Chemoradiotherapy Doses Boost Anal SCC Survival in Northeast India, Suggests Study

While chemoradiotherapy (CCRT) has been the standard of care for anal cancer since 1974, clinical data from high-burden regions like Northeast India remains scarce. To address this gap, researchers from Dr. B. Borooah Cancer Institute in Guwahati evaluated real-world outcomes and toxicities of definitive CCRT for anal squamous cell carcinoma.

Therefore, the retrospective analysis tracked 22 patients with nonmetastatic anal SCC treated with IMRT/VMAT and concurrent 5-FU/MMC between 2017 and 2021. Researchers evaluated primary endpoints of overall survival and locoregional control, excluding cases with prior pelvic irradiation or incomplete clinical records.

Key Clinical Findings of the Study Include:

• Survival Outcomes: The study reported a median overall survival of 46 months for the entire cohort, with survival rates at one, two, and three years reaching 95.7%, 78.3%, and 63.63% respectively.

• Dose-Response Relationship: Clinicians observed that patients receiving a total radiation dose of 54 Gray or higher achieved a significantly superior three-year survival rate of 73.33% compared to only 33.3% for those receiving lower doses, indicating the critical role of dose escalation in this study.

• Anatomic Preservation: Effective local disease control allowed for a three-year colostomy-free survival rate of 60%, with outcomes notably better in patients presenting with T2-stage and node-negative disease compared to those with advanced nodal involvement.

• Technological Advantages: The investigation highlighted that advanced conformal techniques reduced the incidence of severe Grade 3 dermatitis and neutropenia compared to traditional Three-Dimensional Conformal Radiotherapy (3D-CRT), while completely eliminating severe late toxicities.

• Prognostic Variability: Significant survival differences were noted based on disease severity, with Stage IIB patients surviving a median of 67 months compared to only 29 months for those with Stage IIIC disease, emphasizing the impact of baseline tumor staging on longevity.

The results suggest that definitive chemoradiotherapy utilizing 5-fluorouracil and mitomycin C remains a highly effective curative strategy for nonmetastatic anal squamous cell carcinoma in regional clinical settings, providing satisfactory long-term survival and organ preservation, especially when radiation doses reach or exceed 54 Gray.

These findings emphasize that clinicians should prioritize the use of conformal radiation techniques to maximize dose delivery to the tumor while minimizing debilitating pelvic side effects like proctitis or skin fibrosis.

While the retrospective design and small cohort size suggest that these results should be interpreted with care, this work underscores the need for large-scale prospective trials to further optimize dose regimens and explore the integration of novel immunotherapies for high-risk patients.

Reference

Das, A., Nath, J., Das, T., Datta, S., Roy, P. S., Yanthan, Y., Das, J., & Chakraborty, R. (2026). Real-World Outcomes of Chemoradiotherapy for Anal Squamous Cell Carcinoma: Insights from Northeast India. Indian Journal of Surgical Oncology.