Heritability in Cancer

Recently we have looked into the role of heritability in cancers. There have been many studies looking into to this and most have returned similar results. One study done by Kari Hemminki and colleagues found that genetic heritability contributed anywhere from 10-14% in the cancers studied. Another study by Paul Lichtenstein also concluded that inherited genetic factors make a minor contribution to the susceptibility of most neoplasms. This indicates that the environment has the principal role in causing sporadic cancer. Based on these studies I would estimate that the heritability factor of cancer is fairly low. Also because it is so low, selection would not have a major influence on the disease as there is not much to select for. Similarly the effects of inbreeding would also be minimal. However, in certain cases where inheritance does play a role, inbreeding could increase the probability of passing those genes on as it would also increase there exposure to selection.