Gynecomastia (guy-nuh-koh-MAS-tee-uh) is swelling of the breast tissue in boys or men, caused by an imbalance of the hormones estrogen and testosterone. Gynecomastia can affect one or both breasts, sometimes unevenly. Newborns, boys going through puberty and older men may develop gynecomastia as a result of normal changes in hormone levels, though other causes also exist. Generally, gynecomastia isn't a serious problem, but it can be tough to cope with the condition. Gynecomastia is triggered by a decrease in the amount of the hormone testosterone compared with estrogen. Men and boys with gynecomastia sometimes have pain in their breasts and may feel embarrassed. The cause of this decrease can be conditions that block the effects of or reduce testosterone or a condition that increases your estrogen level. Several things can upset the hormone balance, including the following. The hormones testosterone and estrogen control the development and maintenance of sex characteristics in both men and women. Tamoxifen blocks the actions of estrogen, a female hormone. Certain types of breast cancer require estrogen to grow. Tamoxifen is used to treat some types of breast cancer in men and women. It is also used to lower a woman's chance of developing breast cancer if she has a high risk (such as a family history of breast cancer). Use a barrier form of birth control (such as a condom or diaphragm with spermicide) while you are using this medication and for at least 2 months after your treatment ends. Tamoxifen may also be used for purposes not listed in this medication guide. You should not use tamoxifen if you are allergic to it, or if you have a history of blood clots in your veins or your lungs, or if you are also taking a blood thinner such as warfarin (Coumadin). Before using this medicine, tell your doctor if you have liver disease, high triglycerides (a type of fat in the blood), a history of cataract, or a history of stroke or blood clot. Also tell your doctor if you if you are receiving chemotherapy or radiation treatment.
Tamoxifen has emerged as a potential management option for gynecomastia and breast pain due to non-steroidal antiandrogens, and it is considered an alternative to surgery or radiotherapy. The objective of this systematic review was to assess the benefits and harms of tamoxifen, in comparison to other treatment options, for either the prophylaxis or treatment of breast events induced by non-steroidal antiandrogens in prostate cancer patients. We searched CENTRAL, MEDLINE, EMBASE, reference lists, the abstracts of three major conferences and three trial registers to identify ongoing randomized controlled trials (RCTs). Two authors independently screened the articles identified, assessed the trial quality and extracted data. The protocol was prospectively registered (CRD42011001320; Four studies were identified. Tamoxifen significantly reduced the risk of suffering from gynecomastia (risk ratio 9RR0 0.10, 95% CI 0.05 to 0.22) or breast pain (RR 0.06, 95% CI 0.02 to 0.17) at six months compared to untreated controls. Tamoxifen also showed a significant benefit for the prevention of gynecomastia (RR 0.22, 95% CI 0.08 to 0.58) and breast pain (RR 0.25, 95% CI 0.10 to 0.64) when compared to anastrozole after a median of 12 months. Low testosterone levels in men can sometimes lead to a condition called gynecomastia, or the development of larger breasts. It’s responsible for male physical features and also affects a man’s sex drive and mood. When there’s an imbalance of the body’s hormones in men, including testosterone, gynecomastia can develop. Both low testosterone and gynecomastia are often treatable. It’s important to first understand the underlying causes for each condition. This is called hypogonadism, or “low T.” According to the Urology Care Foundation, 1 in 4 men over the age of 45 have low T. Having low testosterone levels can lead to several complications: The male body produces both testosterone and estrogen, although estrogen is usually found at low levels. If a man’s testosterone levels are especially low in comparison to estrogen, or if there is an excess of estrogen activity relative to testosterone, larger breasts may develop. When boys hit puberty and there’s a noticeable change in hormonal activity in the body, gynecomastia may appear.
Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women. Tamoxifen is also used to treat hormonally-responsive breast cancer, but it does so by interfering with the estrogen receptor. However, letrozole is effective only in post-menopausal women, in whom estrogen is produced predominantly in peripheral tissues (i.e. in adipose tissue, like that of the breast) and a number of sites in the brain. In pre-menopausal women, the main source of estrogen is from the ovaries not the peripheral tissues, and letrozole is ineffective. In the BIG 1–98 Study, of post-menopausal women with hormonally-responsive breast cancer, letrozole reduced the recurrence of cancer, but did not change survival rate, compared to tamoxifen. Letrozole has been used for ovarian stimulation by fertility doctors since 2001 because it has fewer side-effects than clomiphene (Clomid) and less chance of multiple gestation. Your doctor will ask you questions about your medical and drug history and what health conditions run in your family. The doctor will also do a physical examination that may include careful evaluation of your breast tissue, abdomen and genitals. Initial tests to determine the cause of your gynecomastia may include: Most cases of gynecomastia regress over time without treatment. However, if gynecomastia is caused by an underlying condition, such as hypogonadism, malnutrition or cirrhosis, that condition may need treatment. If you're taking medications that can cause gynecomastia, your doctor may recommend stopping them or substituting another medication. In adolescents with no apparent cause of gynecomastia, the doctor may recommend periodic re-evaluations every three to six months to see if the condition improves on its own. Gynecomastia often goes away without treatment in less than two years.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own. Tamoxifen is an anti-estrogen therapy commonly used in breast cancer treatment; recent studies have suggested that it can also be used as an alternative to surgery to treat gynecomastia in men. In their systematic review, Kunath and colleagues demonstrated that tamoxifen is effective for the treatment of breast events induced by anti-androgen.