Cancer risk among Holocaust survivors in Israel

We read with interest the article by Sadetzki et al, which confirmed our own findings regarding the increased cancer risk in Israeli Holocaust survivors. The higher risk for cancer of all sites as well colorectal and lung cancer in exposed subjects observed in both studies despite the different methodologies used further validates these results. However, although Sadetzki et al reported no increased risk of breast cancer, we found significant risk estimates of 1.20 to 2.44 depending on birth cohort. We used an ecologic definition for the exposure status in our study. All participants were Jews born in Europe between 1920 and 1945; exposed individuals were those who immigrated to Israel after 1945, whereas nonexposed individuals were those immigrating before 1945. Sadetzki et al doubted whether the groups in our study were comparable, and argued that the individually defined exposure status in their study added robustness to their results. Their exposure definition for the main analysis was based on data created for legal purposes and in our opinion also may have been prone to biases. Applicants for compensation based on the Victims of Nazi Persecution Act of 1957 had to: 1) be Jewish and Israeli citizens; 2) be held in Nazi concentration camps during World War II; 3) immigrate to Israel prior to 1953; and 4) have at least 25% disability. There is ample potential for misclassifications based on these criteria. For example, let us consider 2 applicants who had experienced similar atrocities throughout the war. The first had immigrated to Israel prior to 1953, and therefore was defined as exposed; the other immigrated to Israel after 1953, and thus was defined as nonexposed. Nevertheless, both applicants had identical exposures. Or let us assume that among these 2 applicants with similar exposures, one had a disability level of >25% (exposed), whereas the other had a lower level (nonexposed). Indeed, the Israeli Parliament dealt once and again with the inequalities caused by this legislation and created a series of additional laws in an effort to overcome these gaps, with partial success. In addition to misclassifications imposed by the letter of the law, others may have been introduced by human nature. Many entitled Holocaust survivors did not apply for compensation at all for various (personal, moral) reasons and are underrepresented among the exposed cohort, whereas some nonentitled persons, motivated by financial considerations, did apply and therefore most likely were included in the nonexposed group. Furthermore, Holocaust survivors who had applied directly to foreign governments (eg, Germany, Austria) and consequently were granted pensions based on their legislation were not entitled to apply in Israel, and therefore are not represented in the study cohort. In its annual report of 2010, the State Comptroller of Israel estimated that out of 243,000 Holocaust survivors living in Israel by the end of 2009, 135,000 (56%) were not entitled to any pension, 59,000 (24%) were receiving pensions based on Israeli laws, and 49,000 (20%) were receiving pensions from foreign countries. It is this latter group, whose members most likely would have been defined as exposed and who represent approximately one-fifth of all Holocaust survivors, that is entirely missing from the study cohort. A higher risk of breast cancer associated with exposure to wartime-related hunger was reported not only in our study but also by Elias et al based on individual data and referring to the Dutch “Hunger Winter” (the Dutch famine of 1944-1945) (hazard ratio, 1.48; 95% confidence interval [95% CI], 1.09-2.01). Likewise, Koupil et al reported higher mortality from breast cancer among women who experienced the siege of Leningrad (hazard ratio, 9.9; 95% CI, 1.1-86.5). Indeed, other studies found no similar associations, and the reason may be the different manner of caloric deprivation and the additional factors involved in each of these man-made exposures. Therefore, we conducted a population-based case-control study (regrettably not cited by the authors) regarding Israeli Holocaust survivors in which we explored this association based on individual-based exposure assessment to hunger throughout the war period by unique indices. Our results disclosed a higher risk of breast cancer in women who were severely exposed to hunger throughout the war compared with women with mild exposure (odds ratio, 5.93; 95% CI, 2.05-17.16), and adjusted for potential confounders, including World War II-related posttraumatic stress disorder. Sadly, the Israeli national government has decided to compensate Israeli Holocaust survivors diagnosed with lung and colorectal cancer (thereby fulfilling certain conditions) and deprive patients with breast cancer of a similar compensation based on the results of the research by Sadetzki et al while ignoring our and other researchers’ findings. Because breast cancer is the leading cancer type in Israel and the number of patients with breast cancer noted among Holocaust survivors is not negligible,