Impact of Sites of Metastatic Dissemination on Survival in Advanced Gastroesophageal Adenocarcinoma.

Introduction: Metastatic gastroesophageal adenocarcinoma (GEA) is a heterogeneous disease with an overall poor prognosis. The impact of sites of metastatic dissemination on survival is not well characterized. This study aimed to evaluate whether certain sites of metastatic disease impacts survival.

Methods: A retrospective analysis of 375 patients with metastatic GEA treated at the Princess Margaret Cancer Centre from 2006 to 2016 was performed. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were used to assess the association between sites of metastases and OS adjusting for baseline patient characteristics.

Results: Median duration of follow-up was 47.8 months. Median OS in this cohort was 11.8 months (95% CI: 10.2-12.9 months). Patients with lymph node only disease, compared to those with other sites of metastases, had the longest median OS (20.4 vs. 10.6 months; p < 0.001) and PFS (11.4 vs. 6.3 months; p < 0.001). On multivariable analysis adjusting for relevant clinical factors including age, sex, and Eastern Cooperative Oncology Group performance status, the presence of lung (HR 1.67, 95% CI: 1.23-2.26; p < 0.001) or bone metastases (HR 1.84, 95% CI: 1.31-2.59; p < 0.001) were independently associated with shorter OS. The majority of patients (68%) were treated with palliative intent first-line platinum-based chemotherapy.

Discussion/conclusion: Patients with metastatic GEA have an overall poor prognosis. The presence of lung or bone metastases is an independent risk factor for decreased survival. Prognostic models incorporating sites of metastasis should be considered in the clinical evaluation of metastatic GEA.