Impact of lymphatic and/or blood vessel invasion in stage Ⅱ gastric cancer

AIM:To determine the prognostic value of lymphatic and/or blood vessel invasion (LBVI) in patients with stage Ⅱ gastric cancer.METHODS:From January 2001 to December 2006,487 patients with histologically confirmed primary gastric adenocarcinoma were diagnosed with stage Ⅱ gastric cancer according to the new 7th edition American Joint Committee on Cancer stage classification at the Department of Gastric Cancer and Soft Tissue Surgery,Fudan University Shanghai Cancer Center.All patients underwent curative gastrectomy with standard lymph node (LN) dissection.Fifty-one patients who died in the postoperative period,due to various complications or other conditions,were excluded.Clinicopathological findings and clinical outcomes were analyzed.Patients were subdivided into four groups according to the status of LBVI and LN metastases.These four patient groups were characterized with regard to age,sex,tumor site,pT category,tumor grading and surgical procedure (subtotal resection vs total resection),and compared for 5-year overall survival by univariate and multivariate analysis.RESULTS:The study was composed of 320 men and 116 women aged 58.9 ± 11.5 years (range:23-88 years).The 5-year overall survival rates were 50.7% and the median survival time was 62 mo.Stage Ⅱ a cancer was observed in 334 patients,including 268 T3N0,63 T2N1,and three T1N2,and stage Ⅱb was observed in 102 patients,including 49 patients T3N1,51 T2N2,one T1N3,and one T4aN0.The incidence of LBVI was 28.0% in stage Ⅱ gastric cancer with 19.0% (51/269) and 42.5% (71/167) in LN-negative and LNpositive patients,respectively.In 218 patients (50.0%),there was neither a histopathologically detectable LBVI nor LN metastases (LBVI /LN ,group Ⅰ);in 51 patients (11.7%),LBVI with no evidence of LN metastases was detected (LBVI+/LN ,group Ⅱ).In 167 patients (38.3%),LN metastases were found.Among those patients,LBVI was not determined in 96 patients (22.0%) (LBVI /LN+,group Ⅲ),and was determined in 71 patients (16.3%) (LBVI+/LN+,group Ⅳ).Correlation analysis showed that N category and the number of positive LNs were significantly associated with the presence of LBVI (P < 0.001).The overall 5-year survival was significantly longer in LN-negative patients compared with LN-positive patients (56.1% vs 42.3%,P = 0.015).There was a significant difference in the overall 5-year survival between LBVI-positive and LBVInegative tumors (39.6% vs 54.8%,P = 0.006).Overall 5-year survival rates in each group were 58.8% (Ⅰ),45.8% (Ⅱ),45.7% (Ⅲ) and 36.9% (Ⅳ),and there was a significant difference in overall survival between the four groups (P = 0.009).Multivariate analysis in stage Ⅱ gastric cancer patients revealed that LBVI independently affected patient prognosis in LN-negative patients (P = 0.018) but not in LN-positive patients (P = 0.508).CONCLUSION:In LN-negative stage Ⅱ gastric cancer patients,LBVI is an additional independent prognostic marker,and may provide useful information to identify patients with poorer prognosis.