హెల్త్ & మెడికల్ ఇన్ఫర్మేటిక్స్ జర్నల్

Cancer Treatment 2020 - Outcomes post induction chemotherapy followed by chemoradiation in T4b non-metastatic primary rectal cancer

Abstract

Ahmad Al Zahrani

Background: Role of upfront chemotherapy in locally advanced rectal cancer invading into adjacent structures has not yet been defined. Beside risk of local failure, this entity has high risk for distant metastasis as well.

Patients and methods: Patients with newly diagnosed T4b non-metastatic rectal cancer treated between January 2011 and December 2017 were retrospectively reviewed from a single institution. Primary end point was R0 resection rate.

Results: Thirty eight out of 41 patients were eligible for our study. Median age: 52.5 years (range 29-77). Twenty were males (52.6%). Median distance from anal verge: 6 cm (1.8-15). Median follow up: 28 (20.5-52.2) and 41 months (26.2-63.7) in entire population and R0 resected group, respectively. Oxaliplatin- and irinotecan-based doublet chemotherapy was administered in 35 (92.1%) and 3(7.9%), respectively, (median 7 cycles). All 24 resected patients had R0 resection (63.1%). All resected patients except one case with ulcerative colitis received fluoropyrimidine-based chemoradiation prior to surgery (median radiation dose: 5040 cGY). Standard TME surgery was carried out in 10 patients (26.3%), extended TME surgery was done in 8 patients (21 %), Six patients required pelvic exenteration (15.7%). Complete pathological response was reported in 3 patients (12.5%). Although 17 patients (70.8%) had advanced cN2 disease, 21(87.5%) patients turned to be ypN negative. Three-year progression- free and overall survival in entire population were 52.2% and 78.6%, respectively. For R0 resected group, these figures were 82.2% and 100 %. Distant metastasis rate and and local failure rate in R0 resected group were 4.1 % and 8.3%, respectively.

Conclusions: Induction chemotherapy approach appears promising strategy in this setting. Compared to limited historical control data, we achieved similar R0 resection rate but by far we noted a substantial reduction in distant metastasis rate in resected group. As such this strategy warrants further prospective evaluation in clinical trials.