Mass Screening and Molecular Diagnosis for Lung Cancer

Abstract

Objective. To identify recent efforts to apply molecular biology of lung cancer to early detection, and to discuss problems to be overcome for practical application. Methods. We searched literature dealing with lung cancer susceptibility and early diagnosis by detecting minute amounts of cancer cells. Results. Lung cancer susceptibility: Epidemiologic studies have revealed that there is an increased familial risk of lung cancer. The basis of this inheritance can be partly attributed to polymorphism of drug metabolizing enzymes, enzymes related to the DNA repair system, or cancer-related genes. However, many studies were able to show odds ratio of only less than five. The project for extensive comprehensive analysis of such polymorphisms (SNPs) based on 300000 individuals are currently under way, and this will identify people at an increased risk of lung cancer with a high degree of reliability. Detection of minute amounts of lung cancer cells: There have been numerous efforts to detect lung cancer cells with high sensitivity in clinical specimens such as sputum and blood by use of mutations or methylation of cancer-related genes or expression of epithelial markers. High sensitivity has been reported, however, high sensitivity and high specificity often do not go together. Furthermore, it is sometimes problematic to obtain results reproducibly. Recently, there have been reports on early diagnosis of cancer by analyzing serum protein by mass spectrometry with a high resolution. This technique is expected to be utilized as a powerful tool for mass screening of cancer in the near future. Conclusion. It is hard at present to use the above-mentioned methods for mass screening of lung cancer. For further development, it is absolutely necessary to accumulate clinical specimens with good quality together with corresponding clinical information.