Özet:

Aim: Lung cancer is the most common cause of cancer deaths worldwide. Individualized treatment options occurred with the development of targeted therapy. The best-known genetic alterations which are important in therapy guidance of non-small cell lung cancer (NSCLC) are KRAS, EGFR, ALK, C-ERBB2, PIK3CA, BRAF, ROS1 and AKT. The significance of C-ERBB2 that plays an important role in treatment and prognosis of breast and gastric carcinoma is not known enough in NSCLC. Therefore, a pilot study is designed to show the role and importance of overexpression of C-ERBB2 in NSCLC and to identify the current prevalence and distribution of C-ERBB2 in Turkey in case it may be used as targeted therapy in near future for NSCLC. Material and Methods: In this study, 258 cases, were diagnosed with NSCLC between 2005-2014 in the pathology department of Haydarpasa Numune Training and Research Hospital, were included. H&E stained microscopic slides of cases were re-examined and stained for C-ERBB2 immunohistochemically. Score 1, 2 or 3 was given according to the intensity and completeness of staining. C-ERBB2 scores were then compared with clinicopathological and prognostic features. Results: C-ERBB2 positivity was observed in 6,2% of cases. The positivity was comparatively higher in adenocarcinomas. A statistically significant relationship was not detected between C-ERBB2 positivity and clinicopathological (tumor type, subtype, grade, lymph node metastasis, lymphovascular invasion, pleural invasion, and tumor size) and prognostic features (mortality, overall survival, progression-free survival, recurrence). Conclusion: In this study, C-ERBB2 overexpression was detected in adenocarcinomas almost to a statistically significant degree. However, in NSCLC statistically significant relationship could not be demonstrated between clinicopathological and prognostic parameters and immunohistochemical positivity of C-ERBB2. For this reason, cases with scores of 2 and 3 should be reexamined with in-situ hybridisation or other genetic tests and additional studies should be performed to determine the clinicopathological and prognostic parameters and the response to anti-HER2 treatment.