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Men only account for 1 percent of breast cancer cases, but experts say it’s important to determine if they react to treatment differently. Getty Images
  • The Food and Drug Administration is recommending that men be included in breast cancer treatment clinical trials.
  • Men account for only 1 percent of breast cancer cases overall.
  • Experts say it’s important to examine whether men respond differently to breast cancer treatment than women.
  • The NATALEE clinical trial for breast cancer treatment is currently recruiting men.

Men have breast tissue. Therefore, men can get breast cancer.

But men typically aren’t included in clinical trials for breast cancer treatments.

Treatment for male breast cancer is based on data from women with the disease.

The Food and Drug Administration (FDA) wants that to change. The agency is urging researchers to enroll men in clinical trials for breast cancer treatments.

The FDA recently issued a draft guidance titled, “Male Breast Cancer: Developing Drugs for Treatment.” In it, they recommend including males in clinical trials in an effort to improve clinical management of breast cancer in men.

The draft guidance is open for public comment through October 28.

The American Cancer Society estimates that 2,670 men will be newly diagnosed with breast cancer this year and 500 will die from disease.

Still, male breast cancer is rare, making up less than 1 percent of all breast cancer cases.

“Since there is such a small number of men with breast cancer, including them in clinical trials could potentially take resources from women, who are 99 percent more likely to get it,” said Dr. Constance M. Chen, a board-certified plastic surgeon and breast reconstruction specialist in New York.

“That said, the number of male breast cancer patients is not zero and it is difficult to answer the question of whether male breast cancer patients need different treatment without a study,” she told Healthline.

Chen explained that there’s a lack of randomized data to support specific treatment modalities in men.

“Breast cancer in men may respond differently to treatment than breast cancer in women. So, it could also make sense to create a clinical trial just for breast cancer in men,” she said.

Chen noted that it might be difficult to get enough men to fill a trial, although they could be included in more general trials.

She also said that men tend to be diagnosed at a later stage due to lack of awareness.

“Male breast cancer survival rates are lower than female breast cancer survival rates. The [overall] 5-year survival rate for men is 74 percent, while it is 83 percent for women,” said Chen.

According to, the poorer survival rate in men is seen in early-stage disease. Survival rates for advanced breast cancer are about the same for men and women.

Dr. David J. Park, who specializes in hematology, medical oncology, and hospice and palliative medicine, is a medical director at St. Jude’s Crosson Cancer Institute in California.

Park spoke to Healthline about NATALEE, a clinical trial currently recruiting at more than 200 locations around the world.

NATALEE is accepting men and women to evaluate ribociclib, a CDK4/6 inhibitor with endocrine therapy as adjuvant treatment for HR+/HER2- early breast cancer.

“It’s a phase 3 trial we opened up here at St. Jude that allows men. It’s one of the few I’ve seen since I’ve been in practice and the only one of this large scale,” he said.

Park is about to enroll a participant who’s both male and Korean-speaking, two potential barriers to trials.

“Minorities don’t often get into trials, so it’s even more important. We were able to get the informed consent in his language,” he said.

The participant has completed chemotherapy and radiation. He can now move on to standard of care, which is the endocrine phase, or he can enter the randomized trial.

“Whether he enrolls or not, it’s ultimately his choice, but I’m just happy to give my patients this opportunity,” said Park.

Men generally take more convincing, he said, but there’s no good reason to exclude them from breast cancer clinical trials.

“We’ve used women’s regimens to treat men because the disease seemed to be similar. We’ve been having pretty good results, but we need to formalize these findings. We want high-quality, high-level prospective trials instead of retrospective data. It’s the next level,” explained Park.

It’s not necessary to do overall screening of men, according to Park.

“Screening is all about incidence. Screening, by definition, means doing tests on completely asymptomatic people in the hopes of catching it early. You have to consider the costs — financial, time, false positives, and false negatives,” he said.

As in women, a hard mass in the breast could be a sign of breast cancer. Chen advises men who notice a change in size, shape, or feeling in a breast to see a doctor.

She also cautions that breast cancer isn’t the only disease of the breasts.

Men can also get sarcomas, skin cancers, infections, and other problems in their breasts. Also, if a man has a strong history of cancer or breast cancer in his family, he may want to undergo genetic testing to see if he might be at higher risk of breast cancer. If he is at high risk for breast cancer, he may want to be followed by a breast surgeon or undergo breast surveillance depending on his risk profile,” said Chen.

Park said that screening men with risk factors has been standard for a while.

“Genetic testing is not as big of a barrier, but men being in clinical trials, that’s new,” said Park.