Definitive chemoradiation for oligometastatic esophageal cancer patients.

Abstract

359 Background: When esophageal cancer (EC) is metastatic at diagnosis, prognosis is poor, with 5-year survival of ̃5%. NCCN guidelines recommend palliative treatment or best supportive care. However, guidelines do not stratify by the extent of metastatic disease. Oligometastatic (oligo) disease has been shown in some cancers to portend better survival and more aggressive treatment options may be appropriate. Preliminary data has shown this may be the case for oligo EC, however, consensus recommendations remain palliative in intent. This study aims to compare overall survival (OS) in oligo EC patients treated with a definitive approach (chemoradiotherapy [CRT]) to those treated with purely palliative intent. Methods: Patients with oligo (any histology, ≤5 metastatic foci) EC treated in a single academic hospital between 2009-2020 were retrospectively analyzed in 2021. Patients were divided into definitive and palliative treatment groups; definitive CRT was defined as radiation therapy >40 Gy and >2 cycles of chemotherapy (CT) (+/- induction CT). OS was calculated by measuring the time from the date of diagnosis to the date of death or last follow-up. Survival curves between groups and by various prognostic factors were compared using the log rank test. Results: Of 77 Stage IVB patients, 35 met the pre-specified oligo definition. Of these, 18 received definitive CRT, and 17 palliative treatment (Table). With a median follow-up of 60.8 months, median OS for definitive CRT and palliative groups were 91.4 and 8.2 months, (p<0.01), translating into 5-year OS of 57.7% (95%CI: 33.5-82.0%) vs. 7.5% (95%CI: 0.0-21.6%), respectively. Prognostic factors correlated with increased OS included lower ECOG performance status (PS) (p<0.01), induction CT (p<0.01), N stage (p<0.01), adenocarcinoma (vs. squamous cell carcinoma) (p<0.05), diagnosis in 2013 or later (p<0.05), younger age (p<0.05), and > lymphocyte-to-monocyte ratio (p<0.05). Factors not associated with OS included neutrophil-to-lymphocyte ratio (p=0.39), T-stage (p=0.9), primary site (GEJ, distal, mid, or cervical) (p=0.07), tumor grade (p=0.83), type of spread (hematogenous, lymphatic, or local invasion) (p=0.69), sex (p=0.22), and HER2 status (p=0.07). Conclusions: Within our population, oligo EC patients treated with definitive CRT had significantly improved OS as compared to those treated with palliative only intent. These results suggest there may be a sub-population of oligo EC that would benefit from more aggressive treatment paradigms; thus, further evaluation is warranted.[Table: see text]