Patterns of failure and outcomes in anal adenocarcinoma

Abstract

13503 Background: Adenocarcinoma of the anal canal is a rare malignancy with an aggressive natural history. The purpose of this study is to evaluate the outcomes of a multidisciplinary approach in patients with anal adenocarcinoma. Methods: A retrospective review was performed of patients with anal adenocarcinoma identified from the M.D. Anderson Cancer Center (MDACC) tumor registry between 1983 and 2004. Distal rectal cancers were excluded by pathologic review. Patients were classified according to treatment type: chemoradiotherapy (CXRT) ± local excision or radical surgery (RS) ± chemoradiation. Overall survival, and patterns of failure were assessed. Results: 41 candidate patients were identified. Thirteen patients were excluded (10 misclassified, 3 no treatment or followup at MDACC). Of the remaining 30 patients, 27 had localized disease and were treated with curative intent. 26 patients received radiation, 23 of the 26 with concurrent 5-FU based chemotherapy. Eleven patients (41%) received additional 5-fluorouracil-based adjuvant chemotherapy following primary treatment. Twelve patients were in the CXRT treatment group and 15 were in RS (1 did not receive chemoradiation). Median follow-up was 28 months (range 5–195). Median overall survival for the entire cohort was 59 months with an actuarial 5-year survival of 47%. Rates of recurrence are shown in the table below. Three patients with local failure were treated with salvage abdominoperineal resection and all developed subsequent failure (2 distant, 1 local). The fourth patient refused surgery and subsequently developed disease progression. Conclusions: Adenocarcinoma of the anal canal has a poor prognosis and accurate histologic diagnosis should be pursued. Although limited, our experience demonstrates that the most common pattern of failure is distant. An aggressive multimodal approach results in good local control but improvements in chemotherapeutic strategies are needed. [Table: see text] No significant financial relationships to disclose.