Objective: To determine the age, sex, pattern of presentation, geographical distribution, pattern of management and histopathology subtypes of RCC in Yemeni patients.

Patients and methods: A retrospective study was performed covering the period between January 2004 and December 2008. A total of 67 adult patients had been diagnosed to have RCC during this period. Information extracted and analyzed included the age of the patient, sex, presentation, histopathology subtype & grade and management.

Results: The mean age of the patients was 50.3±13.3 years (range 22-80 yrs). The male: female ratio was 1:1.1. The duration of symptoms varied widely from few weeks to a few years (range 0.5-94 months). 11 cases (16.4%) presented with the so-called “too late triad” consisting of loin pain, haematuria and palpable mass. 7 patients (3%) were diagnosed incidentally. 65 patients (97%) were operated upon; radical nephrectomy was the standard procedure in 60 patients (92.5%), 5 patients (8.3%) had radical nephrectomy and IVC thrombectomy. Partial nephrectomy was indicated in 4 patients (6%). The most common histopathological subtype was clear cell type (43%) and Chromophobic type (19.4%).

Conclusion: We concluded that RCC in adult Yemenis is presented in an earlier age with predominant female gender. Incidental detection of renal carcinoma is lower as compared to western world. Post surgical morbidity and mortality was compatible to that reported in most series.

 Keywords: renal tumor, renal cell carcinoma, hematuria, loin pain, loin swelling, weight loss

Kidney cancer accounts for nearly 2% of all malignancies globally. It occurs with 189000 new cases and 91000 deaths from the disease annually.¹ More than 80% of kidney cancers are renal cell carcinomas.² RCC, which accounts for 2% to 3% of all adult malignant neoplasms, is the most lethal of the urologic cancers. Traditionally, more than 40% of patients with RCC have died of their cancer, in contrast with the 20% mortality rates associated with prostate and bladder carcinomas.³ Approximately 57,760 new cases of RCC and 12,980 deaths are expected to have occurred in the United States in 2009. One fourth to one third of patients present with metastatic disease.⁴ The increasing incidence seen in most parts of the world cannot fully be explained by increasing availability to medical service and use of imaging procedures but also to increases in the prevalence of etiologic risk factors. The incidence globally of kidney cancer varies considerably among different populations and regions. The rates are highest in Western and Eastern Europe, North America, Australia and Scandinavia, intermediate in Southern Europe and Japan, and low elsewhere in Asia, Africa and the Pacific.¹ Few studies are available in the developing countries such as that done in Pakistan, Nigeria and other parts of Africa which indicate that this tumor were often diagnosed in advanced stage. In contrast, in most developed countries more than 50% of these tumors are incidentally detected.⁵ In Yemen there is no any previous study or report describing RCC in Yemeni patients. And the present study will be the first review undertaken to determine the age, sex, pattern of presentation, geographical distribution, and pattern of management and histopathology subtypes of RCC in Yemeni patients. The study was carried out at the Urology & Nephrology center, Althawra Typical Modern Hospital (TMGH) which considered the only referral urology center provides specialized health care for all over Yemen.

In this descriptive retrospective study, we reviewed the data of all patients managed for renal tumors who admitted in the urology department at The Urology & Nephrology center which considered the first and only referral urology center in Yemen and provides specialized tertiary services for all Yemeni governorates. After hospital ethical committee clearance, data was obtained from patients files retrieved from the hospital archives and from the histopathology records. The study submitted from 2004 through December 2008. We estimated that a five-year period would provide enough data for our study. The hospital records of 81 adult patients (age over 17 years) were reviewed; only 67 cases of renal cell carcinoma were confirmed with tissue diagnosis and were included in this study. After selecting the sample, a worksheet was prepared to collect data, which were organized in a database using the software SPSS®, version 15, for descriptive analysis. All the categorical variables were summarized using frequencies and percentages. The cases worksheets were analyzed for age, sex, residency, mode of presentation, duration of the symptoms, type of management, and the duration of hospital stay. The tumor laterality, polarity, size and histopathological typing & grading were also recorded (Table 1 & Table 2). All patients were evaluated for past medical, surgical, family and drug history so that systemic illnesses, associated co- morbidity and possible etiological factors were noted. Local and general examination was done for all patients.

As mentioned earlier, this study was undertaken in the first and only referral urology center in Yemen, so the patients included in this review came from various Yemeni governorates. Table 8 showed the geographical distribution of RCC in Yemen. It is noticeable that 17.9% of RCC cases came from Dhamar and this result not correlated with the population distribution in this governorate. This observation if confirmed later, would give alarm for the importance to study the suspected social and environmental risk factors in this area by more reports in the future. As reported in many series renal cell carcinoma affect males predominantly. Male to female ratio are generally between 1.5:1 and 2.5:1.⁶ This was not our observation, where the ratio of 1:1 indicates a higher occurrence in Yemeni females. For a lesser extent a similar observation was reported in Saudi Arabia by Talic and El Faqih on a group of 33 Saudi patients with RCC; the M:F ratio was 1.3:1.⁷

This observation is difficult to explain. But if confirmed in future reports, would indicate the necessity to investigate Yemeni females closely for suspected risk factors. The mean age for our patients were 50.3±13.3 (range 22-80), with peak incidence in the fourth and fifth decades of life. Thus, the peak incidence of RCC occurs about two decades lower than the 50-70 years peak incidence reported amongst Caucasians.⁸ 32% of our patients were aged ≤40 years old this result is about sixth folds larger than what reported by Jae Hee Suh et al on a group of 838 cases of renal cell carcinoma,² only 5.2% of their patients were ≤40.⁹ This indicates the high incidence of RCC in Yemeni younger adults (≤40 years old). This review showed that flank pain (70%), haematuria 55.22%, palpable mass 37.3% are prominent symptoms of RCC in our patients. The classic triad of flank pain, gross haematuria, and palpable abdominal mass “too late triad” was observed in 16.41% of our patients. Which denotes advanced disease presentation and late detection of the tumor, in contrast to that reported in most series, in which this triad is now rarely found in the developed countries due to early or incidental diagnosis of RCC.¹⁰ Our finding is consistent with that reported by some reviews in other developing countries, like that reported by Badmus TA et al.,⁵ on a group of 18 Nigerian patients which indicated that most cases still present late with loin pain. Loin swelling and haematuria. Paraneoplastic syndromes are found in 20% of patients with RCC.¹⁰ In current study 25.3% of patients presented with anaemia, also polycythemia, hypertension, abnormal liver function, hypercalcemia and hepatomegaly were also detected in our patients but less frequently than expected (Table 9).

The incidentally diagnosed RCC was found with only in 10% of our patient, and this result is so far from that in developed countries in which more than 50% of RCC are now incidentally discovered very early in these communities partly because of increased use of imaging procedures there.¹¹ Table 10 showed the incidence of incidental presentation of RCC in various developing communities. The average size of the tumor mass removed at surgery in this series was 9.3 cm. in the maximal diameter (range 3-20 cm.). Tumor size has ranged from 5 to 8 cm in most series, The mean size reported in the literature was 5.3 cm.¹² This result In Yemeni patients indicates that RCC in our community are relatively bigger at presentation. This finding also closely reflects the late presentation in most of our patients in contrast to early detection in developed societies. Abdominal Ultrasonography was found very useful in establishing the diagnosis in all our patients. The value of surgery in the management of RCC lies on the fact that RCC is relatively resistant to systemic therapy like radiotherapy, chemotherapy or hormone therapy.¹³ Radical nephrectomy, which has been the standard procedure in 60 patients, and was successfully carried out with IVC thrombectomy in 5 patients and in one patient with locally advanced tumor with good results. Morbidity after radical nephrectomy was in 5 patients (8%), 3 of them had lower limp DVT. Two other patients had minor complications. Amongst the patients with radical nephrectomy, mortality were in 3 patients (5%), all of them died of pulmonary embolism few days postoperative. Two of the three died patients had IVC thrombosis, in high level in one of them. Other studies reported mortality rate of 4% and 8%.¹⁴ There is no intraoperative death.

Presentation by stage is compared to other series in (Table 11) 53.7% of our patients presented in Stage I and II and 14.9% presented in Stage VI. These results are compatible with other reports and suggest that there is no delay in the diagnosis and management of RCC patients in Yemen. But a result of 22.4% for stage I is more lesser than reported in other series and may indicate the delay in the patient presentation to the primary medical services as well as the delay in the referral to the tertiary center. The average duration of postoperative hospital stay was 5.8 days (range 2-20 days). Faisal Ghaffar et al.,¹⁵ reported mean hospital stay duration of 13 days. Like mentioned in the literature the most common histopathology subtype in our patients was clear cell type (43%). Chromophobic type also showed a predominance pattern amongst our patients with a percent of (19.4%) which take a higher incidence than reported in most series.¹⁰

The etiology of RCC is poorly understood. The only generally accepted environmental risk factor for RCC is tobacco exposure. Also cadmium exposure, haemodialysis in end stage renal failure and acquired cystic disease of the kidney were established as reported risk factors.⁶ This review showed that these factors are not important in etiology pathogenesis in our community as only (11%) of our patients gave history of tobacco exposure and none of them was industrial worker. Also no cases of acquired cystic disease of the kidney or end stage renal failure were encountered in our study. And by a retrospective study there is no any possibility to establish whether there are any particular risk factors unique to Yemeni population.^16-20

Author declares that there is no conflicts of interest.

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