Posted: Jun 19, 2017
Dr. Preston Sprenkle is an Assistant Professor of Urology at Yale University.
Prostatepedia spoke with him about a trial he’s running on targeted prostate cancer screening.
Why did you become a doctor?
Dr. Preston Sprenkle: My father was a physician. I liked the idea of helping people and doing something that was both intellectually challenging, yet also socially and intellectually rewarding.
I wasn’t sure, though, so after college I worked in consulting for a little while also volunteering in an ER and in some free clinics. I really valued those experiences with patients and the one- on-one interactions. I recognized how much good you can do and how much you can help someone by just listening and being attentive to their needs and concerns. Those experiences solidified my desire to go into medicine.
When I started medical school, I quickly realized that I really enjoyed anatomy and surgery. Urology is a fantastic specialty because you come in contact with a wide variety of patients—from children to very old patients, men and women. Even though most people think urology just centers on men, we actually take care of a lot of women too.
Urology involves a lot of surgeries that can be complicated and take a lot of time and energy, but there is also a lot of one-on-one patient-based care dealing with very personal things like sexual function or urinary function. Urology is somewhat unique among surgical specialties in that we not only operate on patients, but very often follow them for many years, allowing for long-term relationships with our patients.
I then became interested in cancer care. The current challenge is to improve the way we take care of cancer patients. Cancer is scary. Fortunately, in many cases it is very treatable and even curable. But hearing the C-word can be terrifying. Most people shut down and don’t really hear much after learning they’ve been diagnosed, so it can be a little longer process to help them understand that there are opportunities for cure.
What is the thinking behind the clinical trial you’re running?
Dr. Sprenkle: We opened this trial to better understand the relationship between the BRCA2 mutation, or BRCA2 deletion, in men and the incidence of prostate cancer.
There have been several studies showing that men with prostate cancer who have a BRCA2 mutation have a more aggressive prostate cancer more likely to have lymph node positivity.
What we have not been able to identify is where that starts. These men were arguably diagnosed with prostate cancer because they had an elevated PSA. Is their risk higher because they were diagnosed later in the course of their prostate cancer, or is their risk higher because the BRCA2 deletion causes them to have higher-grade prostate cancer?
When we started this trial, there was no information and no long- term prospective studies. (I believe there recently has been a trial that suggests that on a stage-for-stage basis it actually may not be much worse to have BRCA2, but that was not around when we started this trial.)
We are trying to understand the incidence of prostate cancer in this population of men with the BRCA2 mutation. This is, in part, a registry for all men who have a known BRCA2 mutation. We offer them prostate cancer screening with standard techniques: PSA blood tests, DRE, etc. But we also offer an MRI and MR-targeted biopsy to evaluate if there are any radiologic characteristics that could be used.
If 28-30% of men in a general population have prostate cancer with a PSA cut-off of 4, is that the same for men with a BRCA2 mutation? Or should we be screening men with this mutation earlier? Or biopsying them with a lower PSA? Do men with this mutation have a 30% rate of prostate cancer with a PSA of 2?
There is a famous trial called the Prostate Cancer Prevention Trial that used a medication to shrink the prostate. During the trial, they biopsied men if they had an elevated PSA and then at the end of that trial. Even men who didn’t get treatment were biopsied at the end, independent of what their PSA was. The trial gave a tremendous amount of information about what the likelihood is of developing prostate cancer when your PSA is as low as 1. Based on the results of this trial, we know that approximately 8% of men with a PSA of 1 or less have prostate cancer on a random biopsy—even though we typically don’t biopsy those men.
This current trial is an opportunity for us to gain information about how—or if—the incidence of prostate cancer is different in a population of men with a BRCA2 mutation.
Are you just looking for men without prostate cancer with the BRCA2 mutation?
Dr. Sprenkle: Yes. Any man who has at least a 10-year life expectancy qualifies to be screened.