Narrator: : : If you have skin cancer, your doctor might not find it. This is Science Today. Managed care is forcing primary care doctors to diagnose illnesses before sending their patients on to specialists. Behavioral scientist Barbara Gerbert of the University of California, San Francisco did a study to see if primary care doctors correctly diagnosed skin cancer.

Gerbert: In the study we did, we found that primary care physicians were not ready yet to assume this role as gatekeepers for skin cancer. The primary care physicians missed skin cancers up to 50 percent of the time. So you'd sort of have a 50-50 chance if the primary care physician was the one to look at your lesion.

Narrator: : Since skin cancer is the most common cancer, that's a scary thought. Fortunately, Gerbert found that three to four hours of training can bring doctors up to par with dermatologists in identifying it -- which is where they should be.

Gerbert: Because although about 80 percent of people each year visit a primary care physician, not everyone goes to a dermatologist.

Narrator: : For Science Today, I'm Steve Tokar.