[No major difference between population screening for cervical carcinoma at the present screening interval of 5 years and the former interval of 3 years].
OBJECTIVE
To assess the effect of extending the screening interval from 3 to 5 years on the detection of premalignant changes and invasive cervical carcinoma in the restructured population screening programme.


METHODS
Retrospective follow-up study.


METHODS
The results were collected of the 1st round (1996-2000; 277, 377 women) and a part of the 2nd round (2001; 49,622 women; screening interval: 5 years) of the screening programme in Region West, the Netherlands. Histoscores for cervical intraepithelial neoplasia (CIN) 3 and squamous cell carcinoma (n/100 women investigated) and the hit count (sum of the histoscores for CIN 3, adenocarcinoma in situ and (micro)invasive cervical carcinoma) were calculated. Data of women with adenocarcinoma in situ and endocervical (adeno)carcinoma were recorded separately. The results of the 1st and 2nd round of the current screening programme (commenced in 1996) were compared with those of the historical screening programme that commenced in 1976 (screening interval: 3 years).


RESULTS
From the 1st to the 2nd round of the historical screening programme that commenced in 1976, the histoscores for CIN 3 (3.33, 1.88) and squamous cell carcinoma (0.53, 0.19) and the hit count (3.92, 2.15) all diminished significantly. The current restructured programme, which commenced in 1996, showed low starting values for all three parameters, comparable to those in the 2nd round of the 1976 programme; a further reduction (0.16, 0.08; p < 0.01) was seen only in the histoscore for squamous cell carcinoma. In both rounds of both programmes, the histoscores for adenocarcinoma in situ (0.02, 0.02, 0.05, 0.04, respectively) and endocervical adenocarcinoma (0.04, 0.06, 0.05, 0.04) remained stable.


CONCLUSIONS
In the current cervical carcinoma screening programme, with a screening interval of 5 years, the hit count of serious abnormalities remained constant while the incidence of squamous cell carcinoma decreased; this is in contrast to the historical screening programme (commenced in 1976), when both the hit count and the histoscore for CIN 3 diminished significantly. There were indications that cervical screening has no beneficial effect on the prevention of cervical adenocarcinoma.
Vinkesteijn
A S M
AS
Reinier de Graaf Gasthuis, afd. Gynaecologie en Obstetrie, Delft.
Siemens
F C
FC
Boon
M E
ME
Kuypers
J C
JC
Kok
L P
LP
D002277:Carcinoma / Q000175:diagnosis* / Q000453:epidemiology / Q000532:radiotherapy; D015331:Cohort Studies; D016208:Databases, Factual; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D011883:Radium / Q000009:adverse effects / Q000627:therapeutic use; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000532:radiotherapy
D011883:Radium