Clinical efficacy of tumor organoid-guided cancer therapy for locally advanced unresectable or metastatic breast cancer.

Patient-derived organoids (PDOs) may facilitate treatment selection. This retrospective cohort study evaluated the feasibility and clinical benefit of using PDOs to guide personalized treatment in metastatic breast cancer (MBC). Patients diagnosed with MBC were recruited between January 2019 and August 2022. PDOs were established and the efficacy of customized drug panels was determined by measuring cell mortality after drug exposure. Patients receiving organoid-guided treatment (OGT) were matched 1:2 by nearest neighbor propensity scores with patients receiving treatment of physician's choice (TPC). The primary outcome was progression-free survival. Secondary outcomes included objective response rate and disease control rate. Targeted gene sequencing and pathway enrichment analysis were performed. Forty-six PDOs (46 of 51, 90.2%) were generated from 45 MBC patients. PDO drug screening showed an accuracy of 78.4% (95% CI 64.9%-91.9%) in predicting clinical responses. Thirty-six OGT patients were matched to 69 TPC patients. OGT was associated with prolonged median progression-free survival (11.0 months vs. 5.0 months; hazard ratio 0.53 [95% CI 0.33-0.85]; p = .01) and improved disease control (88.9% vs. 63.8%; odd ratio 4.26 [1.44-18.62]) compared with TPC. The objective response rate of both groups was similar. Pathway enrichment analysis in hormone receptor-positive, human epidermal growth factor receptor 2-negative patients demonstrated differentially modulated pathways implicated in DNA repair and transcriptional regulation in those with reduced response to capecitabine/gemcitabine, and pathways associated with cell cycle regulation in those with reduced response to palbociclib. Our study shows that PDO-based functional precision medicine is a feasible and effective strategy for MBC treatment optimization and customization.

Organoid forming potential as complementary parameter for accurate evaluation of breast cancer neoadjuvant therapeutic efficacy.

BACKGROUND: 13-15% of breast cancer/BC patients diagnosed as pathological complete response/pCR after neoadjuvant systemic therapy/NST suffer from recurrence. This study aims to estimate the rationality of organoid forming potential/OFP for more accurate evaluation of NST efficacy. METHODS: OFPs of post-NST residual disease/RD were checked and compared with clinical approaches to estimate the recurrence risk. The phenotypes of organoids were classified via HE staining and ER, PR, HER2, Ki67 and CD133 immuno-labeling. The active growing organoids were subjected to drug sensitivity tests. RESULTS: Of 62 post-NST BC specimens, 24 were classified as OFP-I with long-term active organoid growth, 19 as OFP-II with stable organoid growth within 3 weeks, and 19 as OFP-III without organoid formation. Residual tumors were overall correlated with OFP grades (P < 0.001), while 3 of the 18 patients (16.67%) pathologically diagnosed as tumor-free (ypT0N0M0) showed tumor derived-organoid formation. The disease-free survival/DFS of OFP-I cases was worse than other two groups (Log-rank P < 0.05). Organoids of OFP-I/-II groups well maintained the biological features of their parental tumors and were resistant to the drugs used in NST. CONCLUSIONS: The OFP would be a complementary parameter to improve the evaluation accuracy of NST efficacy of breast cancers.

Identification of GPC3 mutation and upregulation in a multidrug resistant osteosarcoma and its spheroids as therapeutic target.

BACKGROUND: Drug resistance and the lack of molecular therapeutic target are the main challenges in the management of osteosarcomas (OSs). Identification of novel genetic alteration(s) related with OS recurrence and chemotherapeutic resistance would be of scientific and clinical significance. METHODS: To identify potential genetic alterations related with OS recurrence and chemotherapeutic resistance, the biopsies of a 20-year-old male osteosarcoma patient were collected at primary site (p-OS) and from its metastatic tumor (m-OS) formed after 5 months of adjuvant chemotherapy. Both OS specimens were subjected to cancer-targeted next generation sequencing (NGS) and their cell suspensions were cultured under three-dimensional condition to establish spheroid therapeutic model. Transcript-oriented Sanger sequencing for GPC3, the detected mutated gene, was performed on RNA samples of p-OS and m-OS tissues and spheroids. The effects of anti-GPC3 antibody and its combination with cisplatin on m-OS spheroids were elucidated. RESULTS: NGS revealed 4 mutations (GPC3, SOX10, MDM4 and MAPK8) and 6 amplifications (MDM2, CDK4, CCND3, RUNX2, GLI1 and FRS2) in p-OS, and 3 mutations (GPC3, SOX10 and EGF) and 10 amplifications (CDK4, CCND3, MDM2, RUNX2, GLI1, FRS2, CARD11, RAC1, SLC16A7 and PMS2) in m-OS. Among those alterations, the mutation abundance of GPC3 was the highest (56.49%) in p-OS and showed 1.54 times increase in m-OS. GPC3 transcript-oriented Sanger sequencing confirmed the mutation at 1046 in Exon 4, and immunohistochemical staining showed increased GPC3 production in m-OS tissues and its spheroids. EdU cell proliferation and Calcein/PI cell viability assays revealed that of the anti-OS first line drugs (doxorubicin, cisplatin, methotrexate, ifosfamide and carboplatin), 10 µM carboplatin exerted the best inhibitory effects on the p-OS but not the m-OS spheroids. 2 µg/mL anti-GPC3 antibody effectively committed m-OS spheroids to death by itself (76.43%) or in combination with cisplatin (92.93%). CONCLUSION: This study demonstrates increased abundance and up-regulated expression of mutant GPC3 in metastatic osteosarcoma and its spheroids with multidrug resistance. As GPC3-targeting therapy has been used to treat hepatocellular carcinomas and it is also effective to OS PDSs, GPC3 would be a novel prognostic parameter and therapeutic target of osteosarcomas.