Abstract 1460P
Background
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. Sites of metastasis were determined by baseline computed tomography of chest, abdomen, and pelvis, and additional investigations as clinically indicated. 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 patient characteristics, including sites of metastases, and OS.
Results
Patients were primarily male (67%), non-Asian (85%), with Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0–1 (81%). Median follow-up duration 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 months) and PFS (11.4 months). Sites of metastases associated with decreased OS were metastases to the lung with a median OS of 9.6 months, and metastases to the bone, with a median OS of only 8.1 months. On multivariate analysis adjusting for relevant clinical factors including age, sex, and ECOG PS, the presence of lung or bone metastases were independently associated with shorter OS, with hazard ratios of 1.67 (95% CI: 1.23-2.26; p < 0.001) for presence of lung metastases and 1.84 (95% CI: 1.31-2.59; p < 0.001) for presence of bone metastases. Other sites of metastases including liver, peritoneal, adrenal, and ovarian were not associated with decreased OS. Majority of patients (68%) were treated with palliative intent platinum-based chemotherapy.
Conclusions
Patients with metastatic GEA have a poor prognosis. The presence of lung or bone metastases are independent risk factors for decreased survival. Prognostic models incorporating sites of metastasis should be considered in the clinical evaluation of metastatic GEA.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
E. Elimova: Advisory/Consultancy, Research grant/Funding (institution): Bristol-Myers Squibb. All other authors have declared no conflicts of interest.