Last month, Consumer Reports published the results of an extensive investigation of 11 different cancer screenings—and found that a whopping eight are unnecessary (and potentially dangerous) for most people. But why is that the case, and how does it apply to you?

We spoke to Otis Brawley, MD, chief medical officer for the American Cancer Society, who helped explain the phenomenon. “Many hospitals offer free screenings as part of their business plan,” says Dr. Brawley. “They know what the benefit is to the hospital, but we have not known whether it saves lives."

Right, but what’s the big deal, if it’s free? Healthy patients like you often face needless pressure to undergo these health tests that could return false positives, and those false positives might result in unneeded, risky, and costly treatments or diagnostic procedures, like biopsies.

So with that in mind, we got Dr. Brawley to give us the run-down on the tests that fit guys in their twenties and thirties might be encouraged to get—but probably don’t need:

1. Testicular Cancer Screening. About half of testicular cancers occur in men ages 20-34, but the screening—a physical examination of the testicles—is unnecessary unless men have high-risk factors, such as family history, undescended testicle, or HIV. In fact, most testicular cancers are found without screening, and most of these cancers are curable. “Be aware of your body,” says Dr. Brawley. If you notice a problem in the scrotum, get it checked out, but you don’t need to check your scrotum on a weekly or monthly basis.”

2. Oral Cancer Screening. Oral cancer is more than twice as common in men, and a recent spike in cancers linked to HPV (yes, that’s right: there are some risks to oral sex) could cause an increase in oral cancers in men under age 35. The screening, a visual exam of the mouth, is usually performed by a dentist and sometimes includes special dyes or lights—but it’s probably unnecessary, says Dr. Braley, unless men have certain high-risk factors, such as excessive alcohol consumption, smoking, or chewing tobacco.

3. Skin Cancer Screening. Melanoma is among the most common cancers in people under age 30, and the American Cancer Society expects about 45,000 new diagnose among men in 2013. But the effectiveness of skin cancer screenings is unproven, and false-positive tests can lead to biopsies that may result in scarring or infection. Dr. Brawley says that the data suggests most men ages 20-35 don’t need the test unless they’re at high risk. “If a man notices he has a mole that’s changing or comes from a family that has a history of dysplastic nevi (atypical moles), he should get checked out."

Overall, your best advice is this: Have a candid talk with your doc that weighs your personal risk factors against the potential dangers of any screening test. “Men should be told the known, proven harms and benefits of a test,” says Dr. Brawley, “so that they can make informed decisions for themselves about when they’re ready to be screened.”