Salivary expression of soluble HER2 in breast cancer patients with positive and negative HER2 status

BACKGROUND The aim of this study was to investigate the relationship between salivary concentration of the soluble fragment of the HER2 (human epidermal growth factor receptor) protein and its status in mammary tissues. METHODS This case-control study was done in 27 breast cancer patients with no visible metastatic disease treated at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco. Two groups were selected, ie, patients with positive and negative HER2 status in mammary tissue. The salivary HER2 protein concentration was assessed by enzyme-linked immunosorbent assay. The salivary HER2 concentration was compared between the HER2-positive and HER2-negative groups using the Mann-Whitney U test. A P-value <0.05 was considered to be statistically significant. RESULTS No statistically significant difference in salivary HER2 protein expression was found between the case and control groups. There was also no significant difference in clinical characteristics according to positive and negative HER2 status (P>0.05), except for the progesterone hormone receptor which was statistically significant in both the case and control groups (P=0.047). CONCLUSION According to our data, salivary expression of the HER2 receptor may not be a reliable alternative to tissue assessment.