The Study On The Relationship Between Plasma TGF-β1 And Radiation Pneumonitis In Lung Carcimnoma

Objective The purpose of the study was to investigate the correlation between plasma transforming growth factorβ1 (TGF-β1) and histological type,TNM stage of lung carcinoma and observe the effect of TGF-β1 in radiation pneumonitis (RP).Methods plasma samples for 27 diagnosed lung carcinoma patients who had thoracic radiotherapy (RT) at DaLian Radiation Oncology Center were assayed for TGF-β1 before RT(pre RT),at the end of RT(end RT),and during follow-up after RT in 2~3 months. The level of TGF-β1 was measured using an enzyme-linked immunoabsorbent assay (ELISA). According to lung carcinoma TNM stage and histology type count each issue of patient plasma TGF-β1 value, respectively. Comparions within groups were estimated using analysis of variance. To study the relation between TGF-β1 level and radiation pneumonitis, we divided 27 samples into 2 groups: higher groups and lower groups, using t test to compare the radiation pneumonitis incidence. Record the parameters by dose volume histogram (DVH) including percentage of lung volume that received a dose of 20Gy or more (V20). Chi square test was used to assess data for correlations among dose-volumetric parameters. P<0.05 was considered to indicate statistically significant difference.Results Each stage of TGF-β1 level is stageI 444.68±38.89pg/ml,StageⅡ470.81±94.75pg/ml,StageⅢ603.35±124.68pg/ml,stageⅣ613.52±32.43pg/ml, respectively. There is a significant difference of plasma TGF-β1 level among StageI ,StageⅡ,StageⅢand stageⅣof lung cancer(P<0.05).As the increasing of TNM stage and progression of lung carcinoma , serum TGF-β1 level is also increased. According to lung histology type, each type ofTGF-β1 level is squamouscarcinoma 457.75±131.69pg/ml, adenocarcinoma 629.04±16.97pg/ml,small cell lung cancer 502.89±95.43 pg/ml. No significant difference is found in histology type. The plasma TGF-β1 level pre RT(458.32±124.78pg/ml) is significantly lower compared with end RT(563.98±142.54pg/ml)(P<0.05).But there is no significant difference between end RT and follow-up (567.73±227.35pg/ml). use analysis of variance there is no significant differ in 3groups. The incidence of radiation pneumonitis in higher group(40%) is significant higher than the lower group(7%)(P<0.05).In dose-volumetric parameter when V20≥22% the incidence of radiation pneumonitis(45%) is significant higher than V20<22%(6%).Conclusion The results of the current study suggest that plasma level of TGF-β1 might be associated with disease progression of lung carcinoma, but as a tumor marker, it need more data and research. The plasma TGF-β1 level end RT is significantly higher compared with pre RT(P<0.05),especially in higher group the incidence of RP is significantly high. These data demonstrate that plasma TGF-β1 level during thoracic irradiation has a predictive value risking for radiation pneumonitis.TGF-β1 is a useful indicator of risk for development of RP after 3D conformal radiation therapy in patients with lung carcinoma. In dose-volumetric parameters, V20 has an association with RP. When V20≥22%, the incidence of RP is much higher.