DNA aneuploidy, S-phase fraction and nuclear p53 positivity in non-small cell lung carcinoma

Objectives: Surgical resection currently offers the best option for managin g non-small cell lung carcinoma (NSCLC) but its efficiency is limited by su bsequent tumor recurrence. We evaluated whether flow cytometric study and t he p53 gene staining pattern may be useful in this respect. Design and Methods: We took biopsy samples of 40 patients with operable NSC LC to study the frequency of aneuploidy, proliferative activity, and altera tions in the p53 tumor suppressor gene and compared them with clinicopathol ogical parameters such as age, gender, smoking, histological type, tumor si ze, and degree of differentiation. To study DNA content, the nuclei were an alyzed by flow cytometry using a FAGS flow cytometer (Becton-Dickinson) equ ipped with an argon ion laser, with a propidium iodide excitation of 488 nm . We used the immunohistochemical technique for p53 analysis in samples of paraffin-embedded tissue corresponding to the same patients from whom fresh tissue was taken. Results: Nuclear p53 staining was detected in 66.7% of the samples; 69.4% o f the cases revealed aneuploid DNA histograms and 59% presented with an S p hase fraction of more than 12%. Comparison with clinicopathological paramet ers showed that p53 protein was associated significantly with histological classification (p = 0.04), gender (p = 0.01), and smoking (p = 0.04). Conclusions: Immunodetection of p53 overexpression and DNA ploidy in the br onchial epithelium may be a useful tool in any future multifactorial analys is in such tumors for identifying previous lesions that may progress to mal ignancy. Copyright (C) 1999 the Canadian Society of Clinical Chemists.