Preoperative asymptomatic leukocytosis has been reported as a factor that affects morbidity of surgical patients. We sought to identify the relationship between asymptomatic preoperative leukocytosis and postoperative complications in elective colorectal cancer surgery.

The NSQIP database was used to examine the clinical data of patients who had preoperative leukocytosis (white blood cell count more than 11,000/μL) and colorectal cancer resection from 2005 to 2013. Patients with preoperative sepsis, recent steroid use, disseminated cancer, renal failure, pneumonia, and emergently admitted patients were excluded from the study. Multivariate regression analysis was performed to identify outcomes of preoperative leukocytosis.

We evaluated a total of 59,805 patients with a diagnosis of colorectal cancer who underwent colorectal resection. The rate of preoperative asymptomatic leukocytosis was 5.6%. Asymptomatic leukocytosis was associated with preoperative serum albumin level (adjusted odds ratio [AOR] 0.58, p < 0.01) and blood urea nitrogen/creatinine ratio (AOR 1.01, p < 0.01). Preoperative asymptomatic leukocytosis had significant associations with increased mortality (AOR 1.76, p < 0.01) and morbidity of patients (AOR 1.26, p < 0.01). Postsurgical complications that had the strongest associations with asymptomatic leukocytosis were cardiac arrest (AOR 1.78, p = 0.03) and unplanned intubation (AOR 1.61, p < 0.01). Also, infectious complications were significantly higher in patients with leukocytosis (AOR 1.18, p = 0.01).

Preoperative asymptomatic leukocytosis has a prevalence of 5.6% in colorectal cancer resections and carries a significant increased risk of mortality and morbidity. Asymptomatic leukocytosis is associated with preoperative dehydration and malnutrition. Further studies are indicated to validate and explain these findings.