The clinicopathologic spectrum of anal cancer in KwaZulu-Natal Province, South Africa: Analysis of a provincial database

Abstract

Background: The occurrence of the considered rare anal cancer has not been documented in the South African context.

Patients and methods: Analysis of data extracted from a prospectively collected KwaZulu-Natal anal cancer database for the period 2000-2014. Data analysed included demographics, clinical picture, pathology, treatment and outcome. The study outcome measures were clinicopathologic spectrum, treatment and outcome.

Results: The study population comprised 244 patients of mean age 50.1 (SD 14.0) years. The age at presentation was lowest for Black African patients compared to Whites and Indians (p<0.001) and lower for HIV positive vs HIV negative patients (p<0.001). Histology was squamous carcinoma in 208 patients (margin 152, canal 56), adenocarcinoma in 34 (all anal canal), neuroendocrine tumour (1) and melanoma (1). Mean age for squamous carcinoma was 48.8 (SD 14.1) years compared to 58.7 years (SD ±11.1) for adenocarcinoma. Metastatic disease occurred in 22 patients (9%). Patients received definitive (139), palliative (53) and no (52) oncological therapy. Thirty patients (12%) underwent resection, seven of whom had positive margins. Seventy-six patients (31%) have been confirmed dead. The 5-year survival rate was 33.4% (95% CI: 23.4-44.6%). There was a highly significantly worse prognosis for adenocarcinoma compared to squamous cell carcinoma (p=0.038). No significant difference was found in survival prospects based on race and tumour location.

Conclusion: Squamous carcinoma was more common and presented at a young age. Black African patients and HIV positive patients were younger. Adenocarcinoma was associated with poorer prognosis. Race and tumour location had no influence on survival.

Keywords: Adenocarcinoma; Anal; Anorectal; Squamous Carcinoma.