Hormone receptors; association with breast cancer outcome

The authors aimed to evaluate the prognostic (disease outlook) effect of the presence of certain hormone receptors on cancer cells. 

Breast cancer is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). Breast cancer subtypes not only influence treatment options, but also directly affect disease prognosis.

Estrogen and progesterone are hormones whose receptors are found on cancer cells. Through these receptors, estrogen or progesterone can cause cancer cell stimulation and growth. Androgen is another type hormone whose receptor can be present on breast cancer cells, and it is the precursor for estrogen. The most well-known androgen is testosterone. 

Previous studies have shown the increasing relevance of androgen in breast cancer. To date, however, the effect on prognosis has not been well studied. 

The aim of this study was to evaluate the outlook of both androgen receptor positive (AR+) and estrogen receptor positive (ER+) breast cancer.

A total of 905 women with invasive (ability to spread) breast cancer were evaluated. Of these women, 89% had AR+ breast cancer, 70.3% had a combined status of ER+ and AR+ (ER+/AR+) breast cancer while 11.9% were negative for both hormone receptors (ER-/AR-).

The positive outlook of AR+ cancer was significantly dependent on the ER status of the tumor (positive or negative). Overall, women with combined ER+/AR+ breast cancer had an improved prognosis. After a follow up of 11 years, any other combination of receptors (for example, ER-/AR+, ER-/AR-, ER+/AR-) were on average twice as likely to experience return of the cancer. 

The authors concluded that women whose breast cancer was positive for both ER and AR had a significantly improved prognosis. 

This study involved a small group of women and it did not provide significant insight into a particularly relevant or associated treatment.