Prognostic and predictive factors after failure of two drug lines for metastatic gastric adenocarcinomas: A French retrospective study

149 Background: There is no therapeutic consensus after failure of two drug lines for metastatic gastric adenocarcinoma. The theoretical benefit of a third-line chemotherapy has to be weighed with the potential toxicity it could generate. It is essential to have prognostic and predictive factors to better select the candidate patients for a 3rd line chemotherapy. Methods: The medical records of patients (pts) treated in our institute from 2008 to 2018 who received at least two chemotherapy lines have been retrospectively analyzed. The main objective was to look for prognostic factors after failure of two chemotherapy lines. The secondary objectives were to look for predictive factors of progression-free survival, global survival, and RECIST response in 3rd line. Results: Out of a total of 153 pts identified, 68 received at least 2 chemotherapy lines and were eligible for analysis (44%). A third line was initiated for 41 pts (27%). Overall survival from the date of failure of a 2nd line treatment was 4.4 months (95% CI: 3.2-6.2). The median of progression-free survival in 3rd line was 1.68 months (CI 95%: 1.5-3.5 months), 5% of the patients responded to the treatment. In multivariate analysis, a period of less than 12 months between the administration of the 1st line of chemotherapy and the failure of a 2nd line was associated with a Hazard Ratio (HR) for death of 2.7 (p < 0.001; 95% CI 1.44 – 5.1). Pts who did not receive a 3rd line and female patients had a HR for death of 3.7 (p < 0.001; CI 95%: 1,9–7.3), and 2.8 (p < 0.001; 95% CI: 1,3–5.8) respectively. For patients who started a 3rd line: a PS ≥ 2 increased the risk of progression by 4.05 (p < 0.001; 95% CI: 1.1–15.7). Conclusions: Nearly one-third of pts were able to receive a third line chemotherapy. However, the benefit of this chemotherapy is low given the RECIST response rate, and the short overall and progression-free survival medians. Our results suggest that the administration of a third-line chemotherapy should only be considered for pts with 12 months or older ongoing metastatic lesions and whose general health condition is unaltered.