Circulating CD16+ CD56+ Natural Killer Cells in Colorectal Cancer and Their Correlation with Survival

Gülcin SAHINGOZ ERDAL^1,2, Nilgun ISIKSACAN^2,3*, Tamay Seda TASCI^2,3, Murat CİKOT⁴, Pınar
KASAPOGLU ATAR², Nursel KOCAMAZ⁵

1. Department of Oncology, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Saglik Bilimleri University
2. Department of Immunology, Hamidiye Health Science Institute , Saglik Bilimleri University
3. Department of Biochemistry and Immunology, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Saglik Bilimleri University
4. Department of General Surgery, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Saglik Bilimleri University
5. Department of Internal Medicine, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Saglik Bilimleri University, Istanbul, TURKIYE
   *Corresponding Author: Nilgun ISIKSACAN; E-mail: nisiksacan@gmail.com

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.
Key words: carcino-embryonic antigen, Natural killer cells, immune system, colorectal cancer