Impact of positive microscopic resection margins (R1) after gastrectomy in diffuse-type gastric cancer.

INTRODUCTION: Diffuse-type gastric cancer (DTGC) is associated with poor outcome. Surgical resection margin status (R) is an important prognostic factor, but its exact impact on DTGC patients remains unknown. The aim of this study was to assess the prognostic value of microscopically positive margins (R1) after gastrectomy on survival and tumour recurrence in DTGC patients. METHODS: All consecutive DTGC patients from two tertiary centers who underwent curative oncologic gastrectomy from 2005 to 2018 were analyzed. The primary endpoint was overall survival (OS) for R0 versus R1 patients. Secondary endpoints included disease-free survival (DFS), recurrence patterns as well as the overall survival benefit of chemotherapy in this DTGC patient cohort. RESULTS: Overall, 108 patients were analysed, 88 with R0 and 20 with R1 resection. Patients with negative lymph nodes and negative margins (pN0R0) had the best OS (median 102 months, 95% CI 1-207), whereas pN + R0 patients had better median OS than pN + R1 patients (36 months 95% CI 13-59, versus 7 months, 95% CI 1-13, p < 0.001). Similar findings were observed for DFS. Perioperative chemotherapy offered a median OS of 46 months (95% CI 24-68) versus 9 months (95% CI 1-25) after upfront surgery (p = 0.022). R1 patients presented more often early recurrence (< 12 postoperative months, 30% vs 8%, p = 0.002), however, no differences were observed in recurrence location. CONCLUSION: DTGC patients with microscopically positive margins (R1) presented poorer OS and DFS, and early tumour recurrence in the present series. R0 resection should be obtained whenever possible, even if other adverse biological features are present.

Lymph node metastases rate of locoregional and non-locoregional lymph node stations in gastric cancer.

Background: The incidence of lymph node metastases is closely related to the T-stage, and therefore Eastern guidelines advice a D1 lymphadenectomy for early gastric cancer and a D2 lymphadenectomy for advanced gastric cancer. The aim of this study was to compare the lymph node metastases rate in the stations dissected with a D2-lymphadenectomy (stations 8-12) yet spared with a D1-lymphadenectomy, between different T-stages in a Western patient cohort. Methods: For this retrospective study, patients who underwent a gastrectomy in the Amsterdam University Medical Center (UMC), location Academic Medical Center (AMC), between 2011 and 2016 were identified from a prospectively maintained database. The primary outcome was to compare the rate of lymph node metastases in station 8-12 between different cT-stages. Results: One hundred twelve patients met our inclusion criteria. There were no positive lymph nodes in the lymph nodes stations 8-12 in cT1 and (y)pT1-stage tumors. The more advanced cT2-4 and (y)pT2-4 stage tumors show a high metastases rate (11.1% to 40.0%) in the lymph node stations 8-12. Conclusions: The results from this study endorse the Japanese Gastric Cancer Guideline; in early gastric cancer, a D1 lymphadenectomy is sufficient, while in advanced gastric cancer a D2 lymphadenectomy should be performed.

Today's Mistakes and Tomorrow's Wisdom in the Surgical Treatment of Barrett's Adenocarcinoma.

Background: Barrett's esophagus is a premalignant condition caused by longstanding gastroesophageal reflux disease and may progress to low-grade dysplasia, high-grade dysplasia (HGD), and finally esophageal adenocarcinoma. Summary: Barrett's adenocarcinoma can be treated either by endoscopic or surgical resection, depending on the clinical staging. Endoscopic resection is a safe and adequate treatment option for HGD, mucosal tumors, and low-risk submucosal tumors. Its role in the treatment of high-risk submucosal tumors and the role of organ-preserving sentinel node navigated surgery are still under investigation. Esophagectomy with neoadjuvant chemoradiation or perioperative chemotherapy is considered the standard of care for locally advanced Barrett's adenocarcinoma. Regarding operative technique, there is no proven superiority of one technique over another, although a minimally invasive transthoracic technique seems most commonly applied nowadays. In this review, state-of-the-art evidence and future expectations are presented regarding indications for resection, neoadjuvant or perioperative therapy, type of surgery, and postoperative follow-up for Barrett's adenocarcinoma. Key Messages: In Barrett's adenocarcinoma, endoscopic resection is the standard treatment option for low-risk mucosal and submucosal tumors. For high-risk submucosal tumors, endoscopic submucosal dissection with close surveillance and sentinel node navigated surgery are currently being studied. For locally advanced cancer, a multimodal therapy including esophagectomy is the standard of care. Nowadays, in high-volume centers, a minimally invasive transthoracic esophagectomy with an intrathoracic anastomosis is the most common procedure for Barrett's adenocarcinoma.