(CHICAGO, IL) — Patients with cancer willing to undergo chemotherapy were also willing to pay for pharmacogenetic testing, even if it meant waiting 2–3 weeks for results, according to a study reported at the 2012 American Society of Clinical Oncology Annual Meeting.

However, “while patients with cancer have a strong desire to be involved in decision making regarding pharmacogenetic testing, a considerable proportion lacked the necessary knowledge to make informed choices,” said Henrique Hon, MEng, of the Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario, Canada.

Hon and colleagues interviewed a broad cross-section of 278 patients with lung (20%), breast (19%), colorectal (20%), and other (40%) cancer who first completed a baseline questionnaire. The interviews used hypothetical trade-off clinical scenarios outlining use of chemotherapy in either an adjuvant or metastatic setting that assessed efficacy and toxicity of chemotherapy, cost of pharmacogenetic testing, wait time for test results, and prevalence of genetic variation of interest (ie, the likelihood of the test influencing treatment change).

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Of the patients approached, 92% consented to participation, 153 in the adjuvant scenario group and 125 in the metastatic group. Patients in the metastatic group were older (61 vs 58 years; P=0.04), male (62% vs 47%; P=0.01) and had lung and head and neck cancer (34% vs 24%); in the adjuvant group, more patients had breast cancer, 19% vs 8%. This group was also significantly more likely to have had previous chemotherapy, previous targeted therapy, clinical trial experience, and previous genetic/genomic testing.

Among patients who accepted adjuvant chemotherapy (94%), 98.6% accepted pharmacogenetic testing in an idealized scenario where testing was free, the turnaround for results was 1–2 days, and the prevalence of the genetic variations associated with lack of response was 50%. Among those who accepted palliative chemotherapy in the metastatic setting (97%), 97.5% accepted the first two conditions and where prevalence of the genetic variation associated with severe side effects was 5%. Patient acceptance of pharmacogenetic testing declined with advancing age and among chemo-naïve patients, Hon said.

In the adjuvant group, patient perception of a reasonable price for the test was a median of $200 (range: $0-$25,000) and, in the metastatic group, $100 ($0-$5000). Willingness to pay was $1900 ($0-$25,000) in the adjuvant group and $1000 ($0-$15,000) in the metastatic group. “Patients were willing to pay more if they had higher incomes, better understood the scenario, or strongly valued prolonging life,” he reported.

Median acceptable wait time for test results was 21 days (0-90) in the adjuvant scenario and 14 days (1-90) in the metastatic scenario (P=0.12). Longer wait times were more acceptable among non-Caucasians, highly educated patients, and patients who strong valued confirming treatment choice.

The majority of patients (71% adjuvant, 78% metastatic) believed both physician and patient should decide on the need for pharmacogenetic testing; however, 1 in 5 (20% adjuvant; 22% metastatic) admitted they lacked a basic understanding of what pharmacogenetic means and its clinical implications. “Improved education is necessary for patient participation in decision-making,” Dr. Hon concluded.