P-7 Induction chemotherapy in locally advanced rectal cancer: Retrospective report of efficacy and safety in an Argentinean university institution, a feasibility perspective

Abstract

We performed a retrospective study of LAG/GEJ cancers undergoing periop-FLOT during the last two years. The FLOT regimen was applied as in the FLOT4-AIO trial. Pathological tumor regression grade was done according to Modified Ryan Scheme (TRG0: complete response, TRG1: near-complete response, TRG2: partial response, TRG3: poor/no response) and DFS analysis was estimated by Kaplan-Meier method with SPSS.Results: Fifty-nine pts with LAG/GEJ cancers commenced on periop-FLOT. Demographics: male n¼43 (73%), median age 63 (range;34-85), performance status; PS0 n¼29 (49%), PS1 n¼20 (34%), PS2 n¼10 (17%). Tumor location gastric n¼38 (64%), GEJ n¼21 (36%). All of the pts were cT3/T4, and 55 (93%) were cN+. 53 pts (90%) received 4 cycles of neoadj-FLOT. 45 (76%) pts underwent curative surgery, and 40 (89%) of them had D1 lymphadenectomy. R0 resection was achieved in 44 pts (75%). TRG0 n¼5 (8%), TRG1 n¼9 (15%), TRG2 n¼5 (8%) and TRG3 n¼26 (44%) were reached, and 22 pts (37%) were detected as ypN0. 30 pts (51%) started adj-FLOT and 26 pts (44%) completed all cycles. The median follow-up was 11 months (range 4e 27), with a median DFS of 21.8 months (95% CI 18.9e24.9), and 9 of 45 pts (20%) relapsed. Significant differences in DFS between pts who received adj-FLOT (25.4 months, 95% CI 23.1e27) compared with no-adjuvant (13.6 months, 95% CI 10.2e 16.9) were found (p¼0.001), and also among ypN0 (26 months, 95% CI 24-28.1) compared with ypN+ (15.6 months, 95% CI 12.4-18.9) (p¼0.006). No effect of TRG's on DFS were detected (p>0,05). The median OS not reached. 56 pts (95%) had at least one any grade toxicity. Dose reduction was performed in 3 pts (5%). The most common grade 3/4 toxicities were neutropenia (n¼11;19%) and neutropenic fever (n¼7;12%) although we prescribed primary prophylactic G-CSF. Two toxic deaths occurred (3%) during the neoadjuvant period. Compared with the FLOT4-AIO trial, although our pts had a higher PS, they had similar rates of dose reduction (5% vs 6%), completing neoadjuvant (90% vs 90%) and adjuvant (44% vs 46%) treatments. R0 (75% vs 85%) and D2 (11% vs 92%) resection, ypN0 (37% vs 49%) and pCR rates (8% vs 16%) were lower in our pts, due to higher initial clinical stages.Legal entity responsible for the study: The authors.