Ovarian cancer screening.

BACKGROUND: The three most extensively evaluated screening methods for ovarian cancer are pelvic examination, serum CA 125, and transvaginal sonography (TVS). The lack of sensitivity of pelvic examination and serum CA 125 has limited their use in ovarian cancer screening. Currently, the most effective screening method for ovarian cancer is TVS.

METHODS: Transvaginal sonography was performed with a standard ultrasound unit and a 5.0 MHz vaginal transducer. Each ovary was measured in three dimensions and ovarian volume was calculated using the prolate ellipsoid formula (L x H x W x 0.523). An ovarian volume greater than or equal to 20 cm3 in premenopausal women and greater than or equal to 10 cm3 in postmenopausal women was considered abnormal. Also, any internal papillary projection from the tumor wall was considered abnormal. A patient with an abnormal screen had a repeat TVS in 4-6 weeks. Women with a persisting abnormality on TVS underwent pelvic examination, serum CA 125 determination, Doppler flow sonography, and tumor morphologic indexing before operative tumor removal.

RESULTS: Eighty-five hundred asymptomatic women underwent TVS screening. One hundred twenty-one of these women had a persisting abnormality and underwent tumor removal. Fifty-seven patients had serous cystadenomas and eight had primary ovarian cancers. Six patients had Stage IA ovarian cancer, one had Stage IIC ovarian cancer, and one had Stage IIIB ovarian cancer. Only one of these patients had palpable ovarian enlargement on clinical examination and one had an elevated serum CA 125. All patients are alive and well 4-61 months after conventional therapy. The direct cost of TVS screening was highest during the initial years of the program and fell progressively to $30/screen during the 4th year of the study. Worldwide, more than 14,000 women have been screened using ultrasonography, and 19 ovarian cancers have been detected. More than 20,000 patient-screening-years have been accrued, and there have been no deaths from primary ovarian cancer in the screened population.

CONCLUSIONS: Transvaginal sonography screening causes a decrease in stage at detection and a decrease in case-specific mortality. Further study is needed to determine if annual TVS screening will significantly reduce ovarian cancer mortality. The cost for TVS screening is reasonable and is well within the range of that reported for other screening tests.