Testing Biomarkers in Breast Cancer
Breast cancer in the United States
- Comprises approximately 30% of all newly diagnosed cancers in women1
- Is the second leading cause of cancer deaths in women1
- Women have a 1 in 8 lifetime risk of being diagnosed with breast cancer2
Accurate biomarker testing may help personalize patient care3
Breast cancer biomarkers (eg, hormone receptors, HER2) are used to identify patients who may benefit from targeted therapy3
Learn more about select biomarkers
HER2 is amplified and/or overexpressed in 15% to 20% of breast cancers and is associated with aggressive disease4,5
ASCO/CAP Guidelines recommend HER2 testing for all patients with invasive breast cancer6
- Perform HER2 testing on all newly diagnosed patients with breast cancer and on a metastatic site in patients who then develop metastatic disease, if a tissue sample is available6
The updated AJCC 8th edition staging for breast cancer now incorporates HER2 status7
HER2 status has been added to staging in a new clinical prognostic stage grouping to add additional information beyond the anatomic classification.7
- The AJCC 8th edition prognostic groups are based on breast cancer patients having been offered and treated mostly with endocrine and/or chemotherapy and/or anti-HER2 therapy, as appropriate7
Using 8th edition criteria, more than 35% of patients with HER2-positive tumors were reassigned to a stage group higher or lower than would otherwise be assigned using the 7th edition.7
ASCO/CAP=Oncology/College of American Pathologists; AJCC=American Joint Committee on Cancer; ER=estrogen receptor; HER2=human epidermal growth factor receptor 2; M=metastatic status; N=lymph node involvement; PgR=progesterone receptor; T=primary tumor
PD-L1 biomarker testing for triple-negative breast cancer (TNBC)
TNBC accounts for ~15% of all breast cancers9
- Lack estrogen- and progesterone-receptor expression and do not overexpress HER210
- Are associated with an aggressive clinical course, poor prognosis, and a high risk of local and distant recurrence11,12
PD-L1 is a biomarker to help predict tumor responses11,13,14
PD-L1 may be expressed on both tumor cells and tumor-infiltrating immune cells13,15
Triple negative breast cancer (TNBC) tumors are highly immunogenic, with high levels of tumor-infiltrating immune cells, and express programmed death-ligand 1 (PD-L1)16,17
- In a study, approximately 40% of patients with previously untreated unresectable locally advanced or metastatic TNBC tested positive for PD-L118
Binding of the ligand PD-L1 to its inhibitory receptors programmed cell death-1 and B7.1 on T cells can suppress cytotoxic T-cell activity through T-cell deactivation13
Assessing PD-L1 Expression in TNBC
When using the SP142 assay, IC staining for PD-L1 is prevalent across different tumor types19,20
For certain tumor types, such as TNBC, PD-L1 expression in immune cells is higher than in tumor cells, emphasizing the importance of scoring PD-L1 expression in immune cells.11
Assessing PD-L1 Expression in TNBC
FFPE=formalin-fixed paraffin-embedded; NSCLC=non-small cell lung carcinoma; PD-L1=programmed death-ligand 1; TC=tumor cells.
- American Cancer Society (ACS). Cancer Facts & Figures
2018. Atlanta, GA: American Cancer Society Inc.; 2018.
- American Cancer Society (ACS). Breast Cancer Facts 2017-2018. Atlanta, GA: American Cancer Society, Inc.; 2017.
- Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Breast Cancer V.3.2019. © National Comprehensive Cancer Network, Inc. 2019. All rights reserved. Accessed December 10, 2019. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
- Wolff AC, et al. Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline update. J Clin Oncol. 2013;31:3997-4013.
- Howlander N, et al. US Incidence of Breast Cancer Subtypes Defined by Joint Hormone Receptor and HER2 Status. J Natl Cancer Inst. 2014;106(5)
- Wolff AC, et al. Human epidermal growth factor receptor 2 testing in breast cancer. Arch Pathol Lab Med. 2018. doi:10.5858/arpa.2018-0902-SA.
- American Joint Committee on Cancer. AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer; 2017.
- American Joint Committee on Cancer. AJCC Cancer Staging Poster. 7th ed. New York, NY: Springer; 2009.
- Székely B, et al. New therapeutic strategies for triple-negative breast cancer. Oncology (Williston Park). 2017;31:131-137.
- Foulkes WD, et al. Triple-negative breast cancer. N Engl J Med. 2010;363:1938-1948.
- Li M, Li A, Zhou S, et al. Heterogeneity of PD-L1 expression in primary tumors and paired lymph node metastases of triple negative breast cancer. BMC Cancer. 2018;18(1):4. doi: 10.1186/s12885-017-3916-y.
- Lin NU, et al. Clinicopathological features, patterns of recurrence, and survival among women with triple-negative breast cancer in the National Comprehensive Cancer Network. Cancer. 2012;118:5463.
- Chen DS, et al. Elements of cancer immunity and the cancer–immune set point. Nature. 2017;541:321-330.
- Hedge PS, et al. The where, the when, and the how of immune monitoring for cancer immunotherapies in the era of checkpoint inhibition. Clin Cancer Res. 2016;22:1865-1874.
- Mittendorf EA, et al. PD-L1 Expression in Triple-Negative Breast Cancer. Cancer Immunol Res. 2014;2(4):361-370.
- Liu Z, et al. A comprehensive immunologic portrait of triple-negative breast cancer. Transl Oncol. 2018;11:311.
- Gatalica Z, et al. Programmed cell death 1 (PD-1) and its ligand (PD-L1) in common cancers and their correlation with molecular cancer type. Cancer Epidemiol Biomarkers Prev. 2014;23:2965.
- Schmid P, et al. N Engl J Med. 2018;379:2108.
- Emens LA, et al. Presented at: San Antonio Breast Cancer Symposium; December 4-8, 2018; San Antonio, TX.
- Rosenberg JE, et al. Lancet. 2016;387:1909-1920.
- Genentech. Data on File. 2019.
- Fehrenbacher L, et al. Lancet. 2016;387:1837-1846.
- US Food and Drug Administration. https://www.fda.gov/medicaldevices/productsandmedicalprocedures/invitrodiagnostics/ucm301431.htm. Accessed December 12, 2019.
- Roche. VENTANA PD-L1 (SP142) Assay Interpretation Guide for Triple-Negative Breast Carcinoma. 2019.