Background. Lung cancer is the most common cause of morbidity and mortality among all cancers. The dominant type of lung cancer is non-small cell lung cancer. Early diagnosis, rapid and least possible invasive treatment gives the best chance to extend life expectancy. Considering increasing level of NS CLC morbidity it is extremely important to develop cancer diagnostics, which will allow to implement necessary treatment in early stages.

Objectives. The main focus of this paper is to establish level of usability for dimeric form of the pyruvate kinase in NS CLC patient plasma using spectrophotometric method.

Material and methods. Participants of the study were chosen from patients of the Lower Silesian Lung Disease Centre in Wroclaw. Patients were allocated in to two study groups: first containing patients who were diagnosed with adenocarcinoma, second containing patients who were diagnosed with carcinoma planoepitheliale. The control group was chosen from patients who were not diagnosed with cancer. Material in question was plasma, tested on pyruvate kinase activity.

Results. Analysis showed a difference in pyruvate kinase activity between patients in study groups and test group. The highest increase in enzyme activity was found in group of patients diagnosed with carcinoma planoepitheliale (134.5%). In the group of patients diagnosed with adenocarcinoma enzyme activity increase reached 132.1% and in test group, 116%.

Conclusions. Testing enzyme activity of pyruvate kinase can be an additional helpful method in NS CLC diagnoses, besides diagnostic imaging. This method is characterised by high sensitivity and low invasiveness.