From the Guidelines
The standard treatment for anal squamous cell carcinoma (spinocellular carcinoma) is a combination of chemotherapy and radiation therapy (chemoradiation), which has become the standard of care for most patients with localized disease, as recommended by the 2025 ASCO guideline 1. This approach typically involves 5-fluorouracil (5-FU) and mitomycin C (MMC) radiosensitizing chemotherapy, with a total radiation dose of 45-59 Gy. The most recent evidence from the 2025 ASCO guideline 1 supports the use of definitive chemoradiation (CRT) as the standard of care, with fluorouracil (FU) and mitomycin-C (MMC) being the recommended chemotherapy agents. Key points to consider in the treatment of anal squamous cell carcinoma include:
- The importance of human papillomavirus (HPV) infection in the development of anal cancer, with approximately 90% of cases associated with HPV types 16 and 18 1
- The role of regular screening with digital rectal examination and anoscopy for high-risk individuals, such as HIV-positive patients, men who have sex with men, and women with a history of cervical or vulvar cancer 1
- The use of uninterrupted treatment, avoiding gaps, to maximize radiobiological effectiveness 1
- The recommendation for doses of at least 45-50 Gy without a gap, or higher doses if a planned gap is used 1 Overall, the goal of treatment is to achieve complete response and avoid the need for abdominoperineal resection, which involves loss of the anal sphincter and a permanent colostomy, thereby improving quality of life and reducing morbidity and mortality.
From the Research
Anal Cancer Spinocellular
- Anal cancer, also known as squamous cell carcinoma of the anal canal, is a rare type of cancer that affects the anal canal 2.
- The standard treatment for anal cancer is concurrent chemoradiotherapy with 5-fluorouracil (5-FU) and mitomycin-C (MMC) 3, 4.
- This treatment approach has been shown to be effective in preserving sphincter function and avoiding the need for surgical resection 2.
Treatment Outcomes
- Studies have compared the outcomes of patients treated with one versus two cycles of MMC, and found no significant difference in progression-free survival, cancer-specific survival, overall survival, or colostomy-free survival 3.
- The use of 5-FU and MMC has also been evaluated in the second-line treatment of metastatic squamous cell carcinomas of the anal canal, and has been shown to provide tumor control with acceptable tolerance 5.
- In immunocompetent and immunodeficient patients, treatment outcomes with combined modality therapy using 5-FU and MMC have been found to be similar, with no significant differences in overall survival, disease-specific survival, and colostomy-free survival 6.
Toxicity and Side Effects
- Acute grade ≥ 2 toxicities have been reported to be worse in patients treated with two cycles of MMC compared to those treated with one cycle 3.
- Treatment-related deaths have also been reported, highlighting the need for careful monitoring and management of side effects 3.
- The use of 5-FU and MMC in the second-line treatment of metastatic squamous cell carcinomas of the anal canal has been associated with acceptable tolerance, although dose reductions and discontinuation of treatment may be necessary in some cases 5.