Usefulness of Salivary and Serum Auto-antibodies Against Tumor Biomarkers HER2 and MUC1 in Breast Cancer Screening

Background: The aim of this work was to investigate if serum and salivary auto antibodies, isotypes IgG and IgM, against HER2 and MUC1 tandem repeat fragments could play a role in breast cancer screening. Materials and
Methods: Our case-control study was conducted in breast cancer patients, in early stages (n=29), at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco and healthy woman (n=31). Salivary and serum auto-antibodies against HER2 and MUC1 (tandem repeat) were assessed by enzyme-linked immunosorbent assay (ELISA) and compared between patients and healthy women using the Mann Whitney U test. A P-value <0.05 was considered to be statistically significant.
Results: Our data showed higher expression of all serum and salivary autoantibodies in patients as compared to healthy women p<0.05. However, serum IgM anti-MUC1 expression did not show a significant difference between cases and controls (p=0.79). Similarly, salivary IgG anti-HER2 expression did not differ (p=0.15). The correlation between the different isotypes of antibodies revealed that the highest correlation was between salivary IgG anti-HER2 and salivary IgG anti- MUC1(r=0.65). In fact, we have found in saliva the correlation between autoantibodies anti-MUC1 and anti HER2 more important than in serum (r=0.59 and r=0. 55). However, the correlation between serum and saliva values for all antibodies was weak.
Conclusions: Autoantibodies against HER2 and MUC1 may provide a useful approach in breast cancer screening when using both serum and saliva values.