Incidence of invasive cervical cancer preceded by negative screening in high-risk Alaska Native women.
BACKGROUND
Alaska Native women experience higher invasive cervical cancer incidence and mortality rates than US whites despite a long-standing cancer screening programme including recommendations for annual Pap smears.


METHODS
To determine the frequency and results of cytological screening preceding their diagnoses, a histological and medical record review was completed for 44 of 46 Alaska Native cases of invasive cervical cancer from a defined population. An interval cancer (no prior dysplasia and a negative screening report within 3 years of diagnosis) was determined for 23 women. Mean number of negative reports during the 3- and 5-year intervals before diagnosis was 1.7 and 2.6 respectively. The age-adjusted incidence rate for all cervical cancer was 24.0/100,000 women/year and for interval cancer with single and multiple negative reports during the 3-year interval before diagnosis it was 11.6, and 9.6 respectively. Sensitivity of a Pap smear to demonstrate dysplasia during the year before diagnosis was 51%.


CONCLUSIONS
Annual cytological screening of all Alaska Native women with current methods would provide earlier diagnoses for only an additional 15% of cervical cancer cases. Plausible but unproven explanations include rapid progression through precursor stages of neoplasia or random screening errors. Improved or ancillary screening methods appear necessary.
Davidson
M
M
Arctic Investigations Program, Centers for Disease Control and Prevention, Anchorage, AK 99501.
Bulkow
L R
LR
Lanier
A P
AP
Smith
R A
RA
Hawkins
I
I
Jensen
H
H
Kiviat
N B
NB
D000293:Adolescent; D000328:Adult; D000368:Aged; D000413:Alaska / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data*; D004930:Inuit / Q000706:statistics & numerical data*; D008403:Mass Screening; D008875:Middle Aged; D065006:Papanicolaou Test; D012307:Risk Factors; D002578:Uterine Cervical Dysplasia / Q000208:ethnology / Q000473:pathology / Q000517:prevention & control; D002583:Uterine Cervical Neoplasms / Q000208:ethnology* / Q000473:pathology / Q000517:prevention & control; D014626:Vaginal Smears