Usefulness of mass screening for ovarian carcinoma using transvaginal ultrasonography

International Federation of Gynecology and Obstetrics Stage I ovarian carcinoma, which has the worst prognosis among all types of gynecologic carcinoma, has a high cure rate as has been reported, but early diagnosis is difficult and to the authors' knowledge screening methods have not been established. Since 1989, the authors have performed transvaginal ultrasonography (TVS) as a form of screening for ovarian carcinoma. The purpose of the current study was to summarize and evaluate screening results for the last 10 years with respect to ovarian carcinoma diagnosis and risk factors.

Primary screening by TVS was performed in asymptomatic women who participated in annual uterine cervical carcinoma screening. Four scanning sections by TVS were established and all sonograms were recorded. Women with abnormal sonograms (a mass > 30 mm in greatest dimension or a mass with a mixed pattern) received secondary screening and closer examination with a tumor marker and an imaging diagnostic examination. Laparotomy was conducted on all masses with a greatest dimension of >/= 60 mm or on suspected malignant masses. Subject information-related risk factors also were recorded.

Subjects were 183,034 women who participated in primary screening. Of these women, 51,550 were undergoing screening for the first time. The time required for primary screening was 1 minute per subject. Secondary screening was required for 5309 participants (10.3%) and surgery was performed on 324 participants. Twenty-two primary tumors and 2 metastatic tumors were detected for a diagnostic rate of 0.047%. Of the 22 primary tumors, 17 (77.3%) were classified as Stage I carcinoma, with tumor markers positive only for 5 (29.4%). The percentage of the total number of Stage I ovarian carcinoma cases increased after the induction of screening from 29.7% to 58.8%.

These results are significant in that 77.3% of the primary ovarian carcinomas found during the current screening were of curable Stage I. Increased use of TVS screening for ovarian carcinoma may increase the chance for early diagnosis and decrease the mortality of the disease.