Integrative multi-omics analyses to identify the genetic and functional mechanisms underlying ovarian cancer risk regions.

To identify credible causal risk variants (CCVs) associated with different histotypes of epithelial ovarian cancer (EOC), we performed genome-wide association analysis for 470,825 genotyped and 10,163,797 imputed SNPs in 25,981 EOC cases and 105,724 controls of European origin. We identified five histotype-specific EOC risk regions (p value <5 × 10-8) and confirmed previously reported associations for 27 risk regions. Conditional analyses identified an additional 11 signals independent of the primary signal at six risk regions (p value <10-5). Fine mapping identified 4,008 CCVs in these regions, of which 1,452 CCVs were located in ovarian cancer-related chromatin marks with significant enrichment in active enhancers, active promoters, and active regions for CCVs from each EOC histotype. Transcriptome-wide association and colocalization analyses across histotypes using tissue-specific and cross-tissue datasets identified 86 candidate susceptibility genes in known EOC risk regions and 32 genes in 23 additional genomic regions that may represent novel EOC risk loci (false discovery rate <0.05). Finally, by integrating genome-wide HiChIP interactome analysis with transcriptome-wide association study (TWAS), variant effect predictor, transcription factor ChIP-seq, and motifbreakR data, we identified candidate gene-CCV interactions at each locus. This included risk loci where TWAS identified one or more candidate susceptibility genes (e.g., HOXD-AS2, HOXD8, and HOXD3 at 2q31) and other loci where no candidate gene was identified (e.g., MYC and PVT1 at 8q24) by TWAS. In summary, this study describes a functional framework and provides a greater understanding of the biological significance of risk alleles and candidate gene targets at EOC susceptibility loci identified by a genome-wide association study.

Evaluating the Utility of ctDNA in Detecting Residual Cancer and Predicting Recurrence in Patients with Serous Ovarian Cancer.

Ovarian cancer has a high case fatality rate, but patients who have no visible residual disease after surgery have a relatively good prognosis. The presence of any cancer cells left in the peritoneal cavity after treatment may precipitate a cancer recurrence. In many cases, these cells are occult and are not visible to the surgeon. Analysis of circulating tumour DNA in the blood (ctDNA) may offer a sensitive method to predict the presence of occult (non-visible) residual disease after surgery and may help predict disease recurrence. We assessed 48 women diagnosed with serous ovarian cancer (47 high-grade and 1 low-grade) for visible residual disease and for ctDNA. Plasma, formalin-fixed paraffin-embedded (FFPE) tumour tissue and white blood cells were used to extract circulating free DNA (cfDNA), tumour DNA and germline DNA, respectively. We sequenced DNA samples for 59 breast and ovarian cancer driver genes. The plasma sample was collected after surgery and before initiating chemotherapy. We compared survival in women with no residual disease, with and without a positive plasma ctDNA test. We found tumour-specific variants (TSVs) in cancer cells from 47 patients, and these variants were sought in ctDNA in their post-surgery plasma. Fifteen (31.9%) of the 47 patients had visible residual disease; of these, all 15 had detectable ctDNA. Thirty-one patients (65.9%) had no visible residual disease; of these, 24 (77.4%) patients had detectable ctDNA. Of the patients with no visible residual disease, those patients with detectable ctDNA had higher mortality (20 of 27 died) than those without detectable ctDNA (3 of 7 died) (HR 2.32; 95% CI: 0.67-8.05), although this difference was not statistically significant (p = 0.18). ctDNA in post-surgical serum samples may predict the presence of microscopic residual disease and may be a predictor of recurrence among women with ovarian cancer. Larger studies are necessary to validate these findings.

Diagnostic accuracy of frozen section and patterns of nodal spread in high grade endometrial cancer: A secondary outcome of the SENTOR prospective cohort study.

OBJECTIVES: The study aimed to define the accuracy of intraoperative frozen section (FS) for the detection of metastases in sentinel lymph node biopsy (SLNB) and describe the pattern of lymph node (LN) spread and relation to molecular classifiers in patients with high-grade endometrial cancer (EC). METHODS: We performed a secondary outcome of clinicopathologic data from the Sentinel Lymph Node Biopsy versus Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging (SENTOR) prospective cohort study evaluating SLNB in patients with clinical stage I high-grade EC (ClinicalTrials.gov ID: NCT01886066). The primary outcome was the sensitivity of FS of the sentinel lymph node (SLN) specimen, compared to a standardized ultrastaging protocol. Secondary outcomes included the pattern and characteristics of LN spread. RESULTS: There were 126 patients with high-grade EC with a median age of 66 years (range:44-86) and a median Body Mass Index (BMI) of 26.9 kg/m2 (range:17.6-49.3). FS was performed on surgical specimens from 212 hemipelves; SLNs were identified in 202 specimens (95.7%) and fatty tissue alone was identified in 10 specimens (4.7%). Of the 202 hemipelves in which SLNs were identified, 24 were positive for metastatic disease on final pathology. Initial FS correctly identified only 12, yielding a sensitivity of 50% (12/24, 95% CI 29.6-70.4) and a negative predictive value of 94% (178/190, 95% CI 89-96.5). A total of 24 patients (19%) had LN metastases: 16 (13%) had isolated pelvic metastases, 7 (6%) had both pelvic and para-aortic metastases and 1 (0.8%) had an isolated para-aortic metastasis. CONCLUSIONS: Intraoperative FS of SLNs in high-grade EC patients has poor sensitivity. Since isolated para-aortic metastases are rare, para-aortic lymphadenectomy may be omitted in patients in which SLNs were successfully mapped to the pelvis.

Acceptability of bariatric surgery in people with endometrial cancer and atypical hyperplasia: A qualitative study.

OBJECTIVE: In young individuals with obesity, infertility, and endometrial cancer, significant, sustained weight loss through bariatric surgery may result in a durable oncologic and reproductive response. However, it is not known whether bariatric surgery is acceptable to this patient population. We performed a qualitative study to understand the acceptability of bariatric surgery in young individuals with obesity and endometrial cancer or atypical hyperplasia. STUDY DESIGN: All participants were of reproductive age with body mass index [BMI] ≥ 35 and grade 1 endometrial cancer or atypical hyperplasia. Semi-structured interviews were used to explore participant perception of their weight, fertility, and the possibility of bariatric surgery as part of the treatment strategy for their endometrial cancer/atypical hyperplasia. Thematic saturation was reached after 14 interviews. RESULTS: Fourteen participants with a median age of 34 years (range 27-38) and BMI of 42 (33-64) were interviewed. Participants were reluctant to accept bariatric surgery as a treatment option due to 1) lack of knowledge about the procedure, 2) stigma attached to bariatric surgery, and 3) fear of the risks associated with bariatric surgery. Their perception towards their weight, fertility, and cancer diagnosis was characterized by concepts of 'helplessness', 'isolation', 'frustration', and 'guilt'. We observed a significant gap in participant understanding of the complex interplay between their cancer, infertility, and obesity. CONCLUSIONS: More support and resources are required, with patient-oriented counseling focused on the implication of their weight on their cancer diagnosis and fertility, before presenting bariatric surgery as a treatment option.

Factors affecting surgical decision-making in carriers of BRCA1/2 pathogenic variants undergoing risk-reducing surgery at a dedicated hereditary ovarian cancer clinic.

OBJECTIVE: Women with germline BRCA1/2 pathogenic variants have a significantly elevated lifetime risk of ovarian and fallopian tube cancer. Bilateral salpingo-oophorectomy (RRSO) is associated with a 90% reduction in the development of tubal and ovarian cancer. At our tertiary hospital, we have a dedicated clinic where women predisposed to hereditary ovarian/tubal cancer receive counseling on reproduction, risk reduction, surgical prophylaxis, and menopausal aftercare. The objective of this study was to evaluate the choices that Canadian women with BRCA1/2 pathogenic variants make regarding ovarian cancer risk reduction within this highly specialized multidisciplinary clinic. METHODS: This retrospective chart review included all women with confirmed BRCA1/2 mutations referred to the Familial Ovarian Cancer Clinic at Women's College Hospital, Toronto, Canada over a 45-month time period. Patient demographics, preoperative consultation notes and investigations, intraoperative findings, and pathology were recorded. RESULTS: A total of 191 women were included in our cohort; 140 (73.3%) underwent risk-reducing surgery and 51 (26.7%) deferred or declined surgery. In women who underwent surgical prevention (median age 45 [30-72] y), 123 (87.9%) underwent RRSO and 17 (12.1%) chose a risk-reducing bilateral salpingectomy with deferred oophorectomy. Of the women undergoing RRSO, 11 (8.9%) women chose concurrent hysterectomy. Prevalent themes affecting decision-making included fears around premature surgical menopause, family planning, and concerns around development of endometrial cancer related to tamoxifen. CONCLUSION: Women with BRCA1/2 pathogenic variants face challenging decisions regarding risk reduction and care providers must be knowledgeable and supportive in helping women make informed and individualized choices about their care.

Video Summary:http://links.lww.com/MENO/A857 .

Assessment of Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging.

Importance: Whether sentinel lymph node biopsy (SLNB) can replace lymphadenectomy for surgical staging in patients with high-grade endometrial cancer (EC) is unclear. Objective: To examine the diagnostic accuracy of, performance characteristics of, and morbidity associated with SLNB using indocyanine green in patients with intermediate- and high-grade EC. Design, Setting, and Participants: In this prospective, multicenter cohort study (Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging [SENTOR] study), accrual occurred from July 1, 2015, to June 30, 2019, with early stoppage because of prespecified accuracy criteria. The study included patients with clinical stage I grade 2 endometrioid or high-grade EC scheduled to undergo laparoscopic or robotic hysterectomy with an intent to complete staging at 3 designated cancer centers in Toronto, Ontario, Canada. Exposures: All patients underwent SLNB followed by lymphadenectomy as the reference standard. Patients with grade 2 endometrioid EC underwent pelvic lymphadenectomy (PLND) alone, and patients with high-grade EC underwent PLND and para-aortic lymphadenectomy (PALND). Main Outcomes and Measures: The primary outcome was sensitivity of the SLNB algorithm. Secondary outcomes were additional measures of diagnostic accuracy, sentinel lymph node detection rates, and adverse events. Results: The study enrolled 156 patients (median age, 65.5 years; range, 40-86 years; median body mass index [calculated as weight in kilograms divided by height in meters squared], 27.5; range, 17.6-49.3), including 126 with high-grade EC. All patients underwent SLNB and PLND, and 101 patients (80%) with high-grade EC also underwent PALND. Sentinel lymph node detection rates were 97.4% per patient (95% CI, 93.6%-99.3%), 87.5% per hemipelvis (95% CI, 83.3%-91.0%), and 77.6% bilaterally (95% CI, 70.2%-83.8%). Of 27 patients (17%) with nodal metastases, 26 patients were correctly identified by the SLNB algorithm, yielding a sensitivity of 96% (95% CI, 81%-100%), a false-negative rate of 4% (95% CI, 0%-19%), and a negative predictive value of 99% (95% CI, 96%-100%). Only 1 patient (0.6%) was misclassified by the SLNB algorithm. Seven of 27 patients with node-positive cancer (26%) were identified outside traditional PLND boundaries or required immunohistochemistry for diagnosis. Conclusions and Relevance: In this prospective cohort study, SLNB had acceptable diagnostic accuracy for patients with high-grade EC at increased risk of nodal metastases and improved the detection of node-positive cases compared with lymphadenectomy. The findings suggest that SLNB is a viable option for the surgical staging of EC.