Malignant Tumors of the Anus: Spectrum of Disease, Treatment and Outcomes

Huh, Kyu Ha; Lee, Kang Young; Ha, Hyun Soo; Park, Jae Kun; Kim, Nam Kyu; Sohn, Seung Kook; Min, Jin Sik

Abstract

PURPOSE: This retrospective study was performed to evaluate clinicopathologic findings, outcomes according to the treatment modality, and prognostic factors in anal cancer.
METHODS
Among the 64 patients who were diagnosed as anal cancer at our department from September 1986 to December 1999, 55 patients were analysed retrospectively. Nine patients who refused the treatment or whose medical record could not be retrieved were excluded. Concurrent chemoradiotherapy was performed for twenty-seven patients with squamous cell carcinoma. The chemotherapy with 5-FU and cisplatin and the radiotherapy were started at the same time. 750 mg/m2/day of 5-FU was infused intravenously for 5 days and 100 mg/m2 of cisplatin was started on the second day of therapy. The second cycle chemotherapy was given for 5 days before the radiotherapy was completed. A dose of 5,400cGy was given to the primary lesion and whole pelvis including inguinal area. Eight patients with squamous cell carcinoma were treated by surgery including abdominoperineal resection, local excision, or wide excision. Abdominoperineal resection was the primary treatment modality for melanoma of anus.
RESULTS
Among 55 patients with anal cancer, the dominant histologic type was squamous carcinoma (n=35), followed by cloacogenic carcinoma (n=6) and melanoma (n=6). The clinical stages by AJCC were classified as stage I: 4 cases, stage II: 15 cases, stage III: 29 cases, stage IV: 7 cases. The overall 5-year survival rate of anal cancer was 60%. The 5-year survival rate in squamous carcinoma was 79.9% for the concurrent chemoradiotherapy group (n=27) and 54.7% for the surgical resection group (n=8), which was statistically insignificant. Variables affecting the survival rate with statistical significance were age, the initial tumor size, and the state of lymph node and distant metastasis.
CONCLUSIONS
The concurrent chemoradiotherapy for patients with squamous cell carcinoma of the anus offered the same outcomes equivalent to surgical modality and preserved anal sphincter function. Melanoma of the anus exhibited poor prognosis and more systemic recurrence regardless of treatment modality. On univariate analysis for risk factors, age, tumor size, and lymph node and distant metastasis had statistical significance.