Like a lot of tough guys, commercial airline pilot Cpt. Edward J. Wilson has a tattoo on the left side of his chest that he's only too happy to show off.

But his tattoo isn't a skull and crossbones or a heart with his wife's name scrolled across it. Wilson's "tattoo" is a thin red scar and a life-like nipple designed to replace the one he lost when he had a mastectomy ( search) in June of 2000.

At age 47, a time when most men are just starting to fret about heart disease or prostate cancer ( search ), Wilson, a pilot with Alaska Airlines, found himself thrust into the female-centric world of pink ribbon awareness campaigns and flowery hospital wards when he underwent treatment for male breast cancer ( search) — a disease almost identical to the much more common breast cancer in women.

"This disease doesn't really care what sex you are," Wilson said.

The American Cancer Society ( search) estimates that in 2005, some 1,690 new cases of invasive breast cancer will be diagnosed in men in the United States and about 460 men will die from the disease. Breast cancer is about 100 times more common in women, but the numbers among men are on the rise. Because male breast cancer is so rare, delayed diagnosis often results in the disease proving more deadly for men.

"While still curable, more men will likely die of the disease," said Dr. Sharon H. Giordano, assistant professor in the Department of Medical Oncology at The University of Texas M.D. Anderson Cancer Center, who conducts some of the very few studies looking at male breast cancer.

"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," Giordano said. "If they pick up the disease early, men are more likely to be cured."

Like many women diagnosed with breast cancer, Wilson discovered a hard lump under his left nipple, asked his wife to check it out, then decided to have it looked at by his doctor. His doctor said the lump was probably gynecomastia ( search), a harmless over-development of breast tissue usually caused by an excess of the female hormone estrogen, or a lack of the male hormone testosterone. Still, the doctor performed a biopsy just to be sure.

That was on a Wednesday. By Monday, Wilson was told he had breast cancer and would have to undergo a mastectomy, chemotherapy ( search), and possibly even radiation — the same course of treatment used in women with breast cancer. Like many women, Wilson's first reaction was denial.

"What if I don't do anything?" he asked his doctor.

"It will kill you," the doctor said.

Five years later, Wilson remains cancer free with the help of Arimidex ( search), an estrogen-blocking drug, which had only been proven effective in postmenopausal women when he first opted to take it.

Not all men are so lucky.

Nancy Nick of Vero Beach, Fla., lost her father John to breast cancer in 1991 at a time when so little was known about the disease in men that sufferers were often misdiagnosed until the cancer had progressed well beyond effective treatment.

Six years before his death, John Nick had expressed concern about his inverted right nipple, but his doctor dismissed it. It wasn't until four years after John Nick's symptoms first presented that a doctor realized it was cancer. By that time, 20 of his lymph nodes ( search) tested positive for malignancy. Despite six months of chemotherapy, the cancer spread to his bones, eventually killing him.

"My father didn't have to die at 58," says Nancy Nick, who has since started the John W. Nick Foundation in her father's honor.

The foundation, based in Vero Beach, Fla., is set to celebrate its 10th anniversary this November as the nation's only charitable foundation focused on raising awareness of male breast cancer.

"He had [cancer] for eight years and all his doctors said don't worry about it," Nick said.

According to Nick, both the emphasis on breast cancer as a female disease and men's unwillingness to talk about health issues have conspired to shroud male breast cancer in secrecy.

"Men are the worst communicators when it comes to male breast cancer," Nick said. "I had to be [my father's] advocate; I had to fight for his rights."

Nancy Nick wants to see the pink ribbons used to promote breast cancer awareness imbued with a shock of blue to indicate that the disease can also afflict men. Her foundation has even adopted that hypothetical hybrid ribbon as its logo.

But given the small number of men affected by the disease as compared to women, very few resources are dedicated to male-centric research. Fortunately from a research perspective, breast cancer in both sexes seems to be almost identical.

The main risk factors in men and women include aging, heavy alcohol intake, radiation exposure, physical inactivity and obesity, but what does and does not cause breast cancer remains a controversial debate within both the medical and advocacy communities. Medical research has yet to prove any definitive links between a given risk factor and breast cancer, as promising studies and theories are often disproved or cast into doubt by follow up research.

Interestingly, a family history of breast cancer and inherited mutations of genes BRCA1 ( search) and BRCA2 ( search) can also account for the disease in both men and women. But even heredity and the presence of breast cancer genes have recently been shown to be less the risk factors they were once believed to be.

"For most men, [breast cancer] is not a hereditary thing, but it's more likely to be hereditary in men than in women," said Debbie Saslow, director of breast and gynecological cancer at the American Cancer Society.

Saslow said just 10 percent of women with breast cancer actually have a so-called breast cancer gene.

Also, almost all male patients have estrogen receptors, increasing the chances of a recurrence of breast cancer, while only 70 percent of women are estrogen-receptor positive. Still, the effects of the drugs used to block estrogen — which tend to feed breast cancer — have yet to be studied in depth. Early research shows that the drugs can even increase a man's chance of developing prostate cancer, according to Dr. Giordano.

As an unexpected crossover disease, Giordano says an increased emphasis on research of breast cancer in men could even help treatment in women.

"Understanding more about breast cancer in men could help women's knowledge," Giordano said.

October is breast cancer awareness month. Since October 2004, FOXNews.com has published more than 100 stories related to breast cancer. To read a selection of those stories, click on the "Stories" box in the upper right corner of this story.