VALERIE HARPER, who’s waging a valiant fight against cancer, is facing an­other battle with a fierce adversary – “Dancing with the Stars” judge Len Goodman.

The beloved 74-year-old star is competing on the new season of “DWTS,” beginning Sept. 16, after doctors informed her she’s holding her own against the deadly cancer that’s spread to her brain membranes.

But no-nonsense judge Goodman, who regularly lambasts contestants and fellow judges, thinks the show is taking a big risk.

“Len is as touched by Valerie’s story as much as anyone – he is a cancer survivor himself,” a source told The ENQUIRER. “But he sees Valerie’s casting as a stunt that could backfire on him and the show, no matter how it plays out. If Len doesn’t like what he sees on the dance floor and calls out Valerie on it, he’s going to get even more hate mail than he already does. Picking on her would be like booing Mother Teresa.

“And if Valerie has a long run on the show, people are going to think she’s getting a sympathy vote.”

“Dancing with the Stars” has suffered a ratings slide, and it will go from two days a week to one, combining performance and results in one two-hour program.

Producers hope Harper will give the show a boost when she competes against actresses Leah Remini and Elizabeth Berkley and “Jersey Shore” reality star Snooki.

Incredibly, the popular comic actress was given only three to six months to live when she was diag­nosed in January with the vicious cancer that attacks the brain.

But after being confirmed as a “DWTS” competitor on Sept. 4, she revealed: “I feel much better. And my brain scans are looking better too. The doctors tell me there’s less evidence of cancer, which is very unusual. However, they both say it’s not a case of if, but when. And I can live with that.”

Now the heroic star is training hard with her pro partner Tristan MacManus and getting encour­agement and tips from Mary Tyler Moore.

“Valerie doesn’t want sympathy from Len Goodman or anyone else,” assured a friend. “She’s working her tail off and won’t embarrass herself.”