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Introduction: Ex vivo organ cultures (EVOC) were recently optimized to sustain cancer tissue for 5 days with its complete microenvironment. We examined the ability of an EVOC platform to predict patient response to cancer therapy. Methods: A multicenter, prospective, single-arm observational trial. Samples were obtained from patients with newly diagnosed bladder cancer who underwent transurethral resection of bladder tumor and from core needle biopsies of patients with metastatic cancer. The tumors were cut into 250 µM slices and cultured within 24 h, then incubated for 96 h with vehicle or intended to treat drug. The cultures were then fixed and stained to analyze their morphology and cell viability. Each EVOC was given a score based on cell viability, level of damage, and Ki67 proliferation, and the scores were correlated with the patients' clinical response assessed by pathology or Response Evaluation Criteria in Solid Tumors (RECIST). Results: The cancer tissue and microenvironment, including endothelial and immune cells, were preserved at high viability with continued cell division for 5 days, demonstrating active cell signaling dynamics. A total of 34 cancer samples were tested by the platform and were correlated with clinical results. A higher EVOC score was correlated with better clinical response. The EVOC system showed a predictive specificity of 77.7% (7/9, 95% CI 0.4-0.97) and a sensitivity of 96% (24/25, 95% CI 0.80-0.99). Conclusion: EVOC cultured for 5 days showed high sensitivity and specificity for predicting clinical response to therapy among patients with muscle-invasive bladder cancer and other solid tumors.
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BACKGROUND: Gastrinomas, a rare group of neuroendocrine tumors, are responsible for severe peptic disease and diarrhea. Although symptomatic control may be achieved with proton-pump inhibitors (PPIs) and somatostatin analogues (SSAs), data are limited regarding the possible antitumor effect of the peptide receptor radioligand therapy (PRRT) with radiolabeled SSAs in gastrinoma patients. The goal of this study was to assess the effect of PRRT on symptoms, gastrin secretion, and tumor load in patients with progressive malignant gastrinomas. METHODS: We retrospectively studied 11 patients with metastatic gastrinomas followed for a mean period of 6 years. All patients were symptomatically treated with PPIs, and 9 of 11 patients received monthly injections of SSAs; all patients had an Eastern Cooperative Oncology Group score of 0-1, and received PRRT ((90) Yttrium- or (177) Lutetium-DOTATOC) for progressive disease. Serum gastrin measurements and radiological assessment (using the Response Evaluation Criteria in Solid Tumors criteria) were performed before and every 3-6 months following PRRT. RESULTS: PRRT induced symptomatic improvement in all patients. The mean serum gastrin decreased significantly from 4831 mI/L to 932.6 mI/L (normal, 40-108 mI/L; P < .001). Periodic radiological surveillance showed complete response in 1 (9%) patient, partial tumor response in 5/11 (45%) patients, and tumor stabilization in 5/11 (45%) patients. In 7/11 (64%) patients, the antitumor effect of PRRT persisted after a median period of 14 months. Four of 11 (36%) patients died due to tumor progression (median time to progression, 11 months); in this group, the mean survival time after the last PRRT was 14 ± 6.9 months. CONCLUSIONS: PRRT seems to be a promising tool for the management of patients with inoperable or progressive metastatic gastrinomas.