Less than two years after his Hodgkin's lymphoma went into remission, "Survivor" winner and activist Ethan Zohn has announced that he is once again undergoing treatment for cancer, this time in his lung.


Zohn told People magazine that his doctors told him about his relapse on Sept. 14. He is undergoing chemotherapy.


The cancer is "localized in my lung area," the 37-year-old soccer player and television star told the magazine. "But it's good that it's not all over my body."


Zohn's girlfriend, Jenna Morasca, also a "Survivor" winner, was with him when he got his diagnosis. "She's taking it like the rock star that she is," said Zohn. Morasca later told People that they are going to beat the cancer, but it's an even tougher emotional burden than his original diagnosis. "This time was a lot more devastating for me because we'd already been through so much. We really had moved on with our life and we had a lot of stuff we wanted to do that didn't involve cancer — I didn't think we'd have to do this again."


Despite the relapse, Zohn isn't slowing down. He'll be running in the ING New York City Marathon on Sunday (Nov. 6), which he will use as an occasion to raise money for Grassroot Soccer, the charitable organization he co-founded in 2002 to "educate, inspire, and mobilize communities to stop the spread of HIV." Zohn says his doctors have given him the all-clear to run the marathon. "I think he's running it for everyone who has suffered from cancer," said Morasca. "He's not going to let it stop him."


Zohn started chemotherapy on Oct. 18, using a new drug called SGN-35 that targets cancerous cells. His chemotherapy will last 12 weeks, after which he may undergo a stem-cell transplant, possibly involving a donation from one of his brothers. Zohn received a stem cell transplant in 2009.


Zohn and Morasca appeared in this fall's season of "The Amazing Race," but they were eliminated in the episode that aired Oct. 2.

'Survivor' winner and activist Ethan Zohn announces his cancer has returned
Despite the new cancer diagnosis, Zohn will run in the New York City Marathon on Nov. 6