Background: An accumulation of mutations can result in carcinogenesis. Comparing genetic alterations in preneoplastic lesions with those seen in cancer in the same patient may be helpful in the early diagnosis of lung carcinoma or preneoplastic lesions.
Methods: To identify genetic alterations that may play a role in the development of nonsmall cell lung carcinoma (NSCLC), the authors examined the p53 gene and microsatellite markers on chromosome 3p (D3S643, D3S1317), 9p (D9S171, IFNA) in 35 bronchial metaplastic lesions and 28 alveolar hyperplastic lesions from 61 patients.
Results: A total of 8 metaplastic lesions (1 squamous metaplasia and 7 dysplasias) and 3 alveolar hyperplastic lesions (with atypia) showed genetic alterations, including loss of heterozygosity (LOH) of 3p, 9p and mutations of the p53 gene. In an analysis of microsatellite markers, 5 of 35 cases of squamous cell carcinoma (SCC) and 3 of 26 cases of adenocarcinoma (Ad) showed LOH in both preneoplastic lesions and synchronous cancers. Nine patients (25.7%) with SCC and 6 patients (23.1%) with Ad were shown to have mutations of the p53 gene by single-strand conformation polymorphism. In 2 of these 9 patients with SCC, the same mutation was observed in both dysplasia and SCC.
Conclusions: These findings suggest that several genetic alterations may occur in preneoplastic lesions or the early stage of SCC of the lung, whereas the genetic alterations examined appeared to occur relatively late in the pathogenesis of pulmonary adenocarcinoma.