Measles virus antigens in breast cancer

Breast cancer (BC) is the most common cancer in women in Western countries, showing a bimodal age distribution with peaks at 50 and 70 years. Multiple factors are encountered in the etiology of BC, including hereditary and hormonal causes. A few viruses, including MMTV, EBV and HPV have been reported to be associated with BC. This group previously described the presence of the measles virus (MV) in biopsies of patients with Hodgkin's lymphoma. The present study explored MV antigens in BC patients.

A total of 131 patients with invasive BC diagnosed during the years 1998-2005 were studied using immunohistochemistry (IHC) for the presence of MV antigens, hemagglutinin and nucleoprotein. Clinicopathological parameters included age, stage, histological grade and the expression of estrogen and progesterone receptors, HER2/neu, p53, and Ki67.

Hormone receptors and HER2/neu were positive in 54% and 18% of the tumors, respectively. Both MV antigens were detected in 64% of the tumors. All biopsies containing a DCIS component showed MV in DCIS in addition to invasive BC. In univariate analysis, MV correlated with estrogen receptor (p=0.018), low Ki67 index (<40%, p=0.029), low or intermediate grade (p=0.037), age under 50 years (p=0.039), progesterone receptor (p=0.043) and overexpression of p53 (p=0.049). In multivariate analysis, only grade (p=0.011), p53 (p=0.03) and age (p=0.041) remained associated with MV.

This study provides evidence for the presence of MV antigens in a relatively large proportion of BC patients. MV was associated with younger age, lower histological grade and overexpression of p53, suggesting that it may play a role in the development of BC.