"Kelley had a lumpectomy this year at the age of 31," the Party of Five star tells PEOPLE. "Thankfully the tumor was benign, but we were reminded of the importance to stay aware and informed about breast health."
Last year Wolf's mother, Susan Levy, was diagnosed and successfully treated for breast cancer. Both of Kelley's grandmothers were diagnosed with breast cancer, too.
"Because of this, Kelley has been an advocate for early detection and self exams," Wolf says.
The couple will join singer Olivia Newton-John for a week in China. Other celebrities participating in the walk include Leeza Gibbons, and Survivor stars Ethan Zohn and Jenna Morasca.
For more information on the walk, or to make a donation, go to www.greatwalktobeijing.com.