FHIT and ductal breast carcinoma in situ: In the breast, loss of heterozygosity (LOH) at the FHIT locus has been observed in 45% of invasive cancers (Ca) and in 11% of unspecified preneoplastic lesions including usual type ductal hyperplasia (UDH), aprocrine metaplasia, DCIS and intraductal papilloma (Maitra et al, 2001).