{"entity":{"id":"idea-prev-blood-count-trend-flags","kind":"idea","name":"Use the trend in routine blood counts, not a single threshold, to spot cancer","aka":[],"tldr":"A platelet count that is normal but rising year on year, or haemoglobin drifting down, can signal cancer. Records already hold these trends; software could use them.","summary":"Thrombocytosis and unexplained anaemia are known predictors; longitudinal within-person trends are more informative than population thresholds. Propose trend-based alerting in primary care (e.g. a 20% platelet rise over two years within the normal range), evaluated in a linked-data cohort and then an RCT.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (The hardest cancers are found late): Crosby et al., Early detection of cancer (Science 2022)","url":"https://doi.org/10.1126/science.aay9040"}],"tags":[],"related":[],"cancers":[],"sections":["early-detection","diagnostics"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-early-detection"],"keyPapers":["paper-crosby-science"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Within-person trend flags identify at least 20% more incident cancers 6-12 months before diagnosis than threshold-based flags at the same alert rate.","rationale":"Analogous to using individual baselines rather than population cut-offs in other fields; the data is already collected.","test":"Retrospective validation in CPRD or similar linked datasets (small cost); then a prospective pragmatic trial.","maturity":"speculative","actor":"data","cost":"small","horizonYears":3},"route":"/ideas/idea-prev-blood-count-trend-flags/","neighbours":{"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"},{"id":"early-detection","kind":"section","name":"Early Detection & Screening","route":"/fronts/early-detection/"}],"bottleneck":[{"id":"b-early-detection","kind":"bottleneck","name":"The hardest cancers are found late","route":"/bottlenecks/b-early-detection/"}],"paper":[{"id":"paper-crosby-science","kind":"paper","name":"Early detection of cancer","route":"/key-papers/paper-crosby-science/"}]}}