The effect of older age and stage on risk of recurrence and mortality following curative resection, in a national cohort of patients with colorectal cancer.

BACKGROUND

Older patients are routinely excluded from clinical research, limiting understanding of recurrence and mortality in colorectal cancer (CRC) patients over 75 who undergo curative major resection.

METHODS

Using linked data from national cancer, treatment and administrative datasets, we estimated recurrence, CRC-related and non-CRC mortality to 5 years after surgery for patients selected for curative resection in England between 2014 and 2020, who survived >9months. Recurrence was defined using diagnostic and treatment codes.

RESULTS

50,480 patients had curative resection, 15,496 (30.7%) aged >75. Recurrence-free survival at 5-years after resection was 66.2% (95%CI: 65.4%, 67.0%) for patients aged >75 and 77.4% (77.0%, 77.9%) for patients aged 18-75. By 5-years, 13.3% (12.7%, 13.9%) of the older group had died from CRC and 14.2% (13.6%, 14.8%) from non-CRC causes, compared with 7.7% (7.4%, 8.0%) and 3.6% (3.4%, 3.8%) respectively in the younger group. Recurrence-free survival was 22% lower for cancer stage 3 versus stage 1, and 12-13% lower for patients aged >75 versus ≤75.

CONCLUSIONS

Cancer stage was the strongest predictor of recurrence and CRC-related death. In patients selected for surgery, those aged>75 had similar recurrence risk to younger patients, but higher risk of death following recurrence, and were as likely to die from other causes as from CRC.