Most women know that if they find a lump in their breast, they should go to the doctor, stat. But most men don’t, and late diagnosis affects the outcome for breast cancer patients.

Bret Miller first asked about a lump under his nipple at a football physical during his senior year of high school. The doctors told him that calcium can build up during puberty, and the lump would go away on its own.

Seven years later, after he’d graduated from Kansas University and had health insurance through his job at a Kansas City country club, Miller went in for a checkup. He again asked about the lump, which had never gone away.

An ultrasound, a mammogram, and a biopsy later, Miller got a phone call as he was leaving work. The doctor said the preliminary pathology reports showed the lump was breast cancer.

“I was sitting in my car, luckily I wasn’t driving. I was thinking, ‘Where’s Ashton [Kutcher] and all them? Am I getting ‘Punk’d’ right now? This can’t be real,’” Miller said.

Though seven years had passed since Miller first noticed a lump, his cancer had, incredibly, remained in stage 1. After a mastectomy that removed his nipple and a single round of chemo, Miller, now 26, is cancer-free, with about a 1 in 5 chance of developing cancer again.

Miller’s chest is scarred from the experience, but it’s also proudly tattooed with a ribbon, pink in front and blue in back. He’s become a spokesperson trying to raise awareness that men can get breast cancer, too. In 2012, he was named a Warrior in Pink as part of Ford Motor Company’s breast cancer awareness campaign.

“We’re trying to put a splash of blue in a world of pink,” he said. “It’s breast cancer, so women come first, but men can get it, too,” Miller said.

Get the Facts: Breast Cancer Symptoms »

Men have breast tissue, milk ducts, and even milk-producing cells. These tissues become cancerous in rare cases. Just 2,300 men per year in the United States get breast cancer; they make up less than 1 percent of those affected by the disease.

But rates of breast cancer in men have been rising consistently since the 1980s, even though rates in women began to fall about 10 years ago, according to Dr. David Michael Euhus, chief of the breast surgery section at Johns Hopkins University.

“People are dying from it, that’s the frustrating thing,” Miller said. According to government statistics, 430 American men will die of breast cancer this year.

Men often delay seeking treatment because they aren’t aware that lumps in their chest or changes to their nipples are a serious matter. They certainly don’t look for lumps in the regular self-examinations that women are instructed to do.

“I’ll get patients who come in and say, ‘I’ve had this for two years but I didn’t think anything of it,’” said Dr. Kathryn Ruddy, M.P.H., an assistant professor of oncology and the director of cancer survivorship at the Mayo Clinic in Minnesota, who has researched breast cancer in men.

Euhus put it this way: “Men ignore these lumps until they’re big enough to hang your hat on.”

As a result, men’s breast cancer is generally found at a later stage than women’s. More than 40 percent of male patients are diagnosed with stage 3 or 4 cancers, according to a 2006 study published in the Lancet.

Dealing with a disease with such a strong cultural association with women can add emotional challenges to an already grueling treatment regime, according to Ruddy, who has studied male patients’ quality of life.

Oliver Bogler, 48, a cancer researcher at the MD Anderson Cancer Center in Houston, Texas, was diagnosed with breast cancer five years after his wife. The statistical improbability of getting a rare disease that his wife had already had kept Bogler from getting medical attention for a few months. His cancer had spread to his lymph nodes by the time he had surgery.

His circle of friends includes a lot of cancer researchers, and his doctor treats many male breast cancer patients. Even so, “you do have that sort of dissonance,” he said.

“Occasionally I’d check in for the breast center and they said ‘Are you the patient?’ which they wouldn’t have said to a woman. You’re filling out forms that ask whether you’re pregnant and when was your last period,” Bogler said.

On the bright side, Bogler said sharing “a really profound experience” with his wife has brought them closer together.

According to Euhus, breast cancer in men is very much like breast cancer in postmenopausal women. The median age of diagnosis in men is between 67 and 70; in postmenopausal women, it’s 62. Men’s breast cancer is often fueled by estrogen, which men also produce.

“The similarities are pretty striking,” Euhus said.

Doctors extrapolate what they know about women’s cancers to treat men with breast cancer. Survival rates suggest that the approach works, but with numbers so small, there’s room for debate.

“We end up extrapolating our treatment of men from postmenopausal women, but we don’t have great data,” Ruddy said. “We really need more research in this area.”

For instance, the vast majority of men’s breast cancers are estrogen-positive, meaning that estrogen fuels their growth. In postmenopausal women, by contrast, nearly 20 percent have estrogen-negative cancers. Men are also more likely to respond poorly to tamoxifen, the drug used to prevent recurrence of estrogen-positive cancers.

Aromatase inhibitors, another hormone therapy used in post-menopausal women, are not recommended for men, though Ruddy said they can be used if testicular function is also suppressed.

Learn More: Hormone Therapies for Breast Cancer »

Many in the women’s breast cancer community say — amid a sea of pink for breast cancer awareness month — that awareness isn’t the key; research is. But men need both.

Related: We’re Aware — Now What? A Patient’s Perspective on the Need for Research »

“There’s no good basic research on the male disease, no cell lines, no animal models. My treatment was good, but if there are any differences in my disease and that of my wife, we don’t know about them,” Bogler said.

Men are excluded from two-thirds of the studies on breast cancer, and there hasn’t been a single clinical trial on breast cancer devoted entirely to men to date, according to Ruddy.

In some cases, all agree, the exclusion makes sense. But in others, the scientific rationale is missing.

“It seems almost like a kneejerk,” Ruddy said.

Clinical research doesn’t just stand to benefit future patients. It can offer more options to male patients who have caught their cancers later and may face more a dire prognosis.

“For men, those experimental options will be fewer if they don’t have clinical trials they can go to,” Ruddy said.

Keep Reading: Why Patients Can’t Access the Clinical Trials That Might Save Their Lives »

Risk factors for men are fairly well understood, though they don’t account for every case.

Higher estrogen levels raise the risk of breast cancer in men. As in female patients, obesity also drives up risk. Genetic mutations of the BRCA1 and BRCA2 genes are in play in men’s breast cancer, as they are in women’s. But the genes have different effects in men.

In women, the BRCA1 mutation signals greater risk, but in men, BRCA2 does. Yet, among men the two mutations account for a smaller percentage of cancer patients.

The weaker correlation means that genetic screenings are not a good way for men to whittle down their risk. However, the families of men who have had breast cancer would benefit from talking about screening with a genetic counselor, said Euhus.

Don’t expect widespread mammogram screenings either, even if men’s breast cancer continues to affect more people. The best prevention for a disease so rare is awareness, patients and doctors said. Men should know that a suspicious lump in their breast tissue should trigger a quick trip to the doctor.

Miller also thinks men should self-examine. He sells a number of tee shirts to raise awareness of men’s breast cancer. One features two hands on the front with the slogan, “Guys, don’t be afraid to touch yourself.”

Photo courtesy of Bret Miller.