Chemo-Radiation After Upfront Rectal Resections-a Clinical Dilemma

To compare the impact of adjuvant chemo-radiotherapy (ACRT) versus adjuvant chemotherapy (ACT) alone on recurrence and survival in patients with stage II and III rectal adenocarcinoma undergoing upfront curative resection. Prospective observational review of colorectal database at Tata Memorial Hospital from July 2010 to March 2015 identified 84 patients who underwent upfront curative resection for stage II or III rectal cancer. None of the patient received preoperative chemo-radiation. Of these, adjuvant chemo-radiotherapy was administered to 29 patients (ACRT group) and 55 patients received CAPEOX/FOLFOX-based adjuvant chemotherapy (ACT group) alone. At a median follow-up of 20 months, there were 10 recurrences (3 local recurrence) in the ACRT group and 15 (2 local recurrence) in ACT group. The estimated disease-free survival at 3 years in the ACRT group was 62.7% and in ACT group was 49.7% (p = 0.417) with an estimated 3-year overall survival of 74 and 78% in the ACRT and ACT group, respectively (p = 0.241). Subgroup analysis was performed after risk stratifying prognostic features (pT4, pN2, poor differentiation, involved resection margin). Our study does not show any benefit of ACRT over ACT on local control, disease-free and overall survival after upfront rectal cancer resection for low-risk stage II-III. In the subgroup analysis, local recurrence did not occur in patients who did not have poor prognostic features irrespective whether they received ACRT or ACT. Adjuvant chemo-radiation can be avoided in low-risk stage II-III rectal cancer after upfront resection.