Malignancies of the anal canal: a multi-center retrospective analysis in South China population

Malignancies of the anal canal are rare diseases associated with limited reports and insufficient data. The purpose of this study was to evaluate the spectrum of pathological subtypes, therapeutic modalities and prognosis of patients in the Chinese population with anal canal malignancies.

A retrospective consecutive series of patients with malignancies of the anal canal at 4 institutions in China between January 1990 and December 2011 was studied. The patient demographic data, including age, gender, tumor stage, initial symptoms, pathological diagnosis, treatment and survival, were collected and analyzed from the hospitals' databases.

A total of 180 patients (90 males, 90 females) with anal canal malignancies was identified. Their median age was 58 years (range 17-88). The 3 most common pathological subtypes were adenocarcinoma (N-129, 71.7%), squamous cell carcinoma (SCC; N=21, 11.7%) and melanoma (N7equals;15, 8.3%). Ninety-five adenocarcinoma patients and 10 SCC patients were managed with abdominoperineal resection (APR). With a median follow-up time of 28.9 months (range 1-173), the 5-year overall survival (OS) rates for all patients, adenocarcinoma patients, SCC patients and melanoma patients were 41.9, 40.6, 44.5 and 14.8% respectively, and the median OS time were 46.8, 50.1, 52.5 and 25.0 months, respectively (p=0.173).

Adenocarcinoma was the major histological subtype in Chinese patients with anal canal malignancies. APR-based combined modality treatment was the first choice for the past two decades, whereas multidisciplinary treatment was not performed adequately. The management of SCC must be standardized in South China population. In the future, randomized clinical trials are warranted for the optimal treatment options of anal canal adenocarcinoma patients.