Evaluation of biological malignancy of primary lung adenocarcinoma using two-dimensional polyacrylamide gel electrophoresis

Objective: The usefulness of two-dimensional polyacrylamide gel electrophoresis (2-DE) combined with non-enzymatic sample preparation technique of surgically resected primary lung adenocarcinoma was discussed in terms of tumor malignancy. Study Design: Measurement of clinical materials was successful in 70 patients with primary lung adenocarcinoma between 1994 and 1996. We estimated the expression levels of the polypeptides associated with histopathological type as previously described (i.e. polypeptides associated with adenocarcinoma, TA01 ~ 05; polypeptides associated with squamous cell lung carcinoma, TSq01~04; polypeptides associated with neuroendocrine tumor, TS01~04) and proliferating cell nuclear antigen (PCNA) on 2-DE gels at the same time. Based on these data, all adenocarcinoma cases were classified into two groups and we attempted to evaluate the relationship between histopathological factors and prognosis in both groups. Results: We classified 26 cases (37.1%) as adenocarcinoma case with a typical 2-DE pattern and 44 cases (62.9%) as aadenocarcinoma with an atypical 2-DE pattern. The 2-year disease-free survival rates were 69.2% and 27.1% in typical cases and atypical cases, respectively, showing a statistically significant difference (p=0.0011). In stage I cases there was also a statistically significant difference (3-year-disease-free survival rate: typical cases, 94.1%; atypical cases, 46.7%; p = 0.0030). Conclusion: There is a strong possibility that 2DE evaluation may reflect biological malignancy of surgically resected primary lung adenocarcinoma.