SAN FRANCISCO -- For Wanda Zimmerman, donating her time and energy to causes that fight cancer isn't just a matter of doing good deeds. It's a way to say thanks for the technology that saved her and could spare others from the disease's ravages.

Zimmerman, selected as the Giants' honorary bat girl as part of the Major League-wide effort to raise breast cancer awareness, survived the disease twice. She's currently in remission. But she's not in denial.

"You still hold your breath," said Zimmerman, 53. "You can't completely say it's done. You just don't know. Cancer has its own venue."

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She should know. A lifelong Giants fan who shares her birthday (May 6) with Willie Mays, Zimmerman was initially diagnosed with cancer on Oct. 21, 2003. She passed the five-year remission mark and allowed herself to relax.

"I could breathe easy and I was starting to get on with life," said Zimmerman, a Brentwood resident. "I had no idea."

She had no way of knowing that her cancer would return. On Oct. 21, 2010 -- exactly seven years to the day since her first diagnosis -- she learned that she was stricken again.

As Zimmerman related, the cancer appeared in new tissue, but in the same spot as before and it was the same type of cancer. But her doctors couldn't explain how or why it returned.

"It was found only because of the new digital mammography," Zimmerman said. "They told me that had it been with the old mammography, they wouldn't have found it as early as they did."

Through it all, Zimmerman has continued to give her time extensively to the American Cancer Society and Relay For Life.

"It helps me to feel like I'm fighting back, because I understand how important research is," she said.

The Honorary Bat Girl Contest recognizes baseball fans who have been affected by breast cancer and demonstrate a commitment to eradicating the disease.