Prostate cancer (PCa) may be more likely to develop in men who experience large drops or fluctuations in testosterone levels, especially earlier in life, according to researchers.
In a study of 376 untreated hypogonadal men aged 45 to 74 years, PCa developed in 26 men during 2 to 11 years of follow-up, according to findings published in the Journal of Urology. The older a man was when his total testosterone fell to 12.1 nmol/L or below, the lower his lifetime risk of PCa. The risk declined by 32% for each 1-year increase in age at diagnosis.
Experiencing any further swings or drops in testosterone following the hypogonadism diagnosis also was associated with greater PCa risk. A man with a high versus low coefficient of variation, a measure of testosterone fluctuation over time, had 4.9 times the risk. A man with a maximum drop in testosterone that differed by 20% or more from his average or with a relatively large median drop within 2 years had 8.5 and 2.7 times greater risks, respectively. Models incorporated major confounders including family history of PCa, alcohol use, smoking status, and body mass index (BMI).
“Our study is the first to provide evidence of the association between dynamic patterns of T and PCa development and may have substantial clinical impacts on PCa prevention,” Xiaohui Xu, PhD, of Texas A&M University in College Station, Texas, and collaborators wrote.
The investigators speculated that normal prostate cells have a normal range of testosterone level that differs from man to man. Abnormal testosterone drops within an individual might disrupt the stable environment within the prostate and lead to cellular adaptations that possibly give rise to PCa, they explained.
“Maintaining T levels stable may have a significant impact on PCa prevention,” Dr Xu and the team stated. “Also, regular monitoring of T levels in males may be useful earlier in life, e.g. at 40-50 years of age, to establish a baseline from which changes could then be detected.”
With routine monitoring of testosterone levels, clinicians will be able to detect in a timely manner abnormal variations or declines and deliver proper interventions like testosterone therapy to the patient to prevent PCa.
Study limitations included lack of adjustment for medication use and comorbidities, selection of untreated patients, and single center design.
Xu X, Zhang X, Zhong Y, Saad F, Perez-Patron MJ, and Haider K. Dynamic patterns of testosterone levels within individuals and risk of prostate cancer among hypogonadal men: A longitudinal study. J Urol. doi: 10.1016/j.juro.2017.08.117.