Anal canal cancer: Biology and therapy

Introduction: Chemoradiation represents the standard of care for most patients with localized squamous cell carcinoma of the anal canal. In this article, randomized trials and studies on chemoradiation for localized anal cancer are reviewed. Areas covered: Herein the major Phase III randomized controlled trials published on the treatment of anal carcinoma are discussed. A recent randomized trial (Anal Cancer Trial II), after a total follow-up of 5.1 years, demonstrated that there was no difference in the complete response rate or 3-year progression-free survival when 5-fluorouracil (5-FU) with cisplatin chemoradiation was compared with 5-FU plus mitomycin C chemoradiation. Maintenance chemotherapy using 5-FU and cisplatin did not improve 3-year progression-free survival-74 versus 73%. Recent studies have continued to evaluate intensity-modulated radiation therapy for anal cancer in an effort to reduce acute and long-term toxicity from radiotherapy, but no clear answers have emerged. Expert opinion: Studies on tumor biology, patient genetics and predictive marker are warranted to identify patients that are most likely to benefit from newer locoregional and systemic therapies. Intensity-modulated radiation therapy appears to be a promising approach for reducing treatment-related toxicity in anal cancer patients, but its role still remains to be completely defined.