(HealthDay News) — Metastatic castration-resistant prostate cancer (mCRPC) has heterogeneity in positron emission tomography (PET)/computed tomography (CT) imaging phenotype, which has clinical relevance, according to a study published online in JAMA Oncology.
Josef J. Fox, MD, from Memorial Sloan Kettering Cancer Center in New York City, and colleagues performed PET/CT imaging with fluoro-2-D-deoxyglucose F 18 for glycolysis (Glyc) and fluorodihydrotestosterone F 18 for androgen receptor (AR) expression to determine heterogeneity of imaging phenotypes. A total of 133 patients with mCRPC underwent imaging.
The researchers found that each phenotype had an independent negative impact on survival in multivariate analysis, which was most pronounced for AR0Glyc1 lesions, followed by AR1Glyc1 lesions and AR1Glyc0 lesions (hazard ratios, 1.11, 1.05, and 1.03, respectively). Four patient-specific groups emerged when sorted by lesion type: concordant, with all AR1Glyc1; AR predominant, with AR1Glyc1 and varying numbers of AR1Glyc0; Glyc predominant, with AR1Glyc1 and varying numbers of AR0Glyc1; and mixed, with AR1Glyc1 plus AR1Glyc0 and AR0Glyc1.
“With regard to mCRPC lesions, most express ARs, consistent with initial benefit of ARSi [androgen receptor-signaling inhibitor] drugs,” the authors write. “On a patient basis, 49 percent (groups 3 and 4) had at least one AR0Glyc1 lesion — the imaging phenotype with the most negative effect on survival, possibly due to ARSi resistance.”
Several authors disclosed financial ties to the pharmaceutical industry.
Fox JJ, Gavane SC, Blanc-Autran E, et al. Positron Emission Tomography/Computed Tomography–Based Assessments of Androgen Receptor Expression and Glycolytic Activity as a Prognostic Biomarker for Metastatic Castration-Resistant Prostate CancerJAMA Oncol. doi:10.1001/jamaoncol.2017.3588