Prognostic significance of fibrotic focus in invasive ductal carcinoma of the breast: a prospective observational study.

We have already reported invasive ductal carcinomas (IDCs) with fibrotic focus (FF) to be associated with significantly poorer survival than IDCs without FF. The purpose of this study was to prospectively investigate the effect of the presence of FF on the outcomes of 439 patients with IDCs to confirm the prognostic significance of FF, by the multivariate analysis, employing the Cox proportional hazard regression model, as compared with well-known clinicopathological parameters. We also precisely evaluated the prognostic significance of FF from the viewpoint of FF characteristics. The present study demonstrated that the presence of FF is a very useful parameter predicting tumor recurrence (TR), as well as initial distant organ metastasis (IDOM), in lymph node-negative IDCs (P =.024 and P =.026) and in IDCs positive for either or both estrogen receptor (ER) or progesterone receptor (PR) (P =.007 and P =.015), respectively. In addition, FF of >8 mm in diameter was found to be an independent prognostic parameter for TR and IDOM in lymph node-negative patients and patients with IDC positive for either or both ER or PR (P =.005 and P =.018). We conclude that the presence of FF is a very important histologic prognostic parameter for patients with IDCs of the breast.