{"entity":{"id":"idea-bio2-mrd-guided-endocrine-duration","kind":"idea","name":"Use residual disease tests to decide who needs ten years of hormone therapy","aka":[],"tldr":"Extended hormone therapy after breast cancer prevents late recurrence in a minority of women while imposing joint pain, bone loss and sexual side-effects on everyone for a decade. A sensitive residual disease blood test at year five, repeated annually, could show who can safely stop.","summary":"Extended adjuvant endocrine therapy prevents late recurrence in a minority while imposing joint pain, bone loss and sexual side-effects on everyone. Sensitive MRD testing at year five, repeated annually, could identify the persistently negative majority in whom continuation adds little, while intensifying treatment for the positive minority. This inverts the usual escalation-only use of MRD.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (Dormant cells and minimal residual disease): Tie et al., ctDNA analysis guiding adjuvant therapy in stage II colon cancer (NEJM 2022)","url":"https://doi.org/10.1056/NEJMoa2200075"}],"tags":[],"related":[],"cancers":["breast-hr-positive"],"sections":[],"technologies":["mrd-testing","endocrine-therapy"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["late-recurrence","mrd"],"trials":["soft-text","monarche"],"people":[],"bottlenecks":["b-dormancy-mrd","b-toxicity-qol","b-survivorship"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"Stopping endocrine therapy at five years in serially MRD-negative patients gives non-inferior distant recurrence-free survival at ten years, with materially better quality of life.","rationale":"Late recurrence in hormone-receptor-positive breast cancer arises from long-lived dormant cells, exactly the population a sensitive assay should detect. De-escalation guided by a negative test has already been accepted in principle for chemotherapy through genomic assays, so the regulatory and clinical logic is familiar.","test":"A registry-based non-inferiority randomisation at year five, with annual genome-wide MRD testing, patient-reported outcomes as co-primary, and pre-specified rescue for those who convert to positive.","maturity":"speculative","actor":"clinic","cost":"medium","horizonYears":7},"route":"/ideas/idea-bio2-mrd-guided-endocrine-duration/","neighbours":{"cancer":[{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"}],"technology":[{"id":"endocrine-therapy","kind":"technology","name":"Endocrine therapy (SERMs, AIs, SERDs)","route":"/technologies/endocrine-therapy/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"}],"term":[{"id":"late-recurrence","kind":"term","name":"Late recurrence","route":"/terms/late-recurrence/"},{"id":"mrd","kind":"term","name":"Minimal / molecular residual disease (MRD)","route":"/terms/mrd/"}],"trial":[{"id":"monarche","kind":"trial","name":"monarchE","route":"/trials/monarche/"},{"id":"soft-text","kind":"trial","name":"SOFT & TEXT","route":"/trials/soft-text/"}],"bottleneck":[{"id":"b-dormancy-mrd","kind":"bottleneck","name":"Dormant cells and minimal residual disease","route":"/bottlenecks/b-dormancy-mrd/"},{"id":"b-survivorship","kind":"bottleneck","name":"Survivorship and late effects are neglected","route":"/bottlenecks/b-survivorship/"},{"id":"b-toxicity-qol","kind":"bottleneck","name":"Toxicity and quality of life are undervalued","route":"/bottlenecks/b-toxicity-qol/"}]}}