Anna Nasierowska-Guttmejer

The Comparison of Immunohistochemical Proliferation and Apoptosis Markers in Rectal Carcinoma Treated Surgically or by Preoperative Radio-Chemotherapy

Department of Pathology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warszawa

Abstract

The aim of the study was to determine prognostic histopathological and immunohistochemical factors expressed by proliferation and apoptosis markers in patients treated only surgically or by preoperative radio-chemotherapy. The material was obtained from 204 patients; 114 patients underwent an operation, 35 patients had preoperative radiotherapy (2500cGy in 5 fractions for 5 days) and 55 patients were treated with preoperative radio-chemotherapy (5000cGy in 25 fractions for 33 days and 3 courses of chemotherapy 5Fu and Leucovorin). In 204 cases the operative material was examined taking into account: 1. the age, sex, size of tumor, macroscopic features, stage, angioinvasion and perineural invasion, 2. cancer response to the treatment, 3. immunohistochemical factors being the expression of p53, MIB1, bcl-2, bax. In additional, a statistic analysis was carried out using chi-square test and NW method to examine individual parameters and Spearman (R) rank correlation to define the force of dependence. Results: 1. In cases of colorectal cancer treated only operatively, statistically significant correlations occurred among the stage, angioinvasion and perineural invasion. 2. The partial response with regression of the tumor mass less than 2/3 occurred in 90% of patients after short radiotherapy. The complete response (CR) was seen in 15% of cases, the regression of the tumor mass more than 2/3 (PR1) - in 46% of cases and the regression of the tumor mass less than 2/3 of (PR2) - in 39% of cases after preoperative radio-chemotherapy. 3. A. In biopsy taken in 27 patients before radio-chemotherapy expression of MIB1 and bax proved to be statistically significant. The low expression of MIB1 and the high level of bax expression were correlated with the total or near-total response of cancer to the treatment. B. In operative material after radio-chemotherapy a statistically significant dependence occurred among all immunohistochemical markers; regression of the tumor mass less than 2/3 correlated with the low expression of p53, MIB1, bax and bcl-2. 4. The force of dependence among immunohistochemical parameters in patients only after surgical treatment was R=0.2 –- 0.3 and after radio-chemotherapy R=0.8. Conclusion: the expression of proliferation and apoptosis markers was combined with rectal carcinoma after preoperative radio-chemotherapy.