Lobular involvement: prognostic indicator for invasive ductal carcinoma of the breast

One of the striking microscopic appearances of breast carcinoma is malignant transformation of the epithelium of an entire lobule, although the lobular architecture is still preserved. We termed this pathological feature 'lobular involvement'. An investigation was carried out to determine whether lobular involvement would be a useful prognostic indicator for invasive ductal carcinoma. One hundred and fifty cases of invasive ductal carcinoma were included in this study. The lobular involvement, as well as the conventional prognostic factors, was evaluated to find out the correlation with the overall and relapse-free survivals by univariate and multivariate analyses. The lobular involvement was identified in 31 of 150 patients (20.6%). Of the patients with lobular involvement, two had experienced recurrence (6.5%) and one had died (3.2%). The lobular involvement and lymph node metastases were significantly and independently correlated with the overall and relapse-free survivals. The presence of lobular involvement was statistically correlated with the favorable outcome. Lobular involvement can be assumed as a new prognostic indicator for invasive ductal carcinoma.