Background: Role of chemotherapy in patients who continue to have unresectable disease after pre-operative chemo-radiotherapy (CRT) remains largely unaddressed.
Methods: Patients with LA rectal cancer from January 2013 to June 2015 were evaluated. Post-CRT, patients, who were deemed unresectable, were considered for further interim chemotherapy (i-CT).
Results: Seventy six patients (15%) with median age of 38.5 years received i-CT after CRT. About 61.8% patients receiving i-CT managed to undergo a definitive surgery and the extent of surgery was reduced in 48.7% patients. With the median follow up of 19 months, the estimated 2-year event free survival (EFS) of 48% and OS was 56%. The estimated 2-year OS was 81% in mucinous tumors whereas it was 44.4% in signet ring pathology (P=0.045). The 2-year OS of 86% for whom surgery was done vs. 38% (2-year OS) in whom surgery was not done (P=0.011). Survival was better in conservative surgery group vs. total pelvic exenteration (TPE) vs. no surgery (2-year OS: 84% vs. 59.1% vs. 38%; P=0.033). In the CAPE-OX group, 71.4% (14/23) underwent surgery whereas 75.9% (29/47) in the 5-FU plus irinotecan plus oxaliplatin (FOLFIRINOX) group with EFS (P=0.570) and OS (P=0.120). In conservative surgery group, OS was better in FOLFIRINOX (2-year OS: 95.7%) vs. capecitabine plus oxaliplatin (CAPOX) (2-year OS: 70%) (P=0.012).
Conclusions: i-CT can lead to improved resection rates, improved survivals and downstaging with acceptable toxicity. FOLFIRINOX appears to better over CAPOX, specifically in whom conservative surgery is feasible.
Keywords: 5-FU plus irinotecan plus oxaliplatin (FOLFIRINOX); Locally advanced; downstaging; interim chemotherapy (i-CT); rectal adenocarcinoma; unresectable.