Precision Medicine in Oncology
Featuring excerpts used with permission from “Precision Medicine in Oncology: A Look at Lung Cancer Treatment.” Authors: Rebecca Borgert, PharmD, Magellan Rx Management, and Geoffrey R. Oxnard, MD, Associate Professor of Medicine, Dana-Farber Cancer Institute, Harvard Medical School. The full article can be found in the latest Fall 2019 issue of the Magellan Rx Report.
Precision Medicine in Practice: The Lung Cancer Story
A look at the evolution of lung cancer diagnosis and treatment over the past two decades offers the opportunity to explore the tremendous advances made in precision medicine. Of the two major types of lung cancer, small-cell and non-small-cell (NSCLC), the latter accounts for 80% to 85% of all lung cancer diagnoses.1 The most common subtypes of NSCLC are adenocarcinoma, which accounts for approximately 40% of NSCLC diagnoses; squamous cell (epidermoid) carcinoma, which accounts for approximately 25% to 30% of diagnoses; and large-cell (undifferentiated) carcinoma, which accounts for approximately 10% to 15% of diagnoses.1 The remaining 15% of NSCLC diagnoses are attributed to adenosquamous and sarcomatoid carcinoma.
In the U.S., lung cancer is the second most common type of cancer among both men and women, not including nonmelanoma skin cancers, and is second to prostate cancer in men and breast cancer in women. Lung cancer accounts for 13% of all new cases of cancer and mainly occurs in the older population, with most patients diagnosed at 65 years or older and very few patients diagnosed younger than the age of 45.1 Lung cancer is by far the leading cause of cancer death among both men and women. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined.1 The American Cancer Society estimates there will be 228,150 new cases of lung cancer and 142,670 deaths from lung cancer in 2019.
The Role of Precision Medicine in Lung Cancer
Genomic testing is used in patients diagnosed with cancer to look at traits of the specific cancer and further stratify diagnosis, guide treatment selection, and look broadly for gene alterations. The number of biomarkers for the treatment of NSCLC is on the rise, with one genotype identified in 2003, nine genotypes noted in 2012, and 14 genotypes as of 2018.2 The evolution to precision-targeted therapies is a different way to treat patients. This type of treatment has a higher probability of response and is often well tolerated by patients. For a large percentage of patients, a specific genotype still cannot be identified, but for roughly one-third of patients, targeted treatment can help improve outcomes and potentially decrease side effects of therapy. As shown in the figure below, patients have a high probability of response to a therapy that is well tolerated, while experiencing an improved quality of life.
Patient Education on Precision Targeted Therapy3
Results from precision therapy testing may take a few weeks to be returned, which can be a difficult waiting period for a patient newly diagnosed with lung cancer. Physicians are tasked with effectively communicating to patients the importance of using these therapeutic advances as tools to optimize the chance of successful treatment. Helping patients understand the potential benefits of a medication matched to the biomarker identified for their particular cancer can help ease the anxiety of waiting the two weeks before beginning treatment. Patient education regarding precision therapy should include associated benefits such as the possibility of oral medication rather than an intravenous medication; more reliable outcomes with a higher probability of treatment success; and, possibly, better medication tolerance with fewer side effects. Anecdotally, many patients who have taken targeted therapy have reported that taking a pill once daily has helped them feel as if they are not living with lung cancer.
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- “About Non-Small Cell Lung Cancer.” American Cancer Society, https://www.cancer.org/cancer/non-small-cell-lung-cancer/about.html.
- Villalobos, Pamela, M.D., and Ignacio I. Wistuba, M.D. “Lung Cancer Biomarkers.” Hematology/Oncolology Clinics of North America, 2017 Feb; 31(1): 13–29, Feb. 1, 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5137804/.
- Oxnard, Geoffrey, M.D. “Clinical Connections: Precision Medicine in Oncology.” Magellan Rx Management, April 4, 2019, https://www1.magellanrx.com/magellan-rx-events/webinars/.