Risk factors for lymph node metastasis of early gastric cancers in patients younger than 40

This research aims to explore the potential risk factors of lymph node metastasis (LNM) for early gastric cancers in young patients. We retrospectively collected data from 4287 patients who underwent gastrectomy from January 2005 to December 2015 at Linyi People's Hospital. Of these, we enrolled 397 eligible consecutive patients who had early gastric cancer, then divided them into 2 groups according to age (<= 40 years and > 40 years). The association between the clinicopathological factors and LNM was analyzed by univariate and multivariate analysis. Compared to older patients (> 40 years), younger patients (<= 40 years) with early gastric cancer had more diffuse and mixed types (51.1% and 37.8% vs 40% and 8.3%, respectively), less proximal gastric cancer (0% vs 33.8%, P<.01) and higher LNM (33.3% vs 13%, P<.01). Univariate analysis showed tumor invasion depth (P<.01), lymphovascular invasion (P<.01), and E-cadherin expression (P=.024) were associated with LNM in the younger cohort. Multivariate analysis revealed that lymphovascular invasion (OR= 17.740, 95% CI: 1.458-215.843) was an independent risk factor for LNM (P=.024). Further analysis showed 3 patients who were within expanded endoscopic resection indications were positive for LNM. Given the high risk of lymph node involvement in young patients with early gastric cancer, both endoscopic and surgical resection procedures should be performed with caution, and active postoperative surveillance is warranted.