Automated Bone Scan Index and Overall Survival in Metastatic Castration-Resistant Prostate Cancer
In a secondary analysis of the phase III 10TASQ10 trial comparing tasquinimod vs placebo in chemotherapy-naive metastatic castration-resistant prostate cancer, the automated Bone Scan Index (aBSI) was shown to be predictive of overall survival. The findings were reported in JAMA Oncology by Armstrong et al. The aBSI has been automated with artificial neural networks to identify metastatic hot spots in bone scans with minimal supervision.
Study Details
In the double-blind trial, 1,245 patients recruited from 241 sites in 37 countries between March 2011 and August 2015 were randomly assigned 2:1 to receive tasquinimod or placebo until disease progression or unacceptable toxicity. Tasquinimod was associated with significantly improved radiographic progression-free survival but not overall survival. The current analysis is a prospectively planned secondary analysis in the trial; the statistical analysis plan to evaluate the aBSI was locked before the trial was unmasked.
Of the total 1,245 patients, 721 were evaluable for the aBSI; mean age in these patients was 70.6 years (range = 47–90 years). The aBSI (median = 1.07, range = 0–32.6) was significantly associated with overall survival (hazard ratio [HR] = 1.20, P < .001).
Median overall survival according to lowest to highest aBSI quartile was 34.7, 27.3, 21.7, and 13.3 months. C index values for overall survival were 0.63 for the aBSI vs 0.60 for manual lesion counting (P = .03). In multivariate analysis, higher aBSI remained independently associated with overall survival (HR = 1.06, P = .03), time to symptomatic progression (HR = 1.18, P < .001), and time to opiate treatment for cancer pain (HR = 1.21, P < .001).
Conclusions
The investigators concluded, “To date, this investigation is the largest prospectively analyzed study to validate the aBSI as an independent prognostic imaging biomarker of survival in [metastatic castration-resistant prostate cancer]. These data support the prognostic utility of the aBSI as an objective imaging biomarker in the design and eligibility of clinical trials of systemic therapies for patients with [metastatic castration-resistant prostate cancer].”
The study was funded by EXINI Diagnostics AB, a subsidiary of Progenics Pharmaceuticals, Inc, by Active Biotech AB, and by grants from the National Institutes of Health.
Andrew J. Armstrong, MD, of Duke University School of Medicine, is the corresponding author for the JAMA Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
