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.
Evidence was weak that marijuana helps anxiety and sleep disorders
Ageing doesn’t mean a steady descent into misery – evidence suggests that happiness is likely to increase as we head towards old age, but is it that simple?
The Ebola epidemic in Guinea that began early last year has set back the country's fight against malaria, say experts.
New diagnostics can find the DNA that drives a tumor, but evidence that they help patients is missing.
Scientists agree that children raised by same-sex couples are no worse off than children raised by parents of the opposite sex, according to a new study co-authored by a University of Oregon professor.
Children as young as 3 years old will step in to right the wrong if they see someone being mistreated, a study finds. But they aren't as keen as 5-year-olds to dole out punishment.
Millions suffer from SAD in summer as well as winter, and evidence hints that birth season plays a role in who develops the disorder
International panel says climate change is already affecting people's health, but there are steps we can take
A new federal study has answers
When Middle East respiratory syndrome erupted in South Korea, people started wearing masks everywhere, even at weddings. So how good are these masks at stopping MERS or even the flu?