Introduction:

Clinical trials advance science and provide innovative care that is sometimes the only treatment option for people with cancer. Some groups do not have access to clinical trials, excluding them from the benefits of trial participation, and could be considered “scientifically underserved”. Specific to Veterans with prostate cancer, it is unclear how frequently and where prostate cancer clinical trials are offered within the VA, and who may be scientifically underserved. Describing these gaps could identify opportunities for improving Veteran access to cancer clinical trials, ensuring Veterans are afforded the benefits of clinical trial enrollment. To understand gaps in access, we assessed VA site inclusion in prostate cancer clinical trials registered on ClinicalTrials.gov. 

Methods:

In March 2024, using a Python script, we identified all phase 2-3 prostate cancer clinical trial records registered on ClinicalTrials.gov after January 1, 2007, and extracted trial site information. A custom algorithm was used to identify VA sites recorded on ClinicalTrials.gov. We identified the number of unique trials hosted at each VA grouped by trial phase and overall trial status. We manually identified the total number of VA hospitals from the VA directory (va.gov/directory), grouping hospitals by unique address and manually removing duplicates. We then described the proportion of VA sites hosting at least 1 clinical trial, and the proportion of trials with at least 1 VA site. We further identified geographic variation in trial availability by describing the proportion of VA facilities in each census division with at least 1 prostate cancer trial. 

Results:

Of 1,884 registered phase 2 or 3 prostate cancer clinical trials, 118 (6%) included at least one VA site. Of 353 phase 3 trials, 55 (16%) included at least 1 VA site. Of 159 identified VA facilities, 66 (42%) have had at least one phase 2 or 3 prostate cancer clinical trial, while 58 (36%) have had at least one phase 3 trial. As of March 2024, there were 53 VA sites (33%) with a currently active phase 3 prostate cancer clinical trial, 60 (38%) with an active phase 2 or 3 prostate cancer clinical trial, and 8 sites (5%) with >10 currently active prostate cancer clinical trials. Availability of prostate cancer trials at VA sites within census divisions ranged from 3 of 10 VA facilities in the New England census division to 10 of 19 VA facilities in the Pacific census division.

Conclusion:

Veterans treated at VA facilities have access to only 6% of prostate cancer clinical trials. Further, less than half of VA hospitals are sites for at least one prostate cancer clinical trial, and only a third have had a phase 3 prostate cancer clinical trial. There was some geographic variation in VA trial availability, with a higher proportion of Pacific division VA facilities offering trials than New England or Middle Atlantic divisions. These findings suggest Veterans may be scientifically underserved by the current prostate cancer clinical trials enterprise within the VA. Identifying strategies to improve access for Veterans with prostate cancer to the benefits of participating in clinical trials, ideally within the VA, should be a priority. These strategies would also likely be applicable in improving enrollment to other cancer trials in and out of the VA. 

Funding: NIH K12 DK111011, NIH NCI P30CA046592