Outcomes of concurrent chemoradiotherapy versus chemotherapy alone for esophageal squamous cell cancer patients presenting with oligometastases.

Background The potential survival benefits of adding radiotherapy to systemic therapy for esophageal cancer patients with oligometastases are unknown. Methods In this retrospective analysis, patients with stage IV esophageal cancer (according to the American Joint Committee on Cancer Seventh edition staging system) with ≤3 metastases who underwent chemotherapy with cisplatin/paclitaxel between 2012 and 2015 were identified. Patients received chemotherapy (CT) alone vs. concurrent chemoradiotherapy (CCRT) to all metastases. Results Of 461 patients, 97% had squamous cell cancer. One hundred and ninety-six patients (42.5%) received CCRT and 265 (57.5%) underwent CT alone. At week 8, there were 3 (1.5%) complete responses (CR) and 95 (48.5%) partial responses (PR) in the CCRT group, compared to 3 (1.1%) CR and 102 (38.5%) PR in the CT alone group. The overall rate of improvement in dysphagia score was noted in 78.5% of patients in the CCRT group versus 61.5% in the CT alone group (P=0.014). A statistically significant difference was demonstrated in disease control rate between the two groups (81.6% vs. 64.5%, P<0.001). Patients who underwent CCRT had superior median PFS and a trend toward longer median OS compared to those receiving CT alone (8.7 vs. 7.3 months, P=0.002 and 16.8 vs. 14.8 months, P=0.056, respectively). The median OS was 19.3 months in patients who achieved CR/PR, compared to 14.9 months and 9.6 months for patients who had stable disease and progressive disease, respectively (P<0.001). Conclusions Compared to chemotherapy alone, chemoradiation to all sites in patients with esophageal cancer with ≤3 metastases may lead to a modest increase in PFS and a trend toward longer OS. Further investigation of optimal integration of radiotherapy and chemotherapy in these patients is warranted.