Optimal cervical cytology mass screening interval for cervical cancer.
OBJECTIVE
To identify the optimal interval for repeat cervical cytology testing for screening of cervical cancer and dysplasia in healthy female adults.


METHODS
A retrospective cohort study was conducted on 3,804 apparently healthy females without known cervical cancer at baseline from 2005 to 2010. Participants underwent annual health checkups, including cervical cytology testing. This data did not contain human papillomavirus status. Participants with cytological abnormality underwent further examination, including biopsy, to check for cervical cancer. The generalized estimating equation (GEE) was performed to analyze the longitudinal data.


RESULTS
In the groups <40, 40-49, 50-59 and ≥60 years old, the 5-year cumulative incidences (95 % CI) of cytological abnormality were 11.2 % (8.8-13.9 %), 7.6 % (6.2-9.3 %), 4.4 % (3.3-5.7 %) and 2.8 % (1.8-4.2 %), respectively, and the cumulative incidences of cervical cancer were 0.9 % (0.3-2.0 %), 0.1 % (0.0-0.4 %), 0.1 % (0.0-0.5 %) and 0 %, respectively. The odds ratios of the incidence for cervical cancer and cervical dysplasia per year, with GEE models, were 1.5 (95 % CI:1.1-2.0), 1.2 (95 % CI:0.8-1.9), 2.2 (95 % CI:0.5-10.3) and 0 for cervical cancer, and 1.3 (95 % CI:1.2-1.5), 1.3 (95 % CI:1.2-1.5), 1.3 (95 % CI:1.1-1.5) and 1.4 (95 % CI:0.9-2.0) for cervical dysplasia, respectively.


CONCLUSIONS
For patients under 40 years old, the screening for cervical cancer every 2 years should be considered, while for patients of 40-59 years old screening every 2 or 3 years should be considered. Females over 60 years old may only need repeat screening every 5 years.
Division of General Internal Medicine, Department of Medicine, St. Luke's International Hospital, Tokyo, Japan. daikoba@luke.or.jp
Daiki
D
Kobayashi
Osamu
O
Takahashi
Chikako
C
Hikosaka
Tomoya
T
Okubo
Tsuguya
T
Fukui
D000328:Adult; D000367:Age Factors; D002277:Carcinoma / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008403:Mass Screening; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D014626:Vaginal Smears / Q000706:statistics & numerical data*