Precision medicine is a new concept of medical science that treats and prevents diseases by considering the different genes, environments, and lifestyles. It is a medical science made possible with the rapid development of next generation sequencing, which is a large-scale genome information analysis technology, and it is expected to form the basis of advanced medical services in the future. Lung cancer has the most developed target therapy and immunotherapy, and it is one of the most common forms of cancer in precision medicine.

The Liquid Biopsy Lab was established in October 2016 based on liquid biopsy technology, which has been establishing a way to apply the technology to the treatment by maximizing the synergy with traditional genome testing that analyzes the existing tissue body through various innovative clinical studies. 

1. Precision Medicine for Lung Cancer

Lung cancer is a cancer that has the most developed target drugs and immunotherapies, mainly for non-small cell lung cancer. EGFR, ALK, and ROS1 are genetic testing methods that have now become basic tests for the treatment of advanced non-small cell lung cancer. PD-L1 immunohistochemistry is now essential for the prescription of immune checkpoint inhibitors. It is now possible to treat patients with personalized treatment according to their genotype and molecule type, instead of highly toxic chemotherapy, in order to maximize the anticancer effect while minimizing the side effects through diagnostic tests (e.g., genetic and protein tests). In addition, it is expected that the economic benefits of not having to take unnecessary and expensive anticancer drugs are not suitable for the patient.

2. Next Generation Sequencing 

After 15 years and 4 trillion dollars, the Human Genome Project was completed in 2003 to decode 3 billion pairs of human DNA sequences. However, DNA sequencing technology has progressed significantly through the human genome project and now ultra-fast and large-scale sequencing called next generation sequencing (NGS) is currently feasible at a low cost. As a result, cancer gene mutations can be diagnosed in approximately two weeks at a cost of KRW1 million to KRW2 million. If only the EGFR gene mutation testing is required, a highly sensitive PCR method will be enough. However, it is now possible to analyze several disease-related genes in one sample simultaneously through NGS. This advanced life science technology will enable a new era of precision medicine through genome analysis.

3. Liquid Biopsy

Since cancer is diagnosed through the presence of cancer cells in the body, biopsy is an essential basic test. However, biopsy is an open and invasive test that the patient would like to avoid. Lately, re-biopsy has to be performed in order to detect the resistance genes of target therapy, such as T790M mutation, especially in lung cancers. In some cases, cancer tissue is not collected properly despite the difficulty with re-biopsy or impossibility of performing a biopsy. To compensate for this, a technique has been developed to isolate the circulating tumor DNA (ctDNA) from the body fluids (e.g., blood) and conduct oncogene testing. Liquid biopsy is performed by using the DNA isolated from body fluids (e.g., blood, urine, pleural fluid, and saliva), bronchoalveolar lavage fluid, and cerebrospinal fluid. In lung cancer, liquid biopsy is becoming increasingly important because most lung cancer patients are diagnosed with small pieces of tissue or separated cytology, and it is difficult to get the adequate and sufficient amount of DNA needed for genetic testing. To address these shortcomings, KUMC Lung Cancer Center operates a world-class Liquid Biopsy Lab to conduct EGFR gene mutations, including T790M, as well as a liquid biopsy, for next generation sequencing.

4. Importance of Early Lung Cancer Diagnosis

Lung cancer is a representative refractory cancer disease because the lungs are exposed to outside air and carcinogens through smoking. The carcinogenic process is complex that their biological malignancy is bad, and their complex anatomical and physiological structures and functions make early diagnosis difficult. In fact, only 20% of the 1st and 2nd stage lung cancer patients can be treated with surgical resection and most lung cancer patients are diagnosed in the advanced 3rd or 4th stage. Therefore, the importance of early diagnosis of lung cancer cannot be overemphasized and early lung cancer screening using low-dose CT is recommended to a high-risk group of smokers with a smoking history of 30 pack years or more.

5. Importance of Lung Cancer in Non-Smoking Female

Since lung cancer is associated with cigarettes, smoking is an absolute factor in its occurrence. Unlike in the West, however, 30% of all lung cancer patients are non-smokers, especially women. 

Lung cancer reminds us that smoking is an absolute factor in the development of lung cancer. However, 30% of all lung cancer patients are non-smokers, particularly women in the East, including Korea, as compared to the West. The reason why lung cancer occurs in non-smokers, such as women, has not yet been scientifically confirmed, but the fact that target gene mutations (e.g., ALK, ROS1, and EGFR) are found in 70% of the patients, lung cancer is significantly important. When such genetic mutation is diagnosed, the therapeutic effect of target therapy is remarkably high. Therefore, it is important to have regular checkups for an early detection of lung cancer. For women over 40 years old, it is necessary to have early lung cancer screening via low-dose CT (e.g., gastroscopy and colonoscopy) conducted at the Life Cycle Health Examination.