PROSTATE & BREAST
What’s in Common?
In short – more than you think!
Prostate and breast cancer are Australia’s leading “high incidence” cancers, in men & women. But they have more in common than just that. There are a number of aspects to this:
- Family History & Genetic Links
- Prostate & breast cancer rely on hormones to fuel their growth.
Family History of Breast, Ovarian or Prostate Cancer
People with a family history of breast, ovarian or prostate cancer have an increased risk of breast cancer. The increased risk is likely due to genetic factors but it may also be common lifestyle factors, or other family traits.
- Female family members with a history of breast cancer. Most women diagnosed with breast cancer don’t have a family history of the disease. About 15% of women diagnosed with breast cancer have a first-degree female relative (mother, sister or daughter) who’s also had it.
- · Age of family member at breast cancer diagnosis. In general, the younger the relative when diagnosed, the more chance of getting breast cancer. For example, a woman whose mother had breast cancer before age 40 has about twice the risk of a woman without this history.
- Male family members with a history of cancer. People who have a close male relation (father, brother or uncle) with breast cancer have an increased risk of breast cancer.
- Any history of prostate cancer. People who have one or more first-degree relatives (father or brother) with prostate cancer have an increased risk of breast cancer, especially if the prostate cancer was diagnosed when young. This is due to inherited gene mutations related to the risk of both breast and prostate cancers.
- Inherited gene mutations. Families with a history of breast cancer often carry inherited gene mutations.
If you have a family history of breast, ovarian or prostate cancer, it may be due to an inherited gene mutation that increases the risk of these cancers. Talk to your GP and consider seeing a genetic counsellor to discuss genetic testing. Your GP can help you understand how this impacts your risk of cancer.
“Despite having opposite risk factors, studies have shown a direct relationship of prostate cancer with breast cancer due to the similarities in hormonal and genetic mechanisms. Moreover, there is a significant increased risk of breast cancer in patients with prostate cancer who received estrogen therapy”.
Refer: Clinical Breast Cancer. 2010 Refer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7011903/
University of Adelaide - Research in Prostate & Breast Cancer
At the University of Adelaide, Prof. Wayne Tilley’s career has focused on the question of what prostate & breast cancer have in common. Prof. Tilley is known internationally for his work on the diagnosis and treatment of these cancers.
“In the case of prostate, it requires testicular androgens for its growth, at least in all the initial stages, and the same with breast cancer. Some 70-80% of breast cancers are driven by the estrogen receptor which actually requires the ovarian hormone estrogen” he said.
An androgen is a hormone, like testosterone. Before birth and during puberty they are critical for male sexual development. Both men and women have a number of androgens, including estrogen.
“So drugs that actually target the androgen receptor in prostate cancer… are similar to drugs such as tamoxifen…that are used to treat endocrine sensitive breast cancer.”
Prof. Tilley said they now know that both prostate and breast cancers are able to change the requirements for tumour growth. “We’ve been able to model how these changes occur and realise if we’re looking at how prostate cancer adapts to a new drug, we might be able to predict something similar in breast cancer”.
“What we realised a number of years ago is the estrogen-androgen balance in women is important, both in normal mammary gland development and in controlling the growth of the breast tumour cell. So what we think is the androgen receptor is a good player and it acts as a break to constrain the action of the estrogen receptor and if that break was released then the cancers would be more aggressive.”
“But conversely, if we can activate that break, it affords a new opportunity to control estrogen receptor driven growths.”
“So with collaborators around the world we’ve been able to develop new models and test clinically how you could activate this androgen receptor as a potential therapeutic strategy for patients whose tumours have failed with conventional hormone therapies.”
“If you can use these drugs, because they actually have many beneficial effects in women, they actually improve bone density and in some cases libido. If we could actually take them back even earlier, could we actually prevent the development of endocrine resistance or even, could they be used in a prevention setting?”
“So, we’re looking at quite a broad spectrum now of how you might use activation of the androgen receptor in women with breast cancer.”
