An immunohistochemical study of tumour necrosis factor related apoptosis inducing ligand (TRAIL) in lung cancer patients

Lung cancer is a global problem and its incidence is dramatically increasing and expected to become the leading cause of cancer deaths. Several molecular genetic abnormalities have been described in lung cancer, one of the most recent such markers is tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Objective: To throw an outlook on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression in tissue specimens obtained from lung cancer patients. Patients and methods: Fifty Patients were included in this work selected on basis of being presenting with clinical and/or radiological picture suggestive of lung cancer. They were classified histopathologicallyl into two groups, Group I comprised (37) non small lung cancer patients (NSCLC), and Group II comprised (13) small lung cancer patients (SCLC). All patients were subjected to thorough medical history, clinical examination and radiological examination. Fiberoptic bronchoscopic examination was done with different endoscopic sampling and the obtained specimens were subjected to special staining procedure for TRAIL expression by immunohistochemistry. Results: Bronchial biopsy carried the highest diagnostic yield for lung cancer in both groups (60%) and (24%) in groups I and II, respectively. Histopathologically, the majority of cases (86.48%) of group I were adenocarcinoma, (13.5%) were squamous, while all cases of group II (100%) were SCLC. TRAIL expression was positive in 67.6% of group I and in 23% of group II cases. 62.5% of adenocarcinoma patients were TRAIL positive, as well as 40% of squamous cell carcinoma patients while 23.1% only of SCLC were TRAIL positive. There was no statistical significant difference in the degree of cigarette smoking between TRAIL positive and negative subjects. The sensitivity of TRAIL immunostaining in lung cancer was 67.6%, while its specificity was 76.9% with accuracy of 70% in the studied groups. Conclusion: TRAIL is overexpressed in the majority of NSCLC mainly adenocarcinoma which indicate that it may become a new adjuvant line for treatment of such cases