Introduction Emerging evidence suggests that neutrophils, which function as the first line of defence during infections and have been shown to have a multitude of additional roles in immunity, facilitate cancer progression. Neutrophil Extracellular Traps (NETs) are extra-cellular neutrophil derived DNA webs that trap and kill invading pathogens. NETs have been implicated in the promotion of cancer progression and to the development of metastases by sequestering circulating tumour cells. Although NETs have been detected in infection their role in-vivo is unclear.

This study was performed to evaluate any differences in NET formation in patients with Colorectal Cancer compared to healthy individuals.

Method Systemic neutrophils were isolated from consecutive consenting patients with a confirmed diagnosis of Colorectal Cancer and from consenting age-matched Healthy Controls (in the absence of infection). NETs were measured in response to No-Stimulant, IL-8, LPS and f-MLP by fluorescence video-microscopy.

Results 41 patients with a confirmed diagnosis of Colorectal Cancer were evaluated (mean 68.6years, 95% CI 65.2–71.5) and compared to 20 Healthy Controls (mean 69.9years, 95% CI 66.3–73.5). Increases in NET formation were demonstrated in patients with Colorectal Cancer compared with Healthy Controls: No-Stimulant (12,440AFU vs. 9,251AFU, p = 0.0264), IL-8 (13,210AFU vs. 8,620AFU, p = 0.0014), LPS (13,850AFU vs. 11,650AFU, p = 0.0275), f-MLP (12,810AFU vs. 10,790AFU, p = 0.3293).

Conclusion Significant increases in NET formation have been demonstrated in patients with colorectal cancer. These findings suggest that NETs are implicated in cancer development and progression. NETs could represent potential therapeutic targets and merit further investigation in the context of Colorectal Cancer.

Disclosure of interest None Declared.