A Prospective Longitudinal Study to Evaluate Bone Health, Implication of FRAX Tool and Impact on Quality of Life (FACT-P) in Advanced Prostate Cancer Patients

Background: Androgen-deprivation therapy (ADT) as a treatment modality in advanced prostate cancer has deleterious effect on bone mineral density (BMD) and quality of life (QOL). Using FRAX (Fracture Risk Assessment) model, candidates at high risk of fractures can be predicted and appropriate treatment can be initiated at early step to prevent skeletal-related events. Objectives of the present study were to evaluate bone health, implication of FRAX tool in advanced prostate cancer and to see the impact of ADT and Bone-directed therapy (BDT) on FRAX and FACT-P QOL scores.

Material & Method: We conducted a prospective longitudinal study of 83 localized and metastatic prostate cancer patients from March 2017 to Dec 2020. FRAX tool using BMD femoral neck (GE-Lunar) was used to compute the probability of 10-year Major osteoporotic fracture (MOF) and hip fracture risk %. Patients who received monthly Zolendronic acid with or without Vitamin-D/calcium supplementation were classified as BDT group. FRAX and FACT-P were measured at baseline and 12 months follow-up and compared between different therapeutic modalities to see the impact on clinical outcomes.

Results: Majority of patients had skeletal metastasis (78.3%) and high-grade disease at presentation. Secondary osteoporosis was the most commonly (82.05%) observed clinical risk factor (CRF) followed by smoking (19.23%). Hip fracture risk ≥3% accounted for larger proportion of patients than did MOF risk ≥20% (21.2% and 2.5%, respectively). Statistically significant reduction was observed in both MOF and hip fracture risk in BDT group, while worsening on ADT. ADT duration correlated positively with both MOF and hip fracture risk (R=0.148, P<0.001 and R=0.164, P<0.001, respectively). FRAX score accurately predict future fracture events in majority (80%) of high-risk patients. Statistically and clinically significant worsening in PWB, EWB, PCS, FACT-P Total, FACT-P TOI and FAPSI scores were observed in patients on ADT. Statistically and clinically significant improvement was noted in physical well-being in BDT group. However, other QOL domains and FACT-P total scores remained stable.

Conclusions: ADT caused duration depended worsening of FRAX and FACT-P score in these patients while improvements of FRAX were seen on BDT. FRAX tool is advantageous in identifying the patients who require early intervention or therapy to decrease skeletal-related events.