{"entity":{"id":"paper-lichtenstein-twins-cancer-heritability-nejm-2000","kind":"paper","name":"Environmental and heritable factors in the causation of cancer: analyses of cohorts of twins from Sweden, Denmark, and Finland","aka":[],"tldr":"A study of nearly 45,000 pairs of twins in the Swedish, Danish and Finnish twin registers that asked how much of ordinary cancer is inherited. For most cancers the answer was a minor share: the environment, in the broad sense of everything that is not inherited, played the larger part.","summary":"Led from the Department of Medical Epidemiology at Karolinska Institutet, the study combined 44,788 twin pairs from the three Nordic twin registers, linked to the national cancer registers, to estimate the risk of cancer at 28 sites in the twin of an affected person, and modelled the relative contributions of heritable and environmental factors at 11 sites. At least one cancer occurred in 10,803 people among 9,512 pairs. It depended on twin registers and national cancer registers that can be linked person by person.","asOf":"2026-11-03","links":[{"label":"NEJM 2000","url":"https://doi.org/10.1056/NEJM200007133430201"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/10891514/"}],"tags":[],"related":["paper-mucci-nortwincan-heritability-jama-2016"],"cancers":["prostate","colorectal"],"sections":["prevention"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":["karolinska"],"pathways":[],"terms":[],"trials":[],"people":["paul-lichtenstein"],"bottlenecks":["b-hereditary-risk"],"keyPapers":[],"journals":["nejm"],"dependsOn":[],"notes":[],"journal":"New England Journal of Medicine","year":2000,"doi":"10.1056/NEJM200007133430201","pmid":"10891514","authors":"Lichtenstein P, Holm NV, Verkasalo PK, Iliadou A, Kaprio J, Koskenvuo M, Pukkala E, Skytthe A, Hemminki K","paperType":"observational","findings":["Twins of affected people had an increased risk of stomach, colorectal, lung, breast and prostate cancer.","Statistically significant heritability was found for prostate cancer (42 per cent; 95 per cent CI 29 to 50), colorectal cancer (35 per cent; 10 to 48) and breast cancer (27 per cent; 4 to 41).","The authors concluded that inherited genetic factors make a minor contribution to susceptibility to most types of neoplasm, and that the environment has the principal role in sporadic cancer."],"whatItMeans":"It is the reason a family history matters for some cancers and not much for others, and it supports prevention: if most of the risk is not inherited, much of it can in principle be changed. The larger heritability for prostate, colorectal and breast cancer pointed at genetic risk that later genome-wide studies and polygenic scores set out to find.","caveats":["Twin models assume identical and fraternal twins share their environment equally; heritability here means the share of variation in risk in these populations, not the share of any one person's cancer.","Estimates for less common cancers had wide confidence intervals; the larger NorTwinCan study in 2016 reported higher estimates for prostate and breast cancer."]},"route":"/key-papers/paper-lichtenstein-twins-cancer-heritability-nejm-2000/","neighbours":{"paper":[{"id":"paper-mucci-nortwincan-heritability-jama-2016","kind":"paper","name":"Familial risk and heritability of cancer among twins in Nordic countries (NorTwinCan)","route":"/key-papers/paper-mucci-nortwincan-heritability-jama-2016/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"section":[{"id":"prevention","kind":"section","name":"Prevention & Risk","route":"/fronts/prevention/"}],"institution":[{"id":"karolinska","kind":"institution","name":"Karolinska University Hospital","route":"/institutions/karolinska/"}],"person":[{"id":"paul-lichtenstein","kind":"person","name":"Paul Lichtenstein","route":"/people/paul-lichtenstein/"}],"bottleneck":[{"id":"b-hereditary-risk","kind":"bottleneck","name":"Inherited risk is mostly unidentified","route":"/bottlenecks/b-hereditary-risk/"}],"journal":[{"id":"nejm","kind":"journal","name":"New England Journal of Medicine","route":"/journals/nejm/"}]}}