Rate Of Breast Cancer In Men Increasing

Men Are Less Likely Than Women To Be Vigilant

The rate of male breast cancer is on the rise, and the disease in men is usually detected when the tumors are large and have spread, concludes a major study published in the medical journal Cancer.

The findings suggest both that breast cancer in men may have some important biological differences from breast cancer in women, and that men are seemingly less aware than they should be that they can develop breast cancer.

According to the study's lead investigator, Dr. Sharon H. Giordano, a professor at M.D. Anderson Cancer Center, the incidence of the disease has increased significantly in the last 25 years, from 0.86 to 1.08 per 100,000 men.

"Male breast cancer is rare, accounting for less than one percent of all breast cancer, or about 1,600 new cases in the United States in 2004," Dr. Giordano says. "While it's not as high of an increase in cases as that in women, men should be alert to the possibility that the disease could affect them."

Because breast cancer in men is rare, little is known about how it differs from breast cancer in women and how it should be best treated.

Differences Between Men and Women

To assess dissimilarity, Dr. Giordano and her colleagues used information from a National Cancer Institute database called SEER (Surveillance, Epidemiology, and End Results), which is the authoritative source of information on cancer incidence and survival in the US.

They analyzed SEER data from 1973 through 1998 on 2,524 cases of male breast cancer and 380,856 cases of female breast cancer.

Compared to female patients, the investigators found that male patients were significantly older when diagnosed - 67 years versus 62 years of age. They were also more likely to have later stage disease and had more spread of the cancer to their lymph nodes.

"It's perhaps ironic that tumors in men are easier to feel than they are in women, yet the disease is being discovered at a later stage in men than in women," says Dr. Giordano.

One reason for such a late diagnosis may be that men assume they are experiencing a benign condition called gynecomastia, or atypical growth of breast tissue that affects about a third of males at some point in their lives, says Dr. Giordano.

The condition, common in adolescent boys, can come and go over a man's lifetime and "men may think new growth of breast tissue is just another occurrence of this condition," she explains.

Gynecomastia is the most common male breast disorder. It is not a tumor but rather just an increase in the amount of a man's breast tissue.

Usually, men have too little breast tissue to be felt or noticed. A man with gynecomastia has a button-like or disk-like growth under his nipple and areola, which can be felt and sometimes seen.

Gynecomastia, common among teenage boys, is due to changes in hormone balance during adolescence. The same condition is not unusual in older men and is also due to changes in their hormone balance.

Rarely, gynecomastia can occur because tumors or diseases of certain endocrine (hormone-producing) glands cause a man's body to produce more estrogen (the main female hormone).

Furthermore, Dr. Giordano found that the most common types of cancers in men were invasive ductal carcinoma, found in 93.4 percent of the men, and papillary carcinoma, which accounted for 2.6 percent of the cases.

Survival Rates Similar for Men and Women

Yet despite these differences, five-year, 10-year, and median survival were not different between men and women, she says.

Also of interest to the Dr. Giordano was the finding that male patients are more likely than female patients to have estrogen receptor positive tumors, where the estrogen helps the cancer grow.

"We are not sure why this is so, but it may indicate some important differences in tumor biology," she says. "In addition, this implies that use of tamoxifen in men may be as beneficial as it is to many women," says Dr. Giordano.

"Now that we have a clearer understanding of the biology of breast cancer in men, further research is needed to determine the optimal treatment for men," she says.

Always consult your physician for more information. 

Online Resources

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American Cancer Society

Centers for Disease Control and Prevention (CDC)

Healthfinder, US Department of Health and Human Services (HHS)

National Cancer Institute

National Institutes of Health (NIH)

National Library of Medicine

July 2004

Rate Of Breast Cancer In Men Increasing

Differences Between Men and Women

Survival Rates Similar for Men and Women

Breast Cancer in Men

Online Resources

Breast Cancer in Men

According to the American Cancer Society, many people do not realize that men have breast tissue and that they can develop breast cancer.

Until puberty, young boys and girls have a small amount of breast tissue consisting of a few ducts (tubular passages) located under the nipple and areola (area around the nipple).

At puberty, a girl's ovaries produce female hormones, causing breast ducts to grow, lobules (milk glands) to form at the ends of ducts, and the amount of stroma (fatty and connective tissue surrounding ducts and lobules) to increase.

On the other hand, male hormones produced by the testicles prevent further growth of breast tissue.

Many types of breast disorders can affect both men and women. Most breast disorders are benign (not cancerous).

Although men's glands normally produce some estrogen, it is not enough to cause breast growth.

Risk factors for men include:

• Aging - is an important risk factor for the development of male breast cancer. Men with breast cancer average about 65 years of age at the time of their diagnosis.

• Family history of breast cancer - breast cancer risk is increased if other members of the family (blood relatives) have had breast cancer. About 20 percent of men with breast cancer have close male or female relatives with the disease.

• Klinefelter's syndrome - this is a congenital (present at birth) condition that affects about 1 out of 1000 men.

• Radiation exposure - a man whose chest area has been exposed to radiation (usually for treatment of a cancer inside the chest, such as Hodgkin's or non-Hodgkin's lymphoma) has an increased risk of developing breast cancer.

• Liver disease - the liver plays an important role in sex hormone metabolism by producing binding proteins that carry the hormones in the blood. These binding proteins affect the hormones’ activity. Men with severe liver disease such as cirrhosis have relatively low levels of androgen activity and higher estrogen levels. Therefore, they may have an increased risk of developing gynecomastia and breast cancer.

• Estrogen treatment -estrogen-related drugs are sometimes used in hormonal therapy of men with prostate cancer. This treatment may slightly increase their breast cancer risk. However, this risk is small compared with the benefits of this treatment in slowing the growth of prostate cancer.

• Physical inactivity and obesity - recent studies have shown that physical activity reduces women's breast cancer risk and that breast cancer risk is increased by obesity during adult life. Obesity is probably a risk factor for male breast cancer. The reason is that fat cells convert male hormones (androgens) into female hormones (estrogens).

Always consult your physician for more information.