The aim of the study is to assess whether the value of neutrophil-lymphocyte count ratio from the routine preoperative blood test may predict lung tumors' grading.

Lung cancer remains as one of the leading causes of death among oncology patients. Close connection between inflammation and pathogenesis of some neoplasms was determined in a number of studies. Some studies show promise that ratio of neutrophil to lymphocyte count (NLCR) may be recognized as a prognostic marker for several carcinomas: renal, lung and colorectal. The aim of the study is to assess whether the value of neutrophil-lymphocyte count ratio from the routine preoperative blood test may predict lung tumors' grading. During routine preoperative blood tests complete blood count is done and NLCR, WBC, neutrophil and lymphocyte count is noted. After the thoracic surgery intervention and histopathological examination grading of lung tumor is noted.

Inclusion Criteria:

• consecutive thoracic surgery patients with lung cancer grading confirmed by histopathology postoperatively
• preoperative routine complete blood count analysis

Exclusion Criteria:

• infectious disease
• pregnancy
• autoimmunologic disease
• other known conditions or treatments that may influence the blood count (seropositivity for HIV, chemotherapy, and corticotherapy)

Consecutive thoracic surgery patients admitted to SPSK nr 1 in Zabrze between October 2014 and October 2018 with lung tumor qualified for thoracic surgery intervention