Genetic contributions to risk can be estimated. One problem for claims is that a certain proportion of people will get cancer regardless of exposure to hazard. Those that by chance also have a history of negligent exposure, may win a claim.
Evidence from:
MFG Murphy et al. British Journal of Cancer. June (2001) Vol.84 #11 p 146.
A study of childhood cancer rates amongst twins, compared with national data, in England.
13,009 twins born between 1963-89 were eligible for the study. Their histories were checked on what is believed to be a very comprehensive cancer registry.
Registry entries up to 31 Dec 1995 were included.
Roughly 20% fewer cancers were found among twins than were expected. A statistically significant
result.
Comment
This finding is not unique, it confirms for example a 10% reduction in cancer rates among twins seen in
a study from Norway.
Epidemiology of childhood cancers should attempt to account for this effect in their