Holocaust survivors have a small but consistent increase in the risk of developing cancer, in particular colorectal and lung cancers, according to a new study.
The findings offer an example of how extreme population-level tragedies can have an impact on health.
“The data emphasize the importance of learning about the combined effect of several exposures occurring intensely and contemporaneously on cancer risk, such as those that unfortunately occurred during World War II,” said lead author Siegal Sadetzki, MD, MPH, of the Chaim Sheba Medical Center in Israel. “Such inspection cannot be conducted by experimental studies and could only be evaluated by using observational epidemiological surveys.”
During World War II, Holocaust survivors were exposed to a variety of factors that have been linked with cancer, including starvation, overcrowding, infectious diseases, and psychological stress. The researchers studied 152,622 Holocaust survivors who were followed for more than 45 years.
The researchers published their results in Cancer.
This is the largest and most comprehensive observational study assessing cancer risk among Holocaust survivors based on individual data, they stated.
The main analysis was based on a comparison between individuals who were entitled to compensation for suffering persecution during the war and individuals who were denied compensation. A complementary analysis was based on an individual’s country of origin, using a classification of countries during the war that included those directly governed by Nazi Germany as well as non-occupied countries.
Cancer was diagnosed in 22% of those who were granted compensation for suffering persecution during the war vs 16% of those who were denied compensation. Adjusting for birth cohort, sex, country of origin, and period of immigration, both analyses revealed significant increased risks of developing cancer in those who were exposed, the researchers stated.
Survivors who were granted compensation had a 6% higher risk of developing any type of cancer than those who were denied compensation, and they had a 12% increased risk for colorectal cancer and a 37% increased risk for lung cancer.
Those born in occupied countries had an 8% increased risk of developing any cancer over those born in non-occupied countries, as well as increased colorectal cancer and lung cancer risks of 8% and 12%, respectively.
There were no elevated risks for breast cancer and gynecologic cancers among female survivors.
Nutritional risk factors may affect colorectal tumor development. The researchers noted that an association between colon cancer and deficiencies of vitamin D, minerals, calcium, and folic acid has been reported. These deficiencies were prevalent in the ghettos and concentration camps.
The impact of emotional stress on cancer development might be indirect and influenced by lifestyle habits, such as smoking. “This observation might explain the increased risk for lung cancer observed in our study,” they stated.
An accompanying editorial notes that the extreme deprivation experienced by Holocaust survivors and cancer may also have parallels with other extreme population-level events, including in racial/ethnic minority groups who experience severe social deprivation over time.