CHICAGO – The 5-inch vertical scar marking Steve DeLuca’s belly didn’t stop him from posing topless for a new pinup calendar – it’s what got him the job.

The 37-year-old firefighter from suburban Mt. Prospect is on display with 17 other buff amateur models in the 2006 “Colondar,” designed to illustrate that colon cancer isn’t just a disease that hits old people.

Cancer affecting the colon and/or rectum is diagnosed in more than 140,000 Americans each year. About one in nine cases affect people younger than 50, or up to about 15,000 young people annually.

This is among the facts accompanying the photos in the calendar, the latest project created by a support and education group called the Colon Club. The calendar features scantily clad men and women and their scars, along with stories of their diagnosis.

“I’m not embarrassed at all. I had no problems showing the scar,” said DeLuca, featured in May’s photo wearing firefighter gear sans a shirt and next to bikini-clad Marci Westlake, a 36-year-old Sparks, Nev. mother of two who was diagnosed at age 31.

“We’re showing that there is life after this and if it happened to us, it can happen to anybody,” said DeLuca, who was diagnosed at age 33.

Colon Club co-founder Molly McMaster of upstate New York learned she had colon cancer on her 23rd birthday and created the group with a friend whose cousin died of the disease at age 27.

“We want doctors to see that it can happen to people under 50 because you see so many young people getting misdiagnosed,” McMaster said.

DeLuca was diagnosed after a routine physical exam. He had some rectal bleeding symptoms “but everybody blew them off because I had no history of cancer in my family and I was only 33,” he said.

His doctor referred him for a colonoscopy, a cancer screening exam that usually isn’t recommended until age 50 unless there are symptoms or a family history of disease.

Even then, the doctor assured him he likely just had hemorrhoids.

“I was shocked [by the diagnosis],” DeLuca said, “because everybody was blowing it off like it wasn’t going to be a big deal.”

McMaster had classic symptoms – including blood-tainted stools, weight loss, and stomach pains. She said doctors told her she had constipation and irritable bowel syndrome and told her not to worry. After six months, she consulted a different set of doctors who found a cancerous tumor the size of two fists.

Surgery removed the mass, along with two feet of her large intestine. McMaster also had chemotherapy and six years later is still cancer-free.

McMaster posed for the Colon Club’s first Colondar in 2005 in a red bikini, with the scar on her stomach just barely visible.

“It’s kind of like a badge of honor [that shows] we’ve made it through this,” McMaster said.

Most people who are diagnosed at an early age have a genetic form of the disease, said Dr. Durado Brooks, director of colorectal cancer at the American Cancer Society.

The calendar points out that up to about 10 percent of colon cancer cases are caused by genetic mutations.

McMaster’s mother had been treated for polyps in her 30s. McMaster says she should have been screened well before her diagnosis because of her mother’s medical history but didn’t know until after her cancer was found.

The Colondar was inspired by British women who posed nude for a leukemia fundraising calendar and whose story was told in the 2003 movie “Calendar Girls.”

The group’s educational efforts include another in-your-face project, the “Colossal Colon,” a 20-feet long, 4-feet high polyurethane replica of a colon that features polyps, cancer and even hemorrhoids. Group leaders have taken it to sporting events, malls, hospitals and state fairs nationwide to highlight the disease.

“We like to make people laugh and get them talking about colon cancer,” McMaster said. “The next step is to get them screened.”