Follow Up of Women With Simple Ovarian Cysts Detected by Transvaginal Sonography in the Tokyo Metropolitan Area

Abstract

From late 1990 through 1991, 10,294 asymptomatic women participated in a screening program for ovarian tumors at the Tokyo Metropolitan Cancer Detection Center. The screening examination included a Papanicolaou test, colposcopy, digital vaginal examination, and transvaginal ultrasonography using a 5.0-MHz transducer with a 100-Hz sump filter to eliminate low-frequency sounds. Women with abnormalities (ovary greater than 2 cm in diameter, ovarian cyst or mass) underwent a second scan 6 weeks later to exclude functional cysts. Apparent simple cysts in premenopausal women (no papillary component, thick septa, or solid tumor) were rescanned every 3 months and watched carefully for any changes in the nature or size of the cyst. Women with other abnormalities underwent further evaluation, including measurement of serum levels of CA-125, CA-199, and carcinoembryonic antigens (CEAs) and in some cases computed tomographic scanning. Results of the screening program are presented in Figure 1. Of the 372 women with abnormal findings, 32 were diagnosed with a uterine fibroid, and 340 were found to have an adnexal mass. Of these patients, 115 had either an ovarian mass larger than 6 cm in diameter or an elevated blood serum CA-125 level and were referred for exploratory surgery. Eight women refused to undergo surgery and were followed up elsewhere. In the remaining 107, two stage Ia mucinous cyst adenocarcinomas, one stage Ic endometrioid adenocarcinoma, and one endometrial carcinoma metastatic to the ovary were found. In addition, three borderline malignancies were diagnosed.Fig. 1: Breakdown of patients with adnexal masses screened by transvaginal ultrasonography (TV-UST).Two hundred twenty-five of the 340 women had an adnexal mass less than 6 cm in diameter with normal blood serum CA-125 levels and were followed up every 3 months for 75 months. One hundred sixty-five (73 percent) of the masses had regressed by the end of the follow-up period, 80 at the first follow-up examination and most (146) within 12 months. None of the cysts recurred. In 31 (41 percent) women, the mass persisted throughout the follow-up period, and in 29 (13 percent), progression of the adnexal mass occurred, most often (21) within 24 months. Three cysts persisted for 5 years before beginning to grow; one of these was found to have enlarged in the 75th month. Of the 29 women with progression, 9 had either rising CA-125 levels, greatly enlarged cysts (>6 cm), or a multiloculated cyst and underwent surgery. Three women were diagnosed with endometriosis, three with mature teratoma, two with cystadenoma (one serous and one mucinous), and one with an endosalpingeal cyst. In women with normal blood serum CA-125 levels and cysts less than 6 cm in diameter at the time of initial diagnosis, the outcome at 75 months was significantly correlated with ultrasound findings (cystic mass vs. solid or mixed mass, P = .01), mass diameter (<4 cm compared with >5 cm, P = .05), blood serum CEA levels (<0.7 vs. >1.0, P = .02), and blood serum CA-199 levels (<7 vs. >20, P = .001). A multivariate analysis of risk factors for tumor growth was conducted for the 140 women with complete information recorded. Blood serum CA-199 and CEA levels at the time of initial diagnosis were found to be significant predictors of tumor regression (P = .004 and P = .02, respectively). A CA-199 level of 20 IU/mL or higher had a relative probability of tumor regression of 0.34. Similarly, a CEA level of 1.0 IU/mL or higher had relative probability of regression of 0.53.