LAUSR

e16061 Background: Based on results German FLOT-4 study, the FLOT regimen could be considered the new standard chemotherapy regimen for perioperative strategy of resectable GC. Since more and more patients have received neoadjuvant treatment,the efficacy and side effect must be weighted before performing NACT. Two-drug regimens were preferred according to the NCCN guidelines in principle because of their lower toxicity. And three-drug regimens may be applied in medically fit patients with access to frequent evaluation during treatment, to ensure that they can still tolerate surgery after NACT. Methods: We analyzed the data of 79 patients with resectable locally advanced gastric cancer who received the FLOT or FOLFOX regimen as NACT. The group of patients with NAСT FLOT included 44 patients, including 32 men, 12 women. Age in the first group varied from 28 to 80 years, the median age was 59.0 (95% CI 54.1-62.0) The group of patients with the FOLFOX chemotherapy regimen included 35: 17 (48.6%) men and 18 women (51.4%). Age in the second group varied from 60 to 75 years, the median age in the second group was 67.5 (95% CI 62.2-71.0). The second group included significantly older patients U = 137.0; p = 0.0001. Results: The severity of drug pathomorphosis was assessed in a standard way according to the Mandard system, in the first group there were 5 patients - TRG1 (11.4%), 7 patients - TRG2 (15.9%), 9 patients - TRG3 (20.5%), 15 patients TRG4 (34.0%), 5 patients - TRG5 (11.4%), 3 patients it was not evaluated (6.8%). In the second group, 6 patients - TRG1 (17.1%), 2 patients - TRG2 (5.7%), 2 patients - TRG3 (5.7%), 16 patients - TRG4 (45.8 %), 7 patients - TRG5 (20.0%), for 2 patients it was not evaluated (5.7%). Complete pathomorphosis was not statistically different in both groups (p = 0.47). TRG 2 was not statistically different (p = 0.16). The number of registered cases of TRG3 in the first group exceeded (p = 0.06). The frequency of TRG4 and TRG 5 did not differ (p = 0.29). Major pathological regression (TRG1 + TRG2) was 27.3% in the first group and 22.8% (p = 0.65). A decrease in the stage in the first group occurred in 22 patients (50.0%), and in the second group - in 19 patients (54.3%), p = 0.70. yp≤ T2 was diagnosed in 21 out of 79 patients (26.6%), in the first group in 11 patients (25%), in the second group in 10 (28.6%), p = 0.72. Conclusions: the FOLFOX regimen showed similar efficacy in the tumor response grade rate compared to the FLOT regimen, therefore, these two regimes are interchangeable, especially among patients of the older age group or in patients with high risks of a four-component regimen.