STUDIES ON CLINICOPATHOLOGICAL FEATURES OF LUNG-CANCER PATIENTS WITH K-RAS P53 GENE ALTERATIONS - COMPARISON BETWEEN YOUNGER AND OLDER GROUPS/

In order to define the roles of the K-ras and p53 genes in the develop ment of lung cancer, especially in young adults, we compared the clini copathological features of the patients between younger (less than or equal to 45 years, n = 47) and older (>55 years, n = 50) groups. The g ene alterations were examined by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method. The K-ras gene alt erations were detected only in adenocarcinomas, and the p53 gene alter ations in all histologic types of lung cancer. There were no significa nt differences in the frequency of both K-ras and p53 gene alterations between the younger and older groups (9 vs. 11%, 36 vs. 32%). In the younger group, but not in the older one, the percentage for smokers wa s significantly higher in the p53 gene alteration-positive group than for the negative group (65 vs. 30%). As to the prognosis, there were n o significant differences between the p53 gene alteration-positive and -negative cases in both the younger and older groups as well as in al l subjects, while a tendency of poorer prognosis was observed in K-vas gene alteration-positive cases than for the -negative ones with adeno carcinomas. These results suggest that (1) the K-ras and p53 gene alte rations would have no special roles in terms of the lung carcinogenesi s in young adults; (2) a positive relationship between smoking and p53 gene alteration would exist in young adults with lung cancer, and (3) K-rns gene alteration would become a prognostic factor in lung cancer .