Lack of reciprocal translocations in carcinomas.

Among the varied structural chromosomal aberrations present in the common forms of carcinoma, reciprocal translocations generally appear to be lacking. Although the breakpoints may be variable, the chromosomal changes nevertheless commonly result in the loss or gain of particular chromosomal segments. The possible implications of these observations are discussed, especially in relation to the thesis that some of the chromosomal changes in cancer cells are important because they lead to the expression of recessive genes.