Mapping of novel regions of DNA gain and loss by comparative genomic hybridization in esophageal carcinoma in the black and colored populations of South Africa

Esophageal cancer (EC) is the leading cause of cancer death in the Black ma le population in South Africa. Although several oncogenes and tumor suppres sor genes have previously been found altered in this cancer, many novel gen es remain to be identified. To identify the chromosomal location of these u nknown genes, we have analyzed DNA of 29 South African EC patients hy compa rative genomic hybridization. Frequent Loss occurred at chromosome 1p (52%) ,4p (52%),18q (48%), 19p (52%), 19q (55%), and 22q (41%). The most common g ains were detected at Iq (41%), 29 (52%), 3q (72%), 5p (31%), 7p (48%), 7q (45%), 8q (55%), and Xq (69%). High level amplification was detected at 2q2 4-33, 6p21.1-q14, 7p12-q21, 7q11.2-31, 8q22-24, 8q13-qter, 13q21-34, and at 13q32-34. The present comparative genomic hybridization study opens the wa y for additional targeted studies on these particular chromosomal regions t o identify the specific genes involved in the higher susceptibility to spec ific subtypes of esophageal carcinoma in different geographical regions. Th e Loss of 8p (28%) and Xp (17%) in tumors of male individuals may provide c lues to the basis of the sex-biased frequency of occurrence of EC favoring men.