"I'm not the stereotypical face of breast cancer," Elissa Thorner says. "I'm young, I'm energetic, and a lot of my friends still go to bars at night. The cancer scene wasn't the scene I thought I'd be getting into." With her bright blue-green eyes, glossy crop of reddish-blond hair, and marathon and yoga-toned body, Thorner looks like she has never had to spend a day in the hospital -- except for the day that she delivered her daughter, Samantha, now 8. But Thorner has been a regular at breast cancer support groups near Baltimore, where she was "the youngest one literally by 40 years," she says. This month, exactly one year after her radiation treatment for estrogen-receptor-positive breast cancer ended, she turned 25.

Though the median age for women diagnosed with breast cancer is 65, more than 240,000 women in the United States age 40 and under are living with breast cancer. Each year in this country, more than 14,000 women 40 years old and younger are diagnosed with breast cancer, says Boston oncologist Ann Partridge, MD, of the Dana-Farber Cancer Institute. Women who get breast cancer in their 20s and 30s face a whole set of medical, emotional, sexual, and career issues that older women with the disease usually don't have to tackle, she says.

Your career is just taking off in your 20s, or you're making your mark in your 30s, when all of a sudden you have to slam on the brakes and go through treatment -- often about as time-consuming as a full-time job and much more physically draining. Or maybe, like Thorner was at 23, you're adding a grueling lineup of radiation-therapy sessions to a schedule already filled with working, writing your master's dissertation, raising a 7-year-old on your own, volunteering at her school one day a week, heading up PTA meetings, training for a marathon, and dating.

"Young women are less likely to be insured than their older counterparts and are more likely to be single," says Alex Exley, director of information resources at the Young Survival Coalition (YSC), a nonprofit, New York City-based organization devoted to young women with breast cancer. If you're in your 20s and 30s and have breast cancer, you often don't have the solid, decades-old network of friends and family nearby that older women have built up over time, either. You're also more likely to be a new mom or hoping to be one soon. "It's such a difficult time for a young mother," oncologist Partridge says. "You're dealing with a new baby and all the emotions and uncertainty around that, then you add in a diagnosis of a potentially life-threatening disease and the treatments associated with that. You're dealing not only with, 'How will I get through this,' but, 'Will I be able to get through this and see my baby grow up?'"

Only 5 percent of women with breast cancer are under the age of 40 -- a statistic that translates to yet another challenge for young women, according to Exley. "Because breast cancer is rare in young women, it can be very isolating," she says. While women in their 50s and older usually know at least one other person their age with breast cancer, many young women know no one else in their shoes. "In support groups, they often hear older women worrying about seeing their grandchildren grow up, while they are wondering if they'll ever find a partner or be able to have children," Exley says. That was the case for Thorner, who wants to be able to have another child so much that she chose not to have chemotherapy or take tamoxifen. Though she was only 23 at the time, her doctors couldn't say with certainty whether or not those treatments would cause permanent menopause, making her infertile. "The problem of fertility was such a big issue for me, and when I brought it up (in her support group) no one wanted to talk about it," Thorner says.

The YSC was created for just that reason. Partridge advises young women with breast cancer to share their "unique and extraordinary needs" with partners, with members of their medical team, and in online communities, such as the one run by the YSC site at www.youngsurvival.org. Living Beyond Breast Cancer at www.lbbc.org is another online community Partridge frequently recommends to patients. "Communicate as much as possible," she urges. "Look for support, whether it's psychosocial, financial, emotional, nursing services, or from friends, and don't be afraid to take it."