Outcomes data from two large population-based studies suggest that real-world clinical use of the Oncotype Dx breast cancer recurrence test from Exact Sciences, Madison, Wis, is consistent with previous clinical validation studies, including TailoRx, the largest-ever breast cancer treatment trial.1,2 The data reinforce the conclusion that Oncotype Dx can identify patients aged 50 or younger who can be treated with hormone therapy alone. These findings were reconfirmed more recently with the first-reported 10-year outcomes data.
For the 5-year outcomes, an analysis of data from the US National Cancer Database in more than 4,700 women age 40 or younger with node-negative disease showed a distribution of recurrence score results consistent with existing clinical evidence, with as many as 80% of patients having low recurrence score results (0 to 25). Higher recurrence score results were associated with worse 5-year overall survival.
Joseph A. Sparano, MD, FACP, Montefiore Einstein Center for Cancer Care.
Another analysis of data from the Surveillance, Epidemiology, and End Results (SEER) registry of the National Cancer Institute (NCI) provides real-world evidence of the value of the Oncotype Dx test in patients age 50 or younger with node-positive disease (up to three positive nodes). Results from more than 2,500 patients indicated a significant association between recurrence score results and mortality, with 5-year breast cancer-specific mortality of less than 2% among young patients with recurrence scores of 0 to 25 and no or unknown use of chemotherapy reported.
Separately, the first reported 10-year outcomes data from a large cohort of patients using the recurrence score results to guide treatment decisions in clinical practice has confirmed the major findings of the TailoRx study, including those related to distant recurrence risk.3 For this analysis, investigators worked with Clalit Health Services, the largest health services organization in Israel, where the use of chemotherapy was aligned with recurrence score results. The investigators examined medical records of more than 1,300 patients with node-negative breast cancer and applied the recurrence score cut points established by the TailoRx study.4
Steven Shak, MD, Exact Sciences.
The findings showed that patients with recurrence scores up to 25—the vast majority of whom were treated with hormonal therapy alone—had excellent outcomes at 10 years, with low rates of distant recurrence. For the group of patients with recurrence scores from 11 to 25, there were no statistically significant differences in 10-year distant recurrence rates between patients who received chemotherapy and those treated with hormonal therapy alone. These results are consistent with the primary findings of the TailoRx trial.
“Last year, TailoRx established the highest level of evidence and unprecedented precision supporting the use of the Oncotype Dx breast recurrence score test to guide adjuvant chemotherapy treatment for women with early-stage breast cancer,” says Joseph A. Sparano, MD, FACP, associate director for clinical research at the Albert Einstein Cancer Center and Montefiore Health System, and vice chair of the Eastern Cooperative Oncology Group and the American College of Radiology Imaging Network (ECOG-ACRIN) Cancer Research Group.
“The additional insight from the new analyses in young patients is consistent with, and further supports, the value of the recurrence score result in younger women,” says Steven Shak, MD, chief medical officer at Exact Sciences. “We are pleased to see the publication of new real-world evidence that reinforces the paradigm established by the TailoRx study, which has influenced positive treatment guidelines updates over the past 18 months and is having an important impact on global reimbursement and standard use of the Oncotype Dx test.”
For more information, visit Exact Sciences.
References
- Sammons S, Ren Y, Force J, et al. Characterization of Oncotype Dx recurrence score and chemotherapy utilization patterns in young women (≤ 40) with early stage ER+/HER–, lymph node negative breast cancer [abstract P3-08-10, online]. Poster presented at the San Antonio Breast Cancer Symposium, December 10–14, 2019. Available at: www.abstractsonline.com/pp8/#!/7946/presentation/972. Accessed February 14, 2019.
- Petkov VI, Kurian AW, Jakubowski DM, Shak S. Breast cancer-specific mortality (BCSM) in patients age 50 years or younger with node-positive (N+) breast cancer (BC) treated based on the 21-gene assay in clinical practice [abstract P3-07-01, online]. Poster presented at the San Antonio Breast Cancer Symposium, San Antonio, Texas, December 10–14, 2019. Available at: www.abstractsonline.com/pp8/#!/7946/presentation/949. Accessed February 14, 2019.
- Stemmer SM, Steiner M, Rizel S, et al. Ten-year clinical outcomes in N0 ER+ breast cancer patients with recurrence score-guided therapy. NPJ Breast Cancer. 2019;5:41; doi: 10.1038/s41523-019-0137-3.
- Sparano JA, Gray RJ, Makower DF, et al. Adjuvant chemotherapy guided by a 21-gene expression assay in breast cancer. N Engl J Med. 2018;379(2):111–121; doi: 10.1056/nejmoa1804710.
Featured image:
Courtesy Exact Sciences.
