Impact of a pre- and postoperative chemotherapy (Ctx) on overall survival (OS) and progression free survival (PFS) in locally advanced gastric cancer (LAGC).
156 Background: Perioperative Ctx has become standard of care for LAGC. Duration of pre- and post-op Ctx is a matter of debate. Our study evaluated effects of varying durations of pre- and post-op Ctx on PFS and OS. Secondary endpoints were toxicity, reasons for cessation of Ctx and response. We compared the outcome to a group of pts receiving no perioperative Ctx as an internal control. Methods: Pts with LAGC were included in a prospective cohort trial from a single institution from 2007 to 2015. Inclusion criteria were T1-T4, N0-3, M0, AEG (n=27) or gastric cancers (n=65). Initial therapy decisions were made by an interdisciplinary tumor board for all pts. Pts received DDP/5-FU (qw d28 mod FFCD-Protocol, Ychou et al. JCO 2011) for 2 mo, and a 3rd mo of pre-op Ctx in case of non-progression after 2 mo and proceeded to Ctx after surgery for a planned total of six mo of Ctx. Results: 92 pts (53 m; 39 f pts) with a median age of 69 ys (range 33-96) were included. A total of 74 pts were recommended periop Ctx and 18 primary surgery (S). A total of 67 (91%) of the periop Ctx received pre-op Ctx (NA) of which 47 (64%) received 3 mo of pre-op Ctx, 19 (26%) two mo, 1 pt (1%) one mo, and 7 pts refused preop Ctx (9%) of which only 3 proceeded to surgery. Only 53 pts (72 %) received post-op Ctx; 25 pts (34%) received three mo, 9 pts (12 %) two mo, and another 10 pts (14 %) one mo of postop Ctx. Nine pts (13%) in the NA group and 20 pts (39%) in the post-op Ctx group had to stop Ctx due to toxicity after 1 (n=11) and <2 (n=9) mo of Ctx. Only 23 pts (31%) received the planned pre- and postop Ctx of 6 mo in total. Up to 07/2016 a total of 36 deaths were observed (39%). 5 yr PFS was 49% in the group of periop Ctx vs 14% in the S group. PFS in pts receiving a total of < 4 mo of Ctx was 36% vs. 61% in pts receiving 6 mo of Ctx. 3 yr OS was 19% in the S group vs 48% in the Ctx group. The OS in pts receiving < 4 mo was 34% vs.43% in pts with 6 mo Ctx. A pCR after preop Ctx was observed in 2 pts, a PR in 47 pts, a SD in 12 pts, while a PD occurred in 3 pts only. Conclusions: Pre-op Ctx was considerably better tolerated than post-op Ctx and led to fewer Tx cessations. We found a better PFS for pts with >4 mo of periop Ctx, as well as OS was affected by a shorter duration of periop Ctx.