Understanding Ovarian Cancer - the Basics

Flanking the uterus are the two ovaries, each about the size of an almond, which produce eggs and female hormones. Ovarian cancer can occur at any age, even in childhood, but is most common after menopause. The disease accounts for about 22,000 new cases and 16,000 deaths in the U.S. annually.

During her childbearing years, a woman's ovaries deliver eggs to the uterus through the fallopian tubes. The ovaries are susceptible to several types of growths, which are often benign cysts but are sometimes cancerous. The cancer typically has no obvious symptoms until it is well advanced. Early growths can sometimes be detected during a routine pelvic exam.

If ovarian cancer could be readily detected in its earliest stages, more women would be cured. But like many cancers, it usually has spread by the time it is diagnosed. The importance of early detection is clear: About 90% of women live 5 years or more if ovarian cancer is detected early; the rate for all cases is only about 40%. Unfortunately only 25% of ovarian cancers are found at an early stage.

What Causes It?

Most women with ovarian cancer have no family history of the disease, yet a woman is more likely to get the disease if her mother or sister has had ovarian, breast, or uterine cancer; the more relatives affected, the greater the risk. Women who have had few or no children, who delay childbearing until their 30s, or who have trouble conceiving are also at greater risk for ovarian cancer. A link between the number of periods in a women’s life and the risk of ovarian cancer exists.

Some studies have also reported that log-time use of the fertility drug clomiphene citrate, especially if no pregnancy took place, may increase the risk of borderline ovarian tumors. This finding is not clear since infertility it self is a risk to ovarian cancer. Those who have several children, who breastfeed their infants, or who use birth control pills are at reduced risk. The difference may be linked to less frequent ovulation.

Most ovarian cancers occur postmenopause, with half presenting over the age of 65.

A study from the American Cancer Society has found that the risk of death from ovarian cancer was higher in overweight women. Evidence suggests that the more saturated fat a woman eats, the greater her chance of ovarian cancer. Many high-fat foods contain estrogen and all stimulate natural estrogen production. Because most ovarian cancers grow more rapidly in the presence of estrogen, some experts believe that abnormally elevated estrogen in a woman's body promotes the onset of ovarian cancer. Exposure to asbestos is also believed to be a factor in some cases. This was a concern when some of the talcum powders used years ago contained asbestos.

Using postmenopausal hormones for more than 10 years may also slightly increase ovarian cancer risks, but these risks need to be discussed with health care providers and individually weighed.