Medicines that target hormone receptors in breast cancer cells are called hormonal therapies. This form of treatment can be very effective against hormone-receptor-positive breast cancer — having either estrogen or progesterone receptors present in the cancer. Most breast cancers in men are hormone-receptor-positive.
The same kinds of hormonal therapies that work in women also work in men. The medicine with the longest track record is tamoxifen, which belongs to the selective estrogen receptor modulator (SERM) group of medications. This medicine blocks the estrogen receptor, keeping the hormone (estrogen) from getting into the receptor and turning on cancer cell growth. Another form of hormonal therapy is the aromatase inhibitors. This category includes the medicines Arimidex (chemical name: anastrozole), Femara (chemical name: letrozole), and Aromasin (chemical name: exemestane).
Because breast cancer is so uncommon in men, there have been no clinical trials in men to figure out which medicine is best under each circumstance. The United States Food and Drug Administration (FDA) has not approved the medications discussed here for use in men, only for women. But these medicines can still be very effective in men dealing with hormone-receptor-positive disease. The extensive results of hormonal therapy in women can be applied to men dealing with the disease.
For men with early-stage, hormone-receptor-positive disease who are at significant risk of having the cancer come back (recur), hormonal therapies are usually prescribed for 5 years. Your doctor might recommend tamoxifen or an aromatase inhibitor (Arimidex, Femara, or Aromasin). In light of the benefits women have had from extended hormonal therapy, men may also want to consider taking Femara for 5 years after "graduating" from 5 years of tamoxifen.
The same hormonal therapies work for men with advanced (metastatic) hormone-receptor-positive breast cancer. For men with metastatic disease, hormonal therapy is usually continued as long as it is working. If these hormonal therapies have stopped working and the disease shows signs of progression, then hormonal therapy Faslodex (chemical name: fulvestrant) may be considered. If hormonal therapy no longer keeps the cancer under control, then chemotherapy is usually considered.
Because there have been no men involved in the clinical trials for these medications, it's hard to know exactly what the potential side effects are. Some men have reported the following symptoms while taking hormonal therapies:
- loss of sexual desire
- trouble having an erection
- weight gain
- hot flashes
- mood swings
Be sure to discuss any side effects with your doctor so that he or she can help get whatever relief you can.