Running (and finishing) a 5K race wasn’t always on Trish May’s to-do list. Neither was founding and running a company whose purpose is to provide funds for women’s cancer research.

But on a crisp June day in 1994, May, now 53, completed her first race. She joined hundreds of breast cancer survivors along Seattle’s Lake Washington on the annual Shore Run to benefit research. Nearing the finish line, surrounded by cheering supporters, she was exhausted and in tears. “I remember thinking to myself, if I can finish this race, I can beat cancer,” she says.

She also needed time for her battle with breast cancer, diagnosed in 1993, and to deal with her mother’s death from ovarian cancer that same year. May underwent six months of chemotherapy, six weeks of radiation, and five years on the anti-estrogen drug tamoxifen—as well as surgeries for additional lumps.

Initially, her diagnosis prompted her to get involved with cancer fundraising. But she staked out the larger goal of using her business skills to raise money to find a cure.

May had landed at Microsoft in 1985 at the age of 31 with an M.B.A. and four years of marketing experience with Golden Grain Macaroni Co. She rose through a series of marketing positions and was a prime mover behind the product that became Microsoft’s PowerPoint. By 1999, savings from her six-figure salary and the stock options packaged with it easily enabled her to retire comfortably.

No pay. May could have opted for a lifestyle of private jets, worldwide travel, and charity boards, but instead she chose to work. Her husband, Peter, a University of Washington political science professor, did too. May did, however, exchange 70-hour workweeks for a mere 40 to 50 hours a week—and no salary.

“I knew I could write a check for a million dollars, but it wouldn’t necessarily go very far. I needed to invest some money and let it grow and generate an annuity that over time would continue to contribute,” she says. And that’s where her marketing prowess took over.

In the summer of 2002, May sat on the floor of her home in the Seattle suburb of Sammamish sipping water from a bottle, with three large grocery bags of mostly natural or organic goods spilled about her. She was combing through yogurts, energy bars, and more for a product around which to build a company that would generate cash for research on breast and gynecological cancer.

As she sipped, it hit her—water. It is healthy, ubiquitous, and inexpensive. By choosing a commodity, she could create a brand where the cause would be the star. The brand name would be Athena, the Greek goddess of wisdom and war.

May sank over $500,000 in personal funds into her start-up and introduced Athena bottled water to consumers in July 2003. The water is purified tap water with added minerals, similar to Coca-Cola’s Dasani. Using Paul Newman’s food company, Newman’s Own, as a model of outsourcing production, distribution, and transportation, May has concentrated on marketing and building partnerships.

Athena is now the official bottled water on Alaska Airlines flights and is currently available at 5,000 outlets in seven western states. Last year, Houston-based Sysco, the giant food-distribution company that stocks corporate cafeterias, delis, and coffee shops across the country, agreed to make the bottled water available nationwide. The result: This year Athena is expected to sell 14 million bottles and deliver revenues of $2.5 million, up 25 percent from 2006.

Even for a nonprofit with just two salaried employees, bottom-line proceeds in the extremely competitive bottled water category are slim, but they addup. To date, Athena has contributed $130,000 to organizations including Fred Hutchinson Cancer Research Center, the Marsha Rivkin Center for Ovarian Cancer Research, and the University of Washington’s UW Medicine.

“At Microsoft, you had to be the champion of your own product and find creative ways to extend your reach,” recalls May. “We were in a hurry.”

Sounds familiar.