(UroToday.com) The 2023 ESMO annual meeting included a session on prostate cancer, featuring a presentation by Dr. Craig Jones discussing the incidence of fracture related hospitalizations in men with de novo high risk localized and metastatic hormone sensitive prostate cancer (mHSPC), an analysis of routinely collected healthcare data from the STAMPEDE docetaxel and zoledronic acid comparisons.
ADT is the mainstay medical treatment for men with locally advanced (M0) and metastatic hormone sensitive prostate cancer (mHSPC; M1), however, bone loss and increased fracture risk are recognized complications. Indeed, men with prostate cancer have a 42% incidence of osteoporosis. The STAMPEDE trial compared patients treated with ADT ± docetaxel ± zoledronic acid, and no survival benefit was demonstrated with the addition of zoledronic acid. However, long term effects on bone health and fracture risk were not formally collected within the trial. Health systems data through Hospital Episode Statistics for patients in England provides data beyond standard trial follow up permitting evaluation of fracture risk.
Hospital Episode Statistics data were obtained (up to March 2021) for patients randomized to ADT (Arm A), ADT + zoledronic acid (Arm B), ADT+ docetaxel (Arm C) and ADT+ docetaxel + zoledronic acid (Arm E). Zoledronic acid (4 mg) was given as six 3 weekly cycles, then 4 weekly for 2 years:
Fracture related hospitalizations were identified using a prespecified coding framework of ICD10 diagnosis and OPCS procedure codes. Flexible parametric competing risks models were used to estimate 5- and 10 year cumulative incidence of fracture related hospitalizations and subdistribution hazard ratios.
Linked data were available for 2,042 (734 M0, 1,308 M1), with the following CONSORT diagram:
The 5-year cumulative incidence of fracture related hospitalizations for M1 and M0 patients treated with ADT were 23% (95% CI 19-28%) and 11% (95% CI 8-15%) respectively. The 10-year cumulative incidence with ADT in M0 patients was 26% (95% CI 20-33%). Addition of zoledronic acid significantly reduced the incidence of fracture related hospitalizations in M1 patients (sdHR 0.73, 95% CI 0.55-0.97; p=0.015), whereas data were inconclusive in M0 patients (sdHR 0.88, 95% CI 0.59-1.32, p=0.55):
Docetaxel had no significant effect on fracture related hospitalizations in both M1 (p=0.264) and M0 (p=0.570) patients, with no evidence of interaction between zoledronic acid and docetaxel in both M1 (p=0.526) and M0 (p=0.805) patients:
Dr. Parker concluded his presentation discussing the incidence of fracture related hospitalizations in men with de novo high risk localized and metastatic hormone sensitive prostate cancer with the following take-home points:
- The 5-year cumulative incidence of fracture related hospitalizations was high in both M0 and M1 patients treated with ADT
- Docetaxel did not significantly alter the risk of fracture related hospitalization in both M0 and M1 patients
- Zoledronic acid significantly reduced the risk of fracture related hospitalization in M1 patients (sdHR 0.73) but not in M0 patients
- These results support the use of zoledronic acid in men with mHSPC to reduce the risk of fractures
Presented by: Craig Jones, Research Fellow, The Christie NHS Foundation Trust, Manchester, United Kingdom
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2023 European Society of Medical Oncology (ESMO) Annual Meeting, Madrid, Spain, Fri, Oct 20 – Tues, Oct 24, 2023.