Quantitative ultrasound of the calcaneus (QUS): A valuable tool in the identification of patients with non-metastatic prostate cancer requiring screening for osteoporosis

Abstract

Non-metastatic prostate cancer (PCa) patients are at increased risk for osteoporosis and fractures mainly due to androgen deprivation therapy (ADT)-associated hypogonadism, but this remains largely underdiagnosed and untreated. In this study, we examine the value of pre-screening calcaneal QUS in identifying patients who should be referred for screening for osteoporosis using dual-energy X-Ray absorptiometry (DXA). In a single-center retrospective cross-sectional cohort study, we analysed data on DXA and calcaneal QUS measurements systematically collected between 2011 and 2013 in all non-metastatic PCa patients attending our Uro-Oncological Clinic at the Leiden University Medical Center. Receiver operating characteristic curves were used to assess the positive (PPV) and negative (NPV) predictive values of QUS T-scores of 0, −1.0, and − 1.8 in identifying DXA-diagnosed osteoporosis (T-scores ≤ − 2.5 and ≤ −2) at lumbar spine and/or femoral neck. Complete sets of data were available in 256 patients, median age 70.9 (53.6–89.5) years; 93.0 % had received local treatment, 84.4 % with additional ADT. Prevalence of osteoporosis and osteopenia was respectively 10.5 % and 53 %. Mean QUS T-score was −0.54 ± 1.58. Whereas PPV at any QUS T-score was <25 %, precluding the use of QUS as surrogate for DXA in screening for osteoporosis, QUS T-scores of −1.0 to 0.0 had a NPV of ≥94.5 % for DXA T-scores ≤ 2.5 and ≤ −2 at any site, confidently identifying patients least likely to have osteoporosis, thereby significantly reducing the number of patients requiring DXA screening for diagnosing osteoporosis by up to two-third. Osteoporosis screening is a significant unmet need in non-metastatic prostate cancer patients treated with ADT, and QUS may represent a valuable alternative pre-screening strategy to overcome logistics, time demands, and economic barriers encountered with current strategies for osteoporosis screening in these patients. Osteoporosis and associated increased fracture risk are common in non-metastatic prostate carcinoma, mainly due to androgen deprivation therapy, but these often remain underdiagnosed and untreated. We demonstrate that QUS is a safe, less costly pre-screen tool that reduces by up to two-third the number of patients requiring referral for DXA for osteoporosis screening.