Real-world treatment attrition rates in advanced esophagogastric cancer

BACKGROUND: Over the last decade, multiple agents have demonstrated efficacy for advanced esophagogastric cancer (EGC). Despite the availability of later lines of therapy, there remains limited real-world data about the treatment attrition rates between lines of therapy. AIM: To characterize the use and attrition rates between lines of therapy for patients with advanced EGC. METHODS: We identified patients who received at least one cycle of chemotherapy for advanced EGC between July 1, 2017 and July 31, 2018 across six regional centers in British Columbia (BC), Canada. Clinicopathologic, treatment, and outcomes data were extracted. RESULTS: Of 245 patients who received at least one line of therapy, median age was 66 years (IQR 58.2-72.3) and 186 (76%) were male, Eastern Cooperative Oncology Group (ECOG) performance status 0/1 (80%), gastric vs GEJ (36% vs 64%). Histologies included adenocarcinoma (78%), squamous cell carcinoma (8%), and signet ring (14%), with 31% HER2 positive. 72% presented with de novo disease, and 25% had received previous chemoradiation. There was a high level of treatment attrition, with patients receiving only one line of therapy n = 122, 50%), two lines n = 83, 34%), three lines n = 34, 14%), and four lines n = 6, 2%). Kaplan-Meier analysis demonstrated improved survival with increasing lines of therapy (median overall survival 7.7 vs 16.6 vs 22.8 vs 40.4 mo, P < 0.05). On multivariable Cox regression, improved survival was associated with better baseline ECOG and increased lines of therapy (P < 0.05). CONCLUSION: The steep attrition rates between therapies highlight the unmet need for more efficacious early-line treatment options for patients with advanced EGC.