Measurement of HER2 in saliva of women in risk of breast cancer.

HER2 amplification can be present in ductal carcinoma in situ (DCIS). The aim of the present study was to test the feasibility of measuring soluble HER2 in the saliva of patients at risk of breast cancer towards early diagnosis and prognosis. Women with lesions classified as 4 according to BIRADS and women with spontaneous nipple discharge (NAF) were recruited for this study. Quantification of soluble HER2 in saliva was performed using the enzyme immunoassay ELISA. Median values of HER2 were quantified in saliva of the control groups and in the patient groups. The statistical test nonparametric Mann-Whitney was applied for the evaluation of median differences. Although the medians increased with the severity of the clinical status, no significant difference was found in all possibilities (p > 0.05) when comparing the medians among the patients groups. Interestingly, inter-individual HER2 quantity variations in the saliva were detected in this study in some subjects from each group. Considering possible inter-individual variations, research on saliva-based circulating HER2 has to be reinforced to ensure its correct application in diagnosis, treatment and in follow-up of breast cancer patients. Older and current issues surrounding the controversy about the appropriate methods for HER2 evaluation are discussed.