This report describes a positive relationship between vimentin expression in infiltrating ductal breast carcinoma, and high tumour growth fraction. Vimentin expression is potentially a predictor of aggressive behaviour, and such carcinomas may benefit from early adjuvant therapy.
Eighty-four malignant breast neoplasms were stained with monoclonal anti-vimentin and anti-cytokeratin antibodies. The tumour growth fractions were determined by immunostaming cryostat sections with the Ki-67 antibody. Seven (9.2 per cent) of 76 infiltrating ductal carcinomas co-expressed cytokeratin and vimentin intermediate filaments in more than 50 per cent of neoplastic cells. In each case, the corresponding Ki-67 count was ≥40 percent, significantly higher than the mean growth fraction for all tumours examined (P<0.0001). Vimentin immunoreactivity was also positively related to the histological grade of the ductal carcinomas (P<0.002) and inversely related to tumour ER count (P<0.0002) and patient age (P<0.01). No relationship was observed between vimentin positivity and either the presence of axillary nodal metastases or primary tumour size.