Detection Difficulty with Ovarian Cancer

Ovarian cancer is a very difficult disease to detect. Only 20 percent of cases are found early, according to the American Cancer Society, when treatment is more successful.

Part of the problem, "Early Show" co-anchor Maggie Rodriguez said on the broadcast, is that it's hard to pin down the symptoms.

According to a new study from the Journal of the National Cancer Institute, symptoms may have "little value" for early detection of ovarian cancer.

Why is that the case?

CBS News medical correspondent Dr. Jennifer Ashton explained to Rodriguez that symptoms are very common and vague.

"We in the field of gynecology have been trying to educate, not only ourselves and our colleagues, but patients, to be on the lookout for these vague symptoms, because in the past, we thought they really might be good indicators," she said. "It turns out they're not, because things like bloating or stomach swelling, pelvic pain or pressure, change in your eating habits or a change in your urinary habits can be connected with early symptoms of ovarian cancer, but they're not definitive. They're not 100 percent reliable."

Rodriguez said those symptoms could indicate something entirely different.

Ashton agreed, saying they often do.

"(Women) need to pay attention to those symptoms, especially if they're new, and discuss them with their doctor," she said, adding, "But just because they have them doesn't mean they have ovarian cancer."

Ashton says there isn't a widely used screening test, such as a mammogram for breast cancer. Instead, she said, ovarian cancer is screened by a "constellation of things," such as family history, age, weight, and if you've never had children.

She said, "We combine symptoms with your risk factors and other tests like blood tests and ultrasound. We put all those things together to stratify risk."

To reduce your risk of ovarian cancer, Ashton said women can take birth control pills, get pregnant or have their Fallopian tubes tied.

"Those are all protective," she said. "And again, we need better and more accurate detection methods. In the future, that's the key."

The American Cancer Society reports that, last year, 21,550 women were diagnosed with this type of cancer, and 14,600 women die each year of the disease.

Depending on the stage and type of ovarian cancer, the five-year survival rate varies. However, it is generally around 46 percent, according to the Ovarian Cancer National Alliance. Compared with other female-specific cancers, Ashton said, it has a low survival rate. For breast cancer, it's 89 percent. For cervical cancer, it is 71 percent. Ovarian cancer is the fifth-leading cause for cancer deaths in women.