Get ready for the Ben Stiller effect.

The 50-year-old actor revealed on Tuesday that, thanks to PSA blood testing, he was diagnosed with prostate cancer two years ago and had robotic surgery to remove the organ.

In a blog post titled "The Prostate Cancer Test That Saved My Life," he waded deep into the heated debate over the value of PSA screening, urging men "over the age of 40" to talk to their doctors about having the test.

Actress Angelina Jolie's revelation of her breast cancer gene mutation and double mastectomy led to a spike in BRCA testing and preventive mastectomies, which doctors call the Angelina Jolie effect. Will Stiller's testimonial lead to a surge in screening, which has been declining?

"Undoubtedly it will," said Otis Brawley, the American Cancer Society's chief medical officer and a longtime critic of automatic PSA screening. "And I predict more men will be harmed than helped by screening."

"If a man wants to be screened, he should be screened," added Brawley, who has chosen to eschew the practice even though he is in a higher risk group as an African-American. "But he shouldn't make the decision based on what a celebrity feels comfortable doing."

In addition to his blog post, Stiller talked publicly for the first time about his prostate cancer during an interview on Tuesday's Howard Stern Show.

Stiller said he was "lucky enough" to have a "thoughtful internist" who discussed having a prostate-specific antigen (PSA) test at age 46, even though Stiller has no family history of the disease and isn't in a high-risk group. Stiller had a baseline test in 2012 and repeated it in 2014. That led to his diagnosis in June of that year and treatment soon afterward. By September, tests showed he was cancer free.

"If he [the internist] had waited, as the American Cancer Society recommends, until I was 50, I would not have known I had a growing tumor until two years after I was treated," he wrote. "If he had followed the U.S. Preventive Services Task Force guidelines, I would never have gotten tested at all, and not have known I had cancer until it was way too late to treat successfully."

Actually, maybe the cancer would have progressed to an incurable stage — and maybe not.

"There is no way to know," said urologist Serge Ginzburg, the director of Einstein Medical Center's prostate cancer center.

Stiller didn't say what his PSA level was. And he didn't say whether he has suffered from the most dreaded effects of treatment, incontinence and impotence.

But with a Gleason score of 7, indicating a moderately aggressive cancer, the actor's decision to get immediate, curative treatment was wise, Ginzburg said.

"Certainly, at such a young age, having a cancer [with some aggressive features] should be taken seriously," Ginzburg said.

The problem with screening -- as Brawley and the USPSTF have said -- is that many, if not most, prostate cancers grow so slowly that they would never cause harm if left undetected. Screening leads to treatment of many innocuous cancers, leaving many men with permanent urinary and sexual problems. Major studies have found that routine PSA testing has had little impact on death rates.

Stiller wrote that he was not "offering a scientific point of view here, just a personal one," but he also took the task force to task:

"Should we, as the USPSTF suggests, not screen at all? There is growing evidence that these guidelines have led to increased cases of prostate cancers that get detected too late for the patient to survive the disease."

The task force is currently reviewing the latest studies to update its prostate cancer screening guidelines. Kirsten Bibbins-Domingo, the task force chair and a professor of medicine, epidemiology and biostatistics at the University of California, San Francisco, emailed this response:

" When the Task Force last reviewed the evidence on prostate cancer screening in 2012, evidence showed that there is a small potential benefit to screening for prostate cancer and there are significant known harms. As such, the Task Force recommended against routine screening of all asymptomatic men at average risk for prostate cancer. However, the Task Force encourages any man who is concerned about his risk of prostate cancer to talk to his doctor about whether screening is appropriate. This recommendation does not preclude a man choosing to be screened."

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