Predictive value of serum prostate specific antigen in detecting bone metastasis in prostate cancer patients using bone scintigraphy

Abstract

Introduction:Radionuclide bone scan (BS) used to be the investigation of choice for detecting osseous metastases in prostate cancer. Now, with the availability serum prostate specific antigen (PSA) testing, clinicians do have a timely, cost-effective method to determine those patients who are highly unlikely to have osseous metastases. We determine the utility of PSA for predicting the presence of skeletal metastasis on BSs in prostate cancer patients.Materials and Methods:Retrospective analysis of medical records of 322 consecutive prostate cancers patients subjected to BS during the last 3 years was done. 52 cases were excluded due to following reasons: Serum PSA not available, hormonal or other therapy given prior to serum PSA measurement, and/or BS, and symptomatic for bone metastasis. In remaining 270 cases, PSA value and BS were evaluated. BS was performed with Tc99m methylene diphosphonate (MDP) as per the standard protocol.Results:BS was found to be positive in 153/270 (56%) and negative in 117 (46%) patients. Of the 153 positive cases, 108 (70%) had serum PSA > 100 ng/ml, 42 (28%) had PSA of 20-100 ng/ml and only 3 (2%) had PSA < 20 ng/ml. All the patients with PSA > 100 ng/ml had multiple skeletal metastasis. Of the 117 negative cases, 110 (94%) had a PSA < 20 ng/ml, 5 had between 20 and 100 ng/ml and only 2 (1.8%) had PSA > 100 ng/ml. Of the 113 patients with serum PSA < 20 ng/ml, 110 (97.4%) did not show any bony metastasis. 150/157 (95.5%) patients with PSA > 20 ng/ml had bone metastasis. Using this criterion, 110 (40.7%) scans would have been omitted.Conclusions:Serum PSA < 20 ng/ml have high predictive value in ruling out skeletal metastasis. Our data are in corroboration with results from previous studies that BS should be performed only if PSA > 20 ng/ml. Using this cut-off, unnecessary investigation can be avoided. Avoiding BS in this group of patients would translate into a significant cost-saving and reduction in their psychological and physical burden.

Detecting Tumor Metastases

“…In 1994, Vijayakumar et al retrospectively evaluated 90 patients with prostate cancer, on the basis of initial serum-PSA level and bone scans, and found that patients with PSA more than 10 ng/mL had evidence of bone metastasis (Vijayakumar, Vijayakumar, Quadri, & Blend, 1994). Similar results were obtained in another retrospective study conducted by Kamaleshwaran et al where the cut-off value for PSA was set at 20 ng/mL or greater for predicting bone metastases (Kamaleshwaran et al, 2012). In subsequent studies, to determine the correlation between PSA levels and bone metastasis risk, Moreira et al (2015) developed a bone metastasis predictive table using serum PSA level that was further validated by Freedland et al (2016).…”

Determination of the optimal cut-off value of serum prostate-specific antigen in the prediction of skeletal metastases on technetium-99m whole-body bone scan by receiver operating characteristic curve analysis

“…[ 15 ] with 89 newly diagnosed prostate cancer patients found that the incidence of skeletal metastases in their study group is 48.3%, they suggested that bone scan should be the part of initial evaluation in all patients irrespective of Sr. PSA levels. Kamaleshwaran et al [ 16 ] conducted a retrospective study with 270 newly diagnosed prostate cancer patients. The incidence of skeletal metastases in their study was 56% and according to them a staging bone scan can be avoided if Sr. PSA < 20 ng/ml.…”

“…In our study population, we found that the incidence of skeletal metastases is 59.5%, which is almost near to the incidence that was found in studies conducted on Indian patients. [ 15 16 ] Based on the ROC analyses, we found that the accuracy of Sr. PSA test in the prediction of skeletal metastases was good (area under the curve was 0.878), which agrees well with other studies,[ 10 11 ] and the optimal cut-off value of Sr. PSA in the prediction of positive bone scan for skeletal metastases was <29.16 ng/ml, with sensitivity and specificity of 89.0% and 74.6%, respectively. To the best of our knowledge, very few studies used ROC analysis to derive sensitivity and specificity at different possible cut-off values of Sr. PSA in the prediction of skeletal metastases.…”

Associations of Prostate-Specific Antigen, Prostate Carcinoma Tissue Gleason Score, and Androgen Receptor Expression with Bone Metastasis in Patients with Prostate Carcinoma

“…In PCa, this concentration increases with cancer cell overgrowth and PV and damage to the normal prostate tissue structure [28]. This effect is also observed when PCa cells that transfer to the bone in patients with bone metastasis [29]. Indeed, studies showed that PSA has predictive value for PCa bone metastases.…”