presents the clinical and demographic characteristics of our population-based cohort. Overall, we identified 832 men in Olmsted County diagnosed with nonmetastatic prostate cancer from 1995 to 2006. Of the 832 men, 460 (55.3%) underwent RP, 243 (29.2%) received RT, 50 (6.0%) had primary ADT, and 79 (9.5%) chose WW. When compared with other treatment groups, patients who underwent RP were younger and had fewer comorbidities. This group also had a lower baseline PSA value than the RT and ADT groups.
Demographic and Pathologic Characteristics From the Population-Based Cohort of Prostate Cancer Survivors Diagnosed With Nonmetastatic Prostate Cancer in Olmsted County, MN (N=832)a,b
The median follow-up time for the entire cohort was 6.7 years, with 134 individuals (16.1%) experiencing BCR at a median follow-up time of 3.4 years. Overall, there were 146 deaths (17.5%), of which 14 were attributable to prostate cancer (1.7%). The total number of person-years of follow-up was 3384, 1458, 265, and 555 for the RP, RT, primary ADT, and WW groups, respectively.
PSA Surveillance Intensity Within Treatment Groups
From the 832 men in our cohort, we identified a total of 8582 PSA values after treatment for RP, RT, and ADT and after diagnosis for WW (4808 for RP, 2490 for RT, 557 for primary ADT, and 727 for WW). For the RP group (n=460), 79% of all PSA tests occurred in the time period between surgery and BCR or last PSA, and for the RT group (n=243), 86% occurred between treatment and BCR or last PSA. The median number of PSA tests performed from the 2-year landmark to the BCR or last follow-up was 4 (range, 1-33) for the RP group and 5 (range, 1-23) for the RT group.
BCR developed in 95 patients (20.7%) who received primary therapy with RP and 39 (16.1%) who received primary therapy with RT. The median times to BCR for RP and RT were 3.1 and 3.9 years, respectively. Median PSA values at the time of BCR for RP and RT were 0.3 (range, 0.2-177.0) and 3.6 (range, 2.2-19.4), respectively.
Associations Between Posttreatment PSA Surveillance Intensity and Baseline Factors
To characterize the frequency of PSA testing from RP, univariate analysis demonstrated that higher baseline PSA and higher Gleason score (7 and 8-10) were associated with higher frequency of PSA testing (P <.05). After adjustment for clinicopathologic covariates, higher Gleason score remained the only variable that showed a statistically significant association with higher intensity of PSA monitoring in the RP and RT groups. provides the multivariable analysis of the characteristics of covariates tested for PSA frequency for the 4 groups.
Association Between Clinicopathologic Factors and Posttreatment PSA Testing Frequency From a Population-Based Cohort in Olmsted County, MN (N=832)
PSA Surveillance Intensity as a Predictor of BCR and Survival
Because few deaths were attributable to prostate cancer, we performed a 2-year landmark analysis for ACM only. presents the multivariable analysis for ACM with clinicopathologic covariates and intensity of posttreatment PSA monitoring. For the RP treatment group, patient age was associated with a statistically significant risk of ACM (hazard ratio [HR], 1.08; P=.02). Elixhauser index of 3 or more was associated with higher ACM for patients treated with RP (HR, 4.02; P=.003), RT (HR, 2.72; P=.006), and ADT (HR, 4.52; P=.045). In the RT treatment group, increased risk of ACM was also associated with a Gleason score of 7 or more (HR, 2.72; 95% confidence interval, 1.43-5.18; P=.002). Baseline PSA level and clinical stage were not associated with ACM on multivariable analysis. Because there were no deaths in the WW group, the HR was not reportable. Interestingly, higher intensity of posttreatment PSA monitoring failed to provide any improved survival from ACM across all treatment groups.
Multivariable Analysis for All-Cause Mortality With Clinicopathologic Covariates and Intensity of 2-Year Posttreatment PSA Monitoring (N=787)a,b
In testing the association of the intensity of PSA monitoring from the 2-year landmark analysis with time to BCR, we observed no statistically significant effects in the association with higher intensity of PSA monitoring and BCR. Among men who underwent RP, higher risk of BCR was correlated with a Gleason score of 7 or more (HR, 2.53; P<.001) and clinical stage III (HR, 2.08; P=.02). None of the other clinicopathologic covariates was associated with risk of BCR for patients receiving RT on multivariable analysis. For both RP and RT treatment groups, higher intensity of PSA monitoring also failed to provide any improved outcomes with lower BCR on multivariable analysis ().
Multivariable Analysis for Biochemical Recurrence With Clinicopathologic Covariates and Intensity of 2-Year Posttreatment PSA Monitoring (N=599)