Proliferative activity and apoptosis in esophageal squamous cell carcinoma after preoperative irradiation

抄録

Histopathological evaluation of esophageal carcinoma after preoperative irradiation, using the degree of degeneration or the proportion of viable cells to assess the histologic response, has major disadvantages because the viability of cancer cells cannot be predicted accurately. To examine whether tumor proliferative and apoptotic activity could be used as prognostic indicators, we determined the Ki-67 labeling index (LI) and the apoptotic LI in 63 patients with esophageal carcinoma who received preoperative irradiation.
While quantitative and qualitative histopathological assessment showed no relationship to survival, the patients with a low Ki-67 LI (<10%) had a better prognosis than those with a high Ki-67 LI (_??_10%) (P<0.05). The Ki-67 LI was not related to histopathological variables, but increased significantly in the patients with a waiting period (the time between completion of irradiation and surgery) longer than 14 days (P<0.01). Among histologic variables, postoperative depth was the only one related to survival, with a better prognosis in patients undergoing complete resection (P<0.01). The apoptotic LI was correlated with tumor differentiation and showed a tendency to be related to tumor deaeneration. but had no relationship with survival.
These findings suggested that the Ki-67 LI might be a useful prognostic indicator in patients with esophageal carcinoma receiving preoperative irradiation.