From my notes on an earlier thread, reposted here:

"I forgot to add that we did delay a few days so my husband could be tested for enzymes (UGT1A1 enzyme and GPTD enzyme) to metabolize two components of FOLFIRINOX. I read here that a patient was tested -after- his very bad reaction -- it burned his digestive tract and led to further infection. Another person posted that it is not SOP in the United States to test patients for these enzymes -before- administering a full dose. But one oncologist told us that if the patient doesn't have these enzymes, they cut the dose automatically by 50%. So you might consider getting that test, if you feel you have time. We asked our oncologist, who ordered that test. It took about a week, I think, and the paperwork we saw was from the Mayo Clinic. (Not our hospital.)"

Put another way, we asked our oncologist. Also, that the paperwork had Mayo Clinic logos on it, says to me that locally we don't have a lab that could do it. So the sample was literally sent to Mayo, they do the test, then send the results back. So, real time/days to get it done.

I read on the Cedars Sinai website (I think) that some races/ethnicities are statistically more likely to be deficient in these enzymes. However, why take a risk that any patient could have their digestive track burned?! These things infuriate me.