Evaluation of the effectiveness of cervical cancer screening: a case-control study in Miyagi, Japan.
To estimate the effectiveness of screening for invasive cervical cancer, a case-control study was performed in Miyagi, Japan. A total of 198 cases (129 mass screen-detected and 69 outpatient-detected) of invasive cervical cancer were identified between 1984 and 1990. The results of the Papanicolaou smear of these cases were compared to those of 396 age- (+/- 5 years) and area-matched controls. Compared with women who had no prior screening (cases 51.6%, controls 16.2%), women who were screened had an odds ratio (OR) for invasive cervical cancer of 0.14 (95% confidence interval [CI] 0.088-0.230). The OR for the 175 cases of squamous cell carcinoma was 0.13 (95% CI 0.077-0.215), while the OR for the 23 cases of screened women with adenocarcinoma was 0.40 (95% CI 0.091-1.753). The time intervals following the last negative smear were assessed and we found an OR for a one-year interval and a two-year interval of 0.09 (95% CI 0.055-0.163) and 0.17 (95% CI 0.083-0.335), respectively. In conclusion, screening for invasive cervical cancer is not only effective but also the degree of protection is high for one to two years.
Makino
H
H
Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai, Japan.
Sato
S
S
Yajima
A
A
Komatsu
S
S
Fukao
A
A
D000230:Adenocarcinoma / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000517:prevention & control*; D016022:Case-Control Studies; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007564:Japan; D008403:Mass Screening; D008875:Middle Aged; D016017:Odds Ratio; D065006:Papanicolaou Test; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control*; D014626:Vaginal Smears