[Association of serum transforming growth factor-β1 with radiation injury and survival of patients with early-stage nasopharyngeal carcinoma].

OBJECTIVE: To observe the changes in serum transforming growth factor-β1 (TGF-β1) in patients with early-stage nasopharyngeal carcinoma (NPC) after radiotherapy and explore the correlation of serum TGF-β1 with radiation injury and disease-free survival. METHODS: The average serum TGF-β1 level (50.2∓3.2 ng/ml) determined from 32 healthy volunteers was used as the standard value for NPC patients in this trial. Fifty-seven patients with early-stage (T1-2N0-1M0) NPC without prior treatment were divided into two groups with serum TGF-β1 level before treatment lower than or equal to the standard value (group A, 29 cases) and a level beyond the standard value (group B, 28 cases). Serum TGF-β1 level was determined in all the patients before, during and after the radiotherapy to evaluate the radiation injury and therapeutic effect. RESULTS: The serum TGF-β1 level before radiotherapy was significantly lower in group A than in group B (35.4∓1.4 vs 58.8∓1.0 ng/ml, P<0.05). After radiotherapy, acute radiation mucositis and skin reaction was significantly severer in group B (P<0.05). The serum TGF-β1 level before radiotherapy was significantly higher in patients with grade 3 acute radiation mucositis and skin reaction than in those with injuries below grade 3 (54.0∓2.2 vs 42.0∓2.3 ng/ml and 54.3∓2.4 vs 43.4∓2.2 ng/ml, P<0.05). The two groups showed no significant differences in the locoregional failure rate (3.4% vs 7.1%), distant metastasis rate (3.4% vs 10.8%) or disease-free survival (P>0.05). CONCLUSIONS: Radiotherapy can significantly decrease serum TGF-β1 level in early NPC patients. Serum TGF-β1 level before radiotherapy can help predict the degree of acute radiation mucositis and skin reaction, but shows no correlation with disease-free survival of early-stage NPC patients.