In this retrospective study, the relations between changes in cell proliferation kinetics and induced apoptosis in oral squamous cell carcinoma were examined before and after preoperative chemotherapy to clarify significance of such changes. In an additional study, multivariate analysis was performed to attempt to predict changes in cell proliferation kinetics.
Apoptotic index (AI) increased in all cases, although there were some differences in degree. With respect to the change in cell proliferation kinetics, left-shift-type and right-shift-type AI was clearly high before chemotherapy and increased significantly after chemotherapy as compared with the non-effective type of AI.
The 5-year cumulative survival rate was 91% in patients with less than 10% of the exceeding 4 c rate of nuclear DNA content (4 cER) and 62% in patients with 10% or higher 4 cER. In patients with low 4 cER, survival rates were excellent regardless the change in cell proliferation. On the other hand, survival rate was significantly worse in the non-effective type, while survival rates were relatively good in the leftshif t type and the right-shift type: 76% for the left-shift type, 74% for the right-shift type, and 35% for the non-effective type. Thus, we attempted to predict the non-effective type. Clinical stage (UICC), Gcategory (UICC), mitotic index, 4 cER, and AI were entered into logistic regression analysis as covariates. AI and 4 cER were selected as independent variables for the prediction of non-effective type.
In conclusion, left-shift-type and the right-shift-type changes in cell proliferation kinetics seemed to be favorable in terms of induced apoptosis, and had excellent survival rates. AI and 4 cER were the most powerful predictors of the change in cell proliferation kinetics.
