Projects

Project Description

Purpose:

Neoadjuvant chemoradiation therapy followed by Total Mesorectal Excision is the standard of care for locally advanced rectal cancer. Pathological response post-surgery is crucial for planning adjuvant treatment and predicting long-term outcomes. This study evaluated the extent of pathological response after NACRT, described post-treatment histological changes, and analyzed their relationship with clinical outcomes.

Methods:

Resection specimens of rectal cancers treated with NACRT over an 11-year period (2013-2022) were reviewed. Histopathological changes were assessed, and the pathological response was graded using the Modified Ryan Scheme and correlated with various clinical parameters. Survival was analyzed using Kaplan-Meier Analysis. 

Results:

Forty-five clinically stage III rectal cancers were included. The average tumor distance from the anal verge was 5.75 cm. Complete pathological response was observed in 26.66% of patients. Adenocarcinoma NOS was the most frequent residual histological type (69.69%). The circumferential radial margin was involved in 12.12% of patients. Acellular mucin pools were seen in 12 cases and were classified as a complete response. At five years, overall survival was 77.8%, and disease-free survival was 73.3%. Higher regression scores had earlier recurrences although not statistically significant. Ten patients developed systemic recurrence. No significant association was noted between grade and other clinical or pathological factors.

Conclusion:

This study underscores the importance of detailed pathological assessment of rectal carcinomas post-NACRT to guide treatment decisions. Since most recurrences were systemic, patients with a higher regression score (less response) may represent an increased risk group, warranting closer surveillance and consideration of intensified systemic therapy in future protocols.