Quest Diagnostics, a diagnostics services provider in oncology and genetics, has announced that it will provide clinical laboratory testing using the Ki-67 IHC MIB-1 pharmDx (Dako Omnis) immunohistochemistry companion diagnostic for early breast cancer.

On October 13, 2021, the U.S. Food and Drug Administration (FDA) approved Eli Lilly and Company’s Verzenio (abemaciclib), in combination with endocrine therapy (tamoxifen or an aromatase inhibitor), for the adjuvant treatment of adult patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), node-positive, early breast cancer (EBC) at high risk of recurrence and a Ki-67 score of ≥20% as determined by an FDA-approved test. Ki-67 is a marker of cellular proliferation. Verzenio is the first and only CDK4/6 inhibitor approved for this patient population.  

In aligned actions, the FDA also granted pre-market approval to Ki-67 IHC MIB-1 pharmDx (Dako Omnis) from Agilent Technologies Inc. as a companion diagnostic for Verzenio. Quest is the first laboratory to have validated the test in conjunction with Agilent. Since the validation of an IVD assay can take weeks, Quest is committed to providing the test as soon as possible, with plans to make it nationally available by the end of the month. 

“The imminent addition of Ki-67 IHC MIB-1 pharmDx (Dako Omnis) testing to our oncology menu underscores our commitment to providing precision medicine innovations with potential to improve outcomes for patients with cancer,” says Kristie Dolan, general manager, Oncology Franchise, Quest Diagnostics. “It also reflects our ability to create value-producing relationships across healthcare, building on our long-standing precision medicine collaboration with Agilent.”

Early Breast Cancer and Risk of Recurrence

It is estimated that 90% of all breast cancers are detected at an early stage. Although the prognosis for HR+ HER2- EBC is generally positive, 20% of patients will experience recurrence potentially to incurable metastatic disease.1 Risk of recurrence is greatest within the initial two to three years post-diagnosis, particularly in patients with node-positive, high risk EBC.2 Factors associated with high risk of recurrence include: positive nodal status, large tumor size (≥5 cm), high tumor grade (Grade 3), and high rate of cellular proliferation [Ki-67 score (≥20%)].3

Node-positive means that cancer cells from the tumor in the breast have been found in the lymph nodes in the armpit area. Although the breast cancer is removed through surgery, the presence of cancer cells in the lymph nodes signifies that there is a higher chance of the cancer returning and spreading.

Breast cancer has now surpassed lung cancer as the most commonly diagnosed cancer worldwide in females, according to GLOBOCAN. With approximately 685,000 deaths in 2020, breast cancer is the fifth-leading cause of cancer death worldwide.4 In the United States, it is estimated that there will be 281,550 new cases of breast cancer in 2021.5 Approximately 70 percent of all breast cancers are of the HR+ HER2- subtype.5

Featured Image: Illustration of the HER2 breast cancer gene. Illustration: Ibreakstock | Dreamstime


1 Early Breast Cancer Trialists’ Collaborative Group (EBCTCG). Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trials. Lancet. 2005;365(9472):1687-1717. doi:10.1016/S0140-6736(05)66544-0.

2 Verzenio [package insert]. Indianapolis, IN: Eli Lilly and Company.

3 Cheng L, Swartz MD, Zhao H, et al. Hazard of recurrence among women after primary breast cancer treatment–a 10-year follow-up using data from SEER-Medicare. Cancer Epidemiol Biomarkers Prev. 2012;21:800-809.

4 Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021;71(3):209-249

5 National Cancer Institute, SEER. Cancer Stat Facts: Female Breast Cancer. Accessed September 14, 2021.