Readily available clinical variables can predict the long-term risk of death from prostate cancer (PCa) and other causes among men who experience biochemical recurrence of PCa following radical prostatectomy (RP), according to study data presented during the American Urological Association 2020 Virtual Experience.
Using a statistical method called recursive partitioning, investigators found that men at highest risk for PCa-specific mortality (PCSM) are those with a PSA doubling time (PSADT) of less than 9 months and those who preoperatively had high-risk tumors according to D’Amico criteria. Men at highest risk of other-cause mortality (OCM) are those aged 70 years and older with any major comorbidity, lead investigator Timothy J. Daskivich, MD, of Cedars-Sinai Medical Center in Los Angeles, said during a virtual presentation. The study also demonstrated that the 10-year cumulative incidences of PCSM and OCM are low, even among men with high-risk tumors.
“Potential applications of this data include individualizing prognosis for men with biochemical recurrence after radical prostatectomy by readily available clinical variables,” Dr Daskivich said.
The study included 1225 men who had biochemical recurrence (BCR) following RP from 2000 to 2017 identified using the SEARCH database. Men had a median age of 65 years at BCR. Preoperative D’Amico tumor risk was low in 278 patients (23%), intermediate in 520 (42%), and high in 427 (35%). During a median follow-up time from BCR of 5.6 years, 68 patients (6%) died from PCa and 243 patients (20%) died from other causes.
Compared with men who had low-risk tumors by D’Amico criteria, those with high-risk tumors had 4.1-fold and 3.3-fold increased risks for PCSM and metastasis, respectively. A PSADT less than 9 months was significantly associated with nearly 2.5-fold and 2.3-fold increased risks for PCSM and metastasis, respectively.
The 10-year cumulative incidence of PCSM was 4%, 6%, and 14% among men with D’Amico low-, intermediate-, and high-risk tumors, respectively. The 10-year cumulative incidence of metastasis for these risk groups were 5%, 11%, and 16%, respectively. The 10-year cumulative incidence of PCSM was 9% for men with a PSADT of less than 9 months and 4% for those with a PSADT of 9 months or more. The 10-year cumulative incidence of metastasis for these PSADT groups was 16% and 8%, respectively.
Men aged 70 years or older had a 2-fold increased risk of OCM compared with men younger than 65 years. Compared with men who had a Charlson comorbidity score of 0 at BCR, those with a score of 1 2, and 3 or more had significant 1.6-, 1.6-, and 2.4-fold increased risks for death from causes other than PCa, respectively. The 10-year cumulative incidence of OCM for men older than 70 days with at least 1 major comorbidity was 40% or higher.
Competing risks of mortality are a critical consideration for men with BCR after RP, Dr Daskivich said. “The significant heterogeneity and prognosis among these men can be explained by the key and readily available clinical variables outlined in this talk,” he said. “Of note, men in their 70s with any major comorbidity are 2 to 10 times more likely to die of other causes than prostate cancer despite having a biochemical recurrence. Integration of this information into clinical practice can help patients and physicians understand the disease better and hopefully lead to better management.”
Daskivich T, Howard L, Amling C, et al. Long-term competing risks of mortality among men with biochemical recurrence after radical prostatectomy. Presented at the American Urological Association 2020 Virtual Experience. Abstract PD13-04