A study by researchers at RCSI University of Medicine and Health Sciences has found specific causes that contribute to the differences in the immune responses of patients of African and European ancestry to bowel cancer.

For the first time, the study provides useful insight into why outcomes for bowel cancer patients of African ancestry are poorer than for patients of European ancestry. The findings rationalise development of new therapeutic agents that can target these differences in order to improve outcome in bowel cancer patients with African ancestry.

The study is published in the current edition of the Gastro Hep Advances.

Dr Sudipto Das, lead researcher and principal investigator in the RCSI School of Pharmacy and Biomolecular Sciences, said: “The immune response to bowel cancer is known to be reduced in patients of African ancestry compared to patients with European ancestry. In addition, incidence of bowel cancer is known to be higher amongst patients with African ancestry than any other ethnic group. Societal factors such as low income, racial segregation and lower education levels have been associated with reduced rates of bowel cancer screening, resulting in higher incidence of the disease. However, there is little evidence to date on biological reasons for the differences in the progression of the disease between Africans and Europeans.

“For the first time, this study gives us an insight and shows that differences at a gene level between patients with African and European ancestry with bowel cancer may play a role in the immune response that contributes to poorer outcomes for patients with African ancestry.  The study is extremely important for the research and treatment of bowel cancer.”

In the study, an analysis of data from the cancer genome atlas with over 400 bowel cancer patients including patients with African and European ancestry was conducted with the aim of identifying gene level differences between both these ethnically diverse bowel cancer patient populations.

For the first time, this study identified molecules called ‘master regulators’ that control genes associated with anti-cancer immunity in bowel cancer patients of both African and European ancestry. The study found that bowel cancer patients of African ancestry had reduced numbers of these molecules when compared to patients of European ancestry, which is a suggested cause of poor anti-cancer immunity in these patients with bowel cancer.

The findings of this study will inform development of new treatment options with the aim of improving anti-cancer immunity in bowel cancer patients with African ancestry. More importantly, this study provides a clear rationale as to why it is important to assess the molecular differences that impact cancer progression across patients of different ethnic backgrounds.

The study was conducted by RCSI in collaboration with the Albert Einstein Cancer Centre in New York, GeneXplain GMbH, Germany; Columbia University and St Jude’s Children’s Research Hospital, Memphis.