Single cell-derived spheroids capture the self-renewing subpopulations of metastatic ovarian cancer.

High Grade Serous Ovarian cancer (HGSOC) is a major unmet need in oncology, due to its precocious dissemination and the lack of meaningful human models for the investigation of disease pathogenesis in a patient-specific manner. To overcome this roadblock, we present a new method to isolate and grow single cells directly from patients' metastatic ascites, establishing the conditions for propagating them as 3D cultures that we refer to as single cell-derived metastatic ovarian cancer spheroids (sMOCS). By single cell RNA sequencing (scRNAseq) we define the cellular composition of metastatic ascites and trace its propagation in 2D and 3D culture paradigms, finding that sMOCS retain and amplify key subpopulations from the original patients' samples and recapitulate features of the original metastasis that do not emerge from classical 2D culture, including retention of individual patients' specificities. By enabling the enrichment of uniquely informative cell subpopulations from HGSOC metastasis and the clonal interrogation of their diversity at the functional and molecular level, this method provides a powerful instrument for precision oncology in ovarian cancer.

Independent validation of the prognostic significance of invasion patterns in endocervical adenocarcinoma: Pattern A predicts excellent survival.

OBJECTIVE: Recently, the pattern of invasion in usual-type human papillomavirus-associated endocervical adenocarcinoma (AC) was put forward as a novel variable to select patients with favourable prognosis. Based on destructiveness of stromal invasion, three patterns were proposed: A - no destructive stromal invasion, B - focal destructive stromal invasion, and C - diffuse destructive stromal invasion. We aimed to independently validate the clinical significance of this classification-system in 82 AC patients, and explored associations between invasion pattern and somatic mutations. METHODS: All patients surgically treated for FIGO stage IB-IIA usual type AC (1990-2011, n = 82) were retrospectively reviewed and classified into pattern A, B or C. Additional immunohistochemical analyses were performed for p53, MSH6, and PMS2. Moreover, previously obtained data on somatic hotspot mutations in 13 relevant genes was integrated. RESULTS: Of 82 AC, 22% showed pattern A, 37% pattern B, and 41% pattern C. Significant differences were observed between invasion patterns and tumour size, depth of invasion (DOI), lymph-vascular invasion (LVI), and lymph-node metastasis. Significantly fewer mutations were present in tumours with pattern A morphology (p = 0.036). All pattern A patients survived (p = 0.002) without recurrent disease (p = 0.005). In multivariate regression analysis including tumour size, DOI, LVI, and lymph node metastasis, invasion pattern was a strong independent predictor for recurrence-free and disease-specific survival (HR 3.75, 95%CI 1.16-12.11, and HR 5.08, 95%CI 1.23-20.98, respectively). CONCLUSIONS: We have independently validated the clinical significance of invasion patterns for usual type endocervical AC. Pattern A predicts excellent survival, and a clinical trial should prove safety of a more conservative treatment for these patients.