As 2020 and 2021 have shown us, Canadians are becoming more aware — and increasingly concerned — about addressing systemic inequities and racism. From the thousands of Indigenous children found buried at residential school sites to the Black Lives Matter movement, Canadians and Canadian institutions are becoming deeply concerned about equity, diversity and inclusion.
At the same time, medical research has long been known to have an inequity issue, especially in clinical trials. One of the more recent and potentially transformative new types of medicine — precision medicine — is no exception. While precision medicine offers the possibility of customized treatments based on individuals’ genetic background, lifestyle and environmental history, it is also fraught with biases that may undermine its potential.
In precision medicine, genomic markers for a given disease are discovered using extremely large sample sizes — from thousands to hundreds of thousand of people. Small associations are then detected between individual genetic variants and a disease. These genomic variants are typically combined into an additive score, called a polygenic risk score. This score may be validated in clinical medicine to test for disease risk in an individual and used for screening in larger clinical populations.
The potential of precision medicine is only just beginning. It will create new possibilities for assessment and treatment by allowing patients with the highest risk and fastest progression of disease to be identified and prioritized for care. For instance, a 2021 study found that a breast cancer polygenic risk score is useful in parallel with mammograms for identifying women in need of repeated screening.
Precision medicine’s promise shrouds a problem however. Examination of our own research and others’ shows that more than 80 per cent of our recruited genomic samples are of European descent. This problem leads logically to reduced quality of care for patients of different ethnicities. Conducting foundational genomic research with more diverse populations, even if the sample proportion is small, is highly beneficial.
However, engaging historically-oppressed populations in genomics research poses challenges. Often, there is a reasonable distrust in science and government systems and we need to repair relationships with First Nations and other communities.
Patient engagement is paramount and fortunately, platforms exist to support researchers in Canada. The Canadian Institutes of Health Research (CIHR) Support for Patient-Oriented Research SUPPORT Units criss-cross the nation, offering connections for patients to engage in research. Genome Canada supports equity, diversity and inclusion; however funders and researchers need to set a higher bar for recruiting diverse participants into new genomics studies.
We need to be vigilant and purposeful in prioritizing diversity in genomics research to avoid precision medicine becoming the next source of inequality in Canada.
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