Factors Influencing Selection of Active Surveillance for Localized Prostate Cancer.

OBJECTIVE

To determine how well demographic and clinical factors predict the initiation of Active Surveillance (AS).

METHODS

AS has been suggested as a way to reduce overtreatment of men who have prostate cancer; however, factors associated with the decision to choose AS are poorly quantified. Using the Michigan Urological Surgery Improvement Collaborative registry, we identified 2977 men with prostate cancer who made treatment decisions from January 1, 2012, through December 31, 2013. We used chi-square and Wilcoxon tests to examine the association between factors and initiation of AS. Logistic regression models were fit for D'Amico risk categories. Measures of model discrimination and calibration were estimated, including area under the curve (AUC) and Brier score (BS).

RESULTS

Patient age, Gleason score, clinical T-stage, urology practice, and tumor volume (greatest percent of a core involved with cancer and proportion of positive cores) were associated with the decision to choose AS in the intermediate-risk cohort (AUC = 0.875, BS = 0.07) and the complete cohort (AUC = 0.89, BS = 0.10). Patient age, urology practice, and tumor volume were significant in the low-risk cohort (AUC = 0.71, BS = 0.22). The addition of urology practice increased AUC in the low-risk cohort from 0.71 to 0.76 and reduced BS from 0.22 to 0.21.

CONCLUSION

The urology practice at which a patient is seen is an important predictor for whether patients will initiate AS. Predictions were least accurate for low-risk patients, suggesting that factors such as patient preference play a role in treatment decisions.