The association of the IgA levels of serum and whole saliva with the progression of oral cancer

Elevated IgA concentrations in the serum and whole saliva of patients with neoplastic disease have been reported. However, there does not seem to be any information available on the correlation of the secretory immunoglobulins of these patients with the progress of their disease. The whole saliva and sera of 102 cases of squamous carcinoma of the oral mucosa were studied. Patients were subclassified into age-matched groups of primary untreated cancer (21), recurrent cancer (18), and "cured" patients who had been free of disease for at least 9 months (16). A separate group of laryngeal (14) patients was included. Sixteen (16) patients treated by radiation therapy alone were also included to test the effects of radiation on whole saliva IgA. An age-matched group of patients (17) with moderate to severe periodontal disease served as controls. Unstimulated whole saliva was collected for 15 minutes and stored at 0 degrees C. IgA was quantitated by radial immunodiffusion on Hyland and Meloy Laboratory low level plates with 7S and 11S standards. Serum IgA was measured on Hyland plates with serum standards. Protein content of saliva was assayed by the Lowry method. Flow rate was quantitated for the 15-minute collection period. Primary oral and laryngeal cancer patients had a two-fold increase of serum and salivary IgA compared to controls. Recurrent cancer patients had even greater elevation of salivary IgA. Cured patients showed a persistent elevation of serum but a return to normal of salivary IgA. Radiation therapy did not markedly influence the level of salivary IgA. A followup study of 26 patients confirmed this pattern of a drop in whole salivary IgA with cure and a spike with recurrence. It would appear that IgA levels of whole saliva and serum are elevated in oral cancer patients, and that salivary IgA levels may prove useful in distinguishing patients with possible recurrent disease.