Cancer Cytogenetics: An Introduction

The Philadelphia chromosome was the first chromosomal abnormality discovered in cancer using the cytogenetics technique in 1960, and was consistently associated with chronic myeloid leukemia. Over the past five decades, innovative technical advances in the field of cancer cytogenetics have greatly enhanced the detection ability of chromosomal alterations, and have facilitated the research and diagnostic potential of chromosomal studies in neoplasms. These developments notwithstanding, chromosome analysis of a single cell is still the easiest way to delineate and understand the relationship between clonal evolution and disease progression of cancer cells. The use of advanced fluorescence in situ hybridization (FISH) techniques allows for the further identification of chromosomal alterations that are unresolved by the karyotyping method. It overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Subsequently, the development of DNA microarray technologies provides a high-resolution view of the whole genome, which may add massive amounts of new information and opens the field of cancer cytogenomics. Strikingly, cancer cytogenetics does not only provide key information to improve the care of patients with malignancies, but also acts as a guide to identify the genes responsible for the development of these neoplastic states and has led to the emergence of molecularly targeted therapies in the field of personalized medicine.