Is prophylactic lymph node dissection efficacious in salvage esophagectomy after definitive chemoradiotherapy?

Background Salvage esophagectomy for esophageal cancer after definitive chemoradiotherapy (dCRT) is a high-risk surgery, and radical lymph node dissection (RLND) can cause severe complications. However, the significance of RLND in salvage surgery remains unclear.Methods This study included 55 patients who underwent curative-intent salvage esophagectomy after dCRT for esophageal squamous cell carcinoma. We evaluated the prognostic impact of lymph node dissection of each station using efficacy indexes (EIs) and compared the outcomes between RLND and limited lymph node dissection (LLND).Results Nine (16.4%) patients underwent RLND and 46 (83.6%) underwent LLND. Patients who underwent RLND had greater operative blood loss and a greater number of resected lymph nodes compared to patients who underwent LLND (P = 0.053 and 0.002, respectively). However, the incidence of postoperative complications was not significantly different between the groups. The EIs of the cervical and mediastinal lymph nodes were zero because no patients with involved nodes at these stations remained alive at 5 years. In contrast, perigastric lymph nodes had relatively high EIs. Overall and cancer-specific survival did not differ significantly between patients who underwent RLND and those who underwent LLND (P = 0.475 and 0.808, respectively).Conclusions The EIs of the cervical and mediastinal lymph nodes were zero, and RLND did not improve survival. Depending on tumor status, LLND may be sufficient for salvage esophagectomy.