Re: Cancer Incidence in Israeli Jewish Survivors of World War II/Response

Keinan-Boker et al conclude that Jewish European survivors of World War II are at increased risk for cancer and pose the hypothesis that this increased risk is due, in part, to extreme psychological stress they experienced. However, Johansen et al comment that to their knowledge, no study has shown that any psychological factor causes cancer and, to date, there is no convincing evidence that the psychological factors by themselves cause mutations or stimulate cells carrying mutations to proliferate. They propose that World War II survivors probably have a higher risk for cancer because of all other reasons mentioned in Keinan-Boker et al., except for psychological stress.