Salivary epidermal growth factor levels decrease in patients receiving radiation therapy to the head and neck

Objective. The objective of this study was to assess changes in salivary ep idermal growth factor (EGF) in patients receiving radiation therapy to the head and neck and to determine whether salivary EGF levels correlate with t he severity of radiation-induced oral mucositis. Study design. Thirteen patients and 18 control subjects were enrolled in th e study. Saliva was collected before, during (weekly), and after radiation therapy. Salivary total protein (TP) and EGF concentrations were measured a nd correlated with the severity of oral mucositis. The variability in norma lized EGF (ngEGF/mgTP) values and mucositis scores were analyzed with analy sis of covariance, and the adjusted correlation coefficient was calculated. Results. EGF levels decreased (P = .004), whereas TP levels increased over time (P = .039). A strong correlation was seen with decreasing normalized E GF values and more severe mucositis (P = .0001). Conclusion. A strong negative correlation between normalized EGF and mucosi tis severity suggests a possible role for EGF in the progression of radiati on-induced mucosal breakdown.