Control of cell proliferation kinetics of tumor in neoadjuvant chemotherapy for advanced oral squamous cell carcinoma and its prognostic implications

Background. Few attempts have so far been made at studies of the cell proliferation kinetics of the tumor in neoadjuvant chemotherapy for head and neck cancer. We examined the effects of neoadjuvant chemotherapy for advanced oral squamous cell carcinoma in terms of the cell proliferation kinetics of the tumor, and attempted to correlate them with patients' survival. Methods. Fifty-two patients with advanced oral squamous cell carcinoma who received neoadjuvant chemotherapy followed by surgery participated in this study. Cellular DNA content and mitotic index (MI) in tissue samples were measured before and after chemotherapy, using a cell image analyzer. Results. A decrease in both mean DNA content (mean DNA) and MI (left-shift type of change in cell growth kinetics), indicating an accumulation of cancer cells in the G0-G1 phase, was found in 25 patients. An increase in mean DNA with decreased MI (right-shift type), which was found in 13 patients, appeared to be correlated with an accumulation of cancer cells in the S-G2 phase. Neither of these two types of change, which were considered to be a favorable effect, were found in 14 patients (ineffective type). Excellent survival rates were obtained in patients who showed favorable changes in cell growth kinetics (79% for patients with left-shift type and 92% for patients with right-shift type), whereas the survival rate for patients with the ineffective type was extremely poor (14%). The type of change in cell proliferation kinetics was a powerful independent prognostic indicator. Conclusion. Analysis of cell growth kinetics appears to be useful not only as a diagnostic tool to predict patient outcome but also as a means to infer the chemotherapeutic effects in oral squamous cell carcinoma. Received: January 10, 2002 / Accepted: February 27, 2002