Suppression of the postoperative neutrophil leucocytosis following neoadjuvant chemoradiotherapy for rectal cancer and implications for surgical morbidity

Objective: The extent to which neoadjuvant chemoradiotherapy for rectal cancer influences postoperative morbidity is controversial. This study investigated whether this treatment suppresses the normal perioperative inflammatory response and explored the clinical implications. Method: Prospective databases were queried to identify 37 consecutive study patients undergoing definitive surgery following 5-FU/capecitabine-based chemoradiotherapy and 34 consecutive untreated control patients operated upon for rectal or rectosigmoid cancer. Preoperative (< 10 days) and postoperative (< 24 h) neutrophil counts, along with morbidity data, were confirmed retrospectively. Univariate and multivariate analyses assessed the apparent effect of chemoradiotherapy on change in neutrophil count. The latter's association with postoperative morbidity was then examined. Results: Sufficient data were available for 34 study and 27 control patients. Repeated-measures ANCOVA revealed significant differences between their perioperative neutrophil counts (P = 0.02). Of the other characteristics which differed between the groups, only age and tumour location were prognostically significant regarding perioperative change in neutrophil count. Accounting for relevant covariates, chemoradiotherapy was significantly associated with a suppressed perioperative neutrophil leucocytosis. Local postoperative complications affected 25 of 61 patients, who had lower perioperative neutrophil increases than their counterparts (P = 0.016). Conclusion: Chemoradiotherapy appears to suppress the perioperative inflammatory response, thereby increasing susceptibility to local postoperative complications.