June 1, 2021

Impact of disparities on precision medicine

By ION

Nearly 34% of cancer deaths of adults (ages 25-74) in the United States could be prevented if disparities did not exist, according to the AACR Cancer Disparities Progress Report 2020.

Data shows that Blacks have the highest overall cancer death rate, seen specifically in prostate cancer where they are at 111% higher risk of death than white patients with the same cancer.¹ It is the disparities in genomic testing, access to treatment, clinical trial data and other social determinants of health that influence care.

Different patient populations may have different likelihood genetically, which may translate into different molecular profiles by tumor type, as well as different ways that population responds to treatments. Medical guidelines recommend that tumors in patients with advanced disease or who have relapsed be tested for actionable genomic profiles – whether through tissue biopsy or liquid biopsy.

With clinical trials targeting patients with genetic alterations, the results can be skewed because of the study participants. Data from 2018 showed that nearly 80% of participants were of Northern European descent (while they represent only 10% or less of the global population), with only 2% representing Black populations.²

Other social determinants like geographic location (29% less women in rural areas receive radiotherapy after breast surgery for ductal carcinoma in situ than those in urban areas)³ or insurance coverage (27% of those patients without health insurance are less likely to receive neoadjuvant or adjuvant radiotherapy for locally advanced soft tissue sarcoma treated with limb sparing surgery than those with commercial insurance)⁴ are also important factors to consider when thinking about overall access to care.

The first step in looking at treatments for specific cancers is determining the genomic information. Studies have demonstrated that while evaluating Caucasian and Black patients diagnosed a specific breast cancer, there may be some overlapping variants. Yet each race has its own set of variants; many of which are not addressed as the clinical trial data is skewed towards northern Europeans. Healthcare providers may not see the expected longitudinal journey for non-white patients with their other patients.

As the unique genomic profile can impact the outcome, providers will not experience equal access or availability of precision medicine testing and therapies across the country until those determinants and specific race disparities are addressed.

This information is taken from a Precision Medicine meeting sponsored by ION Solutions for its members. To view the presentation, visit: https://www.iononline.com/meetings-login and click on Dr. Patel’s presentation under the Precision Medicine Meeting – ‘Updates in Precision Medicine, March 20, 2021.’