Primary adenocarcinoma of the anus: a retrospective analysis

To report the clinical features and outcome of patients with primary adenocarcinoma of the anus following radiotherapy with or without chemotherapy.

A retrospective analysis was performed on 15 patients referred to Peter MacCallum Cancer Institute between 1981 to 1998 with primary adenocarcinoma of the anus. The median follow-up was 7.5 years. Six patients underwent treatment with curative intent-either chemoradiation or radiotherapy alone. Surgery was mainly limited to either incisional or excisional biopsy. The remaining nine patients were treated with palliative intent because of advanced age, advanced disease, or poor medical status. The biological equivalent doses were calculated for all patients and correlated with time to progression.

None of the curative group had relapsed after a median follow-up of 6.6 years. All except one were alive and well. No patient developed any serious long-term toxicity and all patients avoided colostomy. All patients managed with palliative intent died with persistent locoregional disease with a median survival of 0.8 year.

Primary adenocarcinoma of the anus is a very rare disease that precludes a rigorous analysis. This study demonstrates that radiation and in particular chemoradiation are effective therapies consistent with other recent series and analogous to squamous cell carcinomas of the anus. It also emphasizes the poor prognosis of patients treated with palliative intent.