Fergus Couch, PhD, from the Mayo Clinic, discusses with CancerNetwork about the new research with the CARRIERS study for African American patients with breast cancer.
This abstract was presented by Julie Palmer from Boston University. It’s again from the CARRIERS studies. The CARRIERS study is a large population-based study where we’ve taken approximately 40,000 breast cancer cases and about 35,000 matched controls, so aged-match controls from large cohorts around the United States, so these are the Nurses’ Health Studies, the California Teachers Study, the American Cancer Society Cancer Prevention Studies, and a few others. And we mutation screen those for all the predisposition genes.
Within that very large study, we did have a set of 5,000 African American breast cancer patients, and 5,000 control (patients). And of course, these are agnostic to, there’s no ascertainment by us here, these are people who came into these cohort studies, so they really do represent the underlying African American population. So, we mutation screen the 37 genes there and found some interesting things.
So, obviously BRCA1 and (BRCA2) are still relevant. BRCA1 was a little bit more frequent than we would see in the Caucasian or non-Hispanic white population. But there were a few other interesting findings, so PALB2 for instance was more frequent. It was over 1% frequency in the African American population. It might only be about half that in the Caucasian population. And then we did see that the ATM and CHEK2 genes, which are normally associated with ER-positive breast cancer, were a lot less frequent in the African American population. That of course goes along with the idea that there’s more triple-negative and ER-negative breast cancer that shows up in the African American population. So, it all made perfect sense. And then along those lines, some of the genes that we’ve recently shown to be associated with ER-negative and triple-negative disease, did come up as strong associations in the African American population. So, we’re talking about BARD1, RAD51C, RAD51D, PALB2, these are all very clear drivers of African American breast cancer.
So, the hope is that this had added information for this population, and this study is 5 times bigger than the next previous one, so I think we have some stable estimates of risk now in this population, and we have some age-related effects as well. And so, I think the take home message is that we can help provide maybe a little bit more precision or personal levels of risk assessment for the African American population. Whereas before we were really just borrowing the numbers from the Caucasian population, using it for that purpose, now we can be a little bit more precise and accurate.