[R1 resection for gastric carcinoma]

The results reported in the literature in the context of an R1 situation for a resected gastric carcinoma are not uniform. An R1 situation worsens the prognosis for the long-term survival of patients. This is significant especially for low T stages and lymph node metastasis with 0-≤3 lymph node metastases. In higher tumor stages with extensive lymph node metastases, the survival difference between R0 and R1 resections is lower and frequently no longer significant. The frequency of R1 resection is approximately 5% (range 1.8-9%) and for adenocarcinoma of the esophagogastric junction (AEG tumors)> 10%. The data are mainly related to the oral and aboral resection line but there are only a few specifications on the circumferential margin. The risk of an infiltrated resection line increases with the size of the tumor (>5 cm), T3+4 and pN2/pN3 stages. Poorly differentiated signet ring cell or mucinous adenocarcinomas and carcinomas of the Bormann type 3+4 also lead to an increased R1 rate. In order to achieve an R0 resection, an intraoperative frozen section is the standard approach. Immediate reoperation should be performed in the case of tumor infiltration. If an R1 resection is detected only in the definitive histology, surgical re-excision to achieve an R0 resection is the standard approach in publications. Nevertheless, a reoperation is rare. Only 1 study showed 122 patients with 100% re-operations, which were successfully performed in 50 patients (41% R0). For the R0 group, median survival was extended from 18 months to 23 months. There are only sporadic literature data and no evidence for postoperative additive treatment (chemotherapy, radiotherapy and radiochemotherapy).