Higher levels of testosterone in elderly men can make existing prostate cancer cells to grow faster, a new study has warned.

According to Researchers, men in their 70s and 80s with higher levels of testosterone, including those who undergo hormone replacement therapy (HRT), are at an increased risk of prostate cancer.

However, low testosterone in older men can cause loss of muscle mass, decreased sexual function, fatigue, mood changes, depression and impaired cognition, according to a statement of the University of Western Australia.

HRT may seem the best approach to relieve the symptoms, but scientists now believe more research is needed on this treatment to determine if it does help patients.

The prostate is a small, walnut-sized structure that makes up part of a man’s reproductive system. It wraps around the urethra, the tube that carries urine out of the body.

Symptoms of prostate cancer are: delayed or slowed start of urinary stream; dribbling or leakage of urine; slow urinary stream, straining when urinating, or not being able to empty out all of the urine; blood in the urine or semen, etc.

The link was confirmed by the results from Australia’s largest healthy aging study, The Health in Men Study (HIMS).

Dr Zoe Hyde, from Western Australia’s Centre for Health and Aging who led the study, said while higher levels of testosterone were unlikely to cause cancer, they might make an existing cancer grow faster.

“We need to conduct large-scale, long-term trials of testosterone therapy to see if this risk applies to men receiving testosterone,” Hyde said.

The research is timely because the use of testosterone therapy is growing, and prostate cancer is very common in old age, Hyde said.

Scientists believe that the possibility that high levels of testosterone could make prostate cancer grow faster is concerning. A cancer that would have gone undetected and never caused any problems might now affect health.

The findings are published in the journal Cancer Epidemiology Biomarkers & Prevention reports.