Patient demographics
From January 2010 to December 2018, five hundred and thirty-three patients underwent colorectal cancer resection at our institution. No patients were excluded from the study. One hundred and thirty-six patients were aged between 75-85 years old at the time of surgery. Forty-eight patients were aged 85 or above at the time of surgery. These two groups were compared with the demographic features of each group outlined in Table 1.
The distribution of ASA grading was similar between the two groups, with no significant difference in distribution or prevalence. Hypertension was the most common cardiac comorbidity in both groups (75-85 age group, 63% vs 85+ age group, 71%, p=0.38) with coronary artery bypass grafting being more prevalent within the 75-85 years old group (15% vs 11%, p=0.025). There was also a significantly higher proportion of women in the over 85 group (69% vs 51%, p= 0.043). There was no significant difference between the two groups with regards to distribution of other cardiac comorbidities.
Asthma (15% vs 8 %, p=0.33), COPD (16% vs 8%, p=0.23) and obstructive sleep apnoea (7% vs 0%, p=0.066) in both groups were not statistically different. There was no significant difference in metabolic or autoimmune comorbidities between the two groups. Those in the 85+ group had a higher incidence of renal disease (pre-operative eGFR less than 60) compared to those in the 75-85 year old group (25% vs 46%, p=0.007).