Nordic biological specimen banks as basis for studies of cancer causes and control--more than 2 million sample donors, 25 million person years and 100,000 prospective cancers.
The Nordic countries have a long tradition of large-scale biobanking and comprehensive, population-based health data registries linkable on unique personal identifiers, enabling follow-up studies spanning many decades. Joint Nordic biobank-based studies provide unique opportunities for longitudinal molecular epidemiological research. The purpose of the present paper is to describe the possibilities for such joint studies, by describing some of the major Nordic biobank cohorts with a standardised calculation of the cancer incidence in these cohorts. Altogether two million donors have since 1966 donated more than four million biological samples, stored at -20 degrees C to -135 degrees C, to 17 biobank cohorts in Finland, Iceland, Norway and Sweden. As a result of joint database handling principles, the accuracy of personal identifiers and completeness of follow-up for vital status in all participating biobanks was improved. Thereafter, the cancer incidence was determined using follow-up through the national cancer registries. Biobanks based on random samples of population typically showed slightly lower cancer incidence rates than the general population, presumably due to better participation rates among health-conscious subjects. On the other hand, biobanks including samples for viral screening or clinical testing showed 1.5 to 2.1 fold increased incidence of cancer. This excess was very high immediately after sampling, but for some cancer sites remained elevated for years after clinical sampling. So far, more than 100 000 malignant neoplasms have occurred after sample donation, and the annual increase of the cancer cases in these cohorts is about 10 000. The estimates on the population-representativity of the biobanks will assist in interpretation of generalizability of results of future studies based on these samples, and the systematic tabulations of numbers of cancer cases will serve in study power estimations. The present paper summarizes optimal study designs of biobank-based studies of cancer.
Pukkala
Eero
E
Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland. eero.pukkala@cancer.fi
Andersen
Aage
A
Berglund
Göran
G
Gislefoss
Randi
R
Gudnason
Vilmundur
V
Hallmans
Göran
G
Jellum
Egil
E
Jousilahti
Pekka
P
Knekt
Paul
P
Koskela
Pentti
P
Kyyrönen
P Pentti
PP
Lenner
Per
P
Luostarinen
Tapio
T
Löve
Arthur
A
Ogmundsdóttir
Helga
H
Stattin
Pär
P
Tenkanen
Leena
L
Tryggvadóttir
Laufey
L
Virtamo
Jarmo
J
Wadell
Göran
G
Widell
Anders
A
Lehtinen
Matti
M
Dillner
Joakim
J
D018070:Biological Specimen Banks; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008403:Mass Screening; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D009664:Norway / Q000453:epidemiology; D011159:Population Surveillance; D011785:Quality Assurance, Health Care; D016032:Randomized Controlled Trials as Topic; D012042:Registries; D015203:Reproducibility of Results; D012107:Research Design; D013548:Sweden / Q000453:epidemiology; D014019:Tissue Donors