Læknablaðið - 15.11.1999, Page 10

862
Leghálskrabbameinsleit
á Norðurlöndum til 1995
LÆKNABLAÐIÐ 1999; 85
Könnun á nýgengi og dánartíðni,
markaldri og bili milli skoðana
Kristján Sigurðsson
Sigurðsson K
The Nordic cervical screening programmes
through 1995. Evaluation of incidence and mor-
tality rates, targeted age groups and screening
intervals
Læknablaðið 1999; 85: 862-72
Background: The objective of cervical cancer
screening is to lower the incidence and mortality
rates of the disease. The Nordic countries have a long
experience in cervical cancer screening. Based on
this experience this study evaluates the UICC and EC
guidelines regarding the effectiveness of organized
vs. spontaneous screening, targeted age groups and
screening intervals.
Material and methods: The study analyses the
features of the Icelandic and the Nordic screening
programmes and the observed trends in the incidence
and mortality rates in these countries through 1995.
It also analyses the trends for cytologic preinvasive
lesions at first visit and at second and later visits after
a normal test(s). The frequency of histologic lesions
was calculated for the birth cohort 1920-1926 from
the age of 60 and among women referred for colpo-
scopic examination in 1994.
Results: Organized screening started in all the
Nordic countries except Norway soon after 1960. Up
to 1985 the target age group and screening interval
were most intensive in Iceland. All countries intensi-
Frá Leitarstöð Krabbameinsfélagsins. Fyrirspurnir, bréfa-
skipti: Kristján Sigurðsson yfirlæknir, Leitarstöð Krabba-
meinsfélagsins, pósthólf 5420, 125 Reykjavík. Netfang:
kristjan@krabb.is
Myndir 1,3, 4, 5 og 6 hafa áður birst í Acta Obstet Gynecol
Scand 1999; 78: 478-92 og eru birtar hér með góðfúslegu
leyfi blaðsins.
Lykilorð: leghálskrabbameinsleit, skipuleg eða sjálfboðuð
kembileit, dánartíðni, nýgengi, frumubreytingar, vefjabreyt-
ingar, flöguþekjukrabbamein, kirtilkrabbamein.
fied the screening intervals after 1985. The reduction
in both the mortality and the incidence rates was
greatest in Iceland and Finland, intermediate in
Sweden and Denmark, and lowest in Norway but in
that country organized screening started in 1994. The
age-specific incidence in the 20-29 age group has
been increasing since 1971 in all the Nordic coun-
tries, except in Finland.
In Iceland screening has greatly affected the rate of
all stages of squamous cell carcinoma, but not the
rate of adeno-and adenosquamous carcinomas. The
prevalence of preinvasive disease has increased
signifícantly since 1980. The rate of moderate to
high-grade cytologic changes begins increasing as
early as at 20 years of age and moderate to high-
grade histologic lesions start to accumulate at 24 to
36 rnonths after a normal smear. The rate of these
lesions decreases with the number of negative smears
taken. Moderate to high-grade histologic lesions and
invasive cancer are practically non-existent after the
age of 60 among correctly screened women. A strong
correlation is found between increased attendance
rates and the proportion of cases diagnosed with a
Pap smear at stages IA and IB occult. The latter cases
mainly occur among women under the age of 45 and
start to appear less than two years after a normal
smear.
Conclusions: Well-organised screening is more
effective than spontaneous screening in reducing the
risk of cervical cancer. Screening should preferably
start soon after age 20 with a screening interval of
two to three years. The screening interval can pro-
bably be extended to four years at the age of 50 and
screening could stop at the age of 60 to 64 among
regularly screened women.
Key words: cervical cancer screening, organized screen-
ing vs. spontaneous screening strategies, mortality rates,
incidence rates, cytologic lesions, histologic lesions,
squamous cell carcinoma, adenocarcinoma.
Ágrip
Markmið: Markmið leghálskrabbameins-
leitar er að lækka nýgengi og dánartíðni sjúk-