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The population impact of familial cancer, a major cause of cancer
Author(s) -
Frank Christoph,
Fallah Mahdi,
Ji Jianguang,
Sundquist Jan,
Hemminki Kari
Publication year - 2013
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.28510
Subject(s) - population , medicine , cancer , first degree relatives , risk factor , relative risk , prostate cancer , oncology , breast cancer , disease , esophageal cancer , attributable risk , family history , epidemiology , confidence interval , environmental health
The population attributable fraction (PAF) defines the proportion of a disease that would be prevented if the exposure to a particular risk factor was avoided. Familial risk is a known risk factor for many cancers, but an unbiased estimation of the PAF for familial risk requires a large study population to include rare cancers. PAFs and their corresponding standardized incidence ratios (SIRs) were calculated for familial relative risk among first‐degree relatives (FDRs) and second‐degree relatives (SDRs) diagnosed with the same (concordant) invasive or in situ cancers. Calculations were based on the Swedish Family‐Cancer Database considering 8,148,737 individuals. To assess environmental effects, PAFs were also calculated for concordant cancers among spouses. Almost all cancers showed a significant familial risk. The highest PAFs were found for the common cancers of the prostate (13.94%), breast (7.46%) and colorectum (6.78%) among the FDRs. In the FDRs, the overall PAF for any concordant cancer was 4.20%, but in the SDRs, it was only 0.34%. The overall PAFs for in situ cancers were 0.86% and 0.56% for the FDRs and SDRs, respectively. The overall independent familial PAF was 5.96% for the invasive and in situ cancers in the FDRs and SDRs. The cancers between spouses yielded an overall PAF of 0.14%. For esophageal cancer, the risk among spouses was higher than the familial risk. Our study shows that the overall familial PAF of 5.96%, although underestimated for sex‐specific cancers, ranks as the third most common population burden after tobacco smoking and unhealthy diet.