The Clinical Study Of Lymph Node Micrometastasis Of Gastric Cancer Detected By Immunohistochemistry

Objective:. To investigate the association of 5 year disease free survial rate with clinicopathologic characteristics and lymph node–micrometastasis for patients with pT_1-3N₀M₀ gastric carcinoma.Methods: A total of 120 cases of gastric carcinoma specimens were obtained from resected stage pT_1-3N₀M₀ gastric carcinoma, with 17 lymph nodes ( in average) each patient. Expressions of CK, EMA and CEA in lymph nodes were examined with immunohistochemistry, and it was supposed as positive expression when at least one of the three factors showed immunopositive expression .The relationship among 5 year disease free survial rate, clinicopathological parameters (gender,age,tumor site,tumor diameter,gross type, invasive depth,grade,vassular invasion and lymphatic invasion) and lymph node–micrometastasis was analyzed.Results: The positive expression rates in lymph node were significantly correlated with clinicopathological parameters including tumor diameter (P<0.05), invasive depth(P<0.05) and lymphatic invasion (P<0.05), while no significant correlation was found between positive expression and other parameters. We also found 5 year disease free survial rate was significantly correlated with no other clinicopathological parameters except for tumor diameter (P<0.05) and invasive depth(P<0.05). In summary, the positive rate in lymph nodes was 20.11%(412/2049) belonging to 39 cases of patients with pT_1-3N₀M₀ gastric carcinoma. There are 13 cases (10.83% 13/120) with MCM(micrometastasis) being observed in lymph nodes, and 26 cases(21.67% 26/120) with ITCs(isolated tumor cells) being found in lymph nodes. Besides, 5 year disease free survial rate of patients with immunonegative expression, ITCs and MCM was 88.6%, 87.4% and 51.9%, respectively. The difference on 5 year disease free survial rate showed no significance between patients with ITCs and patients with immunonegative expression or MCM(P>0.05),. while the 5 year disease free survial rate of patients with immunonegative expression was significantly higher than that of patients with MCM(P<0.05). So, the 13 cases with MCM being observed in lymph nodes should be classified as stage pN₁(MCM), while the 81 cases with immunonegative expression in lymph nodes and 26 cases with ITCs being found in lymph nodes should be classified as stage pN₀(I+) and pN₀(I-) respectively.( stage pN₀)CONCLUSIONS: Lymph node–micrometastasis is an important prognostic factor for patient with stage pT_1-3N₀M₀ gastric carcinoma. In this study, lymph node–micrometastasis is an independent prognostic factor for overall survival.It is supposed that chemotherapy may be helpful for postoperative gastric cancer patients with lymph node–micrometastasis, so adjuvant chemotherapy should be adopted in the treatment.Conclusions: Lymph node–micrometastasis is an important prognostic factor for patient with stage pT_1-3N₀M₀ gastric carcinoma. In this study, lymph node–micrometastasis is an independent prognostic factor for overall survival.It is supposed that chemotherapy may be helpful for postoperative gastric cancer patients with lymph node–micrometastasis, so adjuvant chemotherapy should be adopted in the treatment.