Bone scan positivity in non-metastatic, castrate-resistant prostate cancer: external validation study

Abstract

Introduction: Tables predicting the probability of a positive bone scan in men with non-metastatic, castrate-resistant prostate cancer have recently been reported. We performed an external validation study of these bone scan positivity tables. Materials and Methods: We performed a retrospective cohort study of patients seen at a tertiary care medical center (1996-2012) to select patients with non-metastatic, castrate-resistant prostate cancer. Abstracted data included demographic, anthropometric, and disease-specifi c data such as patient race, BMI, PSA kinetics, and primary treatment. Primary outcome was metastasis on bone scan. Multivariable logistic regression was performed using generalized estimating equations to adjust for repeated measures. Risk table performance was assessed using ROC curves. Results: We identifi ed 6.509 patients with prostate cancer who had received hormonal therapy with a post-hormonal therapy PSA ≥2ng/mL, 363 of whom had non-metastatic, castrate-resistant prostate cancer. Of these, 187 patients (356 bone scans) had calculable PSA kinetics and ≥1 bone scan. Median follow-up after castrate-resistant prostate cancer diagnosis was 32 months (IQR: 19-48). There were 227 (64%) negative and 129 (36%) positive bone scans. On multivariable analysis, higher PSA at castrate-resistant prostate cancer (4.67 vs. 4.4ng/mL, OR=0.57, P=0.02), shorter time from castrate-resistant prostate cancer to scan (7.9 vs. 14.6 months, OR=0.97, P=0.006) and higher PSA at scan (OR=2.91, P <0.0001) were signifi cantly predictive of bone scan positivity. The AUC of the previously published risk tables for predicting scan positivity was 0.72. Conclusion: Previously published risk tables predicted bone scan positivity in men with non-metastatic, castrate-resistant prostate cancer with reasonable accuracy.

Performance of 68Ga-labeled prostate-specific membrane antigen ligand positron emission tomography/computed tomography in the diagnosis of primary prostate cancer: a systematic review and meta-analysis

“…There are no specific clinical manifestations in the early stage of prostate cancer, and many patients have metastasized at the time of first diagnosis and lost the best time for treatment, leading to treatment failu-re. Therefore, finding effective diagnostic methods and indicators for early diagnosis of prostate cancer is the key to improve the cure rate as well as the survival rate (20,21). Imaging examination plays an important role in the clinical diagnosis and staging of malignant tumors.…”

Segmented linear correlations between bone scan index and prostate cancer biomarkers, alkaline phosphatase, and prostate specific antigen in patients with a Gleason score ≥7

“…Prostate specific antigen (PSA) levels are often used as an indication for the presence of bone metastases and have been used as a gate-keeper to determine the need for bone imaging. A study carried out by Johnston et al [ 4 ] showed that a higher PSA at scan was significantly predictive of bone scan positivity ( P < .0001). Various studies have also assessed the value of alkaline phosphatase (ALP) in the prediction of bone metastases and suggested that ALP may be the more reliable indicator when stratifying the extent of bone metastases.…”

A new era of the the International Brazilian Journal of Urology

“…Dr. Johnston and colleagues from USA ( 5 ) performed on page 42 an external validation study about bone scan positivity in non-metastatic, castrate-resistant prostate cancer. The authors performed a retrospective cohort study of 6,509 patients with non-metastatic, castrate-resistant prostate cancer and concluded that previously published risk tables predicted bone scan positivity in men with non-metastatic, castrate-resistant prostate cancer with reasonable accuracy.…”