Jerusalem’s Hebrew University has facilitated joint Israeli-Palestinian cancer research that will benefit both populations as well as medical science in general.  

Non-Hodgkin lymphomas (NHL), tumors that could originate from B or T lymphocytes, account for approximately three percent of cancer cases worldwide. Most epidemiological studies of NHL have been carried out in North American and European populations, with a few focusing on East Asian populations. Very few epidemiological studies have been conducted on B-cell non-Hodgkin lymphoma (B-NHL) in Middle Eastern populations.

Since Israelis and Palestinians represent genetically and culturally diverse populations living in geographic proximity, research analyzing their risk factors would enrich science’s understanding of genes versus environment in the causation of lymphoma. Despite sharing the same ecosystem, the populations differ in terms of lifestyle, health behaviors and medical systems.

Both populations report high incidences of NHL, which represents the fifth most common malignancy in Israel and the eighth among Palestinians from Judea and Samaria. As of 2012, Israel also ranked first in the world in NHL incidence rates.

Israeli and Palestinian researchers, under the guidance of Professor Ora Paltiel, director of the Hebrew University-Hadassah Braun School of Public Health and Community Medicine and a senior physician at Hadassah’s hematology department, have conducted a large scale epidemiological study examining risk factors for B-NHL and its subtypes in these two populations.

Recruiting from both the Palestinian Arab and Israeli Jewish populations, the researchers looked at medical history, environmental and lifestyle factors among 823 people with B-cell non-Hodgkin lymphoma (B-NHL) and 808 healthy controls. Using data from questionnaires, pathology reviews, serology and genotyping, they uncovered some risk factors common to both populations and others unique to each population.

Similar Risks

The data, reported in the peer-reviewed journal PLOS ONE, shows that in both populations, overall B-NHL was associated with recreational sun exposure, black hair dye use, a history of hospitalization for infection, and having a first-degree relative with blood cancer.

An inverse association was noted with alcohol use. Certain exposures, including smoking and greater-than-monthly indoor pesticide use, were associated with specific subtypes of B-NHL.

Different Risks

Among Palestinian Arabs, risk factors included gardening and a history of herpes, mononucleosis, rubella and blood transfusion, while these factors were not identified in the Israeli Jewish population. In contrast, risk factors that applied to Israeli Jews only included growing fruits and vegetables and self-reported autoimmune diseases.

The researchers concluded that observed risk factors according to ethnicity could reflect differences in lifestyle, medical systems and reporting patterns, while variations by lymphoma subtypes infer specific causal factors for different types of the disease. These findings require further investigation.

The fact that risk factors operate differently in various ethnic groups raises the possibility of gene-environment interactions, meaning that environmental exposures act differently according to genetic background.This divergence may also reflect differences in diet; cultural habits; socioeconomic, environmental and housing conditions; medical services; exposure to infections in early life or other factors.

Unique Joint Scientific Effort

This study, reflecting a unique joint scientific effort involving Israeli and Palestinian investigators,  demonstrates the importance of cooperative research even in politically uncertain climates. Cancer epidemiology will be enriched through the broadening of analytic research to include understudied populations from a variety of ethnicities and geographic regions.

“Apart from the scientific contribution that this research provides in terms of understanding risk factors for NHL, the study entails important research cooperation among many institutions. The study provided opportunities for training Palestinian and Israeli researchers, and will provide for intellectual interaction for years to come,” said Paltiel.

“The data collected will also provide a research platform for the future study of lymphoma. Epidemiologic research has the potential to improve and preserve human health, and it can also serve as a bridge to dialogue among nations,” she added.

By: United with Israel Staff