When It Comes to Learning Genetic Risks, Patients Have No Regrets

If your genetic background puts you at higher risk for cancer, would you want to know? Or would knowing your risk be too stressful?

That’s what researchers led by Allison W. Kurian, MD, MSc, of Stanford University are trying to find out. So far, it looks like patients have no regrets about learning their cancer risks.¹

Researchers are screening a diverse group of patients and referring those who face a high risk of hereditary breast/ovarian cancer syndrome for a multiplex gene-sequencing panel. In this case, patients were tested with the myRisk 25-gene hereditary cancer test. The test goes much further than traditional BRCA testing, in that it will reveal deleterious mutations that otherwise would not have been known, as well as variants of uncertain significance (VUS).

While the full study will eventually involve 2000 patients, interim results were presented at the San Antonio Breast Cancer Symposium this week, based on screening the first 500 patients. Of the first group, 332 were referred for suspicion of hereditary breast/ovarian cancer.

Patients were given a 25-item evaluation known as the Multidimensional Impact of Cancer Risk Assessment, or MICRA. They took the test both at the time they were first screened and 3 months afterward (a long-term follow-up is planned).

The Findings So Far

The patient group is diverse; while the group was overwhelmingly female (97%), so far they are 43% Hispanic, including 33% who speak Spanish only. One-quarter (25%) have only a high school education. A total of 48% had a history of breast cancer, 5% had had ovarian cancer, and 7% had previously had some other type of cancer, including skin, pancreatic, or colon cancer. Of the group, 11% had a deleterious mutation and 35% had a VUS. The 14 patients who had a deleterious mutation were able to receive clinically appropriate advice on how to reduce their cancer risk, beyond what they would have received from BRCA testing alone.²

When the study began, most of those taking did not think about cancer often or at all (69%), and few (7%) had thoughts of cancer that affected their daily lives. Three months later, after receiving their test results, little had changed for most participants.

MICRA scores at 3 months were low for distress, with a mean score of 2 out of 30, and for uncertainty, with a mean score of 7 out of 45. Scores were better than average for positive testing experiences at 9 out of 15. Most significantly, 82% (CI 72% to 88%) of the participants said they wanted to know all their results, even if the clinical relevance was not fully understood. A very high percentage (87%, CI 79% to 93%) said they never regretted knowing all their results.

The myRisk hereditary cancer risk panel, created by Myriad Genetics, evaluates 25 genes associated with 8 separate cancers: breast, ovarian, colon, pancreatic, endometrial, prostate, gastric, and melanoma. Myriad is supporting the study.

Anne Renee Hartman, MD, vice presdient of clinical development at Myriad Genetics Laboratories, said the patients' high level of comfort with receiving their information did not come as a surprise. "We anticipated this," she said. "If it's discussed appropriately with the patient, there's no need to have anxiety over it."

References

1. Kurian AW, Idos G, McDonnell K, et al. The patient experience in a prospective trial of a multiplex gene panel testing for cancer risk. Presented at the San Antonio Breast Cancer Symposium, December 8-12, 2015. Poster P2-09-07.

2. Idos G. Kurian AW, McDonnell K, et al. Interim analysis of multiplex gene panel testing for inherited susceptibility to breast cancer. Presented at the San Antonio Breast Cancer Symposium, December 8-12, 2015. Poster PD7-01.