P-116 Impact of the number of harvested lymph nodes on survival in Egyptian patients with gastric cancer: Middle Eastern tertiary center experience

Radical gastrectomy with regional lymphadenectomy is the standard of care for all resectable gastric cancers. LN dissection has been debated over the years by different oncologic surgeons. In Japan, D2 lymphadenectomy was considered the standard procedure, whereas, in Asian countries, extended lymphadenectomy achieved superior survival and reduced recurrence rates. On the contrary, in Western countries, D2 lymphadenectomy was not considered a standard of care in clinical practice, possibly due to lower incidence of gastric cancer and lesser confidence of western oncologic surgeons in this procedure as a result of higher rates of surgical complications and perioperative mortality. Therefore, we aimed to estimate the effect of the number of resected LNs on survival outcomes in middle eastern patients with resectable gastric cancer, whether 16 LNs remained the optimal threshold, and whether a specific subset of patients could likely benefit from more dissected LNs. The study cohort included patients who underwent surgical resection for gastric cancers between 2012 and 2014 at the Surgical Oncology Department of South Egypt Cancer Institute (SECI), Assiut University, Egypt, and were treated with chemotherapy, with or without radiotherapy, at the Clinical Oncology Department of Assiut University Hospital, Assiut University, Egypt. We divided patients according to the number of lymph nodes into two groups, those with LN dissection of <16 LNs and those with ≥16 LNs dissected. Patients were followed through their files for 5 years to calculate disease-free survival (DFS) and overall survival (OS). Then, we compared DFS and OS between groups. A total of 136 patients with gastric carcinoma underwent surgical intervention. Upon dividing our patients into 2 groups (those with less than 16 LNs dissected and those with 16 LNs or more dissected), increasing the number of LNs dissected correlated positively with survival; this correlation was mild but significant, with the exception of D1 dissection and DFS. Coincident with recent recommendations of different guidelines, D2 dissection was associated with significantly better OS and DFS (P = .001 and P = .001, respectively). The OS curves of both groups were compared using the log-rank test, demonstrating significantly higher OS for those with 16 LNs or more dissected (log-rank = 8.030; P = .005). The mean OS for the former group was 13.480 ± 1.468 months (95% CI, 10.603-16.357) whereas for the latter group was 20.738 ± 2.065 months (95% CI, 16.690-24.786). Furthermore, DFS for those with lower LNs dissected was significantly different from that of higher LNs dissected (log-rank = 5.465; P = .019). The mean DFS for the former group was 11.240 ± 1.516 months (95% CI, 8.270-14.210) and the mean DFS for the latter group was 17.452 ± 2.012 months (95% CI, 13.510-21.395). Also, we found that patients with T1 tumors who had more LNs dissected translated into better survival. Greater lymph node harvest showed improved survival in gastric cancer. There was a significant positive correlation between survival outcomes and the total number of LNs dissected. Therefore, D2 gastrectomy is recommended, even in early-stage gastric cancer.