Impact of Gleason pattern 5 on prognosis for newly diagnosed metastatic hormone-sensitive prostate cancer with Gleason score >= 8

Objective We evaluated the impact of Gleason pattern 5 presence on prognosis among de novo metastatic hormone-sensitive prostate cancer patients with a Gleason score >= 8. Methods The data of 559 patients diagnosed as metastatic hormone-sensitive prostate cancer with a Gleason score >= 8, who were initially treated with androgen deprivation therapy from 2008 to 2016, were retrospectively collected. Patients were divided into two groups as high and low volume based on the CHAARTED trial criteria. Results The median overall survival of the 559 metastatic hormone-sensitive prostate cancer patients with Gleason score >= 8 was 70 months, with a median follow-up period of 36 months. Gleason pattern 5 was confirmed in 341 patients (61.0%), in which primary Gleason pattern 5 was confirmed in 164 patients (29.3%). The number of patients with high metastatic volume group was 363 (64.9%). In total and high metastatic volume groups, hemoglobin and lactate dehydrogenase were significant factors for predicting overall survival, but both Gleason pattern 5 and primary Gleason pattern 5 did not show a statistically significant difference. In the low-volume metastatic group, the median overall survival in patients with or without primary Gleason pattern 5 was 40 and 78 months, respectively. In multivariate analysis, only primary Gleason pattern 5 was an independent predictive factor for overall survival in the low-volume metastatic group (hazard ratio 2.76, 95% confidence interval 1.88-8.67; P = 0.0026). Conclusion The presence of Gleason pattern 5 was not associated with overall survival in metastatic hormone-sensitive prostate cancer with a Gleason score >= 8. In low-metastatic volume metastatic hormone-sensitive prostate cancer, primary Gleason pattern 5 was a poor prognostic factor, which might show a separate treatment option for this group.