By Dana Sullivan

Add "curing cancer" to the long list of good deeds sisters do for each other: The Sister Study, a groundbreaking 10-year research project conducted by the National Institute of Environmental Health Sciences, is tracking 45,000 siblings, ages 35 to 74, affected by breast cancer. The goal: to find out how the environment and genetics determine who is getting sick. Meet some of the women who are bringing us closer to a cure.

"I thought I was too young to get breast cancer." 
Molly Champion Bobrow, Houston, with sisters Sandra Champion Torres, and Brenda Champion Pattillo

When Molly Champion Bobrow brushed her fingers across her breast and felt a small lump 11 years ago, at age 33, she wasn't especially worried. She had no family history of breast cancer, and she knew most sufferers (87 percent, to be exact) were over 40. So it stood to reason that Molly, one third of the Houston-based Champion Sisters pop and jazz singing group, couldn't imagine breast cancer happening to her.

At the urging of her older sisters, twins Brenda and Sandra, Molly saw her ob-gyn -- who immediately scheduled her for a lumpectomy. The diagnosis: stage I medullary breast cancer, meaning the cancer hadn't spread beyond the breast tissue. Despite catching it early, "I couldn't stop crying," says Molly. "My husband and I were about to start a family. I was devastated." She did manage to find solace in her sisters, though: Brenda and Sandra were by her side for every step of treatment. With just one year and three days separating the women in age, "we're more like triplets," says Molly. After chemotherapy and radiation, she was deemed cancer-free in 1998. But during a routine mammogram seven years later, doctors found a new lump -- this time it was stage I invasive ductal cell carcinoma. Because she did not want to risk going through a third bout of the disease, Molly made the tough decision to get a double mastectomy, followed by reconstructive surgery.

"This time, Molly's attitude was, 'I've done this before and I can do it again. This will not beat me,'" remembers Brenda. After recovering from the procedure, Molly sang with her sisters in every show they'd booked that year -- including one at a Susan G. Komen Race for the Cure. That's where the trio heard about the Sister Study, and they signed on immediately. Since Molly had already found out that she didn't have the mutations in the BRCA1 or BRCA2 genes that are linked to breast cancer, all of the sisters were baffled by the cause, says Sandra, who, like Brenda, is now diligent about getting regular mammograms (recommended annually for all women over 40).

Although she no longer has cancer, Molly can't have children due to the effects of chemotherapy. She does, however, feel like a second mother to her nieces and nephews. She speaks about her experience at events for the Young Survival Coalition, an organization that supports education and research for breast cancer in women under 40. "Molly has been a role model and inspiration to so many people. She has no idea how many women she's given hope to," says Brenda. "With the Sister Study, I want to do my part."

Originally published in FITNESS magazine, October 2008.