Precision Cancer Medicine

The purpose of precision cancer medicine is to define the genomic alterations in the cancers DNA that are driving that specific cancer. Cancer used to be diagnosed solely by a visual microscopic examination of tumor tissue and all patients received the same chemotherapy. Precision cancer medicine utilizes molecular diagnostic & genomic testing, including DNA sequencing, to identify cancer-driving abnormalities in a cancer’s genome. Once a genetic abnormality is identified, a specific targeted therapy can be designed to attack a specific mutation or other cancer-related change in the DNA programming of the cancer cells. Precision cancer medicine uses targeted drugs and immunotherapies engineered to directly attack the cancer cells with specific abnormalities, leaving normal cells largely unharmed.

By testing an individual’s lung cancer for specific unique biomarkers doctors can offer the most personalized treatment approach utilizing precision medicines.

Lung Cancer Biomarkers

PD-1: PD-1 is a protein that inhibits certain types of immune responses, allowing cancer cells to evade an attack by certain immune cells. Drugs that block the PD-1 pathway enhance the ability of the immune system to fight cancer and are referred to as checkpoint inhibitors for their ability to help the immune system recognize and attack cancer. Overall two thirds of lung cancer patients have some expression of PD-1, and one third are “high expressers” meaning over 50% of the tested tumor expresses PD-1.1,2

Epidermal growth factor receptor (EGFR): The EGFR pathway is a normal biologic pathway found in healthy cells. It is involved in regular cellular division and growth. However, certain mutations within the EGFR gene can lead to an overactive EGFR pathway, leading to the development and/or spread of cancer. These cancers are referred to as EGFR-positive, and there are several FDA-approved medications to block the activity of EGFR and slow cancer growth for EGFR-positive cancers. EGFR mutations are most common in individuals who never smoked, woman, people of Asian ethnicity, and those with a type of lung cancer known as adenocarcinoma.3,4

ALK+ Lung Cancer: Approximately 5% of all NSCLC have an identified mutation referred to as the anaplastic lymphoma kinase (ALK) mutation. The ALK mutation is responsible for initiating and promoting cancer growth. Individuals with ALK+ lung cancer tend to be non-smokers or former light smokers; younger, and are a type of NSCLC referred to as adenocarcinoma (based upon the cells affected); and respond worse to standard chemotherapy regimens than patients who do not have the ALK mutation.5

ROS-1+ Lung Cancer: The ROS-1 mutation is an uncommon mutation found in only 1% of individuals with NSCLC. Research has indicated that the ROS-1 mutation plays a role in the development and progression of some lung cancers, and patient characteristics are similar to those who have ALK+ NSCLC.6

Next: Management of Non Small Cell Lung Cancer

Next: Management of Small Cell Lung Cancer

References


1 KEYTRUDA (pembrolizumab) demonstrates superior progression-free and overall survival compared to chemotherapy as first line treatment in patients with advanced non-small cell lung cancer. [Press release.] http://www.mercknewsroom.com/news-release/oncology-newsroom/mercks-keytruda%C2%A0pembrolizumab-demonstrates-superior-progression-free- Accessed June 21, 2016.

2 Borghaei H, Paz-Ares L, Horn L, et al. Nivolumab versus Docetaxel in Advanced Nonsquamous Non–Small-Cell Lung Cancer. New England Journal of Medicine. 2015; 373:1627-1639.

3 OSI Pharmaceuticals. FDA Approves Tarceva as a Maintenance Therapy for Advanced Non-small Cell Lung Cancer. Available at: http://investor.osip.com/releasedetail.cfm?ReleaseID=460783. Accessed April 19, 2010.

4 Zhou C, Wu Y-L, Chen G et al. Erlotinib versus chemotherapy as first-line treatment for patients with advanced EGFR mutation-positive non-small-cell lung cancer (OPTIMAL, CTONG-0802): A multicentre, open-label, randomized, phase 3 study. Lancet Oncology. Early online publication July 22, 2011.

5 Shaw AT, Kim DW, Mehra R, et al: Ceritinib in ALK-rearranged non–small-cell lung cancer. New England Journal of Medicine. 2014; 370: 1189-1197.

6 United States Food and Drug Administration (FDA). FDA expands use of Xalkori to treat rare form of advanced non-small cell lung cancer. Available at: http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm490329.htm. Accessed March 11, 2016.