What should oncologists know about cytogenetics in solid tumors?

Despite the fact that gross chromosome changes in malignant tumors were first described in human solid tumors more than 100 years ago by Arnold [1], cytogenetic analysis of solid tumors is still in its infancy compared to studies of leukemic cells [for review see 2, 3]. Advances in solid tumor cytogenetics have been and still are at the mercy of methodology, with the most limiting factors being: 1) low mitotic index (necessitating short term culture of cancer cells to avoid overgrowth by normal stromal or supporting cells); 2) microbiably infected or necrotic samples (that results in destruction of cancer cells before culturing); and 3) the occurrence of multiple and complex chromosomal changes (which make it difficult to identify the primary chromosome change associated with a specific tumor type). Despite these problems, recent advances in cytogenetic techniques coupled to increasing cooperation between surgeons and pathologists to obtain appropriate tumor material, has resulted in the detailed examination of the karyotypes of a number of tumors with the same histology which in turn has led to the description of a number of specific chromosome changes in solid tumors (Table 1). The number of solid tumors cytogenetically characterized is still small, as well as the number of cases of chromosomally investigated tumors of each subtype. However, several conclusions can already be drawn regarding this area of research.