Age-related differences in staging, treatment and net survival in relation to frailty in adults with colon cancer in England: an analysis of the COloRECTal cancer data repository (CORECT-R) resource.

Objective: To describe the distribution of disease stages, receipt of major surgery, 1-year net survival (NS) and 1-year conditional NS in relation to age and frailty in adults aged ≥50 diagnosed with colon cancer in England.

Methods: We obtained data on adults aged 50-99 diagnosed with colon cancer between 2014 and 2019, followed up through December 2021, from the national population-based COloRECTal cancer Repository. Frailty was assessed using the Secondary Care Administrative Records Frailty (SCARF) index categorised into fit, mild, moderate and severe frailty. Data on major resection were obtained through linkage with Hospital Episode Statistics dataset. Major resection rates were calculated in adults with stage I-III cancer. Descriptive statistics were used as appropriate. One-year NS from cancer diagnosis and 1-year conditional NS were estimated using the Pohar-Perme estimator.

Results: Out of 130 360 individuals (48% females-50% over 75), 48.9% were fit, ranging from 69% in the 50-64 age group to 31% in the 85-99 age group. Over 80% of adults with stage I-III cancer underwent a major resection. This percentage was 58% amongst fit adults aged over 85. One-year NS decreased as age increased across all frailty levels. Differences in NS between the 50-64 age group and the 85-99 age group were reduced in adults who survived beyond 1 year from diagnosis except for severely frail adults.

Conclusion: This population-based study shows that a non-negligible proportion of older adults diagnosed with colon cancer and deemed 'fit' through the SCARF did not receive surgery that may impact their survival.