Ben Stiller has revealed during an interview on the Howard Stern Show that he was diagnosed with prostate cancer two years ago when he was 48.

The actor on Tuesday opened up about how he was able to detect and treat the cancer.

“It came out of the blue for me,” Stiller said. “I had no idea.”

Stiller took part in the interview to help spread awareness, and talk about the Prostate-Specific Antigen (PSA) — a blood test used to measure protein levels, which can help identify prostate cancer.

“So, I had cancer a couple of years ago and I wanted to talk about it,” Stiller tweeted on Tuesday morning. “And the test that saved my life.”

His tweet linked to an article he published on Medium titled, “The Prostate Cancer Test That Saved My Life.”

“I got diagnosed with prostate cancer Friday, June 13th, 2014. On September 17th of that year I got a test back telling me I was cancer free,” Stiller wrote in the article. “The three months in between were a crazy roller coaster ride with which about 180,000 men a year in America can identify.”

In the article he explains the controversy surrounding the PSA test — it runs the risk of leading to over-treatment like radiation or surgery — but the actor ultimately resolves that, from personal experience, he can endorse the test.

“I think men over the age of 40 should have the opportunity to discuss the test with their doctor and learn about it, so they can have the chance to be screened,” he wrote. “After that an informed patient can make responsible choices as to how to proceed.”