Postoperative morbidity and mortality in relation to leukocyte counts and time to surgery after short-course preoperative radiotherapy for rectal cancer

Abstract

Background Preoperative radiotherapy for rectal cancer decreases local recurrence rates, but increases postoperative complications. Impaired postoperative leukocyte reaction after preoperative short-course radiotherapy has been reported. The aim was to assess postoperative morbidity and mortality in relation to leukocyte reaction and the time interval between radiotherapy and surgery. Materials and methods A retrospective analysis of patients included in the Stockholm I and II trials, randomising patients to surgery alone or to 5 × 5 Gy with immediate surgery, identified pre- and postoperative leukocyte values for 274 patients. Results In the surgery alone group ( n = 144), all but three patients (2%) reacted with leukocytosis (ratio post/preoperative >1.0) on day 1 and all but 9 (6%) on day 5. In the radiotherapy group ( n = 130), 40 (31%) became leukopenic (<4 × 10 9 cells/L) after radiotherapy, 29 (22%) reacted abnormally (leukopenia or ratio ⩽1.0) on day 1 and 66 (51%) on day 5 (all p < 0.001). Preoperative leukocyte counts did not influence postoperative morbidity, but a poor response on day 1 increased the risk of sepsis ( p < 0.05) and mortality (6/29 (21%) vs. 6/101 (6%), p < 0.05). An interval of 10 days or more between the start of radiotherapy and surgery also had an impact on mortality; 6/17 (35%) vs. 6/113 (5%), p = 0.001. In a logistic regression analysis, the time interval and age were independent predictors of mortality. Conclusions Impaired postoperative leukocyte reaction is frequent after short-course radiotherapy and increases the risk of postoperative complications and death. A longer than recommended radiotherapy–surgery interval also appears to be detrimental for postoperative death, independently of leukocyte response.