Results of screening for uterine cervical cancer in a model district over a period of 20 years

Tsuyama town of Miyagi Prefecture in Japan has a population of about 5000. This town was selected as a model district for the screening of uterine cervical cancer in 1966 and yearly screening tests have been carried out subsequently. In the present study, the results for 20 years up to 1985 are summarized and analyzed. In the first year, 1966, 397 of 1956 women above the age of 30 years participated the study, with the rate of participation of 24.9%. Invasive carcinoma was found in 1, carcinoma in situ (CIS) in 3 and dysplasia in 1. Invasive carcinoma was found in 3 subjects during the 20years. All these cases were experienced prior to 1972, and none appeared after 1972. After the beggining of the screening in 1966, the rate of participation increased, staying above 30% after 1972. Three cases of CIS were found in 1966, followed by occasional detection subsequently, until the total of 7 cases were found. Dysplasia was found almost every year, giving the total of 33 cases. In 1985, among the total number of 1106 women above the age of 50 years, 371 or 33.5% were never examined in the screening test over the 20 year period between 1966 and 1985. In 1985, among the total number of 1383 women above the age of 40 years, 608 or 44.0% were not examined during the 10 year period between 1976 and 1985. Though the rate of participation in the screening test for uterine cervical cancer in a model district exceeded 30%, the number of subjects who have never been examined were found to be unexpectedly high.