A new study is questioning whether treating prostate cancer early makes a difference.

According to the study from Oxford University, men who were diagnosed early and chose to closely monitor their disease were just as likely to survive at least 10 years as those who got treated.

Researchers also found that those who were monitored saw their cancers get worse. Those who had treatment suffered from side effects.

"For something like this that is so complicated and where there are so many different opinions and strong elements of truth and science behind it, it's easier to discuss with the physician and ultimately decide what the best thing is to do," says Dr. Howard Adler, the medical director of the prostate care program at Stony Brook Medicine.

The American Cancer Society's chief medical officer says, "It's a challenging process to explain to people that certain cancers just don't need to be treated."

The study was published online in the New England Journal of Medicine.