[Evaluation of mass-screening for cervical cancer in Santo-Cho. Effect of repeat cytological screening]

A cytological screening program for the early detection of cervical cancer was started in the county of Santoh-Choh, north-eastern Shiga Prefecture in 1969. During the first four years between 1969 and 1972 all of the women aged more than 35 resident in this county took part in the screening program, and cervical cancer was found in 15 women out of a population of 2,960. The annual detection rate of 0.25% for the disease during this period was significantly higher than the average rate of 0.16% for the whole of Shiga Prefecture. Cervical cancer detection frequency in this county has subsequently been reduced over 7 years to about one third (0.09%) of the frequency before 1972. In this county, cervical cancer was found in three women who had received the annual repeat screenings more than three times. Re-evaluation of the previous smears in these patients revealed that two smears should have been diagnosed as positive. The present findings indicate that the effects of a mass-screening program may be improved by (1) the participation, at least once, in the screening program by all female residents, (2) annual repeat screening for more than three years and (3) adequate quality and/or accuracy control in the laboratory.