Vimentin-positive invasive breast carcinoma of no special type: A breast carcinoma with lethal biological characteristics.

Vimentin is a stable mesenchymal immunohistochemical marker and is widely recognized as a major marker of mesenchymal tumors. The purpose of the present study was to investigate if the vimentin expression status might serve as a significant predictor of outcomes in patients with invasive breast carcinoma of no special type (IBC-NST) and to investigate, by comprehensive RNA sequencing analyses, the mechanisms involved in the heightened malignant potential of vimentin-positive IBC-NSTs. This study, conducted using the data of 855 patients with IBC-NST, clearly identified vimentin expression status as a very important independent biological parameter for accurately predicting the outcomes in patients with IBC-NST. RNA sequence analyses clearly demonstrated significant upregulation of coding RNAs known to be closely associated with cell proliferation or cellular senescence, and significant downregulation of coding RNAs known to be closely associated with transmembrane transport in vimentin-positive IBC-NSTs. We conclude that vimentin-positive IBC-NSTs show heightened malignant biological characteristics, possibly attributable to the upregulation of RNAs closely associated with proliferative activity and cellular senescence, and downregulation of RNAs closely associated with transmembrane transport in IBC-NSTs.

Tumor budding and fibrotic focus-proposed grading system for tumor budding in invasive carcinoma no special type of the breast.

Tumor budding grade is a very useful histological prognostic indicator for colorectal cancer patients. Recently, it has been also reported as a significant prognostic indicator in invasive breast carcinoma patients. Our group and others have previously reported that the presence of a fibrotic focus in the tumor is a very useful histological finding for accurately predicting the prognosis in patients with invasive carcinoma of no special type (ICNST) of the breast. The purpose of the present study was to investigate whether a grading system incorporating tumor budding in a fibrotic focus is superior to the conventional grading system for tumor budding to accurately predict outcomes in patients with ICNST. According to our new grading system, we classified the tumors into grade I (164 cases), grade II (581 cases), and grade III (110 cases), and the results clearly demonstrated the significant superiority of the new grading system over that of conventional tumor budding alone for accurately predicting outcomes in patients with ICNST. Our findings strongly suggest that tumor cells and tumor-stromal cells interaction play very important roles in tumor progression rather than tumor cells alone.