The use of androgen deprivation therapies to prevent precancerous prostate abnormalities developing into aggressive prostate cancer may have adverse effects in men with precancers with specific genetic alterations, according to data from a preclinical study recently published in Cancer Discovery, a journal of the American Association for Cancer Research.
"The growth and survival of prostate cancer cells are very dependent on signals that the cancer cells receive from a group of hormones, called androgens, which includes testosterone," said Thomas R. Roberts, Ph.D., co-chair of the Department of Cancer Biology at the Dana-Farber Cancer Institute and professor of biological chemistry and molecular pharmacology at Harvard Medical School in Boston, Mass.
Previous findings from two major randomized, placebo-controlled prostate cancer chemoprevention trials revealed that androgen deprivation therapy reduced the overall risk for low-grade prostate cancer. However, both trials also revealed a high cumulative risk for high-grade prostate cancers that has caused concern among experts.
High-grade prostatic intraepithelial neoplasia is a prostate abnormality that is considered to be a major precursor to prostate cancer. Loss of the tumor suppressor PTEN is detected in 9 to 45 percent of clinical cases.
Using a mouse model of PTEN-driven high-grade prostatic intraepithelial neoplasia, Roberts and his colleagues investigated whether surgical or chemical androgen deprivation could prevent the cancer precursor from progressing to more aggressive disease.
"When we castrated the animals, we thought the tumors would shrink and they did initially," Roberts said. "However, they then grew back and became invasive."
The results of this preclinical study suggest that prophylactic reduction of the most active form of androgen, or blocking androgen receptor function, might have unintended consequences in some men.
"Stretching our data even further, these findings suggest that as men age and their testosterone levels decrease, loss of testosterone might actually encourage indolent prostate tumors to become more aggressive," Roberts said. "This suggests that testosterone supplements might be a good thing for the prostate, even though current wisdom suggests the opposite."
Roberts noted that these results should be interpreted with caution because the prostate glands of mice are different from their human counterparts. More data on human tumors are needed to evaluate whether the data from this mouse study are applicable to men.
American Association for Cancer Research: http://www.aacr.org
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Naked mole rats enjoy exceptionally long, healthy lives, and there's more than good genes at work
Scientists say impact of bringing forward girl’s first period by 2.7 months is likely to be modest
Melbourne-based study of children given nut protein with probiotic has transformed the lives of 80% of those who took part in clinical trial
Sunshine police take note, the latest guidelines from the UK's health advisory body NICE suggest we should actively seek out some rays
Choosing the viral targets for the seasonal flu vaccine is a gamble. Sometimes, like this year, the flu wins
Predicted lung cancer deaths for women in Europe set to reach 14.24 per 100,000 of population in 2015
Media reports of a recent study suggesting a wide variety of common drugs can increase the chances of getting dementia are more sensationalism than science
A recent sharp drop in new Ebola infections in West Africa is prompting scientists to wonder whether the virus may be silently immunizing some people at the same time as brutally killing their neighbors.
Five Disneyland workers have been diagnosed with illness
The first batch of a vaccine against Ebola is on its way to Liberia and trials are expected to start soon.