LOS ANGELES — It's a classic chicken/egg conundrum. Men with a family history of prostate cancer are thought to be more likely to develop the disease themselves, so it is recommended they get screened for the disease more often.

But frequent screenings make it more likely a prostate tumor will be found — including tumors that are not dangerous. So are those men with a father or brother with the disease more likely to have a tumor diagnosis because of genetics — or because they are more likely to be screened? A new study from Sweden released Thursday suggested the answer was a little bit of both.

The lifetime risk of a man dying from prostate cancer is about 3 percent, a proportion that has remained constant for at least three decades. But during that same period, the lifetime risk of being diagnosed with prostate cancer has risen from about 9 percent to 16 percent, largely as a result of increased screening. That screening has become increasingly controversial.

Studies have shown that screening, mostly using the prostate-specific antigen (PSA) test, has increased the number of cancer diagnoses, the number of biopsies and other surgical procedures and the number of complications from those procedures while failing to lower the mortality rate. The fact is, most elderly men have prostate tumors that are harmless. And most prostate tumors themselves are harmless and can be safely ignored.

But researchers currently have no ready way to distinguish between those that are safe and those that are aggressive and will become life-threatening, so when a tumor is observed, it is most often treated — with all the expense and complications that entails.