Tough topics. Ben Stiller revealed Tuesday, October 4, that he was diagnosed with prostate cancer two years ago at the age of 48.

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The Emmy winner, now 50, opened up about his battle with the disease for the first time during an interview on SiriusXM's The Howard Stern Show, explaining that he and his doctor were able to detect and treat the cancer.

Ben StillerBen Stiller
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"It came out of the blue for me. I had no idea," Stiller explained to host Howard Stern. "At first, I didn't know what was gonna happen. I was scared. It just stopped everything in your life because you can't plan for a movie because you don't know what's gonna happen."

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The Zoolander actor then explained why he decided to finally announce the news, saying, "I wanted to talk about it because of the [PSA] test … I feel like the test saved my life."

Ben Stiller Christine TaylorBen Stiller and his wife Christine Taylor.
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A prostate-specific antigen test, or PSA test, is a blood test typically used to screen males for prostate cancer. The test examines and measure the amount of PSA in a patient's blood; PSA is an antigen produced by cancerous and noncancerous tissue in the prostate.

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"It's the second most deadly cancer, but it's about one of the most curable," Stiller explained to Stern, 62, Tuesday morning.

When the Night at the Museum star was first diagnosed, he immediately called his close friends as well as fellow actor Robert De Niro, who beat prostate cancer several years ago. "The first thing I did when I got diagnosed was get on the internet to try to learn. I saw De Niro had had it. I called him right away," he explained.

Stiller, who is married to actress Christine Taylor, also broke the news to his two children, daughter Ella, 14, and son Quinlin, 11. "I told them I had something I had to deal with," he said. "They were pretty cool with it."

Through it all, the Meet the Fockers actor has remained grateful. "Afterwards, it just gives you an appreciation for life," he told Stern. "Every six months I'm taking my PSA test to make sure I'm clear."

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