Predictors of survival after metastasectomy of oligometastatic recurrence following gastroesophageal cancer treatment.

Abstract

e16060 Background: Recurrent gastroesophageal (GE) carcinomas carry a poor prognosis and are usually treated with palliative chemotherapy (CTX). However, recent studies suggest that certain patients with oligometastatic recurrence can have long term survival after metastasectomy. Appropriate patient selection for metastasectomy remains a challenge, as few predictors of overall survival (OS) after metastasectomy have been identified. Our primary aim was to identify predictors of OS following metastasectomy in GE cancers. Methods: We conducted a retrospective study of GE cancer patients treated from 2007 to 2015 using the Princess Margaret Hospital Cancer Registry. We included patients who underwent curative-intent surgery or definitive chemoradiation (CRT) for localized GE cancer who then had single organ recurrence treated with metastasectomy. The probability of OS from date of recurrence was estimated with the Kaplan Meier method. Predictors of OS after metastasectomy for isolated recurrence were determined using Cox proportional hazards analysis. Covariates included time to recurrence (interval from curative-intent surgery or completion of definitive CRT), site of recurrence (lung/non-lung), sex, age and race (Asian/Non-Asian). Within the multivariable model, predictors with a p-value less than 0.05 were deemed significant. Results: Of 44 patients, median age was 58 years (28-78), and 59% were male. Primary sites were: esophagus 25%, GE junction 41% and gastric 34%. Treatment of the primary was: surgery alone 13%, surgery and (neo)adjuvant CTX 76%, and CRT 11%. Recurrent sites were brain 22%, ovary 20%, lung 18%, bone 7%, adrenals 7%, liver 7%, distant lymph node 6%, and other 13%. The median follow up time was 38.9 months. The 1, 3 and 5-year (yr) OS following metastasectomy were 79% (95% CI 68-92%), 40% (27-58%) and 28% (16-49%). Univariable analysis revealed that time to recurrence greater than 1 yr (HR=0.45 95% CI 0.21-0.93, p=0.032) and lung site recurrence (HR=0.16 95% CI 0.04-0.67, p=0.012) were associated with longer OS. On multivariable analysis, only lung site recurrence was significant (HR=0.12 95% CI 0.03-0.54, p=0.0056). The 1, 3 and 5-yr OS for patients after resection of isolated lung recurrence were 100% (95% CI 100-100%), 86% (63-100%) and 69% (40-100%). Conclusions: In our study, patients with isolated pulmonary recurrences demonstrated prolonged overall survival following metastasectomy. These patients could be considered for resection following recurrence of GE cancer. [Table: see text]