For years Sam Rivera never told anyone of his bout with breast cancer. It was a “feminine” disease, he figured, one branded with a pink ribbon. But after meeting his wife, also a breast cancer patient, Rivera has made it his mission to get the word out: Dude, it can happen to you, too.

“Before, if somebody asked about my scar, I’d tell them it was a fight and leave it at that,” recalls Rivera, who will join thousands of others on Saturday morning to walk in the 17th annual Miami/Fort Lauderdale Susan G. Komen Race for the Cure. “It was like my dark secret.”

Male breast cancer is about 100 times less common among men than among women. Fewer than 1 percent of all breast carcinomas occur in men, and the mean age of diagnosis is between 60 and 70 years old. The American Cancer Society estimates that 2,190 men will be diagnosed with breast cancer in the United States this year and the disease will kill 410. In comparison, 226,870 new cases of invasive breast cancer and 63,300 new cases of in situ breast cancer will be diagnosed in women this year. The disease will kill 39,510 women.

The prognosis for men, as with women, is good if the cancer is caught early, and recent studies have found that men and women with the same stage of breast cancer have the same outlook for survival. But here’s the catch: Because men — and their doctors— don’t always consider breast cancer as a possible diagnosis, some men don’t get treatment until the latter stages of the disease.

“They present with a later stage because they simply are not aware,’ says Dr. Carmen Calfa, an oncologist at Memorial Breast Cancer Center and the Riveras’ doctor. “They let it go longer. They don’t think it can happen to men.”

Dr. Charles Vogel, a breast cancer specialist at the University of Miami’s Sylvester Comprehensive Cancer Center at Deerfield Beach, concurs. Most of the men who are referred to him “come with a lump you can already feel and it’s more likely that their lymph nodes are involved and more likely to be at a more advanced stage of disease. In contrast a significant number of the women are picked up very early.”

Vogel attributes this early detection in women to a concerted effort to get them to do breast-self-exams and submit to mammograms. He calls male breast cancer “an orphan disease.” Its rarity makes it difficult for researchers to conduct clinical trials and even the best intentioned campaigns tend to focus on women. “Every group should be putting a statement out about men, too,” he adds.

Vogel recommends that every man with breast cancer be tested for genetic mutations that can lead to cancer. And men who have relatives with breast cancer — as does Rivera — should be on alert. Mutations in some genes, especially the BRCA2, puts men at greater risk of developing breast and prostate cancer. An aggressive form of skin cancer called melanoma is also more common among people who have BRCA2 mutations.

Recently researchers reported in the journal Nature Genetics that they had identified another mutation, a gene known as RAD51B, connected to male breast cancer.

Calfa of Memorial says the incidence of men with breast cancer is going up in some populations, attributing this to changes in risk factors and diet. A strange spike in breast cancer among men in the military, particularly men who lived and worked at Camp Lejeune, N.C., has prompted researchers from the Centers for Disease Control and Prevention to look at contaminated drinking water at the Marine Corps base as an explanation. Dozens of male Marines, sailors and their families have developed breast cancer at Camp Lejeune.