Tommy Chong is battling cancer once again. The Cheech & Chong star, 77, revealed in an interview with Us Weekly on Tuesday, June 16, that he is undergoing treatment for rectal cancer.

"I've had some medical issues lately," Chong told Us at the 826LA 10th anniversary party in Santa Monica, Calif. "I got diagnosed with rectal cancer."

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The That '70s Show alum was previously diagnosed with prostate cancer in 2012. A vocal advocate for the decriminalization of marijuana, Chong turned to the drug for relief in his first round of cancer and told Us he is doing the same now.

"I'm using cannabis like crazy now, more so than ever before," the famed comic said. "I'm in treatment now. I've been — just the case either way, either I get healed or I don't. But either way, I’m going to make sure I get a little edge off or put up."

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In addition to his herbal aid, Chong told Us that he has found solace and comfort in Joel S. Goldsmith's 1998 book, Spiritual Power of Truth. "It's what’s kept my head up," he said of the spiritual writing. "So that's my book."

The veteran actor extolled the virtues of marijuana when fighting cancer in 2012, telling CNN that the drug in various forms was helping to cure his disease.

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"I've got prostate cancer, and I'm treating it with hemp oil, with cannabis," he explained to Don Lemon. "So [legalizing marijuana] means a lot more to me than just being able to smoke a joint without being arrested... I'm taking it as a medicine."