Allelic loss of chromosome 10q23 is associated with tumor progression in breast carcinomas

To determine the status of chromosome 10q23 in primary breast carcinomas, ill situ and invasive carcinomas were analysed for allelic loss using microsatellite markers spanning the 10q23 region. No LOH was seen in pure intraductal carcinomas (0/20 cases). On the other hand, LOH was observed in 40% (17/42) of invasive carcinomas (P=0.0005). Interestingly, in situ lesions found in invasive tumors displayed LOH. Allelic loss was also significantly associated with loss of the estrogen receptor (P=0.011). Thus, loss of the 10q23 is strongly associated with tumor progression.