MALIGNANT ANAL TUMORS IN THE CHINESE POPULATION IN HONG-KONG

Malignant anal tumours are rare cancers but are particularly common in Switzerland, Poland and Brazil. Very little is known about this condi tion in the Chinese population. A retrospective study, covering an 11- year period, was performed. A total of 18 patients were treated at the Prince of Wales Hospital, Hong Kong. There were eight squamous cell c arcinomas, seven adenocarcinomas and one each of adenosquamous carcino ma, malignant melanoma and leiomyosarcoma. Bleeding per rectum, with o r-without perianal pain, was the main presenting symptom. Abdominoperi neal resection was the treatment modality used in most cases. Adenocar cinomas, seen mainly in males, accounted for about 39% of cases, a fig ure much higher than that published elsewhere. Another 44% of patients , predominantly females, had squamous cell carcinoma. None had a posit ive past history of sexually transmitted disease. The local prevalence of HPV infection is much lower than in the Western world, and the rol e of HPV in the oncogenesis of anal tumours in the Chinese population awaits elucidation.