§ Lord Alton of Liverpoolasked Her Majesty's Government:
Further to the Written Answer by Lord Hunt of Kings Heath on 16 January (WA 159), what are the assumptions made in Patrick Carroll's study entitled Abortion And Other Pregnancy-Related Risk Factors In Female Breast Cancer. [HL3071]
§ Lord Hunt of Kings HeathThe key assumption is that pregnancy-related factors are the main causes of the increasing incidence of breast cancer and these are the only variables considered in the analysis. While reproductive history is important, it is not the only influence; for example, genetic predisposition, the development of the breast screening programme and obesity will also affect incidence.
The main analysis in the report compared cumulative abortion rates and incidence of breast cancer and found a close correlation. However, correlation does not prove causation and the hypothesis linking abortion and breast cancer is still only a theory. Other factors that have increased over the same time period such as divorce rate could also show a correlation that would turn out to be spurious.