For men over 70, PSA screening usually isn’t recommended based on USPSTF guidelines. It’s not a hard rule, but more of a general recommendation based on the risks and benefits. If anyone wants to know why, I’m happy to explain.
It’s very likely that President Biden didn’t get a PSA test—which is completely normal for someone his age. He probably started having symptoms from the cancer spreading to his bones, which led doctors to investigate and eventually discover the metastatic prostate cancer.
It doesn’t really make sense to think he knew he had prostate cancer and chose not to treat it, letting it spread. If he had ever had an elevated PSA, it would’ve been worked up and likely treated long before it got to this point.