Chemoradiotherapy for squamous cell cancer of the anal canal: a systematic review

Squamous cell cancer of the anal canal is a rare tumour for which there remains uncertainty regarding optimal therapy. A systematic review was conducted to summarise the evidence examining concurrent chemotherapy and radiotherapy or different chemotherapy regimens in combination with radiotherapy. MEDLINE, EMBASE and conference proceedings were searched for relevant randomised controlled trials. Outcomes of interest were colostomy rate, local failure, overall survival, disease-free survival, adverse effects and quality of life. Six randomised controlled trials were identified. Two trials reported lower colostomy and local failure rates for concurrent 5-fluorouracil (5-FU) plus mitomycin C (MMC) and radiotherapy compared with radiotherapy alone. The omission of MMC from this regimen resulted in higher colostomy and local failure rates and lower disease-free survival. Induction chemotherapy followed by concurrent 5-FU plus cisplatin and radiotherapy resulted in a higher colostomy rate than concurrent 5-FU plus MMC and radiotherapy. Haematological toxicity rates were lower in patients who received radiotherapy with 5-FU alone or 5-FU plus cisplatin compared with 5-FU plus MMC. No benefit was seen for the addition of induction or maintenance chemotherapy to concurrent chemoradiotherapy. The available evidence continues to support the use of radiotherapy with concurrent 5-FU and MMC as standard treatment for cancer of the anal canal to decrease colostomy and local failure rates.