GENETIC-MARKERS IN LUNG-TUMORS

Several somatic genetic changes can be detected in lung tumours, which might help to distinguish them from other tumours, and may also permit some distinctions between the subclasses recognised on histological criteria. It is conceivable that a new classification based on genotype, rather than phenotype, may have some utility in prognosis. At present the numbers of lung tumours studied in this way are small. Moreover, in many studies cell lines have been used rather than primary tumour material. However, the advent of DNA analysis, using the polymerase chain reaction technique, enables genotype analysis to be performed on very small amounts of DNA, such as can be extracted from bronchoscopy biopsies or even archival formalin-fixed material. Thus very large numbers of tumour samples can be studied by a rapid, relatively inexpensive technique, so that within the next few years a detailed knowledge of somatic genetic changes in lung tumours will accumulate, allowing their clinical significance to be evaluated.