Page 74 - Risk quantification and modification in older patients with colorectal cancer

Chapter 4
Patients and methods
Study population
All patients aged 70 years or older with surgical treatment for colorectal cancer between 1 January 2014 and 31 December 2016 in three teaching hospitals in The Netherlands (Hagaziekenhuis in The Hague, Diakonessenhuis in Utrecht, and the Reinier de Graaf Gasthuis in Delft) were included in this cohort study. Patients with acute or urgent surgery, transanal endoscopic microsurgery (TEM), stage IV colorectal carcinoma, or a synchronous second malignancy were excluded.
The primary outcome for this study was overall survival. Secondary outcomes were postoperative complications (surgical, cardiopulmonary, delirium, and other complications), readmission within 30 days and (temporary) discharge to a rehabilitation centre or nursing home.
Data collection
Preoperative patient characteristics and surgical outcome parameters were retrieved from the prospectively collected Dutch Colorectal Audit (DCRA). We complemented this with data from electronic medical records (EMR) for geriatric parameters. Follow-up on survival status was available until 1 February 2018 through a linkage with the Municipal Personal Records Database.
From the DCRA we retrieved the following data: age, gender, ASA score, comorbidity and oncological data (i.e. tumor type, tumor location, and staging), surgical approach (open or laparoscopic), type of surgery (acute, urgent or elective), postoperative complications, hospital stay, readmissions within 30 days, and 30- day mortality. The Charlson comorbidity index (CCI)10 was calculated for all patients. Postoperative complications registered in this audit were subdivided into surgical complications, cardiopulmonary complications and other complications. Any complication refers to the number of patients with one or more complications. When two or more surgical complications occurred, the most severe surgical complication was registered. Surgical complications included wound infections, bleeding, ileus and complications that needed intervention (including anastomotic leaks). Cardiopulmonary complications consisted of pulmonary complications (pneumonia, atelectasis, pulmonary embolism, pulmonary insufficiency or other pulmonary complications) and cardiac complications (myocardial infarction, heart failure, arrhythmia, angina pectoris, cardiac arrest, or other cardiac complications).
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