A formula for predicting the risk of a positive second-look laparotomy in epithelial ovarian cancer: implications for a randomized trial.

Abstract

To develop a formula to predict the risk of a positive second-look laparotomy. A retrospective review was performed on 89 patients who underwent second-look surgery following a complete clinical remission after cis-platin- or carboplatin-based chemotherapy. Logistic regression was used to develop a formula to predict the probability of a positive second look based on age, stage, grade of tumor, residual disease after initial surgery, and histologic type. We identified three groups based on estimated probabilities: low probability (0.25 or less), intermediate probability (0.26-0.74), and high probability (0.75 or more). The low-probability group had an 8% chance of a positive second look, the high-probability group had an 82% chance of a positive second look, and the intermediate-probability group had the correct outcome predicted only 61% of the time. Survival curves paralleled these results and were significantly different for each group. Using known prognostic factors, a formula can aid in implementation of a randomized clinical trial to test the efficacy of second-look laparotomy. This formula could exclude patients not suitable for randomization and give the investigator a better idea of the expected survival of various subgroups.