5-alpha reductase inhibitors For BPH Linked to Higher, Not Lower, PSA Levels

MedicalResearch.com Interview with:
Teemu J Murtola, MD, PhD, adjunct professor
University of Tampere, Faculty of Medicine and Life Sciences
Tampere University Hospital, Department of Urology
Tampere, Finland

MedicalResearch.com: What is the background for this study?

Response: A previous study called Prostate Cancer Prevention Trial
(PCPT) showed that finasteride, which belongs to a drug group called
5alpha-reductase inhibitors lowers serum PSA and increases sensitivity
of PSA to detect high-grade prostate cancer in men who had little or
no symptoms of the lower urinary tract. We postulated that this effect
would increase the accuracy and benefits of PSA-based prostate cancer
screening.

Finnish Randomized Study of Screening for Prostate Cancer was a large
trial of over 80,000 men randomized either to be screened for prostate
cancer with a PSA test at 4-year intervals or to be followed for
prostate cancer incidence and mortality via national registries. Three
consecutive screening rounds were commenced between 1996-2008. In the
current study we compared the effects of PSA-based screening on
prostate cancer risk and mortality separately among men who were using
5alpha-reductase inhibitors finasteride or dutasteride and among men
who were not.


MedicalResearch.com: What are the main findings?

Response: Contrary to what we expected, men using 5alpha-reductase inhibitors
had higher median PSA level, not lower, than the non-users. Among the
users PSA-level did not predict high-grade prostate cancer as
effectively as it did among the non-users. Further, prostate cancer
screening did not affect prostate cancer incidence and mortality among
the users of 5alpha-reductase inhibitors, whereas among the non-users
prostate cancer screening led to higher prostate cancer incidence and
lower prostate cancer-specific mortality compared to the control arm.

Our results on PSA level and detection of high-grade cancer differ
from previous reports because in clinical practice finasteride and
dutasteride are used in management of benign prostatic hyperplasia,
which in turn affects PSA apparently more than 5alpha-reductase
inhibitors do. This highlights the fact that although randomized
clinical trials are ideal for estimating causal effects of a drug, the
results may not be directly generalizable to clinical practice if the
indications for drug usage are different compared to the trial setting.

MedicalResearch.com: What should readers take away from your report?

– Users of finasteride or dutasteride have higher, not lower median
PSA compared to non-users if they are using the drugs for management
of benign prostatic hyperplasia (BPH)

– Finasteride or dutasteride usage does not improve accuracy of
efficacy of PSA-based prostate cancer screening when the drugs are
being used for BPH management. In fact PSA screening has less effect
on prostate cancer incidence or mortality among finasteride or
dutasteride users compared to the non-users.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Large, high-quality population-based epidemiological studies are
essential to see whether phenomenons observed in randomized clinical
trial setting are observed also in the real-world clinical practice.
Such studies should be encouraged.

MedicalResearch.com: Is there anything else you would like to add?

Response: I have received consultant fees from Astellas and Janssen-Cilag and
lecture fees from Astellas, GSK and Janssen-Cilag

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:

Outcomes of prostate cancer screening by 5-alpha reductase inhibitor usage
Journal of Urology
ISSN 0022-5347
Accepted/In press – 10 Feb 2017

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