Response Prediction to Neoadjuvant Chemotherapy Prior to Interval Debulking Surgery and the Outcome of Responders Compared to Nonresponders

Introduction: Neoajuvant Chemotherapy (NACT) followed by Interval Debulking Surgery (IDS) is an acceptable therapeutic approach for selected patients with advanced stage Ovarian Carcinoma (OvC) and Primary Peritoneal Carcinoma (PPC) patients. Our aim was to assess whether the combined presence of reduction of the diameter of the largest tumor mass and of the CA125 level predict response to Neoadjuvant Chemotherapy (NACT). Material and methods: Clinicopathological data were abstracted from medical records of consecutive OvC and PPC patients who received paclitaxel + carboplatin NACT and underwent IDS. Computed tomography (CT) images before NACT and prior to IDS where compared. Response to NACT prior to IDS was determined according to the combined presence of two parameters: 1. Reduction in the greatest diameter of the largest CT tumor mass by 50% and 2. Reduction of the CA 125 level to ≤ 75 U/ml. No response was determined when both of these parameters where not observed. Results: Of 50 study group patients 10 (20.0%) had a response and 40 (80.0%) had no response to NACT. Optimal debulking (< 1 cm) was achieved in all responders and in 92.5% of nonresponders. The median progression free survival was similar in responders and nonresponders. The Overall Survival (OS) was 62.2% in responders and 22.6% in nonresponders (p = 0.40). The median OS was 51 months in the nonresponders and was not reached by responders. Conclusion: The proposed method of response prediction to NACT is simple and seems to identify patients who have a poor outcome after IDS.