How the Models Can Be Used in Clinical Care
Dr Armstrong explained to Cancer Therapy Advisor that the models have direct applicability to patient care. Physicians can use the nomogram available in the publication to first determine the total risk score for each of their patients. If a physician chooses this approach, the risk score for each of the 11 risk factors in their patients will have to be determined from the nomogram. A total of the 11 individual scores provide the final risk score, which can then be used to ascertain the probability of 1-year, 2-year, and 3-year survival from the Kaplan-Meier curves provided for the probability of survival.
“Although treatment with enzalutamide was used to derive this model, it does not tell physicians what to treat patients with,” Dr Armstrong said. He indicated that they are in the process of developing an app that features a user-friendly approach to prognostication with a mobile device.
In the second approach, a physician is only required to determine the number of risk factors in the patient, which in turn will provide information on probability of survival.
“Our validated prognostic model incorporates variables routinely collected in chemotherapy-naïve men with mCRPC treated with enzalutamide, identifying subsets of patients with widely differing survival outcomes that provide useful information for external validation, patient care, and clinical trial design,” the authors wrote.
Dr Armstrong explained that in evaluating a new drug for mCRPC, this model can help in the design of a clinical trial. For example, it will provide guidance on the number of patients the trial will require to enroll and how long the trial may take to read out based on the number of events that will need to be reached.
- Armstrong AJ, Lin P, Higano, CS, et al. Development and validation of a prognostic model for overall survival in chemotherapy-naïve men with metastatic castration-resistant prostate cancer [published online September 10, 2018]. Ann Oncol. doi: 10.1093/annonc/mdy406
- Beer TM, Armstrong AJ, Rathkopf DE, et al. Enzalutamide in metastatic prostate cancer before chemotherapy. N Engl J Med. 2014;371:424-433.
- US Food and Drug Administration. FDA approves enzalutamide for castration resistant prostate cancer. https://www.fda.gov/drugs/informationondrugs/approveddrugs/ucm613543.htm. Updated July 16, 2018. Accessed October 6, 2018.
- US Food and Drug Administration. FDA approves abiraterone acetate in combination with prednisone for high-risk metastatic castration-sensitive prostate cancer. https://www.fda.gov/drugs/informationondrugs/approveddrugs/ucm596015.htm. Updated February 8, 2018. Accessed October 6, 2018.