Is pre-emptive pharmacogenetic testing in CRC patients viable within a community oncology clinic?

A recent study has shown that it is possible to implement pre-emptive pharmacogenetic testing into a community-based oncology clinic with results interpretation available for colorectal cancer patients before their scheduled initiation of chemotherapy.

“As pharmacogenetic testing in oncology expands, pharmacists should be prepared to optimize supportive medication regimens as well as chemotherapy with pharmacogenetic results,” said the researchers, led by Tiana S Luczak from the Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, US.

Luczak and her team conducted a single-arm proof-of-concept study at a large community-based health system. Patients provided samples for pharmacogenetic testing through an external vendor prior to chemotherapy initiation. An oncology pharmacist provided pharmacogenetic interpretation and pharmacogenetic-guided therapeutic recommendation to the treating provider.

Of the 40 patients recruited, 24 (60 percent) had a UGT1A1 variant, and all (100 percent) were DPYD*1/*1. Twenty-nine patients (72.5 percent) had available results for interpretation prior to the scheduled chemotherapy initiation (p<0.014).

Twenty (87 percent) of the 23 patients whose results were available in ≤5 weekdays were communicated with the treating provider before their chemotherapy session. Notably, a total turnaround time of ≤5 days significantly correlated with pharmacogenetic testing feasibility in a community-based oncology setting (p=0.03).

“Pharmacogenetics, in hand with precision medicine in oncology, represents an opportunity to holistically tailor a patient’s treatment regimen using both somatic and germline variants to improve efficacy and decrease toxicity,” the researchers said.

“Colorectal cancer patients represent a population with frequent use of fluoropyrimidine and irinotecan and are an ideal opportunity for implementation of pre-emptive pharmacogenetics as evidence supports pharmacogenetic testing for DPYD and UGT1A1 to reduce fluoropyrimidine and irinotecan toxicities,” they added.