Samhita writes about a study that tries to look into why black American women who suffer from breast cancer are likelier than white American women to die. I’ve only read the article about the study that she links to, but it’s well worth it.
Black women with breast cancer are more likely to suffer from a more aggressive and harder-to-treat type of tumor than other women, according to a study of more than 2,100 Houston patients.
In research that cautions against putting too much emphasis on socioeconomic factors, scientists at the University of Texas M.D. Anderson Cancer Center reported Monday that tumor biology is a component in the lower rates of breast cancer survival among black women.
Researchers have known for some time that black women are less likely than whites to get breast cancer, but more likely to die from it. Although tumor biology has been implicated in previous research, more attention has gone to access to health care, differing treatments, socioeconomic status and racial bias.
The research is good insofar as it differentiates two of the three possible reasons why this is so. First, there is obvious socioeconomics: black women are likelier to have no health insurance, live in areas where the hospital system is worse, be discriminated against in treatment, and so on.
The second obvious reason is genetics. It’s plausible that when humans migrated out of Africa, one of the mutations they carried with them made them slightly more resistant to tumors. Apparently one of the mutations made them more susceptible to getting breast cancer, so there’s no reason why they wouldn’t also get less potent cancers.
But there’s a third reason, which the research doesn’t seem to distinguish from the second. Treatment of tumors is tailored to non-black people. The countries where most medical experiments are done have a white or Asian majority, and the black people who do live in them tend to be poor and marginalized enough that they’re underrepresented among test subjects. So the drugs that make it to the market tend to be the ones that work on white and Asian people the best. Since genetically humans are humans, these drugs are generally also the ones that work on black people at best, but the correlation is not perfect.
Although it’s relatively straightforward to disentangle the first possible reason from the other two, disentangling the second from the third is extremely difficult, except in one case: when there is total lack of treatment. If untreated tumors are likelier to kill black women than non-black ones, we can know the second cause applies. With treated tumors, it’s possible to devise a standard for racially-neutral treatment, but there’s no guarantee any existing treatment will meet it.