Survival analysis between patients with invasive ductal and invasive lobular breast cancer

Differences in overall survival (OS) and disease-free survival (DFS) between patients with invasive ductal (IDC) and invasive lobular breast cancer (ILC) are controversial.

The study population was selected from a database of 5,689 female patients with invasive breast cancer. In order to focus on the impact of tumour histology, all primary metastatic patients and patients with adjuvant chemotherapy or anti-hormonal treatment were excluded. Only patients with pure invasive lobular and invasive ductal histology were included.

Multivariate survival analyses of 2,058 eligible patients confirmed tumour histology as an independent prognostic factor for OS in invasive breast cancer (p = 0.046) but not for DFS (p = 0.599). Kaplan-Meier survival analysis of OS between IDC and ILC patients showed a statistically significantly better OS for patients with ILC (p = 0.0302). DFS was not statistically different (p = 0.6659) between IDC and ILC. Univariate survival analyses of tumour size, tumour grading and nodal status in our study population were highly statistically significant for OS and DFS (p < 0.0000).

Patients in our study population with ILC have significantly better OS than patients with IDC. Differences in DFS are not statistically significant.