B08 - Characteristics and outcomes of advanced gastric cancer patients treated with at least three lines of chemotherapy: analysis on 300 Italian real-world cases

Abstract

Background: Although 2nd-line chemotherapy (CT) has consistently demonstrated survival benefit compared with best supportive care in several randomized trials, there is no evidence that further treatment lines may improve the prognosis of advanced gastric cancer (AGC) patients (pts). However, offering CT beyond 2nd-line is possible for those who are still in good conditions. Patients and methods: Starting from a large cohort of 868 AGC pts, we retrospectively analyzed baseline parameters, tumor characteristics, and treatment data of those treated with 3 lines. Cross-tables and X2 test were used to describe categorical features. Kaplan Meier methods and Cox regression analyses were used to evaluate the impact of treatment intensity and progression-free survival (PFS) achieved in previous lines on 3rd-line PFS (PFS-3). Results: Of 300 pts, 208 were male (69.3%) with a median age of 65 years (range 27-84). The most common site of primary tumor was gastric body (30%); 45.3% of cancers had an intestinal histotype, 46.7% were G3-G4 and 14% HER2-positive. More than 50% of pts had multiple metastatic sites at the time of 3rd line therapy start. Overall, 45.7% of pts received a single-agent CT, 46% a doublet, and 3.7% a triplet regimen [4% unknown]. The most used agents were fluoropyrimidines (46.3%), followed by taxanes (36%), CPT-11 (34.3%), and platinum salts (13.7%). A biologic agent was administered in 1.7% of pts. Median PFS-3 was 2.8 mo and median 3rd-line OS was 5.1 mo. Pts who had experienced a shorter 1st-line PFS (<7.6 mo) had a worse prognosis compared with those who had achieved a longer one [PFS-3: 2.6 mo (95%CI 2.3-2.9) vs 3.3 mo (95%CI 2.6-3.9),p = 0.002). Also, a shorter 2nd-line PFS (<3.5 mo) impacted negatively on median PFS-3 [2.6 mo (95%CI 2.3-2.9) vs 3.1 mo (95%CI 2.5-3.7),p < 0.0001). Pts who received single-agent CT had shorter median PFS-3 compared with those treated with a combination regimen [2.5 mo (95%CI 2.1-2.9) vs 3.3 mo (95%CI 2.8-3.8),p = 0.003]. Conclusions: Our real-world study confirms that a significant proportion of pts receive 3rd-line treatment in clinical practice, and it provides information about disease histological features, type of treatment prescribed, as well as useful data of survival outcome. Having achieved longer PFS in previous treatment lines or a higher treatment intensity impacted positively on prognosis. Further efforts are warranted to define the best therapy sequences and to identify the optimal candidate for a 3rd-line CT.