Treatment outcomes of esophageal squamous cell carcinoma with cM1 lymph node without organ metastasis

Stage IVB esophageal cancer typically has a poor prognosis; patients with non-regional lymph-node metastasis (cM1 LYM) but no organ metastasis generally fare better. However, comprehensive reports on treatment outcomes are limited. We included 158 patients with esophageal squamous cell carcinoma (ESCC) and cM1 LYM without organ metastasis treated at our institute between October 2006 and November 2022; their treatment outcomes were assessed, and prognostic factors were evaluated. The 3-year overall survival (OS) rates for all patients and those treated with surgery, chemoradiotherapy, chemotherapy, or palliative radiotherapy were 43.7%, 60.7%, 38.5%, 22.4%, and 20.0%, respectively. Surgery or chemoradiotherapy significantly improved OS compared to chemotherapy. Univariate and multivariate analyses identified significant OS prognostic factors: Eastern Cooperative Oncology Group performance status (ECOG PS) (1/2 vs. 0), type of cM1 LYM areas (two areas vs. thoracic area), and clinical response (stable/progressive disease vs. complete/partial response). In the subgroup receiving surgery or chemoradiotherapy, both analyses identified ECOG PS (1/2 vs. 0) and clinical response (stable/progressive disease vs. complete/partial response) as prognostic factors for OS. ESCC patients with cM1 LYM without organ metastasis had relatively good survival; those with good PS and a favorable clinical response especially achieved long-term survival. Because patients who underwent surgery or chemoradiotherapy had significantly better OS than those treated with chemotherapy, appropriate localized treatment might be necessary even in these cases.