Utilization of a uniform grading system for interpreting serous ovarian cancer.

Abstract

The purpose of the study was to implement a uniform system for assigning tumor grade in serous ovarian cancer and evaluate its correlation with response to conventional chemotherapy. Serous ovarian cancer tumor samples were retrospectively reviewed by 3 pathologists who were blinded to the original report. Samples were scored for architectural pattern, nuclear pleomorphism, and mitotic activity. Sum scores from these 3 indices were used to classify tumors as low grade or high grade. A total of 21 patients were identified as low-grade tumors and 21 were identified as high-grade tumors. Of low-grade tumors, 16 (76%) were found to be platinum resistant, defined as recurrent or persistent disease, 180 days from completion of the final cycle of chemotherapy, Of 21 patients defined as high grade, 9 (43%) were platinum resistant (P = .028). Utilization of a uniform grading system retrospectively correlates with platinum sensitivity.