Prognostic implications of histological tumor regression (Böhm's score) in patients receiving neoadjuvant chemotherapy for high grade serous tubal & ovarian carcinoma

Primary objective of this study was to determine prognostic significance of Bohm's histopathological regression score in patients who received neoadjuvant chemotherapy (NACT) for treatment of high grade serous (HGS) tubal & ovarian carcinoma.This was a retrospective cohort study of patients who received NACT between 2010 and 2015. The 3 point histopathological regression score of Böhm was used to classify chemotherapy response. Survival outcomes between the 3 different subgroups was analysed and compared with standard clinico-pathological variables using the Cox proportional hazards model and log-rank test.Study cohort comprised 111 patients. Chemotherapy response score (CRS) 3 was observed in 47 (42.4%) and CRS 1and CRS 2 in 22 (19.8%) and 42 (37.8%) women respectively. Women with CRS score of 1 and 2 combined showed a three-fold increased risk of progression on both univariate and multivariate assessment (HR 3.54; C.I 2.19-5.72, p < 0.001). The median overall survival for patients with CRS 1 was 34 months, CRS 2 was 30 months and 47 months for CRS 3. CRS 1 and 2 combined was the only variable that held significance in prediction of reduced overall survival on multivariate assessment (HR 3.26, C.I 1.91-5.54, p 0.0006). CRS 1 and 2 were also associated with 5.15-fold increased risk of relapse within 6 months of completion of chemotherapy (Odds ratio OR 5.15, C.I 0.07-0.47, p - 0.002).CRS is an independent prognosticator of survival and reliable predictor of relapse within 6 months in advanced high grade serous tubal and ovarian carcinoma patients receiving NACT.