Correlation of the rate of metastasis-free survival with the presence of pathogenic germline genetic mutations in patients with prostate cancer at a community practice.

Abstract

70 Background: Loeb et al. recently highlighted that academic physicians were statistically more likely to recommend genetic testing to prostate cancer patients per NCCN guidelines compared to physicians at community practices. Several articles have outlined the rate of pathogenic mutations and metastasis free survival (MFS) for prostate cancer patients treated at academic institutions. However, there is a relative paucity of equivalent data regarding patients treated at community urology clinics. We felt it was important to retrospectively review data from our large community based uro-oncology practice and present our findings in an effort to clarify this topic. Methods: We collected data on 562 prostate cancer patients treated at our multidisciplinary uro-oncology clinic between 2016 and 2018. We found 363 patients that satisfied the inclusion criteria of having germline genetic mutation testing and at least 1 year of follow-up. Patients were stratified into three categories based on the results of their germline genetic test: negative for germline mutations, positive for germline pathogenic mutations, or positive for VUS (variant of uncertain significance) mutations. Analysis of variances (ANOVA) was conducted to assess for any differences in age, Gleason score, metastasis rate, and MFS across the groups. A significance level of.05 was used. Results: All patients were treated according to guideline recommendations as was standard for the practice. There was no statistically significant difference in average age or Gleason score between the groups. There was also no statistically significant difference between the MFS across the three groups. Although the metastasis rate and MFS in the group without any mutations (9.8%, 18.3 months) was clinically significant compared to the groups with pathogenic mutations (7.5%, 16.5 months) and VUS mutations (7%, 16.6 months), the differences were not statistically significant (p=.754 and.127 respectively). Conclusions: In our community based uro-oncology practice, we found no statistically significant difference in MFS between patients with pathogenic germline mutations, patients without germline mutations, and patients with VUS mutations at 1 year of follow-up. This does not exclude the possibility of an impact of germline mutations on MFS as the data matures to reach 5 or more years of follow-up.[Table: see text]