Novel Clinical-Genomic Risk Group Classification for Localized Prostate Cancer
As reported in the Journal of Clinical Oncology, Spratt et al have developed an integrated clinical-genomic risk classifier for predicting distant metastasis in patients with localized prostate cancer. The classifier uses National Comprehensive Cancer Network® (NCCN) risk categories and risk classification on the Decipher® 22-gene expression assay.
Study Details
In the study, 2 multicenter cohorts (n = 991) were used for training and validation of the clinical-genomic risk groups, and 2 additional cohorts (n = 5,937) were used for reclassification analyses. The risk classifier was developed by summing points assigned to NCCN low-, intermediate-, and high-risk groups and points assigned for the Decipher risk categories, yielding a six-tier risk grouping system, corresponding to very-low–, low-, favorable-intermediate–, unfavorable-intermediate–, high-, and very-high–risk groups. The six-tier system was also converted into a three-tier risk grouping, analogous to the NCCN low-, intermediate-, and high-risk groups. Decipher risk categories were defined using cutpoints for low (< 0.45), intermediate (0.45–0.60), and high (≥ 0.60) risk.
Risk Classification
After a median follow-up of 8 years in the training cohort, 10-year distant metastasis rates for NCCN low, favorable-intermediate, unfavorable-intermediate, and high-risk groups were 7.3%, 9.2%, 38.0%, and 39.5%, respectively. The 3-tier clinical-genomic risk groups had 10-year distant metastasis rates of 3.5%, 29.4%, and 54.6% for low-, intermediate-, and high-risk, respectively; rates were 0%, 25.9%, and 55.2% in the validation cohort, respectively.
C-indices were 0.84 for the clinical-genomic risk grouping system, 0.73 for NCCN scoring, and 0.74 for Cancer of the Prostate Risk Assessment in the validation cohort. Overall, 30% of patients in the NCCN low-, intermediate-, and high-risk groupings and 67% in the NCCN six-tier risk groupings were reclassified in the integrated three-tier and six-tier systems.
The investigators concluded: “A commercially available genomic classifier in combination with standard clinicopathologic variables can generate a simple-to-use clinical-genomic risk grouping that more accurately identifies patients at low, intermediate, and high risk for metastasis and can be easily incorporated into current guidelines to better risk-stratify patients.”
The study was supported by the Prostate Cancer Foundation and the Department of Defense.
Daniel E. Spratt, MD, of the Department of Radiation Oncology, University of Michigan School of Medicine, is the corresponding author of the Journal of Clinical 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®.
