Abstract
BACKGROUND: Natural killer cells, which play a role in the innate immune system, are cells in the early defence system against infections and tumours. The aim of this study was to investigate the role of NK cells in stage 3 colorectal cancer (CRC) and their relationships to serum carcinoembryonic antigen (CEA) levels, obesity, and survival. METHOD: CD16+CD56+ NK cells were analyzed by flow cytometry in newly diagnosed stage 3 CRC patients and healthy controls. Associations with survival, obesity, and serum CEA were evaluated. RESULTS: The rate of NK cells was found to be lower in the CRC patients than in the healthy control subjects. The reduced NK cell rate was associated with reduced survival. A negative correlation was determined between NK cells and age, serum CEA levels, and obesity at the time of diagnosis. CONCLUSION: As the study results suggest that the NK cell rate could be effective in predicting prognosis in stage 3 CRC patients, they could also be of guidance for further studies with larger patient populations.