Influence of stage at cancer diagnosis on NHS hospital care costs in England: a national, retrospective, population-based cohort study using individual patient-level data.

[BACKGROUND] Estimates of the cost of cancer care are crucial for the economic evaluation of screening interventions and other early cancer diagnosis initiatives. However, data on the cost of cancer is scarce. This study estimated National Health Service (NHS) hospital care costs for eight cancer types by stage at diagnosis in England.

[METHODS] This national, retrospective, population-based cohort study used individual patient-level data collated by the National Disease Registration Service, NHS England. We included patients aged 50-79 years who were diagnosed with a colorectal, head and neck, liver and bile duct, lung, lymphoma, oesophageal, ovarian, or pancreatic cancer in England between Jan 1, 2014, and Dec 31, 2017. For each patient, we obtained linked national health-care records, incorporating all inpatient hospital care, outpatient activity, and accident and emergency department attendances, and costed these using a payer perspective. Patients were excluded if registration was death certificate only, records related only to a secondary metastatic site, sex and cancer type were incompatible, death status or date were uncertain, or there were zero health-care costs from 6 months before diagnosis to end of follow-up. Net, cancer-related, regression-adjusted hospital care costs were reported for each cancer type and stage overall, annually, and by phase of care. Within each annual period and phase, mean monthly costs were also estimated.

[FINDINGS] Of 359 106 cancer records registered, 345 629 cancers were available for analysis, and 333 657 cancers were included in the analysis (147 334 [44·2%] occurred in female patients and 186 323 [55·8%] in male patients; 303 227 [90·9%] among participants of White ethnicity, 4452 [1·3%] among participants of mixed or other ethnicity, 7870 [2·3%] among participants of Asian ethnicity, 4179 [1·3%] among participants of Black ethnicity, and 13 929 [4·2%] among participants of unknown ethnicity). Overall costs were higher at later stages for colorectal, head and neck, lymphoma, and ovarian cancers with mean stage IV costs of £37 838, £36 657, £42 667, and £45 871, respectively. Costs for liver and bile duct, lung, oesophageal, and pancreatic cancers were highest for those diagnosed at stage II (£28 356, £29 553, £33 640, and £39 351, respectively), and slightly lower at stages I, III, and IV. Health-care costs were highest in the initial treatment and the end-of-life phases of care. Within each phase, mean cost per month increased with stage for most cancer types studied, though fewer months of follow-up were observed in each phase for liver and bile duct, lung, oesophageal, and pancreatic cancers.

[INTERPRETATION] Cancer-related NHS hospital care costs by stage at diagnosis differed between cancer types; this heterogeneous pattern could inform detailed and nuanced economic evaluations of early detection initiatives.

[FUNDING] GRAIL Bio UK.