Background Prescribing patterns in primary care could demonstrate early clinical features of cancer and windows of opportunity for timely investigation. Aim Analyse primary care prescription patterns prior to a pancreatic cancer diagnosis. Design and Setting Retrospective cohort study using linked primary care and cancer registry data from patients diagnosed with pancreatic cancer in England between 2011-2018. Method Prescription records registered in the Clinical Practice Research Datalink were analysed in the five years pre-diagnosis. Eight categories of prescriptions which may be used to treat clinical features of pancreatic cancer were included (anti-emetics, anti-reflux medications, insulin, other hypoglycaemic agents, opioids, non-opioid analgesics, neuropathic analgesics and non-steroidal anti-inflammatories). Poisson regression was used to estimate the inflection points for increased prescribing above baseline. Results Among 12,990 patients, 669,287 prescriptions were analysed. Insulin was the least common prescription (7% patients), anti-reflux the most common (53% patients). Insulin prescribing increased 19 months pre-diagnosis (95% confidence interval CI=14.2-23.8), rising earlier in females (25 months; 95% CI=17.4-32.5) than males (11 months; 95% CI=5.8-16.2). Prescriptions for other hypoglycaemic agents increased 13 months (95% CI=7.7-18.5), anti-reflux and opioid analgesic prescribing 7 months (95% CI=5.4-8.6 and 4.4-9.6, respectively) and anti-emetics and non-opioid analgesics 5 months (95% CI=2.9-7.1 and 3.2-6.8, respectively) prior to diagnosis. Conclusion The early increase in insulin prescribing suggests tumour-induced type 3c diabetes, highlighting an opportunity for earlier diagnosis in a small proportion of patients. Opportunities for earlier diagnosis through investigation and referral also exist in patients prescribed anti-emetic, anti-reflux, and analgesic medications in primary care.
Morel et al. (Thu,) studied this question.