Page 194 - Risk quantification and modification in older patients with colorectal cancer

Chapter 10
overall survival (OS) after elective CRC surgery. Using a population-based multi- centre database, we assessed these preoperatively collected geriatric characteristics as predictors for poor surgical outcomes. ADL dependency, experiencing at least one fall in the last 6 months, and being at risk of delirium were associated with a higher likelihood of overall mortality, even after adjustment for age, gender, tumour stage, and American Society of Anesthesiologists (ASA) Physical Status classification. We showed that compared to low-risk patients, high-risk patients (> 2 out of 4 impairments) had more postoperative complications and worse OS; almost 50% of these patients died within three years of surgery. These geriatric predictors also showed associations with the need for additional care after surgery. We have suggested that these geriatric predictors could be useful in a prediction model designed specifically for older patients.
In Chapter 5 we studied skeletal muscle mass and density as a prognostic factor for poor outcomes of CRC surgery. In an observational study among patients with non-metastatic CRC, lumbar skeletal muscle mass and density were measured from a single CT-image. We found very little prognostic value in lumbar skeletal muscle mass and density. Previously published cut-off values for radiologically assessed low skeletal muscle mass and density did not apply to older patients and did not discriminate between patients at risk and not at risk. These conclusions were not altered when skeletal muscle mass and density were analysed by gender-specific quartiles or as a linear measure. We have shown that physical functioning reflected by the use of a mobility aid has better potential as a predictor for complications and survival then a single CT-measurement of muscle mass or muscle density. Radiologically assessed muscle mass cannot be used as a prognostic marker for outcomes of CRC surgery unless age, gender and BMI specific cut-off points become available.
In Chapter 6, a preoperative geriatric risk prediction model is presented for severe complications after elective surgery, developed in 1088 patients with stages I-III CRC. Strong predictors were rectal cancer, gender, a history of COPD or Emphysema, a history of thromboembolic events (Deep Venous Thrombosis or Pulmonary Embolism), functional dependency, the use of a mobility aid, a previous delirium and polypharmacy. Age alone was no longer a predictor in this cohort. High-risk patients had up to 30% predicted risk for severe complications. Estimated discrimination of our model was AUC 0.65 by using the LASSO
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