Clinical significance of detection of p53 protein in exhaled breath condensate of patients with non-small cell lung cancer

Abstract

Objective To study the clinical significance of the detection of p53 protein in exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC). Methods EBC and plasma of 98 patients with NSCLC were collected,p53 protein expression in EBC and plasma was detected by enzyme-linked immunosorbent assay,and the data were compared with those of 98 healthy controls. p53 protein expression in cancer tissue of 98 patients with NSCLC was detected by immunohistochemistry. p53 protein expression in EBC and plasma and positive expression rate of p53 protein in cancer tissue were compared among patients with different lung cancer type,stage,histologic type,tumor size,and lymph node metastasis,smoking history. The specificity and sensitivity of diagnosis of p53 protein in patients with NSCLC were analyzed by ROC curve. Results ① The level of p53 protein in EBC of patients with NSCLC was significantly higher than that in healthy control group [(233.99±7.91) ng/L vs ( 130. 26 ± 4. 73) ng/L,P ＜0. 01]. The level of p53 protein in serum of patients with NSCI.C was significantly higher than that in healthy control group [(292. 58 ± 8. 79) ng/L vs (141. 66±3. 33) ng/L,P ＜0. 01]. ② The level of p53 protein in EBC of patients with central lung cancer was higher than that in patients with peripheral lung cancer [(248. 22 ± 8. 58) ng/L vs (215. 78 ± 6.61) ng/L,P＜0. 01]. ③The level of p53 protein in EBC of patients with positive immunostaining group was higher than that in negative group [(249.77 ± 8.07) ng/L vs (216.86 ± 7.44) ng/L,P ＜ 0. 05]. ④The level of p53 protein in serum of smokers was significantly higher than that in non-smokers [(310.18 ± 9.04) ng/L vs (254. 55 ± 6. 91) ng/L,P ＜0. 01]. ⑤The positive expression rate of p53 protein in cancer tissue was 47. 96% (47/98). ⑥The sensitivity and specificity of diagnosis of p53 protein were 95. 90% and 90. 04% in plasma,and those were 92. 90% and 79. 59% in EBC. The cut off values of p53 protein were respectively 175. 68 ng/L and 166. 26 ng/L in EBC and serum. Conclusions The detection of p53 protein in EBC of patients with NSCLC is helpful for the diagnosis of lung cancer. Key words: p53 protein; Exhaled breath condensate; Non-small cell lung cancer