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

BackgroundPreoperative 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 methodsA 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.ResultsIn 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 × 109 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.ConclusionsImpaired 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.