Rouba-Ali Fehmi

BRCA Status Dictates Wnt Responsiveness in Epithelial Ovarian Cancer

Abstract The association of BRCA1 and BRCA2 mutations with increased risk for developing epithelial ovarian cancer is well established. However, the observed clinical differences, particularly the improved therapy response and patient survival in BRCA2-mutant patients, are unexplained. Our objective is to identify molecular pathways that are differentially regulated upon the loss of BRCA1 and BRCA2 functions in ovarian cancer. Transcriptomic and pathway analyses comparing BRCA1-mutant, BRCA2-mutant, and homologous recombination wild-type ovarian tumors showed differential regulation of the Wnt/β-catenin pathway. Using Wnt3A-treated BRCA1/2 wild-type, BRCA1-null, and BRCA2-null mouse ovarian cancer cells, we observed preferential activation of canonical Wnt/β-catenin signaling in BRCA1/2 wild-type ovarian cancer cells, whereas noncanonical Wnt/β-catenin signaling was preferentially activated in the BRCA1-null ovarian cancer cells. Interestingly, BRCA2-null mouse ovarian cancer cells demonstrated a unique response to Wnt3A with the preferential upregulation of the Wnt signaling inhibitor Axin2. In addition, decreased phosphorylation and enhanced stability of β-catenin were observed in BRCA2-null mouse ovarian cancer cells, which correlated with increased inhibitory phosphorylation on GSK3β. These findings open venues for the translation of these molecular observations into modalities that can impact patient survival. Significance: We show that BRCA1 and BRCA2 mutation statuses differentially impact the regulation of the Wnt/β-catenin signaling pathway, a major effector of cancer initiation and progression. Our findings provide a better understanding of molecular mechanisms that promote the known differential clinical profile in these patient populations.

Presence and extent of lymphovascular invasion in surgical stage I squamous cell carcinoma of the cervix: a comprehensive, international, multicentre, retrospective clinicopathological study

The aim of this study was to determine whether the presence and extent of lymphovascular invasion (LVI) is prognostic in surgical stage I cervical squamous cell carcinoma (SCC). All available tumour slides and/or paraffin blocks from 426 patients with stage I cervical SCC treated surgically with curative intent were collected from 18 institutions and retrospectively analysed. Presence and extent of LVI (focal <5 spaces, extensive ≥5 spaces) were assessed on scanning magnification in large haematoxylin and eosin slide sets in 366 cases. Progression-free survival (PFS) was calculated as the time from surgery to first progression or death or last follow-up, whichever occurred first. Overall survival (OS) was defined as the time from surgery to death or last follow-up. Clinicopathological and statistical analyses were performed on 97 patients with the International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IA and 329 patients with stage IB SCC of the cervix. LVI, both focal and extensive, was more frequent in stage IB than in stage IA (p<0.001). Patients with stage IB carcinomas with extensive LVI had worse PFS [hazard ratio (HR) 2.86; 95% confidence interval (CI) 1.49, 5.49; p=0.005] and OS (HR 2.88; 95% CI 1.38, 6.02; p=0.012) than those with focal or no LVI. In stage IA, in contrast, the presence and extent of LVI did not associate with PFS (p=0.926) or OS. Extensive LVI was not statistically correlated with PFS and OS in substages IA1, IA2 or IB2. PFS (HR 3.7; 95% CI 1.61, 8.46; p<0.001) and OS (HR 4.18; 95% CI 1.58, 11.04; p=0.002) in stage IB1, and PFS (HR 7.78; 95% CI 0.87, 69.82; p=0.039) in stage IB3 were diminished in the presence of extensive LVI. In conclusion, in patients with FIGO stage I cervical SCC, the presence and extent of LVI has prognostic significance in stage IB carcinoma, and quantifying LVI is recommended.