While the number of oral-cancer cases diagnosed annually—about 30,000 in this country—has remained steady, the victims have changed. There’s been a fivefold increase in oral cancer in people under age 40, particularly women.

And while smoking and drinking are still the biggest risk factors, one-quarter of all patients are not smokers.

A study by Johns Hopkins University found human papillomavirus in one-fourth of oral-cancer patients. The rise in HPV and oral sex has been linked to oral cancer in young women.

“One problem,” says Brian Hill, director of the Oral Cancer Foundation and an oral-cancer survivor, “is that dentists are still looking for the stereotypical smoker” when screening for cancer.

How do you know if your dentist does a thorough check for oral cancer? In an exam, Hill says, a dentist should pull out the tongue for a good look—most cancers occur at the base of the tongue—and run a finger along the edges to feel for lumps. He or she should feel the floor of the mouth and the sides of the neck.

When oral cancer is caught early, there’s an 80-percent survival rate. Because it is usually caught late, half of such patients die within five years.

According to the Oral Cancer Foundation (oralcancerfoundation.org), symptoms include

• a sore or lesion in the mouth that does not heal within two weeks.

• a lump or thickening in the cheek.

• a white or red patch on the gums, tongue, tonsil, or lining of the mouth.

• a sore throat or feeling that something is caught in the throat.

• difficulty chewing or swallowing.

• difficulty moving the jaw or tongue.

• numbness of the tongue or other area of the mouth.

These symptoms can be caused by other, less serious problems.

While suspicious spots may have to be biopsied, some dentists use tools such as the Oral CDx brush or the ViziLite to first rule out cancer and the need for a biopsy.

Some dentists may suggest keeping an eye on a lesion. Oral surgeon Steven Guttenberg warns against watching too long: “This cancer doubles every six weeks. If you wait, it could be too late.”