Isoenzyme(s) of glutathione transferase (class Mu) as a marker for the susceptibility to lung cancer: a follow up study.

Glutathione transferase are divided into three classes: Alpha, Mu and Pi. Isoenzyme(s) from one of these classes, class Mu, is dominantly inherited and can be determined by activity measurements directed towards the substrate trans-stilbene oxide. The frequency of this phenotype has been measured in patients with bronchial carcinoma and in control subjects matched for age and smoking history. After combining an earlier study from our laboratory (Carcinogenesis, 7, 751-753, 1986) with the additional material presented here (control smokers, n = 114, lung cancers, n = 125) non-cancer smokers had an increased number of subjects who expressed class Mu isoenzymes (58.3% of total n = 192) compared with lung cancer patients (36.6% of total n = 191; P less than 0.0001). The pathology of lung tumors related to the lack of class Mu isoenzymes which occurred most frequently in patients with adenocarcinomas. It is concluded that the gene expressing class Mu isoenzymes may be a host determinant of genetic susceptibility to lung cancer among smokers.