Abstract Background As compared to invasive breast cancer- no special type (IBC-NST), Invasive lobular cancer (ILC) traditionally shows loss of function of the E-cadherin- catenin membrane complex, frequent downregulation of E-cad expression and is significantly more associated with Multiple Ipsilateral Breast Carcinoma (MIBC). Nevertheless, E cadherin downregulation was also described in MIBC with IBC-NST phenotype. MIBC was suggested to have a more aggressive biologic nature than unifocal disease, Epithelial mesenchymal transition (EMT) has been suggested as an attribute to such poorer prognosis. The transcription factor Snail commonly acts as one of the earliest switches of the EMT process and E-cadherin downregulation is one of its major downstream effects. Causation and association links between EMT and MIBC in different types of breast cancer needs further elucidation. Objective to investigate whether the association betweenE-cadherin downregulation and MIBC is attributed to EMT and whether such association and expression of EMT markers is differentially presented in ILC and IBC-NST. Methods This study was conducted retrospectively on 77 breast cancer cases diagnosed at Ain Shams University Hospitals (2012-2022). We included all ILC cases meeting study criteria (20 unifocal, 14 MIBC) and randomly selected sets of IBC- NST cases (13 unifocal, 16 MIBC) and mixed ductolobular IBC (7 unifocal, 7 MIBC). Immunohistochemical expression of E-cadherin and Snail was evaluated and compared in different study groups with subsequent statistical analysis. Results E- cadherin expression showed 15/40 (37.5%) negative expression, 15/40 (37.5%) with low expression, and 10/40 (25%) with high expression in the unifocal group, compared to 14/37 (37.8%) negative result, 13/37 (35.1%) low E-cadherin expression, and 10/37 (27%) with high E-cadherin expression in the MIBC group. There was no significant difference in E-cadherin expression regarding focality neither in all cases (p-value: 0.97) nor in each of the histological subgroups (p-values: 0.34 for IBC- NST, 1.00 for mixed, 0.2 for ILC). On the other hand, Snail expression was extensive in 24/37 MIBC cases (64.86%) as compared to 17/40 unifocal cases (42.5%), this was statistically significant (p-value: 0.038). Conclusions E-cadherin downregulation doesn’t seem to contribute to MIBC whether ILC, mixed or IBC-NST, however snail overexpression is significantly associated with MIBC. This suggests that EMT may have a role in multiplicity of IBC.
Read full abstract