Fiskekonsum og kreftrisiko blant norske kvinner - The Norwegian Women and Cancer Study (NOWAC)

Abstract

SAMMENDRAG

Ved Institutt for samfunnsmedisin, Universitetet i Tromsø, er det over mange år bygget opp en landsdekkende

prospektiv undersøkelse kalt ’Kvinner, livsstil og helse’/’Kvinner og kreft’. Studien er primært

designet for å undersøke risikofaktorer for kreft, og i særdeleshet brystkreft. Siden 1991 har drøyt 100 000

tilfeldig utvalgte kvinner, født 1927-1965, blitt inkludert i studien. Svarprosenten er omlag 60. Deltakerne

har fylt ut et spørreskjema med noe varierende innhold, men med en del felles kjernespørsmål. Detaljgraden

når det gjelder kostholdsinformasjon varierer. Av de vel 100 000 kvinnene som deltar har omlag halvparten

fylt ut et oppfølgingsskjema. Vi er særlig interessert i å studere en eventuell effekt av et høyt fiskekonsum på

kreftrisiko. Spørsmålene om konsum av fisk og fiskeprodukter er validert mot fettsyresammensetningen i

serum fosfolipider. Studien inngår i multi-senter prosjektet EPIC – the European Prospective Investigation

into Cancer and Nutrition. For å kunne sammenlikne kostdata fra de ti deltakerlandene er det utarbeidet en

intern kalibreringsmetode basert på et strengt standardisert dataprogram for 24-timers kostholdsintervju. I

Norge vil det bli gjennomført omlag 1800 kostholdsintervju over telefon.

Hjartåker A, Engeset D, Brustad M, Lund E.

Fish consumption and cancer risk among Norwegian

women – The Norwegian Women and Cancer Study (NOWAC).

Nor J Epidemiol 2000; 10 (1): 63-70.

ENGLISH SUMMARY

The Norwegian Women and Cancer study, NOWAC (in Norwegian: ’Kvinner, livsstil og helse’/’Kvinner og

kreft’) is a large population-based cohort study primarily designed to examine factors related to cancer, other

illnesses, and mortality in a prospective manner. In particular, it is designed for investigation of breast

cancer. Since the establishment in 1991, more than 100 000 Norwegian women born 1927-1965 have been

included in the cohort. The participants are randomly sampled, and the response rate is about 60%. The

participants have received a mailed letter of invitation requesting informed consent and a self-instructive

questionnaire. After sufficient follow-up time, events will be identified by linkage to the Cancer Registry of

Norway and to the registry of death certificates at Statistics Norway. Dietary data have been collected

through a food frequency approach. Some 70 000 women have given detailed information about their diet

during the last year, whereas more scarce dietary data are collected from the rest of the participants. A large

number of the women have reported their dietary intake twice. Along with information on “usual” diet,

special attention is given to the consumption of marine foods. Based on earlier findings we want to examine

a potential protective effect of fish consumption on breast cancer risk. The questions on marine food consumption

have been validated against serum phospholipid fatty acid composition. In addition to the national

analyses, NOWAC is part of the large multi-centre study EPIC – the European Prospective Investigation

into Cancer and Nutrition. To calibrate dietary data across centres a computer based 24-h recall program is

developed. A sub-sample of about 1800 of the NOWAC participants will be interviewed using this program.

The interviews are performed by telephone. Building a biological bank is another important part of EPIC,

and we are planning to collect blood samples via mail for a sub-sample of the Norwegian participants.