Colon Cancer Surgery in Aged Patients: Surgical and Functional Outcomes

Colon cancer is the fourth most diagnosed cancer of all age groups and the third most common in individuals aged 80 or over in Finland. Curative surgery is the primary treatment choice for colon cancer. However, physical and mental functioning of older people varies considerably from very fit to frail individuals with short life expectancy. Increasing numbers of recommendations and guidelines have recently been published regarding preoperative care planning and prognosis assessment in older patients. However, studies on the impact of surgery on postoperative outcomes and functional recovery are lacking.

This thesis aimed to analyse operative and functional outcomes of elective and curatively aimed colon cancer among patients aged 80 years and over. A further aim was to examine preoperative factors influencing postoperative outcomes in the short- and long-term.

The material in Studies I and II consisted of patients operated on in four Finnish secondary and tertiary hospitals between 2005 and 2016. The data, which included 387 patients, were collected from the colorectal databases of the hospitals concerned. Study I evaluated preoperative risk factors affecting postoperative outcomes and survival in the short- and long-term. Severe complications were more common in patients living in assisted living accommodations and in patients with a history of hospitalisation six months before surgery. The 30-day and one-year mortality rates were significantly higher in patients with serious postoperative complications than in patients overall (30 % vs. 6.0% and 45% vs. 15%).

Study II focused on long-term overall survival after surgery comparing patients who survived over three months to patients who died within three months after surgery. Cardiovascular (13/29, 45 %) and surgical reasons (7/29, 24 %) were the most common causes of death within three months after surgery. However, advanced age, living in assisted living accommodation, multiple underlying diseases, and tumour stage according to TNM-classification were independently associated with shorter survival in patients who survived at least three months after surgery. The study showed that patients who were in good health before surgery, even with severe postoperative complications, had long-term outcomes and survival rates comparable to those of their unselected younger counterparts.

Prospective observational Studies III and IV were conducted in nine Finnish hospitals between April 2019 and August 2020. Study III, which included 161 patients, examined surgical outcomes within 30 postoperative days. Study IV, which included 167 patients, analysed changes in support for activities of daily living and mobility one-year after surgery.

Study III demonstrated that surgical outcomes among the fittest patients were comparable to those of younger patients. Surgeons should therefore not hesitate to perform invasive surgery based on age or comorbidities alone. The Clinical Frailty Scale (CFS), used as a frailty screening tool, predicted early postoperative complications well. Patients who were vulnerable or frail with CFS ≥3 had significantly more complications than patients in good health with CFS 1-2 (48 % vs 16%). The study concluded that CFS may be a user-friendly and quick screening implement for surgeons when assessing and identifying preoperative risks for postoperative complications.

Study IV showed that functionally independent and fit patients retained their independence in daily activities and mobility well during the first postoperative year. Preoperative optimisation of haemoglobin and preoperatively planned early rehabilitation and discharge are recommended for all patients. Patients needing more support with activities of daily living, having restricted mobility, or a history of cognitive impairment may require careful preoperative risk assessment, treatment planning and specific prehabilitation and postoperative rehabilitation planned jointly with a geriatrist before invasive cancer treatment.

In conclusion, this thesis showed that aged patients 80 years or over who are preoperatively appropriately selected and optimised, coped equally successfully with invasive cancer surgery with convergent short-and long-term outcome results as did their younger unselected counterparts. Careful assessment of the risks of surgical treatment, optimisation of patients´s physical performance and comprehensive treatment planning with the patient and relatives to avoid under-or overtreatment may be beneficial for aged colon cancer patients.