An innovative method developed for the early diagnosis of lung cancer using only blood testing

An innovative method has been developed for the early diagnosis of lung cancer by only testing blood.
 
A research team led by Professor Hong Sung-hoi of Korea University’s School of Biosystems and Biomedical Sciences has developed GCC2, a new biomarker of lung cancer.

※ Title of Paper : GCC2 as a New Early Diagnostic Biomarker for Non-Small Cell Lung Cancer

Lung cancer is currently the most common cancer and the leading cause of cancer-related deaths worldwide, and the 5-year relative survival rate of all patients with lung cancer after diagnosis is not high. The earlier diagnosis of lung cancer is a key to improving survival rates. Annual screening guidelines for lung cancer recommend using tests such as chest X-rays, low-dose computed tomography, and positron emission tomography. However, these imaging procedures are expensive and difficult to repeat as they carry a risk of radiation.

Therefore, a low-risk diagnostic method using liquid biopsies and biomarkers in blood samples is urgently needed for the early diagnosis of lung cancer. GCC2, identified by the research team, has demonstrated that it can be not only a reliable prognostic marker for the early diagnosis of lung cancer, but is also a convenient biomarker for asymptomatic lung cancer patients through GCC2+ exosomes obtained from peripheral blood. In particular, since it does not involve any collection and identification of tissue specimens from patients for biopsy, this method can minimize the inconvenience and risk posed by lung cancer diagnoses.

Exosomes, small-sized vesicles secreted from cells, contain various cellular materials. The research team identified the GCC2 protein, the levels of which were higher in the exosomes derived from early-stage non-small cell lung cancer (NSCLC) patients than those from healthy controls. The GCC2 protein, a trans-Golgi network membrane protein, performs an intracellular transport function. The marker, which was detected only in lung cancer cell lines through proteomic analysis, increased with the progression of the pathological stage. In other words, GCC2 expression levels were significantly higher in the early stage of lung cancer, hence exhibiting excellent performance in diagnosing lung cancer.

The expression levels of the GCC2 protein in exosomes secreted from the plasma of patients with early-stage (pathological stage 1) NSCLC were significantly higher than those of healthy controls. Analyzing the receiver operating characteristic (ROC) curve, the research team determined the diagnostic sensitivity and specificity of exosomal GCC2 to be 90% and 75%, respectively. Its ROC value of 0.844 indicates that the GCC2 protein can distinguish the exosomes secreted from patients with early NSCLC from those of healthy controls, proving that GCC2 makes an ideal biomarker for early-stage NSCLC.

“Early diagnosis is important to increase the survival rate of lung cancer patients, but current testing methods such as tissue biopsy can be physically burdensome for patients. This newly proposed diagnostic method for lung cancer using blood samples is more convenient for patients and thus expected to contribute to improving the survival rate of lung cancer patients through early diagnosis,” said Professor Hong.

This research was funded by Korea University's Research-Driven Hospitals Program and Bio & Medical Technology Development Program. It was published in the online edition of Cancers, an excellent academic journal of oncology, on October 31.