Osteopontin expression profiles predict pathological and clinical outcome in breast cancer.

BACKGROUND

Osteopontin (OPN) overexpression in breast cancer has been associated with adverse pathological and clinical outcomes. In this study, the OPN expression profiles were examined in a cohort of breast cancer patients.

PATIENTS AND METHODS

RNA extraction and reverse transcription were performed on breast carcinomas (n = 127) and normal tissues (n = 33). Transcript levels were determined using real-time PCR.

RESULTS

The OPN-a levels decreased with increasing TNM stage and worse clinical outcome. The OPN-b levels increased with tumour grade and Nottingham Prognostic Index (NPI) stage, were higher in patients who died of breast cancer than in those who were disease-free after 10 years and predicted disease-free survival. The OPN-c expression was associated with tumour grade and poor prognosis. Furthermore, the expression levels predicted local recurrence, disease-free survival and bone metastases.

CONCLUSION

OPN expression profiles are significantly associated with tumour grade, stage and patient prognosis in breast cancer. OPN-c is likely to be of particular utility as a prognostic marker and should be included in future validation studies.