Competing breast cancer tests vie for attention from clinicians and payers at the San Antonio Breast Cancer Symposium.
The practice-changing results from TAILORx found that certain women with intermediate risk scores on the Oncotype DX test could be treated with endocrine therapy alone. In the aftermath, this weekend’s San Antonio Breast Cancer Symposium (SABCS) offered a forum for comparing new data for competing tests to direct breast cancer treatment.
Myriad Genetics touted results for EndoPredict, a test popular in Europe that company officials say is gaining ground with US payers because it can be used in both node-negative and node-positive cancers. Data presented included one from an independent research team in Germany, which found that EndoPredict high-risk patients who received adjuvant chemotherapy had 3-year disease-free survival of 96.3%, compared with 91.5% for high-risk patients who did not receive chemotherapy.1
Meanwhile, Genomic Health, maker of Oncotype DX, presented follow-up results to TAILORx, including a study on the negative impact of chemotherapy on quality of life, and a 500-patient study that researchers said showed the test’s value in both node negative and node positive cancers.
The issue of how the competing tests compare has been debated for some time. In 2016, there was considerable debate when the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO) split in their recommendations for Oncotype DX. A review of the clinical utility of Oncotype DX in the International Journal of Women’s Health concluded that while Oncotype DX was largely responsible for the decline in chemotherapy use in the United States since 2004, the test was expensive, and “the development and eventual validation of other genomic assays could potentially reduce test costs.”
The authors said while Oncotype DX is “well-validated in the node negative population,” clinicians will await results from the RxPONDER trial on its usefulness in the node-positive population.
TAILORx, presented in June at ASCO’s annual meeting, was designed to help personalize treatment for women 18 to 75 years of age with hormone receptor (HR)-positive, HER2-negative, axillary node (AN)-negative breast cancer, whose tumors were 1.1 cm to 5.0 cm in size and who had a mid-range recurrence score of 11 to 25.
Before these results, Oncotype DX did not offer a clear decision whether to use chemotherapy alongside hormone treatment. The trial showed that most women in this intermediate range could avoid chemotherapy, but it was advised for many women younger than age 50. The results also confirmed that hormone therapy alone is the right choice for those with a score of 0-10, and adding chemotherapy is called for when a score is 26 or higher.
Myriad officials said the data presented in San Antonio, coupled with payer response, show EndoPredict is poised to gain ground in the United States.
“Women with breast cancer, and the clinicians caring for them, will benefit from a single comprehensive solution to answer critical clinical questions about long-term prognosis, the need for adjuvant chemotherapy, and the need for extended endocrine therapy,” Johnathan Lancaster, MD, PhD, chief medical officer for Myriad, said in a statement.
In an interview with The American Journal of Managed Care®, Lancaster said the research presented at SABCS shows that EndoPredict is the most “comprehensive precision medicine test for women today,” due to its ability to give predictive information out to the 15-year mark. Lancaster said the results from the German researchers were “icing on the cake” alongside data from Myriad’s academic collaborators, who presented papers that reviewed a series of prospective studies2 and, for the first time, tracked the accuracy of EndoPredict scores out to 15 years.3
In this study, 95.5% patients using EndoPredict who were classified as low risk were free from early distant recurrence (0-10 years), and 95.7% were free from late distant recurrence (5-15 years). Among patients who were high risk, only 80.3% were free from early distance recurrence and 84.1% were free from late distant recurrence. Said lead author Martin Filipits, PhD, of the Institute for Cancer Research at the University of Vienna, the result suggests the test “can help select patients who can safely forgo extended endocrine therapy beyond 5 years.”
At SABCS, Ivana Sestak presented findings that confirmed results of 5 prospective studies involving 3746 patients with HR-positive, HER2-negative breast cancer who have received 5 years of endocrine therapy alone or in combination with chemotherapy.2 In 2016, Sestak co-authored a study in the Journal of the National Cancer Institute that concluded EndoPredict provided more useful information than Oncotype DX, in part because of the information about nodal status.
In the interview, Lancaster said Sestak’s results showed that Oncotype DX wasn’t designed to work as well on node-positive cancers and 19% of the patients in this group who used the test had a recurrence despite being classified as low-risk. For this reason, he said, “Payers have been massively on board.”
Ron Rogers, executive vice president for corporate communications at Myriad Genetics, said these results were causing payers to “vote with their feet,” and that 97% of those in the United States now cover the test, including Medicare.
Both EndoPredict and Oncotype DX are among the breast cancer tests included in the NCCN guidelines. In October, Genomic Health announced that NCCN had listed the Oncotype DX Recurrence Score as the only “preferred” test to help physicians make decisions regarding chemotherapy for patients with node-negative early-stage breast cancer.