Prognostic significance of glycoprotein pMQ1 in breast cancer

Background: A novel glycoprotein, pMQ1, is positively correlated with increasing histological grade in malignant astrocytmas. Cerebral metastases from breast cancer have also been found to contain pMQ1-positive cells. This study aimed to determine the role of pMQ1 in primary, breast cancer. Methods: Breast cancer specimens were analysed for pMQ1 by immunohistochemistry. The expression of pMQ1 was correlated with conventional prognostic indicators. Kaplan-Meier analyses were performed to compare clinical outcome between pMQ1-positive and pMQ1-negative tumours. Results: pMQ1 was expressed in most of the breast cancer specimens. The surrounding normal tissue margins and benign breast tissues always lacked pMQ1 expression. A significant positive correlation was observed between pMQ1 expression and histological grade, the presence of lymphovascular invasion and Nottingham Prognostic Index. Cancers that were pMQ1-positive were significantly more likely to develop a local recurrence. Conclusion: pMQ1 appears to be a tumour-associated protein. The positive correlation of pMQ1 with histological grade, presence of lymphovascular invasion and Nottingham Prognostic Index suggests that it confers an adverse prognosis.