Efficiency of Cytological Screening for Detection of Cervical Squamous Carcinoma

A study in the county of Uppsala 1991–1994

Abstract

Squamous carcinoma of the uterine cervix accounts for a considerable mortality among gynecological malignancies, although both the incidence of and mortality from cervical cancer have decreased in the Nordic countries since 1970. The reduction is a result of the cytologic screening program, through which precursor lesions can be detected and removed. Our aim was to determine why women in the county of Uppsala get cervical cancer despite extensive gynecological screening.

A retrospective study of all women (43 cases) who developed histologically verified cervical squamous carcinoma in the county of Uppsala during the years 1991 to 1994 was undertaken. A central computer database covering all histopathological and cytological material made it possible to compare each woman's previous smears or lack of smears with her cancer diagnosis.

Twenty women (47%, mean age at diagnosis 64.4 years) had not undergone cytological screening. Twenty-three women (53%) had been screened at least once within 6 years before tumor diagnosis. Of these, 11 (mean age 47.5 years) had had normal smears for the last 6 years, 8 (mean age 44.3 years) had shown abnormal cytology for less than one year and 4 (mean age 39.0 years) had shown abnormal cytology for more than one year and up to 6 years before their cervical cancer diagnosis.

Women with cervical squamous carcinoma, who are not covered by the gynecological screening program (47%) are at increased risk of developing cervical cancer compared with other women. Consequently the average age of non-screened women developing cancer is considerably higher (64.4 years) than that of women with cancer screened previously (44.9 years). In 26% of the total group of women with cervical squamous carcinoma previous cytology displayed normal features.