The effects of neoadjuvant chemoradiotherapy on physical fitness and morbidity in rectal cancer surgery patients

BackgroundNeoadjuvant chemoradiotherapy (NACRT) followed by surgery for resectable locally advanced rectal cancer improves outcome compared with surgery alone. Our primary hypothesis was that NACRT impairs objectively-measured physical fitness. We also wished to explore the relationship between fitness and postoperative outcome.MethodIn an observational study, we prospectively studied 27 consecutive patients, of whom 25 undertook cardiopulmonary exercise testing (CPET) 2 weeks before and 7 weeks after standardized NACRT, then underwent surgery. In-hospital post-operative morbidity and mortality were recorded. Patients were followed up to 1 year for mortality. Data was analysed blind to clinical details. Receiver-operating characteristic (ROC) analysis defined the predictive value of CPET for in-hospital morbidity at day 5.ResultsOxygen uptake (V˙O2 in ml kg−1 min−1) at estimated lactate threshold (θˆL) and at peak exercise (V˙O2 at peak in ml kg−1 min−1) both significantly decreased post-NACRT: V˙O2 at θˆL 12.1 (pre-NACRT) vs. 10.6 (post-NACRT), p   < 0.001 (95%CI −1.7, −1.2); V˙O2 at peak 18.1 vs. 16.7, p   < 0.001 (95%CI −3.1, −1.0). Optimal V˙O2 at θˆL and peak pre-NACRT for predicting postoperative morbidity were 12.0 and 18.1 (V˙O2 at θˆL – AUC = 0.71, 77% sensitive and 75% specific; V˙O2 at peak – AUC = 0.75, 78% sensitive and 76% specific). Optimal V˙O2 at θˆL and peak post-NACRT for predicting postoperative morbidity were 10.7 and 16.7 (V˙O2 at θˆL – AUC = 0.72, 77% sensitive and 83% specific; V˙O2 at peak – AUC = 0.80, 85% sensitive and 83% specific).ConclusionNACRT before major rectal cancer surgery significantly decreased physical fitness as assessed by CPET.Trials Registry NumberNCT01334593.