Prostate Cancer Patients' Understanding of the Gleason Scoring System: Implications for Shared Decision-Making.

The Gleason scoring system is a key component of a prostate cancer diagnosis, since it indicates disease aggressiveness. It also serves as a risk communication tool that facilitates shared treatment decision-making. However, the system is highly complex and therefore difficult to communicate: factors which have been shown to undermine well-informed and high-quality shared treatment decision-making. To systematically explore prostate cancer patients' understanding of the Gleason scoring system (GSS), we assessed knowledge and perceived importance among men who had completed treatment (N=50). Patients were administered a survey that assessed patient knowledge and patients' perceived importance of the GSS, as well as demographics, medical factors (e.g., Gleason score at diagnosis), and health literacy. Bivariate analyses were conducted to identify associations with patient knowledge and perceived importance of the GSS. The sample was generally well-educated (48% with a bachelor's degree or higher) and health literate (M=12.9, SD=2.2, range=3-15). Despite this, patient knowledge of the GSS was low (M=1.8, SD=1.4, range=1-4). Patients' understanding of the importance of the GSS was moderate (M=2.8, SD=1.0, range=0-4) and was positively associated with GSS knowledge (p<.01). Additionally, GSS knowledge was negatively associated with years since biopsy (p<.05). Age and health literacy were positively associated with patients' perceived importance of the GSS (p<.05), but not with GSS knowledge. Patient knowledge is thus less than optimal and would benefit from enhanced communication to maximize shared treatment decision-making. Future studies are needed to explore the potential utility of a simplified Gleason grading system and improved patient-provider communication.