Radical therapy with or without chemotherapy in highly malignant non-metastatic prostate cancer: interim analysis of a prospective non-randomized controlled study / 中华放射肿瘤学杂志

ABSTRACT

Objective:To compare the efficacy and safety of standard treatment with or without adjuvant chemotherapy in patients with highly malignant non-metastatic prostate cancer.Methods:In this prospective non-randomized controlled study, consecutive non-metastatic prostate cancer patients with pathologically proven Gleason score of 9-10 or Gleason score of 5 admitted to Peking University First Hospital were enrolled. Four to six cycles of chemotherapy using docetaxel ± carboplatin regimen were added or not after standard radical therapy. The primary end point was 5-year event-free survival (EFS), and the secondary end points were distant metastasis-free survival (MFS), overall survival (OS), and treatment-related adverse events. The survival curve was drawn by Kaplan-Meier method. The differences between two groups were analyzed by log-rank test.Results:A total of 176 patients were consecutively enrolled from November 2019 to January 2022 of which 138 patients received only standard radical therapy (control group), and 38 patients received adjuvant chemotherapy after standard radical therapy (chemotherapy group). The median follow-up time was 13.4 (2.0-34.0) months. All patients survived. The 30-month EFS rates in the chemotherapy and control groups were 100% and 85.6%, respectively ( P=0.064). There were no events in the chemotherapy group, while there were 12 cases of events in the control group, including 6 cases of biochemical recurrence and 6 cases of imaging progression. The 30-month MFS rates in two groups were 100% and 91.9%, respectively ( P=0.205). After the 1 vs. 2 propensity score matching, the EFS and MFS rates in two groups were 100% vs. 85.7% ( P=0.056), and 100% vs. 92.2% ( P=0.209), respectively. The incidence rates of grade 2 and above urinary toxicity in the chemotherapy and control groups were 2.6% and 7.2% ( P=0.354), respectively. The incidence rates of grade 2 and above rectal toxicity were 5.3% and 5.1% ( P=0.711), respectively. Grade 3 and above chemotherapy-related toxicity in the chemotherapy group were leukopenia (31.6%), thrombocytopenia (2.6%) and alopecia (13.2%). Conclusion:The addition of adjuvant chemotherapy after standard radical therapy tends to improve the overall EFS of patients with highly malignant prostate cancer, and the adverse effects are tolerable, which should be confirmed by long-term follow-up results.