It is a widely expressed belief that predictive multiplex somatic genomic testing represents the ability to transform cancer care by identifying targetable alterations in multiple cancer genes. Do oncologists share this belief? How do they intend to use such tests in practice?

In a study reported in the Journal of Clinical Oncology, Stacy W. Gray, MD, AM, of Dana-Farber Cancer Institute, Boston, and colleagues surveyed physicians at a tertiary-care National Cancer Institute–designated comprehensive cancer center about their current use of somatic testing, attitudes about multiplex testing, and confidence in their knowledge of genomics as well as their ability to use and explain genomic information in practice.¹ They found considerable variation in intentions to incorporate such testing into clinical practice and frequent reporting of low “genomic confidence.”

Profile Study

In the study, all faculty members who provide clinical care to adult patients with cancer at Dana-Farber Cancer Institute/Brigham and Women’s Hospital were recruited between September 2011 and January 2012 to participate in the survey prior to the initiation of enterprise-wide multiplex testing as part of the Profile study. In the first part of the study, all patients with cancer were offered OncoMap, a test for 471 alterations in 41 cancer-related genes.

Test results were tiered based on clinical utility. Tier 1 results (genomic variants proven to be clinically relevant) and tier 2 results (potentially actionable genomic variants) could be returned to the patient’s provider with patient consent; disclosure of alterations of uncertain significance (tier 3 results—ie, all other genetic variants) was prohibited.

Physician Survey

The survey contained questions on use of genetic testing before the introduction of Profile (baseline testing), anticipated impact of testing, and sociodemographic and practice characteristics. Physicians were asked to estimate the proportion of patients who they would test, how often they would disclose results to patients, and how often they would use results in making treatment recommendations. They were also asked about the terms that they would use to describe multiplex testing to patients and about how much they agreed or disagreed with the decision to prohibit disclosure of tier 3 alterations.

A “genomic confidence” scale was constructed by combining three questions on physician confidence in their knowledge about genomics, ability to explain genomic concepts to patients, and ability to make treatment recommendations based on genomic information.

Baseline Data

Of 276 physicians contacted, 13 were ineligible and 160 (61%) completed the survey. Of respondents, 57% were medical oncologists, 29% surgeons, and 14% radiation oncologists, 37% were female, and 83% were research principal investigators.

Prior to the introduction of the Profile program, physicians ordered tumor genomic testing for an average of 24% of patients (range, 0%–100%), with testing for KRAS (25%), EGFR (24%), BRAF (24%), C-KIT (13%), BRC-ABL (13%), and JAK2 (9%) being most common.

Many physicians were “not very confident” or “not confident at all” in their knowledge of genomics (22%), ability to explain genomic concepts to patients (14%), or ability to make treatment recommendations based on genomic data (26%). The largest group of respondents rated themselves as “somewhat confident” in these three areas (approximately 50% in each category), whereas approximately 25% to 35% rated themselves as “very confident.” The average score on the genomic confidence scale indicated an average response of “somewhat confident.”

In analysis adjusting for potential confounders, high genomic confidence was associated with being a medical oncologist, being a researcher, and high baseline genomic test use.

Predicted Use of Testing

Overall, 18% of physicians stated they would test ≤ 10% of patients, whereas 25% said they would test 91% to 100%. Approximately 85%, 55%, and 42% of physicians felt that tier 1, tier 2, and tier 3 genomic alterations, respectively, should be discussed with patients, with approximately 15%, 25%, and 30%, respectively, indicating “do not know.” Approximately 70%, 50%, and 40% felt that tier 1, tier 2, and tier 3 wild-type results should be discussed with patients, with approximately 10%, 20%, and 25% indicating “do not know.”

Terms to describe testing to patients most frequently cited by physicians included tumor testing (77%), molecular testing (72%), tumor profiling (66%), genetic testing (62%), and biomarker testing (41%). On open-ended questioning, other terms physicians indicated they would use included tumor fingerprinting, treatment target testing, molecular biology testing, scanning for actionable mutations, and personalized therapy testing.

A majority of physicians indicated that OncoMap testing would “somewhat” or “greatly” increase patient treatment options (73%), prognostic information (62%), patient satisfaction (80%), time required to discuss treatment options with patients (73%), research opportunities (> 90%), and professional satisfaction (80%); 22% felt that OncoMap testing would increase their clinical uncertainty.

Predictors of Attitudes Toward Testing

Logistic regression modeling controlling for potential confounders was used to assess the effects of years since medical school, sex, type of physician (medical oncologist or radiation oncologist vs surgical specialist as reference category), researcher (vs nonresearcher) status, number of new patients each month, percentage of patients tested at baseline (prior to Profile), percentage of patents recommended for phase 1 of Profile, and confidence in genomics on the likelihood of wanting to test a majority of patients, disclosing tier 1 and tier 2 results, using tier 1 and tier 2 results to inform treatment recommendations, and agreeing with the policy prohibiting return of tier 3 results.

The analysis showed that higher genomic confidence was significantly associated with wanting to test a majority of patients (adjusted odds ratio [OR] = 6.09, P < .001), likelihood of disclosing tier 1 results (OR = 2.14, P < .05), likelihood of using tier 1 (OR = 2.46, P < .05) and tier 2 results (OR = 2.89, P < .05) to inform treatment recommendations, and disagreement with the policy of prohibiting disclosure of tier 3 results (OR = 0.38, P < .05).

Physicians with higher baseline genomic testing were significantly more likely to favor disclosing tier 2 results (OR = 1.02, P < .05). Medical oncologists were significantly less likely to favor disclosing tier 2 results (OR = 0.24, P < .05) and to believe that tier 2 results would help inform treatment recommendations (OR = 0.16, P < .05) compared with surgical specialists. No other significant associations were found.

The investigators concluded:

Physicians at a tertiary-care National Cancer Institute–designated comprehensive cancer center varied considerably in how they planned to incorporate predictive multiplex somatic genomic tests into practice and in their attitudes about the disclosure of genomic information of uncertain significance. Given that many physicians reported low genomic confidence, evidence-based guidelines and enhanced physician genomic education efforts may be needed to ensure that genomically guided cancer care is adequately delivered. ■

Disclosure: The study was supported by the Dana-Farber Cancer Institute and a grant from the American Cancer Society. For full disclosures of the study authors, visit jco.ascopubs.org.

Reference

1. Gray SW, Hicks-Courant K, Cronin A, et al: Physicians’ attitudes about multiplex tumor genomic testing. J Clin Oncol 32:1317-1323, 2014.