The Potential Use of Saliva to Detect Recurrence of Disease in Women with Breast Carcinoma

Background: Approximately 1 woman in every 10 will develop breast cancer in her lifetime. It has been shown that screening for breast cancer can reduce breast cancer mortality. The use of a saliva-based test could prove to be very useful in post-operative and/or adjunctive therapy management of breast cancer patients.

Methods: The following study was undertaken to establish the possible usefulness of the salivary protein product of the oncogene c-erbB-2 in following patients diagnosed with carcinoma of the breast. Included in this study were 25 patients with a mean age of 54 years with varying histological diagnoses and stages of carcinoma of the breast. ELISA assays for c-erbB-2 and CA 15-3 were performed on serum and stimulated whole saliva samples collected on all patients prior to any adjunct therapy or surgery and sequentially during therapy.

Results: The results of the GLM analyses using marker concentration as the dependent variable and treatment regimen and the serial assessments as independent variables yielded a significant overall model for both the serum (P < 0.007) and salivary (P < 0.017) c-erbB-2 markers. The model for serum c-erbB-2, however, exhibited a significant difference for treatment regimen (P < 0.001) with the chemotherapy and radiation treatment regimen being significantly different (P < 0.001) from the other treatment therapies. Time (serial assessments) was not significant. The model for the salivary c-erbB-2 marker was reversed. Treatment regimen was not significant for this model; however, time (serial assessments) was significant (P < 0.002). The serum and salivary CA 15-3 marker models yielded no significant results. Paired t-test analyses indicated that only the salivary c-erbB-2 concentrations exhibited a significant difference between the pre- and post-therapy values (t = 4.245, P < 0.0001). Additionally, salivary c-erbB-2 displayed greater percent reductions across all therapies as compared to the other markers.

Conclusions: This preliminary study appears to indicate that c-erbB-2 protein expression in saliva may be a very useful diagnostic tool for measuring patient response to chemotherapy and/or surgical treatment of their disease.