‘Seinfeld’ star Michael Richards, 74, revealed a shocking health crisis in his new memoir “Entrances and Exits,” set to hit shelves on June 4.

During a routine checkup in the summer of 2018, Richards was blindsided with a stage 1 prostate cancer diagnosis after tests revealed elevated PSA levels. “I thought. well, this is my time. I’m ready to go,” Richards told PEOPLE. “But then my son came to mind just a few seconds later and I heard myself saying, ‘I’ve got a 9-year-old and I’d like to be around for him. Is there any way I can get a little more life going?’”

After a concerning biopsy result, Richards’ doctor urged him to have his entire prostate removed. “It had to be contained quickly. I had to go for the full surgery. If I hadn’t, I probably would have been dead in about eight months.”

“I had over 40 journals I’d kept over the years and wanted to do a full review of my life,” Richards said. “I’m turning 75, so maybe wanting to do that is something that comes with being my age. I wanted to connect with feelings and memory. I’m surprised at how much I was able to remember.”