The cell cycle profile test is a prognostic indicator for breast cancer patients treated with postoperative 5-fluorouracil-based chemotherapy.

OBJECTIVE The cell cycle profile test is suggested to be an independent prognostic indicator for breast cancer patients. To further clarify the prognostic value, we applied this to breast cancer patients treated with postoperative 5-fluorouracil-based chemotherapy. METHODS A total of 153 breast cancer patients, who were treated with postoperative 5-fluorouracil-based chemotherapies, were randomly selected. Specific activities of cyclin-dependent kinases 1 and 2 in the tumor samples were analyzed. Patients were divided into three categories (low, intermediate or high risk) based on cell cycle profile analysis. RESULTS The proportions of the cell cycle profile categories were 39% for low risk, 10% for intermediate risk and 45% for high risk, respectively. Although the cell cycle profile test did not show a significant predictive power for relapse-free survival (high vs. low risk; P = 0.052), the cell cycle profile categories were significant prognostic factors in a subgroup of 98 patients with fewer than three involved nodes (high vs. low risk, P = 0.004). Multivariate analyses also indicated that a cell cycle profile parameter (high vs. low risk) was an independent prognostic indicator from the number of involved nodes and clinical stage in this subgroup (hazard ratio = 2.46, P = 0.01). Interestingly, the prognostic power of the cell cycle profile test was significant in 75 patients treated with oral 5-fluorouracil derivatives alone (hazard ratio = 6.29 for high vs. low risk, P = 0.02). CONCLUSIONS These findings suggest that the cell cycle profile test is useful for predicting a higher risk of relapse in patients treated with postoperative 5-fluorouracil-based chemotherapy.