FISH analysis showed erbB-2 gene amplification and p53 deletions in selected CIS, as well as a marked chromosome 17 copy number heterogeneity in all six CIS examined.
We examined loss of heterozygosity (LOH) for two loci on chromosome 17p (D17S5 and TP53), and erbB-2 gene amplification, in primary breast cancers from 67 Brazilian patients.
TP53 alteration in primary tumour was significantly associated with the following parameters: positive node status, T status > 1, negative oestrogen receptor status, negative progesterone receptor status, presence of ERBB2 gene amplification, and invasive ductal histology.
Since p53 mutations as well as c-erbB-2 amplification were detected almost selectively in Grade 3 cases but were not associated with lymph nodal status in invasive breast cancer, these two gene alterations could be indicators of prognosis of disease independent of lymph nodal status.