Surgical outcomes of post chemoradiotherapy unresectable locally advanced rectal cancers improve with interim chemotherapy, is FOLFIRINOX better than CAPOX?

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 38% (2-year OS) in whom surgery was not done (P=0.011). Survival was better in conservative surgery group . total pelvic exenteration (TPE) no surgery (2-year OS: 84% . 59.1% . 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%) . 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.