Sydney, Australia, Jan 18 (efe-epa).- Androgens, the male sex hormones, may have a positive impact in the treatment of breast cancer with immediate implications for women with estrogen receptor-driven metastatic disease, according to a new study published on Monday.
The research published in Nature Medicine and conducted by researchers at the University of Adelaide in collaboration with the Garvan Institute of Medical Research could be historic in treating the disease.
The researchers looked at the role of androgens – commonly thought of as male sex hormones but also found at lower levels in women – as a potential treatment for estrogen receptor-positive breast cancer.
“This work has immediate implications for women with metastatic estrogen receptor positive breast cancer, including those resistant to current forms of endocrine therapy,” said Theresa Hickey, head of the Breast Cancer Group, who co-lead the study.
Hickey said the need for alternative treatment strategies had renewed interest in androgen therapy for breast cancer.
Previous studies had produced conflicting evidence on how best to therapeutically target the androgen receptor for the treatment of breast cancer, which caused widespread confusion and hampered clinical application.
Androgens, which include several types of male hormones, such as testosterone, stimulate the development of secondary male sexual characteristics like the beard.
Estrogens induce the appearance of secondary female sexual characteristics that are not directly involved in reproduction. These include breasts.
In normal breast development, estrogen stimulates and androgen inhibits growth at puberty and throughout adult life.
Abnormal estrogen activity is responsible for the majority of breast cancers, but the role of androgen activity in the disease has been controversial.
Androgens were historically used to treat breast cancer, but knowledge of hormone receptors in breast tissue was rudimentary at the time and the treatment’s efficacy was misunderstood.
Androgen therapy was discontinued due to virilizing side effects and the advent of anti-estrogenic endocrine therapies.
While endocrine therapy is standard-of-care for estrogen receptor-positive breast cancer, resistance to these drugs is the major cause of breast cancer mortality.
The researchers using cell-line and patient-derived models found that androgen receptor activation by natural androgen or a new androgenic drug had potent anti-tumor activity in all estrogen receptor-positive breast cancers.
These included even those resistant to current standard-of-care treatments. In contrast, androgen receptor inhibitors did not affect.
Wayne Tilley, who co-headed the team of researchers, said the study provided “compelling new experimental evidence” that androgen receptor stimulating drugs can be more effective than existing or new standard-of-care treatments.
Australian and American scientists plan to begin an international phase 3 clinical trial in the second quarter of 2021 to evaluate the impact of Enobosarm, an androgen receptor activating agent.
The trials will involve patients with estrogen and androgen receptor-positive metastatic breast cancer who have failed endocrine therapy.
Stephen Birrell, a breast cancer specialist and pioneer in androgens and women’s health who was part of the Adelaide based team, pointed out that the seminal finding had application beyond the treatment of breast cancer, including breast cancer prevention and treatment of other disorders also driven by estrogen. EFE-EPA