02945nas a2200445 4500000000100000000000100001008004100002260001200043653001100055653002100066653001800087653002700105653001100132653001300143653001100156653002400167653001400191653001800205653003500223653002900258653001300287653001700300100001200317700001700329700001200346700001700358700001100375700001500386700001200401700001400413700001800427700001100445700001500456700001800471245011000489300001400599490000700613520186500620022001402485 2022 d c2022-1210aBiopsy10aBreast Neoplasms10aBreast cancer10aChemotherapy, Adjuvant10aFemale10aHormones10aHumans10aNeoadjuvant Therapy10aorganoids10abiopsy sample10acomplete pathological response10aneoadjuvant chemotherapy10aorganoid10apersonalized1 aDan Shu1 aMeiying Shen1 aKang Li1 aXiaojian Han1 aHan Li1 aZhaofu Tan1 aYu Wang1 aYang Peng1 aZhenrong Tang1 aChi Qu1 aAishun Jin1 aShengchun Liu00aOrganoids from patient biopsy samples can predict the response of BC patients to neoadjuvant chemotherapy a2581-25970 v543 aPROPOSE: Neoadjuvant chemotherapy has been widely used in locally advanced and inflammatory breast cancer. Generally, complete pathological response after neoadjuvant chemotherapy treatment predicts survival. Studies have shown that patient-derived organoids can be used in cancer research and drug development. Therefore, we aimed to generate a living organoid biobank from biopsy samples to predict the response of patients to neoadjuvant chemotherapy. METHOD: We generated a living organoid biobank from locally advanced breast cancer patients receiving neoadjuvant chemotherapy. When the patient received neoadjuvant chemotherapy, the organoids were treated with similar drugs, thereby simulating the situation of the patient receiving treatment. RESULT: We successfully constructed organoids from breast cancer biopsies, demonstrating that organoids can be generated from a small sample of tissue. The phenotype of breast cancer organoid often agreed with the original breast cancer according to the blinded histopathological analysis of H&E stain tissue and organoid sections. In addition, our data confirm that the patient's response to chemotherapy closely matches the organoids' response to drugs. CONCLUSION: Our data indicate that patient-derived organoids can be used to predict the clinical response of breast cancer patients to neoadjuvant chemotherapy in vitro and to screen drugs that have different effects on different patients. Key messageComplete pathological response (pCR) after adjuvant chemotherapy can predict, survival, therefore, predicting patient response to neoadjuvant chemotherapy is critical.Patient-derived organoids (PDOs) matched the original tumour in terms of histopathology, hormone receptor levels and HER2 receptor status.Patient-derived organoids can predict the responsiveness of patient to neoadjuvant chemotherapy. a1365-2060