Research indicates that women who have multiple pregnancies, who breast feed their children, or who take oral contraceptives for some period of time reduce their risk of ovarian cancer. Researchers believe this effect is due to the interruption in the ovulation cycle. Genetics is also thought to play a role in a small percentage of cases. Women with two or more close relatives who have had ovarian cancer have a 50 percent chance of also developing the disease. When a women has a family history of ovarian cancer, some physicians may recommend that the ovaries be removed as early as age 35 in order to prevent the disease.
Ovarian cancer is difficult to diagnose because it often imitates other diseases.
Generally, enlargement of the ovaries is the first and major symptom of ovarian cancer. Several research groups are evaluating the efficacy of using ultrasound in the early detection of ovarian cancer. While traditional ultrasound is not reliable in distinguishing malignant from benign tumors, a modification, called transvaginal ultrasound, can improve the rate of detection of ovarian cancer. A second modification, called Doppler ultrasound, can detect the higher level of blood flow which is present in malignant tumors but not in benign ovarian cysts. NCI is supporting research in a number of institutions to evaluate the usefulness of a protein called CA125 in the early detection of ovarian cancer.