Cardiopulmonary Exercise Testing for Predicting Early Outcomes after Major Cancer Resection: A Systematic Review

Background: Postoperative complications after major surgery are thought to be associated with reduced fitness. Surgical cancer patients are often malnourished, cachexic and subject to neoadjuvant chemotherapy resulting in low preoperative fitness levels. This review examined the associations between aerobic fitness, as determined objectively by preoperative cardiopulmonary exercise testing (CPEX), and short-term morbidity after cancer surgery. Methods: A literature search using databases of PubMed, Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the Cochrane Library for studies that examined associations between preoperative CPEX variables and postoperative complications following surgery for the ten commonest cancers. Results: A total of 21 observational studies were identified with 4957 patients that underwent CPEX testing prior to lung, colorectal, liver, oesophagogastric, bladder and pancreas resections. The median sample size was 105 patients (range 64 - 1684). No studies were found for breast or brain cancers or lymphoma. In lung cancer patients undergoing thoracotomy, a VO2peak ≤ 15ml/kg/min was associated with an increased risk of respiratory complications and death. None of the studies in other cancer types had adequate sample sizes to report on mortality. CPEX testing had mostly poor to average discriminatory accuracy to predict postoperative morbidity in other cancer resection surgeries. Findings across studies were inconsistent, and detection and selective reporting biases were likely to be significant. Conclusion: The utility of CPEX testing prior to cancer surgery is questionable and currently should not be used as a discriminatory tool, except in patients undergoing lung cancer resection by thoracotomy. Larger studies with more robust methodologies are currently required to determine the utility of CPEX.