Surgical outcomes following colorectal cancer resections in patients aged 80 years and over: results from the Australia and New Zealand Binational Colorectal Cancer Audit

Aim: The primary aim was to compare the 30-day morbidity and mortality in patients aged ≥80 years undergoing surgery for colorectal cancer with those aged <80 years. The secondary aim was to identify independent outcome predictors. Method: This was a retrospective study of patients undergoing surgery for colorectal cancer between January 2007 and February 2018. Patients were divided into those <80 years and those ≥80 years at the time of surgery. Data had been collected prospectively by the Australasian Binational Colorectal Cancer Audit and included patient demographics, site and stage of tumour, comorbidity, operative details, American Society of Anesthesiologists score (ASA), pathological staging, 30-day mortality and morbidity (medical and surgical). Univariate and multivariate analyses were used to identify predictors of 30-day morbidity and mortality. Results: During the study period, 4600 out of 20 463 (22.5%) patients were ≥80 years. They had a greater 30-day mortality after both colonic (97/2975 [3.3%] vs. 66/7010 [0.9%], P < 0.001) and rectal resections (50/1625 [3.1%] vs. 36/9006 [0.4%], P < 0.001) compared with younger patients. They also had an increased length of stay (colon cancer, 9 vs. 7 days; rectal cancer, 10 vs. 8 days; P < 0.001) and medical complications (colon cancer, 23.5% vs. 12.7%; rectal cancer, 25.2% vs. 11.2%; P < 0.001). Surgical complications were equivalent. Age ≥80 years was not an independent predictor of 30-day morbidity or mortality. Patients ≥80 years who were ASA 2/3 and had rectal cancer seemed to fare worse in terms of 30-day mortality (ASA 2, 22%, 95% CI 9%–36%, P < 0.001; ASA 3, 11%, 95% CI 4%–19%, P< 0.001). Conclusions: Postoperative morbidity and mortality are significantly greater in patients ≥80 years undergoing colorectal cancer surgery. Any recommendation for surgery in this age group should take into account patient comorbidity and not be based on age alone.