Determination of the Ki-67 threshold value for predicting lymph nodes involvement in patients with gastric cancer

The search for biological markers to assess metastatic involvement of the lymph nodes in gastric cancer is one of the key steps in determining treatment tactics. The role of Ki-67 as a marker of cell proliferation in gastric cancer remains relevant. The aim of our study is to determine the Ki-67 threshold value for predicting the lymph nodes metastases. A retrospective analysis of 154 patients with gastric cancer showed an independent and statistically significant relationship between the depth of tumor invasion T (p = 0.002), the differentiation grade G (p = 0.010), the value of the Ki-67 index (p < 0.0001) and metastatic involvement of the lymph nodes. Using ROC analysis we found that Ki-67 ≥ 45 % correlates with the optimal level of sensitivity (55.9 %), specificity (84.2 %) and accuracy (73.4 %) of the method AUC 0.738 (p >< 0.043; 95 % CI 0,654–0,823). When evaluating the overall survival of patients>< 0.0001) and metastatic involvement of the lymph nodes. Using ROC analysis we found that Ki-67 ≥ 45 % correlates with the optimal level of sensitivity (55.9 %), specificity (84.2 %) and accuracy (73.4 %) of the method AUC 0.738 (p < < 0.043; 95 % CI 0,654–0,823). When evaluating the overall survival of patients >0.043; 95 % CI 0,654–0,823). When evaluating the overall survival of patients with Ki-67 > 45 %, we found that the median OS was 32 months [HR 2.2; 95 % CI 1.2–3,9; p = 0.005], while it was not reached in the group with Ki-67 < 45 %.A Ki-67 level of ≥ 45 % is the optimal threshold for determining the likelihood of lymph node metastasis in gastric cancer.