||5R21CA143170-03 Interpret this number
||New England Research Institutes, Inc.
||Exogenous Testosterone and Risk of Cancer
6. PROJECT SUMMARY/ABSTRACT
Since the 1940s, it has been generally accepted in the medical community that the growth of prostate
cancer is androgen-dependent,3 and prostate cancer risk is the primary safety concern with use of exogenous
testosterone.4, 5 Prescription testosterone has been available in the U.S. for more than 50 years, but patterns
of uptake have recently changed. U.S. sales of testosterone have increased more than 1500% considering
1994-2002, with sharp increases in the most recent years.6 Researchers have noted that the increase in
uptake is occurring in the absence of changes in recommendations for testosterone use,7 e.g., an expansion of
approved indications. There is very little information regarding the characteristics of users, and clinical trials
have not provided long-term safety data regarding the prostate cancer risk of testosterone products.5, 6 There
have been no prior epidemiologic studies of exogenous testosterone products and prostate cancer risk,
possibly because of the large number of men needed to capture sufficient numbers exposed to testosterone.
The research intent of this application is to cost-efficiently use a unique existing resource, the
Saskatchewan Health Services Databases, in order to fill the knowledge gap surrounding exogenous
testosterone use and prostate cancer and deliver the first population-based epidemiologic study on this topic.
The provincial government of Saskatchewan provides health coverage to nearly all residents, and the existing
data contain >500,000 males and >30 years of observation time from a defined geographic area, with cancer
outcome information available from a provincial cancer registry.57, 58, 105 Testosterone exposures are captured
in electronic prescribing records and are not subject to error based on patient recall, with dose and duration of
We plan to use a retrospective, matched cohort study design and longitudinal analysis methods to estimate
the risk of prostate cancer incidence and recurrence, incidence of severe prostate cancer, prostate cancer
mortality, and breast cancer incidence among males exposed to exogenous testosterone compared to age-
matched males not exposed. We will also descriptively examine patterns of testosterone use to better
understand the characteristics of users. The diverse expertise of the research team includes
pharmacoepidemiology, biostatistics, clinical endocrinology, and oncology, and the team has a demonstrated
history of manuscript productivity relevant to the publication plans of the project. The public health relevance of
the proposal is high, given the increasing using of testosterone as 'hormone replacement therapy' and the
potential for newly repeating 'the estrogen disaster' among women for prostate cancer among men.16 The
clinical implications for the patient are a cessation of testosterone therapy, if increased risks are found.
Regardless of the direction of results, our findings will serve the federal health goals of pharmacovigilance for
Population-based patterns of prescription androgen use, 1976-2008.
, Ranganathan G.
, Tinsley L.J.
, Lund J.L.
, Kupelian V.
, Wittert G.A.
, Kantoff P.W.
, Morales A.
, Araujo A.B.
Pharmacoepidemiology and drug safety, 2014 May; 23(5), p. 498-506.