Most prostate cancers don't need to be treated because the disease won't kill or even hurt most of the men who get it.

But there's one group of men who have more to worry about than the rest of us -- because for them, prostate cancer really can carry deadly risk.

And it's the same group of men that need to worry more about cancer overall: smokers.

A new study finds that men who smoke the most are not only more likely to get prostate cancer -- they're actually much more likely to have aggressive tumors and are far more likely to die of the disease than men who don't smoke.

Researchers tracked 5,366 prostate cancer patients for an average of 8 years and found that 10 percent of them died of the disease.

Like I said, it's not deadly -- most of the time.

But active smokers were 61 percent more likely to be among the 10 percent who died than those who had never smoked. They were also 61 percent more likely to suffer a recurrence of the disease than non-smokers.

The researchers also wrote in the Journal of the American Medical Association that the heaviest smokers are most likely to suffer: Men who puff a pack a day for 40 years or two packs a day for 20 years are 82 percent more likely to die of the disease than non-smokers.

The study doesn't show why smokers get more aggressive prostate cancers -- but let's take a wild guess here and say it's probably the mouthful of burning carcinogens.

If you're thinking this is a good time to quit, you're on the right track -- but don't put it off. The researchers say it took 10 tobacco-free years for the heaviest smokers to lose their extra death risk.

That's not the only reason to finally kick your butts.

In addition to the well-known risks such as lung cancer, emphysema and that odor that follows smokers everywhere, cigarettes have been linked to everything from penis shrinkage to lower intelligence.

Unlike that prostate risk, you don't have to wait a decade after quitting to see some results -- some of the benefits appear almost immediately.

Since a two-pack-a-day habit can cost more than $7,000 a year in some parts of the United States, the first benefit won't even be in your body -- it'll be in your wallet.