One of the main differences between lobular breast cancers and ductal carcinomas is the presence of inactivating E-cadherin gene mutations in lobular breast cancers.
Here we have analyzed the coding region of CDH1 for mutations using denaturing high performance liquid chromatography and found 4 mutations in 83 ductal carcinomas (5%) and 3 mutations in 25 lobular carcinomas (12%).
Epithelial cadherin (E-cadherin) gene and protein alterations are implicated in the existence of two clearly distinct types of tumors in the stomach (isolated cell and glandular carcinomas), breast (lobular and ductal carcinomas), and thyroid (papillary and follicular carcinomas), as well as in the occurrence of poorly differentiated foci in colorectal and prostate adenocarcinomas.
A higher frequency of down-regulation of the E-cadherin protein expression was found in invasive lobular carcinomas than in invasive ductal carcinomas, although this difference was of borderline significant (P = 0.084).
The absence of mutations in the E-cadherin gene and its conserved expression suggest that inactivation of E-cadherin does not contribute significantly to the invasion or metastatic potential of ductal carcinomas of the breast.