Top Line: Does the proportion of Gleason pattern 4 disease present in pre-treatment prostate biopsies influence treatment outcomes?
The Study: Obviously the proportion of pattern 4 is important as grade group 3 disease has worse outcomes than grade group 2. But this study asked if the overall amount of pattern 4 was associated with worse outcomes. Think 12 of 12 cores positive for 3+4 (higher absolute amount of pattern 4) versus 1 of 12 cores positive for 4+3 (lower absolute amount of pattern 4). This retrospective review used data from 497 patients with intermediate risk prostate cancer (86% 3+4, 14% 4+3) treated with LDR brachytherapy. Pathology reports from the prostate biopsies included the Gleason score for each core and the percentage of the core involved. The authors calculated the estimated absolute percentage of tissue positive for Gleason 4 disease (eAPP4). They did this by using the overall percent of all cores positive and then various possible percentages of Gleason 4 disease (10-40% for Grade Group 2 and 60-90% for Grade Group 3). While overall grade groups were not associated with clinical outcomes, eAPP4 was associated with the cumulative incidence of recurrence and metastasis free survival. eAPP4 performed best at predicting outcomes when a value of 30% pattern 4 was used for cores with 3+4 and when 80% pattern 4 was used for cores with 4+3.
TBL: In this retrospective study of patients with intermediate risk prostate cancer treated with LDR brachytherapy, the estimated absolute percentage of pattern 4 disease was associated with the risk of recurrence and metastasis. | Casey, Radiother Oncol 2023
The Study: Obviously the proportion of pattern 4 is important as grade group 3 disease has worse outcomes than grade group 2. But this study asked if the overall amount of pattern 4 was associated with worse outcomes. Think 12 of 12 cores positive for 3+4 (higher absolute amount of pattern 4) versus 1 of 12 cores positive for 4+3 (lower absolute amount of pattern 4). This retrospective review used data from 497 patients with intermediate risk prostate cancer (86% 3+4, 14% 4+3) treated with LDR brachytherapy. Pathology reports from the prostate biopsies included the Gleason score for each core and the percentage of the core involved. The authors calculated the estimated absolute percentage of tissue positive for Gleason 4 disease (eAPP4). They did this by using the overall percent of all cores positive and then various possible percentages of Gleason 4 disease (10-40% for Grade Group 2 and 60-90% for Grade Group 3). While overall grade groups were not associated with clinical outcomes, eAPP4 was associated with the cumulative incidence of recurrence and metastasis free survival. eAPP4 performed best at predicting outcomes when a value of 30% pattern 4 was used for cores with 3+4 and when 80% pattern 4 was used for cores with 4+3.
TBL: In this retrospective study of patients with intermediate risk prostate cancer treated with LDR brachytherapy, the estimated absolute percentage of pattern 4 disease was associated with the risk of recurrence and metastasis. | Casey, Radiother Oncol 2023