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

UNLABELLED

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.

SUMMARY

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.