Precision Medicine in Cancer Care: We Know Better, So Why Don’t We Do Better?

Precision medicine, or personalized medicine, considers a person’s genes, environment, and lifestyle in preventing, diagnosing, and treating a disease. Precision diagnostic tests like those that assess hereditary cancer risk, pharmacogenomics (how the body metabolizes drugs, vitamins, and supplements), and the genetic mutations causing an individual’s cancer enable personalized treatment. These tools have been shown to provide cost and, more importantly, survival benefits to cancer patients. Despite its effectiveness, precision medicine is not routinely used. As a result, patients may suffer unnecessary side effects from non-tailored cancer treatments. This represents a clear example of what is often called the “research-to-practice gap” – despite significant research supporting precision medicine for cancer care, people rarely receive it.

Benefits of Precision Medicine

Early Detection

We know that some people carry genes that have been inherited from family members, which can put them at higher risk for developing cancer. Having clinical genetic testing that confirms an increased risk of hereditary cancer can impact lifestyle changes and potential prophylactic actions to decrease cancer risk. It can also mean health plan coverage for screening tests earlier or more frequently than is standard coverage. Detecting cancer at an earlier stage, rather than a later stage, can increase the likelihood of a cure. Knowing personalized cancer risk can empower individuals to manage their health.

‍Tailored Treatment

Like our unique fingerprints, we all have unique variations in our genes that affect how we break down medications. Pharmacogenetics testing identifies genetic differences that affect drug metabolism. Some people are poor metabolizers of certain medications, vitamins, or supplements and do not process these drugs as quickly as expected, causing increased side effects. Super metabolizers process drugs much more rapidly than expected, making certain drugs less effective. Without pharmacogenomic testing, patients will not know if they are poor metabolizers or super metabolizers. This can result in increased side effects, such as fatigue, nausea, and respiratory depression, and it can lead to wasted money on medications that do not work. These risks are exceptionally high for chemotherapy, as starting chemotherapy without knowing how you metabolize drugs can lead to hospitalizations or even death. Our clinical experience provides many examples of patients who suffered devastating side effects from cancer treatment medications that could have been avoided with pharmacogenetic testing.

Cutting-edge, Rarely Used

Precision medicine in oncology has resulted in a paradigm shift in cancer care. Rather than using chemotherapy to treat cancer based on its location, we can now tailor treatment to specific mutations. For example, national guidelines recommend molecular testing on all advanced-stage non-small cell lung cancer patients to look for targetable mutations. These cancers can be treated with non-chemotherapy agents, decreasing side effects and increasing survival rates. With such clear benefits, one would think all stage IV lung cancer patients would get mutational testing to look for targetable mutations, but this is not the case. Despite the recommendations that all stage IV NSCLC patients undergo molecular testing, a recent study showed that only 20-22% of patients completed this testing.³

Why Hasn’t This Been Implemented?

Unfortunately, this is not uncommon; research findings can take up to 17 years to make their way into clinical practice⁴. To ensure that all patients benefit from these research breakthroughs as early as possible, we must understand and address the reasons underlying the limited use of interventions with solid research support, such as precision medicine treatment in oncology care. Some contributing factors to the underutilization of genomic testing include the following:

Provider limitations of time, understanding, and resources for ordering and interpreting genetic test results. Educating providers and supporting them increases the incidence of these tests being ordered.⁵
companies dictate reimbursement based on strict guidelines as part of their business practice, which can be difficult for an individual to navigate.
The testing guidelines we use now are cancer site-specific, focusing on the location of the cancer, not the mutation that is driving the cancer.⁶
Implementation of these research breakthroughs can occur when guidelines are focused on cancer mutations, not cancer locations.⁶

Where Do We Go From Here?

Precision medicine can save money, time, and lives. The difficulty is implementing this in today’s medical practice. Bridging the gaps in implementing precision medicine within our current healthcare system will provide financial and survival benefits. Precision medicine allows us to examine what drives cancer and deliver personalized treatment. It is time for oncology care to be proactive, precise, and personal.

‍

Written By:

Marianne Gault, MSN, BS, RN, OCN, is the Head of Clinical Services, Kadance

Hannah Frank, PhD, is a Clinical Psychologist and Implementation Scientist, The Warren Alpert Medical School of Brown University

‍

References

Haslem, D. S., Chakravarty, I., Fulde, G., Gilbert, H., Tudor, B. P., Lin, K., ... & Nadauld, L. D. (2018). Precision oncology in advanced cancer patients improves overall survival with lower weekly healthcare costs. Oncotarget, 9(15), 12316.
Hippman, C., & Nislow, C. (2019). Pharmacogenomic testing: clinical evidence and implementation challenges. Journal of personalized medicine, 9(3), 40. Hippman, Catriona, and Corey Nislow. "Pharmacogenomic testing: clinical evidence and implementation challenges." Journal of personalized medicine 9.3 (2019): 40.
Schilsky, R. L., & Longo, D. L. (2022). Closing the gap in cancer genomic testing. N. Engl. J. Med, 387, 2107-2110.
Morris, Z. S., Wooding, S., & Grant, J. (2011). The answer is 17 years, what is the question: understanding time lags in translational research. Journal of the royal society of medicine, 104(12), 510-520.
Waterhouse, D. M., Ward, P., Arnal, S., Neubauer, M., Drosick, D. R., Davies, D., & Mendenhall, M. A. (2023). Closing the testing gap: standardization of comprehensive biomarker testing for metastatic non–small-cell lung cancer in a large community oncology practice. JCO Oncology Practice, 19(6), e951-e956.
Tsimberidoll, A., Chen, H.Z., Nimeri, H., Kurzrock, R., Conneran, T. (2024, October 15-16). Rethinking tissue based classification of cancer, is it time to change to molecular classification? [Conference presentation]. Precision Oncology and Diagnostics Conference, Chicago, Il, United States.