Response to “Women’s Knowledge of Genomic Testing and Precision Medicine in Breast Cancer Treatment Decision-Making”

We would like to thank authors Robles-Rodriguez et al. (2024) for their recent article on patient perceptions and knowledge of genomic science in the treatment of breast cancer. The authors appropriately note that physicians may lack knowledge about genomic science, as it is not covered extensively in medical training. The same is true of nursing education (Thomas et al., 2023). Additionally, ever-expanding applications of genomics in cancer care have led to improved survival and expanded treatment options; however, the knowledge and competence of the cancer care team to apply the science, order and interpret correct tests, analyze test results, and share information with patients and families for shared decision-making is complex and daunting and creates confusion for patients and families. Correct and consistent use of terminology in this complex area is essential.

We would like to note that some of the genomic terms may not have been accurately defined. Robles-Rodriguez et al. (2024) state: “Genetic testing checks for variants or changes in a person’s DNA, but genomic testing examines a tumor’s molecular composition. Advances in genomic testing have led the way toward precision medicine, a treatment that is specific to a tumor’s genetic polymorphism” (p. 199).

The authors are describing germline and somatic (tumor) testing. Germline testing identifies variants associated with inherited cancer risk, and somatic testing identifies acquired variants in the tumor. The difference between genetics and genomics is in the amount of material analyzed. Genetics typically looks at one or a few genes, and genomics looks at the entire genome or all of an individual’s DNA and interaction with environmental factors. It is possible to analyze the entire human germline genome to better understand inherited risk for developing diseases.

A polymorphism is a variant with a frequency in the general population of greater than 1% (Richards et al., 2015). The use of the term polymorphism is not recommended, as it does not clarify the clinical meaning of a variant.

Germline variants are classified by pathogenicity (benign, likely benign, unknown significance, likely pathogenic, and pathogenic). Somatic variants are classified in tiers by actionability. Tier I lists variants with strong clinical significance in diagnosis, prognosis, or treatment and are included in clinical practice guidelines. Variants of potential clinical significance are classified as tier II, variants of unknown significance as tier III, and benign or likely benign as tier IV.

Precision medicine includes more than a dichotomous categorization of “germline as genetic” and “tumor as genomic,” which is not fully representative of all the types of genomic testing that are done in breast cancer (and other cancers as well) (Pichler et al., 2024). Genomic analysis for precision diagnosis and treatment in breast cancer is done for many purposes:

• To identify germline risk (inherited pathogen variants)
• To determine likelihood of recurrence (prognostic) and subsequent benefit from systemic adjuvant therapy (predictive) (e.g., gene expression analysis such as Oncotype DX^®)
• Comprehensive germline and somatic analysis in the advanced setting (stage IV) to determine biomarker status and eligibility for targeted therapy (e.g., PIK3CA-activating genomic alteration and treatment with alpelisib) (National Comprehensive Cancer Network, 2024)
• To predict drug response (e.g. genotyping of CYP2D6 alleles to determine tamoxifen metabolizer status)

The methodology in this study included that the researchers defined these terms to participants. Using consistent and accurate definitions is critical in all discussions and education about genetic/genomic terms, whether it be among healthcare professionals or patients and families. When terms are not accurately applied, the risk of error increases (Friend et al., 2021). The Oncology Nursing Society Genomics and Precision Oncology Learning Library has a taxonomy of terms that relate to genomic and precision medicine, as well as many professional resources and tools to facilitate patient education (www.ons.org/learning-libraries/precision-oncology). The umbrella term is biomarker and biomarker testing and then further separated by whether one is testing the germline or the tumor (somatic).

As Robles-Rodriguez et al. (2024) note, patients want and desire information about precision medicine. Accurate and consistent definition and usage of genomic terms is an important first step in this process. Improving one’s own genomic literacy and using correct terms is critical to ensure that the benefits of genomics can be realized across the cancer care continuum (Chapman et al., 2019; Martin et al., 2021).

About the Authors

Suzanne M. Mahon, DNS, RN, AOCN^®, AGN-BC, FAAN, is a professor emeritus in the Department of Internal Medicine in the School of Medicine and in the Trudy Busch Valentine School of Nursing at Saint Louis University in Missouri and Patricia Friend, PhD, APRN-CNS, AOCNS^®, AGN-BC, is an associate professor and program director in the Marcella Niehoff School of Nursing at Loyola University Chicago in Maywood, IL. No financial relationships to disclose. Mahon can be reached at suzanne.mahon@health.slu.edu, with copy to ONFEditor@ons.org.

The Author Responds

The authors would like to thank Drs. Suzanne Mahon and Patricia Friend for their feedback and thorough review of our article. We completely agree that health professionals of all disciplines may struggle with the knowledge, language, and terminology around genomic science, which could lead to confusion among patients and families. This becomes even more difficult when we deal with underserved communities in which literacy levels and language also play major barriers to shared decision-making.

When we designed this study, we utilized terms and definitions found in patient education materials such as those from the National Cancer Institute and American Cancer Society. You are correct that germline (genetics) and somatic (genomic or tumor testing) are the specific scientific terms, but not the terms commonly heard by our patients.

The terms that were used in the focus groups and those that the women in this study recognized were around genetic testing and not around tumor testing. Most of the women had limited knowledge of the terms we asked them about, with only a few whose awareness of genetic testing was limited to BRCA testing. The authors do not believe that adding more complicated terms or definitions would have had influence in the awareness or knowledge of these individuals or affect the outcomes of the study. So, when you brought attention to our use of terms in this paper, particularly in the sentence referring to polymorphism, that was not a term used with the focus groups.

However, in our paper, and in other articles that consider variants in genes, such as Sheng et al. (2024), recently published in the Oncology Nursing Forum, polymorphism is a term that was used. Our use of the term polymorphism is in line with this description: “Polymorphism, as related to genomics, refers to the presence of two or more variant forms of a specific DNA sequence that can occur among different individuals or populations. The most common type of polymorphism involves variation at a single nucleotide (also called a single-nucleotide polymorphism, or SNP)” (National Human Genome Research Institute, 2024, para. 1).

Genetics is defined by the National Human Genome Research Institute (2018) as “the study of genes and their role in inheritance” (para. 2). They define genomics as “the study of all of a person’s genes . . . including interaction of those genes with each other and with the person’s environment” (National Human Genome Research Institute, 2018, para. 3). Collins et al. (2021) note in their study of genetics and genomics that “the focus of genomics research has recently moved beyond analyzing DNA variation to studying patterns of gene expression in individual cells” (p. 3).

The American Cancer Society (2023) notes this about genomics: “On a broad level, genomics is helping researchers learn more about the gene and protein changes inside different cancer cells. This is being used to develop newer cancer treatments aimed at these gene and protein changes” (para. 6).

The purpose of this study, which we succeeded in confirming, is that there is an incredible amount of research and knowledge about genetics and genomics, specifically in cancer care. But this knowledge has not been translated to clinical treatment and is especially not seen in the care of low-income, uninsured, and diverse populations of women. We all should try to learn more and to stay current on research, but we must also be sure that students (in nursing and medicine) are learning what they need to about these exciting breakthroughs that will improve cancer care. And we need to see these new and innovative treatments being used with all our patients with cancer, including those in community cancer centers.

Again, thank you for your review and feedback. We will continue to strive to educate our underserved community and ensure they receive accurate information that can help improve their care.

About the Author

Evelyn Robles-Rodríguez, DNP, APN, AOCN^®, is the director of outreach, prevention, and survivorship at MD Anderson Cancer Center at Cooper in Camden, NJ. No financial relationships to disclose. Robles-Rodríguez can be reached at robles-evelyn@cooperhealth.edu, with copy to ONFEditor@ons.org.