Ethan Zohn

Survivor winner Ethan Zohn's cancer is back after 20 months of remission.

The 37-year-old said he was told by doctors back on September 14 that his Hodgkin's lymphoma had returned in his chest only and not all over his body.

"I don't want fear or cancer to define me, but it's always in the back of your mind," he said, adding that he faces 12 weeks of chemotherapy treatment.

SGN-35, which targets the cancerous cells and will prevent him from losing his hair, may be supplemented by a stem-cell transplant from one of his brothers.

He tells People magazine regarding that:

"But the doctors won't tell me which ... they didn't want me to start treating one differently than the other. Of course my whole family is taking bets on it."

Zohn isn't letting the cancer get him down and he is planning to run the NYC Marathon on November 6 to raise money for his Grassroot Soccer organization.

We wish him nothing but the best.

Just last month, for the first time since being diagnosed with cancer (specifically a rare form of Hodgkin's disease), Ethan Zohn was finally feeling better.

Three months of chemotherapy had the Survivor winner back on track.

"I was off chemo," he says. "I was running up to seven miles" in preparation for November's New York City Marathon. "I was happy, I was going out."

"I went up to Boston to see the family and was feeling great."

But then the other shoe fell.

We're pulling for you, Ethan Zohn.

On August 26, his doctor called with post-chemo test results – and they're not good: "My cancer is back," Zohn said. "I have never been so scared in my life."

"It was a complete punch in the face," says the reality TV star.

When the news hit, Zohn decided to wait until doctors started him on a new course of treatment before sharing the news with family, friends and the world.

Follow the link to continue reading about Zohn's struggle.

During Survivor: Africa, Ethan Zohn outwitted, outplayed and outlasted the competition.

Now, the reality TV champion has an even bigger fight on his hands:

Last week, Zohn was disagnosed with a rare form cancer called CD20-positive Hodgkin's Lymphoma; he began chemotherapy on Friday.

"This is the ultimate game of Survivor," Ethan told People, "and there's really only one outcome, and that's to win. There's no other option."

The survival rate for those suffering from regular Hodgkin's disease is around 90 percent.

For years, Zohn has been dating Survivor: The Amazon winner Jenna Morasca. She vows to remain by his side throughout this ordeal.

"I will fight with every fabric of my being to get him through this," Morasca said.