Retrospective cohort study of denosumab therapy duration and osteonecrosis of the jaw and skeletal events in bone-metastatic prostate cancer

Denosumab reduces skeletal-related events in bone-metastatic prostate cancer, but carries a cumulative risk of medication-related osteonecrosis of the jaw (ONJ). The treatment duration that best balances these risks has not been established in clinical settings. A nationwide retrospective cohort study in South Korea evaluated the association between duration of denosumab treatment and the 3-year cumulative incidence of ONJ and skeletal events. The study, using Korean Health Insurance Review and Assessment Service data, enrolled 3307 men with bone-metatatic castration-resistant prostate cancer (CRPC). Three-year risk for ONJ increased with duration of denosumab therapy: the risk ratio for 7.1 versus ≤ 6 months was 2.22, the risk ratio for ≥13 months versus ≤ 6 months was 8.29. The risk of skeletal events was lower with 7-12 months of denosumab therapy compared with 6 or fewer months, but was not further reduced by treatment beyond 12 months. The authors conclude that these findings support individualized reassessment of denosumab treatment after approximately one year rather than routine indefinite continuation.