The length of negative proximal resection margin does not significantly influence on the prognosis of Siewert type II adenocarcinoma of esophagogastric junction with or without neoadjuvant chemotherapy.

Background: Optimal length of proximal resection margin (PRM) for locally advanced Siewert type II adenocarcinoma of esophagogastric junction (AEG) remained undetermined. Especially, the relationship between PRM length after neoadjuvant chemotherapy (NAC) and survival were seldom reported. Methods: A total of 108 consecutive locally advanced Siewert type II AEG patients were enrolled. The clinicopathological characteristics, PRM length and survival outcomes were collected. Cox proportional hazard model was used to compare the hazard rates of survival and recurrence between patients with length above and below the cut-off value. Univariable and multivariable analyses were performed to analysis association between PRM length and prognosis. Results: The mean PRM length was 13mm (range: 1-45 mm). PRM status was independent factor for recurrence-free survival (RFS) (HR 3.177, 95%CI 1.098-9.193, Conclusions: A positive status of PRM appears to be associated with adverse survival outcomes of patients with locally advanced Siewert type II AEG after surgery. However, for patients with negative status, the length of the PRM does not influence survival, regardless of whether they undergo surgical resection alone or NAC followed by surgery.