Viola Heinzelmann-Schwarz

Geneva Homologous Recombination Deficiency Test Is Predictive of Survival Benefit From Olaparib and Bevacizumab Maintenance in Ovarian Cancer

PURPOSE The ability of the Geneva homologous recombination deficiency (HRD) test to predict progression-free survival (PFS) in patients with high-grade ovarian cancer treated with poly (ADP-ribose) polymerase inhibitors has been demonstrated. Its performance with respect to overall survival (OS) has not been assessed yet. METHODS Using the final results of the PAOLA-1/ENGOT-ov25 phase III clinical trial with a median follow-up of 5 years, we evaluated the Geneva HRD test on 468 samples as part of the ENGOT HRD European Initiative. Results were evaluated in terms of final PFS and OS in the olaparib + bevacizumab and placebo + bevacizumab arms and compared with the Myriad MyChoice HRD test. RESULTS Final PFS was consistent with previously published data and confirmed the predictive value of the Geneva HRD test with a hazard ratio (HR) of 0.41 (95% CI, 0.30 to 0.57) for HRD-positive patients. The results for OS showed a HR of 0.56 (95% CI, 0.37 to 0.85) for HRD-positive patients and 1.6 (95% CI, 1.1 to 2.3) for HRD-negative patients. These results are consistent with those observed with the Myriad test, including the negative OS trend in the HRD-negative subgroup treated with olaparib + bevacizumab (HR, 1.2 [95% CI, 0.83 to 1.8]). A subgroup analysis of patients with intermediate HRD scores showed that the normalized large-scale state transition score used by the Geneva HRD test had both predictive and prognostic value. CONCLUSION The Geneva HRD test predicts PFS and OS benefit from olaparib + bevacizumab. The potential detrimental effect of olaparib + bevacizumab on OS in the HRD-negative population is hypothesis-generating and needs to be confirmed prospectively.

De novo detection of somatic variants in high-quality long-read single-cell RNA sequencing data

In cancer, genetic and transcriptomic variations generate clonal heterogeneity, leading to treatment resistance. Long-read single-cell RNA sequencing (LR scRNA-seq) has the potential to detect genetic and transcriptomic variations simultaneously. Here, we present LongSom, a computational workflow leveraging high-quality LR scRNA-seq data to call de novo somatic single-nucleotide variants (SNVs), including in mitochondria (mtSNVs), copy number alterations (CNAs), and gene fusions, to reconstruct the tumor clonal heterogeneity. Before somatic variant calling, LongSom reannotates marker gene-based cell types using cell mutational profiles. LongSom distinguishes somatic SNVs from noise and germline polymorphisms by applying an extensive set of hard filters and statistical tests. Applying LongSom to human ovarian cancer samples, we detected clinically relevant somatic SNVs that were validated against matched DNA samples. Leveraging somatic SNVs and fusions, LongSom found subclones with different predicted treatment outcomes. In summary, LongSom enables de novo variant detection without the need for normal samples, facilitating the study of cancer evolution, clonal heterogeneity, and treatment resistance.

Targeting Cancer-Associated Glycosylation for Adoptive T-cell Therapy of Solid Tumors

Abstract Chimeric antigen receptor (CAR) T-cell therapy has improved outcomes for patients with chemotherapy-resistant B-cell malignancies. However, CAR T-cell treatment of patients with solid cancers has been more difficult, in part because of the heterogeneous expression of tumor-specific cell surface antigens. In this study, we describe the generation of a fully human CAR targeting altered glycosylation in secretory epithelial cancers. The expression of the target antigen—the truncated, sialylated O-glycan Sialyl-Thomsen-nouveau (STn) antigen—was studied with a highly STn-specific antibody across various different tumor tissues. Strong expression was found in a high proportion of gastrointestinal cancers, including pancreatic cancers, and in gynecologic cancers, in particular ovarian and endometrial tumors. T cells expressing anti-STn CAR were tested in vitro and in vivo. Anti-STn CAR T cells showed activity in mouse models, as well as in assays with primary ovarian cancer samples. No considerable toxicity was observed in mouse models although some intraluminal expression of STn was found in gastrointestinal mouse tissue. Taken together, this fully human anti-STn CAR construct shows promising activity in preclinical tumor models, supporting its further evaluation in early clinical trials.

Should MMMT still be treated with adjuvant taxane-based combination chemotherapy?

Abstract Background Malignant mixed Mullerian tumors of endometrial (MMMT-E) and ovarian (MMMT-O) origin are associated with poor prognosis. Suggestively epithelial-driven tumors, their treatment has shifted from anthracycline or ifosfamide-based towards taxane-based chemotherapy. It remains unclear whether this change associates with better outcomes. Patients and methods A conjoined Australian and Swiss patient cohort of MMMT-E (N = 103) and MMMT-O (N = 17) was compared to patients with adenocarcinoma of the endometrium (EC, N = 172) and ovary (OC, N = 189). Clinicopathological characteristics, FIGO stage, first-line treatment, and patient outcomes were analyzed. The generated hypothesis was verified in an US-American cohort with high-grade serous ovarian cancer (HGSOC, N = 1290) and MMMT-O (N = 450) using immunohistochemistry and next-generation sequencing. Results Early stage I/II MMMT-E showed a survival plateau after 2.5 years, with no recurrence or death observed afterwards. Relapse-free survival was significantly worse in MMMT-E treated with platinum/taxanes (P = 0.024) compared to non-taxane regimen. Hypothesizing that also MMMT-O might benefit from an adjuvant non-paclitaxel regimen, a second independent cohort of MMMT-O and HGSOC patients was examined. p53 mutations dominated in both cancers with comparable frequency. PI3KCA and KRAS mutations were less frequent: they were more frequent in MMMT-O than in HGSOC (P = 0.015 and P = 0.018, respectively). MMMT-O responded better to a combination of carboplatin with anthracyclines than with taxanes (73.9% vs. 39.4%). Conclusion Early stage I/II MMMT-E patients have excellent prognosis if no recurrence has appeared within the first 2.5 years. In MMMT-E, platinum/anthracycline or ifosfamide regimen associated with better outcomes than platinum/taxanes regimens. This might also apply to MMMT-O.

High‐grade serous peritoneal cancer follows a high stromal response signature and shows worse outcome than ovarian cancer

In the era of personalized medicine, where transition from organ‐based to individualized genetic diagnosis takes place, the tailoring of treatment in cancer becomes increasingly important. This is particularly true for high‐grade, advanced FIGO stage serous adenocarcinomas of the ovary (OC), fallopian tube (TC), and peritoneum (PC), which are currently all treated identically. We analyzed three independent patient cohorts using histopathologically classified diagnosis and various molecular approaches (transcriptomics, immunohistochemistry, next‐generation sequencing, fluorescent and chromogenic in situ hybridization). Using multivariate Cox regression model, we found that PC is more aggressive compared with advanced‐stage OC independent of residual disease as shown by an earlier relapse‐free survival in two large cohorts (HR: 2.63, CI: 1.59–4.37, P < 0.001, and HR: 1.66, CI: 1.04–2.63, P < 0.033). In line with these findings, transcriptomic data revealed differentially expressed gene signatures identifying PC as high stromal response tumors. The third independent cohort (n = 4054) showed a distinction between these cancer types for markers suggested to be predictive for chemotherapy drug response. Our findings add additional evidence that ovarian and peritoneal cancers are epidemiologically and molecularly distinct diseases. Moreover, our data also suggest consideration of the tumor‐sampling site for future diagnosis and treatment decisions.

Maintenance Therapy with Aromatase Inhibitor in epithelial Ovarian Cancer (MATAO): study protocol of a randomized double-blinded placebo-controlled multi-center phase III Trial

Abstract Background A high percentage of epithelial ovarian cancers (EOC) express the estrogen receptor (ER), which is an ideal target for endocrine therapy. Letrozole is a proven, potent aromatase inhibitor, extensively tested and used in the treatment of ER positive breast cancer. In addition, it seems a potent drug for patients with heavily pre-treated OC as demonstrated in several distinctive settings. However, it has never been evaluated prospectively in a maintenance setting for ovarian cancer after standard of care. The here proposed trial aims to define a population of EOC patients, who would benefit from the effectiveness of the generic agent letrozole, with little expected toxicity and thus beneficial impact on overall quality of life (QoL). Methods In this international multicenter randomized, placebo-controlled phase III trial at clinical centers in Switzerland, Germany and Austria, we plan to include 540 patients with primary, newly diagnosed FIGO Stage II to IV and histologically confirmed low- or high-grade serous or endometrioid epithelial ovarian/fallopian tube/peritoneal cancer. Patients are randomized in a 1:1 ratio into two groups: receiving blinded study treatment (letrozole or placebo tablets). When assuming a HR of 0.7, a median PFS of 18 months in the control arm and a median PFS of 25.7 months in the treatment arm, a two-sided alpha level of 5%, 3.5 years recruitment and 1.5 years observation time, we expect 330 events to have occurred within these 5 years in the total cohort yielding a power of 90%. Follow-up data for the whole cohort will be collected for up to 10 years and for the low-grade cancer for up to 12 years. Discussion The here proposed randomized phase III trial aims to identify patients with EOC in the maintenance setting, who benefit from the effectiveness of the letrozole, by proving its efficacy whilst maintaining a high standard of QoL due to the limited toxicity expected in comparison to the current alternative drugs on the market for this treatment phase. Trial registration This trial is registered at clinicaltrials.gov under the identifier NCT04111978. Registered 02 October 2019.

P-cadherin overexpression is associated with early transformation of the Fallopian tube epithelium and aggressiveness of tubo-ovarian high-grade serous carcinoma

Abstract Tubo-ovarian high-grade serous carcinoma (HGSC) with proficient homologous recombination (HR) DNA repair (HRP) accounts for approximately 50% of cases and is associated with platinum-resistance and poor prognosis. We hypothesize that the acquisition of hybrid phenotypes displaying both epithelial and mesenchymal (E/M) features may be involved in the malignant transformation and tumour dissemination in this subgroup. Therefore, we analysed, by digital pathology, the expression and prognostic significance of 3 classic cadherins (E-cadherin, epithelial marker; N-cadherin, mesenchymal marker; and P-cadherin, candidate marker of hybrid E/M) in 577 formalin-fixed paraffin-embedded human samples representing the putative stepwise serous carcinogenesis in the Fallopian tube epithelium (FTE). We observed a non-canonical N-to-P-cadherin switch along the carcinogenic progression, with a statistically significant overexpression of P-cadherin in pre-malignant and malignant samples, compared to the control FTE. Interestingly, this overexpression was most pronounced in precursor lesions and HGSC cells from malignant ascites. Tumours with high P-cadherin expression were significantly associated with worse overall survival, especially in the subgroup without BRCA1/2 mutations. Transient P-cadherin knock-down resulted in in vitro significant reduction of functional hybrid E/M hallmarks, namely decreased anoikis resistance, reduced collective migration and invasion in a representative platinum-resistant HRP cell line. Taken together, our results suggest that P-cadherin overexpression is an early event in the serous carcinogenesis and may be involved in hybrid E/M activation in HRP-HGSC, further supporting this adhesion molecule as a promising biomarker for this poor prognostic subgroup.

MAintenance Therapy With Aromatase Inhibitor in Epithelial Ovarian Cancer (MATAO)

The purpose of this study is to evaluate the efficacy of addition of letrozole to the standard maintenance therapy in subjects following a primary diagnosis of Estrogen-receptor (ER) positive high and low grade epithelial ovarian cancer (including fallopian tube and primary peritoneal cancer) and subsequent primary treatment surgery and chemotherapy. Half of the participants will receive to the standard maintenance treatment, letrozole, whilst the other half receives placebo. The study's primary hypothesis is that the treatment with letrozole increases progression free survival in comparison to the maintenance standard treatment (superiority trial).