Do women >or=50 years of age need as much screening as women <50 years after they have had negative screening results?
To assess the adequacy of a routine screening to identify cervical intraepithelial neoplasia 2 or worse (CIN2+) in women over 50 years of age, a retrospective cohort was set in six Italian organised population-based screening programmes. In all, 287 330 women (1 714 550 person-years of observation, 1110 cases) screened at age 25-64, with at least two cytological screening tests, the first negative, were followed from their first negative smear until a biopsy proven CIN2+ lesion or their last negative smear. For women aged 25-49 and 50-64 years, crude and age-standardised detection rate (DR), cumulative risk (CR), adjusted hazard risk for number of previous negative screens, probability of false-positive CIN2+ after two or more smear tests were calculated. Detection rate is significantly lower over 50 years of age. Multivariable analysis shows a significant protective effect from four screening episodes (DR=0.70, 95% CI: 0.51-0.97); the effect of age >or=50 is 0.29 (95% CI: 0.24-0.35). The CR of CIN2+ is at least eightfold higher in women <50 (CR=2.06, 95% CI: 1.88-2.23) after one previous negative test than in women >or=50 years with four screens (CR=0.23, 95% CI: 0.00-0.46). Over 50 years of age, after four tests at least three false-positive cases are diagnosed for every true positive. Benefits arising from cytological screening is uncertain in well-screened older women.
Armaroli
P
P
SCDO Epidemiologia dei Tumori, Centro Prevenzione Oncologica Regione Piemonte and Azienda Ospedaliero-Universitaria S. Giovanni Battista di Torino, V. San Francesco da Paola 31, Torino 10123, Italy.
Gallo
F
F
Bellomi
A
A
Ciatto
S
S
Consonni
D
D
Davi
D
D
Giorgi-Rossi
P
P
Iossa
A
A
Mancini
E
E
Naldoni
C
C
Polla
E
E
Ronco
G
G
Serafini
M
M
Vergini
V
V
Zanier
L
L
Zappa
M
M
Segnan
N
N
D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D014626:Vaginal Smears / Q000379:methods; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology