Long term outcome after combined modality treatment for anal cancer
Background. The aim of the retrospective study was to evaluate the effectiveness and toxicity of radiochemotherapy in patients with squamous cell carcinoma of the anal canal treated at a single institution.
Patients and methods. Between 1/2003 and 9/2010, 84 patients were treated with radical radiochemotherapy at the Institute of Oncology Ljubljana, Slovenia. The treatment consisted of 3-dimensional conformal external beam radiotherapy with concurrent chemotherapy (5-fluorouracil and mytomycin C), followed by brachytherapy or external beam boost. The toxicity of therapy and its effectiveness were assessed.
Results. The treatment was completed according to the protocol in 79.8% of patients. The median follow-up time of 55 survivors was 53 months (range: 16-105 months). The 5-year locoregional control (LRC), disease-free survival (DFS), disease-specific survival (DSS), overall survival (OS) and colostomy-free survival (CFS) rates were 71%, 68%, 81%, 67% and 85%, respectively. No treatment-related mortality was observed. The most frequent acute side-effect of the treatment was radiodermatitis (grade 3-4 in 58.2% of patients). LENT-SOMA grade 3-4 late radiation side effects were observed in 15 (18%) patients. In patients with brachytherapy boost a trend of less late side effects was observed compared to patients with external beam boost (P=0.066). On multivariate analysis, complete clinical disease response was identified as an independent prognostic factor for LRC, DFS and DSS, the salvage surgery for LRC and DFS, whereas Hb below 120 g/l retained its independent prognostic value for OS.
Conclusions. Radiochemotherapy provides an excellent disease control and the survival with preserving anal sphincter function in majority of patients. Surgical salvage with abdominoperineal resection for persistent or recurrent disease has curative potential.