Department of pathology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences, Beijing 100021, Department of etiology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences, Beijing 100021, Department of abdomenal surgery, Cancer Hospital and Institute, Chinese Academy of Medical Sciences, Beijing 100021
Aim: To study the expression of Fhit protein in lung cancers and its potential relevance in the diagnosis and prognosis of lung cancers. Methods: Tissue microarrays (TMA) and Immunohistochemistry (IHC) were performed in 321 cases of lung cancers. Fhit protein was tested by the S-P immunohistochemistry method upon tissue microarrays. Results: In our TMA blocks comprising 321 cases of lung cancer, there were 253 (78.8 %) cases valid for Fhit protein assessment. Total loss or marked reduction of Fhit expression (-, +) were seen in 170 cases (67.1 %). Fhit protein loss in NSCLCs (non-small cell lung carcinoma was significantly lower than in SCLCs (small cell lung cancers) (p < 0.05), in most squamous cell carcinomas (85 out of 105, 81.0 %), and in a smaller portion of adenocarcinomas (53 out of 109, 48.6 %; p < 0.05). The loss or marked reduction of Fhit expression was more common in tumours occurring in smokers and male patients (133 out of 191, 69.6 %; 135 out of 189,71.4 %) as compared to nonsmokers and female patients (29 out of 62, 46.8 %; p < 0.005 and 29 out of 64, 45.3 %; p < 0.005). However, the expression of Fhit protein was not associated with histopathologic grading, clinical staging, lymph node metastasis or survival time. Conclusions: 0ur studies showed thatthe loss or reduced expression of Fhit, a tumour suppressor gene is a frequent occurrence in lung cancers, with variations amongst different histological subtypes.The loss or marked reduction of Fhit expression was more frequent in smokers. This study showed that tissue microarrays can be used efficiently for evaluation of the expression of certain tumor markers.