Cancer incidence and mortality among members of the Danish resistance movement deported to German concentration camps: 65-Year follow-up

The widespread belief that a stressful life event increases cancer incidence and mortality was investigated in a unique cohort of all Danish male political prisoners, who survived the extremely stressful experience of life in German concentration camps between 1943 and 1945. A virtually complete cohort of all 1,322 Danish male political prisoners who survived deportation to German concentration camps were followed up for cancer incidence and all-cause and cancer-specific mortality from 1946 through 2010. Standardized ratios and 95% confidence intervals were calculated from the observed and expected numbers of cancers or deaths, the latter based on national rates. We observed slightly increased standardized cancer incidence ratio (SIR 1.16; 95% CI, 1.06-1.27), particularly of smoking- or alcohol-related cancers (SIR 1.31; 95% CI, 1.15-1.49) and nonsignificantly increased SIR of immune system- and hormone-related cancers (SIR 1.17; 95% CI, 0.80-1.65 and 1.05; 95% CI, 0.81-1.34 respectively). Both the standardized all-cause mortality ratio (SMR 1.11; 95% CI, 1.05-1.18) and cancer specific mortality ratio (SCMR 1.17; 95% CI, 1.01-1.26) were slightly increased, particularly from smoking- or alcohol-related cancers (SCMR 1.25; 95% CI, 1.06-1.45). The minor increased cancer incidence and cancer mortality among the survivors is probably not directly associated with exposure to this extreme stressful event, but may be indirectly mediated through behavioral responses to psychological stress, as reflected in the increased incidence of and mortality from tobacco- and alcohol-related cancers.