviating specific cancer related symptoms, cannot be delineated. In general, however, yoga therapy, as a complementary therapeutic modality, has viable evidence based role, for alleviating several extremely distressing symptoms experienced by cancer patients.

This brief review is based on an abstract presented as an eposter at the Pan African Congress of Integrative Medicine meeting in Cape Town, SA in May 2017.

The author declares no conflict of interest.

1. Yoga Journal and Yoga Alliance. USA: Yoga in America study; 2006. p. 2–87.
2. Greenlee H, Balneaves LG, Carlson LE, et al. Clinical practice guidelines on the use of integrative therapies as supportive care in patients treated for breast cancer. J Natl Cancer Inst Monogr. 2014;50:346–358.
3. Deng GE, Frenkel M, Cohen L, et al. Evidence-based clinical practice guidelines for integrative oncology: complementary therapies and botanicals. J Soc Integr Oncol. 2009;7(3):85–120.
4. Horneber M, Bueschel G, Dennert G, et al. How many cancer patients use complementary and alternative medicine: a systematic review and meta- analysis. Integr Cancer Ther. 2012;11(3):187–203.
5. Call MC, Ward A, Heneghan C. Yoga in adult cancer: a pilot survey of attitudes and beliefs among oncologists. Curr Oncol. 2015;22(1):13–19.
6. Cancer Facts & Figures. USA: American cancer society journal; 2017. p. 1–71.
7. Ferlay J, Soerjomataram I, Ervik M. Globocan 2012: Estimated Cancer Incidence and Mortality Worldwide in 2012. France: International agency for research on cancer 2012; 2012.
8. Cancer. World Health Organization; 2017.
9. Global Cancer Facts & Figures. USA: American cancer society; 2012.
10. Caraceni A, Portenoy RK. A working group of the IASP task force on cancer pain. An international survey of cancer pain characteristics and syndromes. Pain. 1999;82:263–274.
11. Goedendorp MM, Gielissen MF, Verhagen CA, et al. Development of fatigue in cancer survivors: a prospective follow-up study from diagnosis into the year after treatment. J Pain Symptom Manag. 2013;45(2):213–222.
12. Israel AS. Recognition and treatment of sleep disturbances in cancer. J Clin Oncol. 2009;27(35):5864–5866.
13. Daut RL, Cleeland CS. The prevalence and severity of pain in cancer. Cancer. 1982;50(9):1913–1918.
14. Strang P. Cancer pain - A provoker of emotional, social and existential distress. Acta Oncol. 1983;37(7-8):641–644.
15. Grossman SA. Undertreatment of cancer pain: Barriers and remedies. Support Care Cancer. 1993;1(2):74–78.
16. Ripamonti C, Dickerson ED. Strategies for the treatment of cancer pain in the new millennium. Drugs. 2001;61(7):955–977.
17. Iihara H, Fujii H, Yoshimi C, et al. Control of chemotherapy-induced nausea in patients receiving outpatient cancer chemotherapy. Int J Clin Oncol. 2016;21(2):409–418.
18. Allard P, Maunsell E, Labbe J, et al. Educational interventions to improve cancer pain control: A systematic review. J Palliat Med. 2001;4(2):191–203.
19. Conroy T, Marchal F, Blazeby JM. Quality of life in patients with oesophageal and gastric cancer: an overview. Oncology. 2006;70(6):391–402.
20. Costanzo ES, Lutgendorf SK, Mattes ML, et al. Adjusting to life after treatment: distress and quality of life following treatment for breast cancer. Br J Cancer. 2007;97(12):1625–1631.
21. Menefee LA, Monti DA. Nonpharmacologic and complementary approaches to cancer pain management. J Am Osteopath Assoc. 2005;105(11sup 5):S15–20.
22. Goldstein MS, Brown ER, Barbash BR, et al. The use of complementary and alternative medicine among Californian adults with and without cancer. Evid Based Complement Altern Med. 2005;2(4):557–565.
23. Smith KB, Pukall CF. An evidence-based review of yoga as a complementary intervention for patients with cancer. Psychooncology. 2009;18(5):465–475.
24. Anderson JG, Taylor AG. Use of complementary therapies for cancer symptom management: Results of the 2007 national health interview survey. J Altern Complement Med. 2012;18(3):235–241.
25. Chandwani KD, Ryan JL, Peppone LJ, et al. Cancer-related stress and complementary and alternative medicine: A review. Evid Based Complement Alternat Med. 2012. 2012:979213.
26. Vadiraja SH, Rao MR, Nagendra RH, et al. Effects of yoga on symptom management in breast cancer patients: A randomized controlled trial. Int J Yoga. 2009;2(2):73–79.
27. Greenlee H, Reyes PMJ, Balneaves LG, et al. Clinical practice guidelines on the evidence-based use of integrative therapies during and after breast cancer treatment. CA Cancer J Clin. 2017;67(3):194–232.
28. Karsnitz D, Ward S. Spectrum of anxiety disorders: diagnosis and pharmacologic treatment. J Midwifery Womens Health. 2011;56(3):266–281.
29. Teunissen SCCM, Graeff A, Voest EE, et al. Are anxiety and depressed mood related to physical symptom burden? A study in hospitalized advanced cancer patients. Palliat Med. 2007;21(4):341–346.
30. Kolva E, Rosenfeld B, Pessin H, et al. Anxiety in terminally Ill cancer patients. J Pain Symptom Manage. 2011;42(5):691–701.
31. Mitchell AJ, Ferguson DW, Gill J, et al. Depression and anxiety in long-term cancer survivors compared with spouses and healthy controls: A systematic review and meta-analysis. Lancet Oncol. 2013;14(8):721–732.
32. Kissane DW, Grabsch B, Love A, et al. Psychiatric disorder in women with early stage and advanced breast cancer: a comparative analysis. Aust N Z J Psychiatry. 2014;38(5):320–326.
33. Kadan LNS, Vanderwerker LC, Block SD, et al. Psychiatric disorders and mental health service use in patients with advanced cancer. Cancer. 2005;104(12):2872–2881.
34. Miovic M, Block S. Psychiatric disorders in advanced cancer. Cancer. 2007;15(110):1665–1676.
35. Aass N, Fossa SD, Dahl AA, et al. Prevalence of anxiety and depression in cancer patients seen at the Norwegian Radium Hospital. Eur J Cancer. 1997;33(10):1597–1604.
36. Brown LF, Kroenke K, Theobald DE, et al. The association of depression and anxiety with health-related quality of life in cancer patients with depression and/or pain. Psychooncology. 2010;19(7):734–741.
37. Groenvold M, Petersen MA, Idler E, et al. Psychological distress and fatigue predicted recurrence and survival in primary breast cancer patients. Breast Cancer Res Treat. 2007;105(2):209–219.
38. Streeter CC, Whitfield TH, Owen L, et al. Effects of Yoga Versus Walking on Mood, Anxiety, and Brain GABA Levels: A Randomized Controlled MRS Study. Journal of Alternative and Complementary Medicine. 2010;16(11):1145–1152.
39. Kim YH, Kim HJ, Ahn SD, et al. Effects of meditation on anxiety, depression, fatigue, and quality of life of women undergoing radiation therapy for breast cancer. Complement Ther Med. 2013;21(4):379–387.
40. Carlson LE, Doll R, Stephen J, et al. Randomized controlled trial of mindfulness-based cancer recovery versus supportive expressive group therapy for distressed survivors of breast cancer. J Clin Oncol. 2013;31(25):3119–3126.
41. Taso CJ, Lin HS, Lin WL, et al. The effect of yoga exercise on improving depression, anxiety, and fatigue in women with breast cancer: a randomized controlled trial. J Nurs Res. 2014;22(3):155–164.
42. Dhruva A, Miaskowski C, Abrams D, et al. Yoga breathing for cancer chemotherapy-associated symptoms and quality of life: results of a pilot randomized controlled trial. J Alternat Complement Med. 2012;18(5):473–479.
43. Pruthi S, Stan DL, Jenkins SM, et al. A randomized controlled pilot study assessing feasibility and impact of yoga practice on quality of life, mood, and perceived stress in women with newly diagnosed breast cancer. Glob Adv Health Med. 2012;1(5):30–35.
44. Diagnostic and statistical manual of mental disorders: DSM-5. 5th ed. Washington, D.C: USA: American Psychiatric Association; 2013.
45. WHO. Major Depression among Adults. National institute of mental health; 2010.
46. Kessler RC, Berglund P, Demler O, et al. The epidemiology of major depressive disorder: results from the National comorbidity survey replication (NCS-R). Journal of the American Medical Association. 2003;289(3):3095–3105.
47. Raison CL, Miller AH. Depression in cancer: new developments regarding diagnosis and treatment. Biol Psychiatry. 2003;54(3):283–294.
48. Coyne JC, Stefanek M, Palmer SC. Psychotherapy and survival in cancer: the conflict between hope and evidence. Psychol Bull. 2007;133(3):367–394.
49. Bottino SMB, Fraguas R, Gattaz WF. Depressão e cancer [[Depression and cancer]. Rev Psiq Clin. 2009;36(3):109–115.
50. Massie MJ. Prevalence of depression is patients with cancer. J Natl Cancer Inst Monogr. 2004;32:57–71.
51. Fann JR, Rich TAM, Katon WJ, et al. Major depression after breast cancer: a review of epidemiology and treatment. Gen Hosp Psychiatry. 2008;30(2):112–126.
52. Grabsch B, Clarke DM, Love A, et al. Psychological morbidity and quality of life in women with advanced breast cancer: A cross-sectional survey. Palliat Support Care. 2006;4(1):47–56.
53. Onitilo AA, Nietert PJ, Egede LE. Effect of depression on all-cause mortality in adults with cancer and differential effects by cancer site. Gen Hosp Psychiatry. 2006;28(5):396–402.
54. Pirl WF, Greer JA, Traeger L, et al. Depression and survival in metastatic non-small-cell lung cancer: effects of early palliative care. J Clin Oncol. 2012;30(12):1310–1315.
55. Harbi AKS. Treatment-resistant depression: therapeutic trends, challenges and future directions. Patient Prefer Adherence. 2012;6:369–388.
56. Caneja DCM, Espliego A, Parellada M, et al. Polypharmacy with antidepressants in children and adolescents. Int J Neuropsychopharmacol. 2014;17(7):1063–1082.
57. Keller MB, Cullough MJP, Klein DN, et al. A comparison of nefazodone, the cognitive behavioral-analysis system of psychotherapy and their combination for the treatment of chronic depression. N Engl J Med. 2000;342(20):1462–1470.
58. Van HL, Dekker J, Peen J, et al. Identifying patients at risk of complete nonresponse in the outpatient treatment of depression. Psychother Psychosom. 2008;77(6):358–364.
59. Santarsieri D, Schwartz TL. Antidepressant efficacy and side-effect burden: a quick guide for clinicians. Drugs Context. 2015;4:212290.
60. Saeed SA, Antonacci DJ, Bloch RM. Exercise, yoga and meditation for depressive and anxiety disorders. Am Fam Physician. 2010;81(8):981–986.
61. Uebelacker LA, Broughton MK. Yoga for depression and anxiety: a review of published research and implications for healthcare providers. R I Med J. 2013;99(3):20–22.
62. Prathikanti S, Rivera R, Cochran A, et al. Treating major depression with yoga: A prospective, randomized, controlled pilot trial. PLoS One. 2017;12(3):e0173869.
63. Streeter CC, Gerbarg PL, Whitfield TH, et al. Treatment of major depressive disorder with iyengar yoga and coherent breathing: a randomized controlled dosing study. J Altern Complement Med. 2017;23(3):201–207.
64. Rao RM, Nagendra HR, Raghuram N, et al. Influence of yoga on mood states, distress, quality of life and immune outcomes in early stage breast cancer patients undergoing surgery. Int J Yoga. 2008;1(1):11–20.
65. Rao RM, Raghuram N, Nagendra HR, et al. Effects of an integrated yoga program on self-reported depression scores in breast cancer patients undergoing conventional treatment: a randomized controlled trial. Indian J Palliat Care. 2015;21(2):174–181.
66. Taylor TR, Barrow J, Makambi K, et al. A Restorative Yoga Intervention for African-American Breast Cancer Survivors: a Pilot Study. J Racial Ethn Health Disparities. 2017;5(1):62–72.
67. Cramer H, Lauche R, Klose P, et al. Yoga for improving health-related quality of life, mental health and cancer-related symptoms in women diagnosed with breast cancer. Cochrane Database Syst Rev. 2017;1:CD010802.
68. Danhauer SC, Tooze JA, Farmer DF, et al. Restorative yoga for women with ovarian or breast cancer: findings from a pilot study. J Soc Integr Oncol. 2008;6(2):47–58.
69. Milbury K, Mallaiah S, Lopez G, et al. Vivekananda yoga program for patients with advanced lung cancer and their family caregivers. Integr Cancer Ther. 2015;14(5):446–451.
70. Everdingen MH, Rijke DJM, Kessels AG, et al. Prevalence of pain in patients with cancer: a systematic review of the past 40 years. Ann Oncol. 2007;18(9):1437–1449.
71. Breitbart WS, Park J, Katz AM. Psycho-Oncology. 2nd ed. USA: Oxford University Press; 2010.
72. Facts about Cancer Pain. USA: American cancer society; 2015.
73. Gupta N, Patel FD, Kapoor R, et al. Pain management in cancer. Internet Journal of Pain, Symptom Control and Palliative Care. 2007;5(1):83–89.
74. Deandrea S, Montanari M, Moja L, et al. Prevalence of under treatment in cancer pain. A review of published literature. Ann Oncol. 2008;19(12):1985–1991.
75. Wanchai A, Armer JM, Stewart BR. Complementary and alternative medicine use among women with breast cancer: a systematic review. Clin J Oncol Nurs. 2010;14(4):E45–55.
76. Thomas EM, Weiss SM. Nonpharmacological interventions with chronic cancer pain in adults. Cancer Control. 2000;7(2):157–164.
77. Carson JW, Carson KM, Porter LS, et al. Yoga for women with metastatic breast cancer: results from a pilot study. J Pain Symptom Manage. 2007;33(3):331–341.
78. Galantino ML, Greene L, Archetto B, et al. A qualitative exploration of the impact of yoga on breast cancer survivors with aromatase inhibitor-associated arthralgias. Explore. 2012;8(1):40–47.
79. Andrews PL, Axelsson M, Franklin C, et al. The emetic reflex in a reptile (Crocodylus porosus). J Exp Biol. 2000;203(pt 10):1625–1632.
80. Miller F. Nausea and vomiting in pregnancy: the problem of perception-is it really a disease? Am J Obstet Gynecol. 2002;186(5 Suppl):S182–183.
81. Borison HL, Carthy LE. Neuropharmacologic mechanisms of emesis. In: Laszlo J, editors. Antiemetics and Cancer Chemotherapy. USA: Williams and Wilkins; 1983. p. 6–20.
82. Metz A, Hebbard G. Nausea and vomiting in adults-a diagnostic approach. Aust Fam Physician. 2007;36(9):688–692.
83. Herrstedt J, Dombernowsky P. Anti-emetic therapy in cancer chemotherapy: current status. Basic Clin Pharmacol Toxico. 2007;101(3):143–150.
84. Coates A, Abraham S, Kaye SB, et al. On the receiving end patient perception of the side effects of cancer chemotherapy. Eur J Cancer Clin Oncol. 1983;19(2):203–208.
85. Dennert DBM, Wit DR, Schmitz PIM, et al. Patient perception of the side-effects of chemotherapy: the influence of 5HT3 antagonists. Br J Cancer. 1997;76(8):1055–1061.
86. Passik SD, Kirsh KL, Rosenfeld B, et al. The changeable nature of patients’ fear regarding chemotherapy: implications for palliative care. J Pain Symptom Manag. 2001;21(2):113–120.
87. Sun CC, Bodurka DC, Weaver CB, et al. Rankings and symptom assessments of side effects from chemotherapy: insights from experienced patients with ovarian cancer. Support Care Cancer. 2005;13(4):219–227.
88. Wagland R, Richardson A, Armes J, et al. Treatment-related problems experienced by cancer patients undergoing chemotherapy: a scoping review. Eur J Cancer Care. 2015;24(5):605–617.
89. Herrstedt J, Dombernowsky P. Anti-emetic therapy in cancer chemotherapy: current status. Basic Clin Pharmacol Toxicol. 2007;101(3):143–150.
90. Escobar Y, Cajaraville G, Virizuela JA, et al. Incidence of chemotherapy-induced nausea and vomiting with moderately emetogenic chemotherapy: ADVICE (Actual data of vomiting incidence by chemotherapy evaluation) study. Support Care Cancer. 2015;23(9):2833–2840.
91. Ballatori E, Roila F, Ruggeri B, et al. The impact of chemotherapy-induced nausea and vomiting on health-related quality of life. Support Care Cancer. 2007;15(2):179–185.
92. Vidall C, Dielenseger P, Farrell C, et al. Evidence-based management of chemotherapy-induced nausea and vomiting: a position statement from a European cancer nursing forum. Ecancermedicalsci. 2011;5:211.
93. Raghavendra RM, Nagarathna R, Nagendra HR, et al. Effects of an integrated yoga programme on chemotherapy-induced nausea and emesis in breast cancer patients. Eur J Cancer Care. 2007;16(6):462–474.
94. Anestin AS, Dupuis G, Lanctôt D, et al. The effects of the bali yoga program for breast cancer patients on chemotherapy-induced nausea and vomiting: results of a partially randomized and blinded controlled trial. J Evid Based Complementary Altern Med. 2017;1:2156587217706617.
95. Raaf DPJ, Klerk DC, Timman R, et al. Differences in fatigue experiences among patients with advanced cancer, cancer survivors, and the general population. J Pain Symptom Manag. 2012;44(6):823–830.
96. Goedendorp MM, Gielissen MF, Verhagen CA, et al. Development of fatigue in cancer survivors: a prospective follow-up study from diagnosis into the year after treatment. J Pain Symptom Manag. 2013;45(2):213–222.
97. Curt GA, Breitbart W, Cella D, et al. Impact of cancer-related fatigue on the lives of patients: new findings from the Fatigue Coalition. Oncologist. 2000;5(5):353–360.
98. Spichiger E, Frohlich MC, Denhaerynck K, et al. Prevalence and contributors to fatigue in individuals hospitalized with advanced cancer: a prospective, observational study. Int J Nurs Stud. 2012;49(9):1146–1154.
99. Annunziata MA, Muzzatti B, Mella S, et al. Fatigue, quality of life and mood states during chemotherapy in Italian cancer patients. Tumori. 2013;99(1):e28–33.
100. Irvine D, Vincent L, Graydon JE, et al. The prevalence and correlates of fatigue in patients receiving treatment with chemotherapy and radiotherapy. A comparison with the fatigue experienced by healthy individuals. Cancer Nurs. 1994;17(5):367–378.
101. Oh HS, Seo WS. Systematic review and meta-analysis of the correlates of cancer-related fatigue. Worldviews Evid Based Nurs. 2011;8(4):191–201.
102. Peters MEWJ, Goedendorp MM, Verhagen CAHHVM, et al. Fatigue and its associated psychosocial factors in cancer patients on active palliative treatment measured over time. Support Care Cancer. 2016;24(3):1349–1355.
103. Servaes P, Gielissen MF, Verhagen S, et al. The course of severe fatigue in disease-free breast cancer patients: a longitudinal study. Psychooncology. 2006;16(9):787–795.
104. Lawrence DP, Kupelnick B, Miller K, et al. Evidence report on the occurrence, assessment and treatment of fatigue in cancer patients. J Natl Cancer Inst Monogr. 2004;32:40–50.
105. Quinten C, Maringwa J, Gotay CC, et al. Patient self-reports of symptoms and clinician ratings as predictors of overall cancer survival. J Natl Cancer Inst. 2011;103(24):1851–1858.
106. Oldervoll LM, Loge JH, Lydersen S, et al. Physical exercise for cancer patients with advanced disease: a randomized controlled trial. Oncologist. 2011;16(11):1649–1657.
107. Reed CSN, Carlson LE, Daroux LM, et al. A pilot study of yoga for breast cancer survivors: physical and psychological benefits. Psychoncology. 2006;15(10):891–897.
108. Cohen L, Warneke C, Fouladi RT, et al. Psychological adjustment and sleep quality in a randomized trial of the effects of a Tibetan yoga intervention in patients with lymphoma. Cancer. 2004;100(10):2253–2260.
109. Cramer H, Lauche R, Klose P, et al. Yoga for improving health-related quality of life, mental health and cancer-related symptoms in women diagnosed with breast cancer. Cochrane Database Syst Rev. 2017;1:CD010802.
110. Roth T. Diagnosis and management of insomnia. Clin Cornerstone. 2000;2(5):28–38.
111. Klink M, Quan SF. Prevalence of Reported Sleep Disturbances in a General Adult Population and their Relationship to Obstructive Airways Diseases. Chest. 1987;91(4):540–546.
112. Grandner MA, Martin JL, Patel NP, et al. Age and sleep disturbances among american men and women: data from the u.s. behavioral risk factor surveillance system. Sleep. 2012;35(3):395–406.
113. Grunstein R. Insomnia. Diagnosis and management. Aust Fam Physician. 2002;31(11):995–1000.
114. Bloom HG, Ahmed I, Alessi CA, et al. Evidence-based recommendations for the assessment and maintenance of sleep disorders in older adults. J Am Geriatr Soc. 2009;57(5):761–789.
115. Stewart R, Besset A, Bebbington P, et al. Insomnia comorbidity and impact and hypnotic use by age group in a national survey population aged 16 to 74 years. Sleep. 2008;29(11):1391–1397.
116. Manjunath NK, Telles S. Influence of Yoga and Ayurveda on self-rated sleep in a geriatric population. Indian J Med Res. 2005;121(5):683–690.
117. Ong JC, Manber R, Segal Z, et al. A randomized controlled trial of mindfulness meditation for chronic insomnia. Sleep. 2014;37(9):1553–1563.
118. Collins JJ, Byrnes ME, Dunkel IJ, et al. The measurement of symptoms in children with cancer. J Pain Symptom Manage. 2000;19(5):363–377.
119. Israel AS. Recognition and treatment of sleep disturbances in cancer. J Clin Oncol. 2009;27(35):5864–5866.
120. Savard J, Morin CM. Insomnia in the context of cancer: a review of a neglected problem. J Clin Oncol. 2001;19(3):895–908.
121. Theobald DE. Cancer pain, fatigue, distress, and insomnia in cancer patients. Clin Cornerstone. 2004;6(S1):S15–21.
122. Graci G. Pathogenesis and management of cancer-related insomnia. J Support Oncol. 2005;3(5):349–359.
123. Savard J, Liu L, Natarajan L, et al. Breast cancer patients have progressively impaired sleep-wake activity rhythms during chemotherapy. Sleep. 2009;32(9):1155–1160.
124. Danhauer SC, Mihalko SL, Russell GB, et al. Restorative yoga for women with breast cancer: Findings from a randomized pilot study. Psychooncology. 2009;18(4):360–368.
125. Vadiraja SH, Rao MR, Nagendra RH, et al. Effects of yoga on symptom management in breast cancer patients: A randomized controlled trial. Int J Yoga. 2009;2(2):73–79.
126. Mustian KM, Sprod LK, Janelsins M, et al. Multicenter, randomized controlled trial of yoga for sleep quality among cancer survivors. J Clin Oncol. 2013;31(26):3233–3241.
127. Constitution of WHO: principles. USA: World health organization; 1946.
128. Sieberer RU, Karow A, Barthel D, et al. How to assess quality of life in child and adolescent psychiatry. Dialogues in Clinical Neuroscience. 2014;16(2):147–158.
129. Dowell MI. Measures of self-perceived well-being. J Psychosom Res. 2010;69(1):69–79.
130. Ware JE, Kosinski M Gandek B. SF-36 Health Survey: Manual & Interpretation Guide. USA: Quality Metric; 2000.
131.  Health-related quality of life. Centers for disease control and prevention. USA: CDC; 2016.
132. Ware JE, Kosinski M, Keller SD. SF‐36 Physical and Mental Health Summary Scales: A User’s Manual. The Health Institute, USA: New England Medical Centre; 1994.
133. EuroQol Group. EuroQol: a new facility for the measurement of health‐related quality of life. Health Policy. 1990;16(3):199–208.
134. Skevington SM, Arthur MP, Somerset M. Developing items for the WHOQOL: a study of contemporary beliefs about quality of life related to health in Britain. British Journal of Health Psychology. 1997;2(1):55–72.
135. Ferrell BR, Dow KH, Grant M. Measurement of the quality of life in cancer survivors. Qual Life Res. 1995;4(6):523–531.
136. Conroy T, Marchal F, Blazeby JM. Quality of life in patients with oesophageal and gastric cancer: an overview. Oncology. 2006;70(6):391–402.
137. Heydarnejad M, Hassanpour DA, Solati DK. Factors affecting quality of life in cancer patients undergoing chemotherapy. Afr Health Sci. 2011;11(2):266–270.
138. Vila SH, Kasl SV, Jones BA. Prognostic significance of psychosocial factors in African-American and white breast cancer patients: a population-based study. Cancer. 2003;98(6):1299–1308.
139. Maisey NR, Norman A, Watson M, et al. Baseline quality of life predicts survival in patients with advanced colorectal cancer. Eur J Cancer. 2002;38(10):1351–1357.
140. Coates AS, Hurny C, Peterson HF, et al. Quality of life scores predict outcome in metastatic but not early breast cancer. international breast cancer study group. J Clin Oncol. 2000;18(22):3768–3774.
141. Montazeri A. Quality of life data as prognostic indicators of survival in cancer patients: an overview of the literature from 1982 to 2008. Health Qual Life Outcome. 2009;7:102.
142. Singh P, Chaturvedi A. Complementary and alternative medicine in cancer pain management: a systematic review. Indian J Palliat Care. 20154;21(1):105–115.
143. Danhauer SC, Tooze JA, Farmer DF, et al. Restorative yoga for women with ovarian or breast cancer: findings from a pilot study. J Soc Integr Oncol. 2008;6(2):47–58.
144. Harder H, Parlour L, Jenkins V. Randomised controlled trials of yoga interventions for women with breast cancer: A systematic literature review. Support Care Cancer. 2012;20(12):3055–3064.
145. Siedentopf F, Billing UI, Gairing S, et al. Yoga for patients with early breast cancer and its impact on quality of life a randomized controlled trial. Geburtshilfe Frauenheilkd. 2013;73(4):311–317.
146. Sharma M, Lingam VC, Nahar VK. A systematic review of yoga interventions as integrative treatment in breast cancer. J Cancer Res Clin Oncol. 2016;142(12):2523–2540.
147. Carlson, Linda E, Michael S, et al. Mindfulness-based stress reduction in relation to quality of life, mood, symptoms of stress and immune parameters in breast and prostate cancer outpatients. Psychosom Med. 2003;65(4):571–581.
148. Fouladbakhsh JM, Davis JE, Yarandi HN. A pilot study of the feasibility and outcomes of yoga for lung cancer survivors. Oncol Nurs Forum. 2014;41(2):162–174.
149. Danhauer SC, Addington EL, Sohl SJ, et al. Review of yoga therapy during cancer treatment. Support Care Cancer. 2017;25(4):1357–1372.