In some cases, essential information about the stage of the tumor process is provided by laboratory data. Thus, the discovery in the peripheral blood of patients with lung cancer of a large number of immature cells or thrombocytopenia may indicate the presence of metastases in the bone marrow.

According to the opinion, with a simultaneous change in the serum content of albumin, alkaline phosphatase and transaminase, the probability of liver damage reaches 92%. However, in our observations, we traced a similar picture only in 8.5% of morphologically verified cases. The definition of alkaline phosphatase is more important. So its elevated content in the serum (discriminant level 92U / l) is observed in the presence of liver metastases in 64.4%. The disadvantage of this study is its low specificity: weak toxic effects on the liver, causing fatty infiltration, alcohol intake, drugs, and inflammatory diseases of the hepato-biliary zone can cause an increase in its blood level. An increase in the concentration of alkaline phosphatase may also be due to bone pathology.At the same time, the excess of the discriminant level of its content in blood serum more than twice, except for patients with lung cancer with metastases to the liver, was observed by us only in some cases of a paracancic infection accompanied by acute destruction of the lungs.

The g- glutamyltranspeptidase g is more sensitive to metastatic liver damage : we noted its normal indicators (discriminant level 63 U / l) in only 14.9% of morphologically proven cases. On the other hand, exceeding the upper limit of the norm by more than 2 times, only in one of our observations was not associated with metastasis of lung cancer, but was due to mechanical jaundice of non-tumor genesis. when using g – glutamyl transpeptidase for the diagnosis of hepatic metastases, it was even possible to obtain 94% sensitivity of the method, and et al. (1991) noted a statistically significant increase in the level of the enzyme in all patients with lung cancer with liver metastases compared with the group of patients without metastases.

The presence of hepatic metastases can also indicate an elevated serum lactate dehydrogenase, especially LDH-4 and LDH-5, aldolase.

The relatively low specificity of laboratory tests requires, if the metastatic process is suspected, additional studies are required. Of considerable practical interest is the detection of severe hyperfermentemia in the absence of clear ultrasonoscopic signs of lung cancer metastases in the liver. Computer tomography carried out in a similar situation allowed us to detect previously not diagnosed metastases of lung cancer in four cases. Thus, the negative conclusion of ultrasound examination of the liver with severe hyperfermentemia is not a sufficient argument to stop the diagnostic search. On the other hand, according tothe combination of hyperfermentemia with focal changes during ultrasonoscopy exhausts the diagnostic process and does not require morphological verification of the detected changes.

There is a definite dependence of the level of carcino-embryonic antigen in the blood on the stage of lung cancer, primarily in glandular and undifferentiated histological forms. Our observations show that already a CEA content of more than 15 ng / ml is a poor prognostic sign and requires additional studies of the liver, bone skeleton and other organs to exclude secondary lesions. In peripheral lung tumors, one should not forget that the possibility of their metastatic nature leads to a higher critical level —50 ng / ml. However, only by the level of antigen can not be accurately determine the prognosis of the disease. A similar point of view is held.

In differentiated forms of lung cancer, it is of practical interest to study the content of a neuron-specific enolase, the high numbers of which may indicate the presence of metastases in the central nervous system.