[Prognostic value of heterozygosity loss in chromosome 3p in non-microcytic bronchogenic carcinoma]

Recent advances on carcinogenesis have led to the recognition of different patterns of behaviour of non-small cell lung cancers apart from those guided by the TNM staging system and the histologic subtype. The frequent genetic loss on chromosome 3p in all kinds of lung carcinoma leads to the suspect of the presence of a tumor suppressor gene located in that place. The aim of this work was to compare the different clinical features and evolution after treatment of the patients with non small cell lung carcinoma with and without loss of heterozygosity (LOH) on 3p.

Forty-five operated on non-small cell lung cancer patients were evaluated. The mean age was 64.4 years and all the patients were male. Seven patients had been previously treated for another epithelial neoplasm. 82.2% of the patients were heavy tobacco smokers. Most of the tumors (62.2%) were squamous cell carcinomas. Samples of tumoral and non tumoral lung tissue were immediately frozen after surgery. DNA from the tissue was extracted; then PCR amplification of microsatellites in regions 3p14 and 3p21 was performed. To determine the LOH in the regions analyzed a polyacrylamide gel electrophoresis was performed.

Twenty-five percent of the informative samples for 3p14 and 21.9% for 3p21 showed LOH. There was an statistical relationship between the LOH on 3p14 and the history of tobacco smoking and the adenocarcinoma histologic subtype (p < 0.05). There was a higher number of relapses and a shorter disease-free interval in those patients harboring 3p21 LOH.

LOH on 3p can be detected in non-small cell lung carcinoma. Patients with loss of heterozygosity on 3p21 have a worse evolution after a curative intended surgical resection.