Correlation between the lymphocytic infiltration of tumors and the proliferative activity of cancer cells from surgically treated esophageal carcinoma.

To evaluate the correlation among the biological behavior of cancer cells, the local immune response of the host, and survival of patients with esophageal carcinoma, we investigated the proliferative activity of cancer cells by immunostaining with the Ki-67 monoclonal antibody in 95 cases of surgically resected esophageal squamous cell carcinoma and compared them with the extent of lymphocytic infiltration of the tumor (LI) in the same specimens. The mean Ki-67 score of 43 tumors with low-grade LI was 46.7% and it was not different from that of 52 tumors with high-grade LI (49.4%, p = 0.441). A significant correlation between the Ki-67 score and the clinicopathological characteristics of tumors (depth of tumor invasion, lymph node metastasis, and stage) was detected. However, in the same stage, the survival of patients with a low Ki-67 score was not different from that of patients with a high Ki-67 score. On the other hand, even no significant correlation between the extent of LI and the clinicopathological characteristics of tumors was found; the 5-year survival rate of 17 patients with high-grade LI (13.9%) was significantly better than that of 15 patients with low-grade LI (0%, p = 0.07) in stage III. These facts indicate that proliferative activity might correlate with the tumor progression, however, when the survival is compared in the same stage, the local immune response such as the extent of lymphocytic infiltration of the tumor might be the better prognostic factor than proliferative activity in patients with esophageal cancer.