Distinct histopathological features are associated with molecular subtypes and outcome in low grade serous ovarian carcinoma.

Low grade serous ovarian carcinoma (LGSOC) demonstrates unique clinical and molecular features compared to other ovarian cancer types. The relationship between common histological features of LGSOC and molecular events, such as hormone receptor expression patterns and MAPK gene mutation status, remains poorly understood. Recent data suggest some of these molecular features may be biomarkers of response to recently introduced biologically-targeted therapies, namely endocrine therapy and MEK inhibitors. We utilize a cohort of 63 pathologically-confirmed LGSOC cases with whole exome sequencing and hormone receptor expression data to investigate these relationships. LGSOC cases demonstrated uniformly high oestrogen receptor (ER) expression, but variable progesterone receptor (PR) expression intensity. 60% and 37% of cases demonstrated micropapillary and macropapillary patterns of stromal invasion, respectively. 63% of cases demonstrated desmoplasia, which was significantly associated with advanced disease stage and visible residual disease after cytoreductive surgery. MAPK-mutant cases (KRAS, BRAF, NRAS) more frequently demonstrated macropapillary stromal invasion, while Chr1p loss was associated with desmoplasia and low PR expression. Presence of micropapillary stromal invasion and low PR expression were associated with significantly poorer survival after accounting for stage and residual disease status. Together, these data identify novel relationships between histopathological features and molecularly-defined subgroups in LGSOC.

Whole exome sequencing of low grade serous ovarian carcinoma identifies genomic events associated with clinical outcome.

OBJECTIVES: Low-grade serous ovarian carcinoma (LGSOC) is a distinct, rare, ovarian cancer type characterised by younger patient age and intrinsic chemoresistance. Understanding the molecular landscape is crucial for optimising targeted therapy. METHODS: Genomic data from whole exome sequencing of tumour tissue was analysed in a LGSOC cohort with detailed clinical annotation. RESULTS: 63 cases were analysed and three subgroups identified based on single nucleotide variants: canonical MAPK mutant (cMAPKm: 52%, KRAS/BRAF/NRAS), MAPK-associated gene mutation (MAPK-assoc: 27%) and MAPK wild-type (MAPKwt: 21%). NOTCH pathway disruption occurred across all subgroups. Tumour mutational burden (TMB), mutational signatures and recurrent copy number (CN) changes varied across the cohort with co-occurrence of chromosome 1p loss and 1q gain (CN Chr1pq) a recurrent feature. Low TMB and CN Chr1pq were associated with inferior disease-specific survival (HR 6.43; p < 0.001 and HR 3.29, p = 0.011 respectively). Stepwise genomic classification in relation to outcome resulted in four groups (TMB low; CN Chr1pq; MAPKwt/MAPKassoc; cMAPKm). 5 year disease-specific survival was 46%, 55%, 79% and 100% respectively for these groups. The two most favourable genomic subgroups were enriched for the SBS10b mutational signature, particularly the cMAPKm subgroup. CONCLUSIONS: LGSOC comprises multiple genomic subgroups with distinct clinical and molecular features. Chr1pq CN arm disruption and TMB represent promising methods to identify individuals with poorer prognosis. Further investigation of the molecular basis for these observations is required. MAPKwt cases represent around a fifth of patients. NOTCH inhibitors represent a candidate therapeutic strategy worthy of exploration across these cases.

Multiomic Characterization of High-Grade Serous Ovarian Carcinoma Enables High-Resolution Patient Stratification.

PURPOSE: High-grade serous ovarian carcinoma (HGSOC) is the most common ovarian cancer type; most patients experience disease recurrence that accumulates chemoresistance, leading to treatment failure. Genomic and transcriptomic features have been associated with differential outcome and treatment response. However, the relationship between events at the gene sequence, copy number, and gene-expression levels remains poorly defined. EXPERIMENTAL DESIGN: We perform multiomic characterization of a large HGSOC cohort (n = 362) with detailed clinical annotation to interrogate the relationship between patient subgroups defined by specific molecular events. RESULTS: BRCA2-mutant (BRCA2m) and EMSY-overexpressing cases demonstrated prolonged survival [multivariable hazard ratios (HR) 0.40 and 0.51] and significantly higher first- and second-line chemotherapy response rate. CCNE1-gained (CCNE1g) cases demonstrated underrepresentation of FIGO stage IV cases, with shorter survival but no significant difference in treatment response. We demonstrate marked overlap between the TCGA- and Tothill-derived subtypes. IMR/C2 cases displayed higher BRCA1/2m frequency (25.5%, 32.5%) and significantly greater immune cell infiltration, whereas PRO/C5 cases had the highest CCNE1g rate (23.9%, 22.2%) and were uniformly low in immune cell infiltration. The survival benefit for cases with aberrations in homologous recombination repair (HRR) genes was apparent across all transcriptomic subtypes (HR range, 0.48-0.68). There was significant co-occurrence of RB loss and HRR gene aberrations; RB loss was further associated with favorable survival within HRR-aberrant cases (multivariable HR, 0.50). CONCLUSIONS: These data paint a high-resolution picture of the molecular landscape in HGSOC, better defining patients who may benefit most from specific molecular therapeutics and highlighting those for whom novel treatment strategies are needed to improve outcomes.

Ovarian carcinosarcoma is a distinct form of ovarian cancer with poorer survival compared to tubo-ovarian high-grade serous carcinoma.

BACKGROUND: Ovarian carcinosarcoma (OCS) is an uncommon, biphasic and highly aggressive ovarian cancer type, which has received relatively little research attention. METHODS: We curated the largest pathologically confirmed OCS cohort to date, performing detailed histopathological characterisation, analysis of features associated with survival and comparison against high-grade serous ovarian carcinoma (HGSOC). RESULTS: Eighty-two OCS patients were identified; overall survival was poor (median 12.7 months). In all, 79% demonstrated epithelial components of high-grade serous (HGS) type, while 21% were endometrioid. Heterologous elements were common (chondrosarcoma in 32%, rhabdomyosarcoma in 21%, liposarcoma in 2%); chondrosarcoma was more frequent in OCS with endometrioid carcinomatous components. Earlier stage, complete resection and platinum-containing adjuvant chemotherapy were associated with prolonged survival; however, risk of relapse and mortality was high across all patient groups. Histological subclassification did not identify subgroups with distinct survival. Compared to HGSOC, OCS patients were older (P < 0.0001), more likely to be FIGO stage I (P = 0.025), demonstrated lower chemotherapy response rate (P = 0.001) and had significantly poorer survival (P < 0.0001). CONCLUSION: OCS represents a distinct, highly lethal form of ovarian cancer for which new treatment strategies are urgently needed. Histological subclassification does not identify patient subgroups with distinct survival. Aggressive adjuvant chemotherapy should be considered for all cases, including those with early-stage disease.

Clinicopathological Determinants of Recurrence Risk and Survival in Mucinous Ovarian Carcinoma.

Mucinous ovarian carcinoma (MOC) is a unique form of ovarian cancer. MOC typically presents at early stage but demonstrates intrinsic chemoresistance; treatment of advanced-stage and relapsed disease is therefore challenging. We harness a large retrospective MOC cohort to identify factors associated with recurrence risk and survival. A total of 151 MOC patients were included. The 5 year disease-specific survival (DSS) was 84.5%. Risk of subsequent recurrence after a disease-free period of 2 and 5 years was low (8.3% and 5.6% over the next 10 years). The majority of cases were FIGO stage I (35.6% IA, 43.0% IC). Multivariable analysis identified stage and pathological grade as independently associated with DSS (p < 0.001 and p < 0.001). Grade 1 stage I patients represented the majority of cases (53.0%) and demonstrated exceptional survival (10 year DSS 95.3%); survival was comparable between grade I stage IA and stage IC patients, and between grade I stage IC patients who did and did not receive adjuvant chemotherapy. At 5 years following diagnosis, the proportion of grade 1, 2 and 3 patients remaining disease free was 89.5%, 74.9% and 41.7%; the corresponding proportions for FIGO stage I, II and III/IV patients were 91.1%, 76.7% and 19.8%. Median post-relapse survival was 5.0 months. Most MOC patients present with low-grade early-stage disease and are at low risk of recurrence. New treatment options are urgently needed to improve survival following relapse, which is associated with extremely poor prognosis.

Integrated molecular characterisation of endometrioid ovarian carcinoma identifies opportunities for stratification.

Endometrioid ovarian carcinoma (EnOC) is an under-investigated ovarian cancer type. Recent studies have described disease subtypes defined by genomics and hormone receptor expression patterns; here, we determine the relationship between these subtyping layers to define the molecular landscape of EnOC with high granularity and identify therapeutic vulnerabilities in high-risk cases. Whole exome sequencing data were integrated with progesterone and oestrogen receptor (PR and ER) expression-defined subtypes in 90 EnOC cases following robust pathological assessment, revealing dominant clinical and molecular features in the resulting integrated subtypes. We demonstrate significant correlation between subtyping approaches: PR-high (PR + /ER + , PR + /ER-) cases were predominantly CTNNB1-mutant (73.2% vs 18.4%, P < 0.001), while PR-low (PR-/ER + , PR-/ER-) cases displayed higher TP53 mutation frequency (38.8% vs 7.3%, P = 0.001), greater genomic complexity (P = 0.007) and more frequent copy number alterations (P = 0.001). PR-high EnOC patients experience favourable disease-specific survival independent of clinicopathological and genomic features (HR = 0.16, 95% CI 0.04-0.71). TP53 mutation further delineates the outcome of patients with PR-low tumours (HR = 2.56, 95% CI 1.14-5.75). A simple, routinely applicable, classification algorithm utilising immunohistochemistry for PR and p53 recapitulated these subtypes and their survival profiles. The genomic profile of high-risk EnOC subtypes suggests that inhibitors of the MAPK and PI3K-AKT pathways, alongside PARP inhibitors, represent promising candidate agents for improving patient survival. Patients with PR-low TP53-mutant EnOC have the greatest unmet clinical need, while PR-high tumours-which are typically CTNNB1-mutant and TP53 wild-type-experience excellent survival and may represent candidates for trials investigating de-escalation of adjuvant chemotherapy to agents such as endocrine therapy.

Structural Variants at the BRCA1/2 Loci are a Common Source of Homologous Repair Deficiency in High-grade Serous Ovarian Carcinoma.

PURPOSE: The abundance and effects of structural variation at BRCA1/2 in tumors are not well understood. In particular, the impact of these events on homologous recombination repair deficiency (HRD) has yet to be demonstrated. EXPERIMENTAL DESIGN: Exploiting a large collection of whole-genome sequencing data from high-grade serous ovarian carcinoma (N = 205) together with matched RNA sequencing for the majority of tumors (N = 150), we have comprehensively characterized mutation and expression at BRCA1/2. RESULTS: In addition to the known spectrum of short somatic mutations (SSM), we discovered that multi-megabase structural variants (SV) were a frequent, unappreciated source of BRCA1/2 disruption in these tumors, and we found a genome-wide enrichment for large deletions at the BRCA1/2 loci across the cohort. These SVs independently affected a substantial proportion of patients (16%) in addition to those affected by SSMs (24%), conferring HRD and impacting patient survival. We also detail compound deficiencies involving SSMs and SVs at both loci, demonstrating that the strongest risk of HRD emerges from combined SVs at both BRCA1 and BRCA2 in the absence of SSMs. Furthermore, these SVs are abundant and disruptive in other cancer types. CONCLUSIONS: These results extend our understanding of the mutational landscape underlying HRD, increase the number of patients predicted to benefit from therapies exploiting HRD, and suggest there is currently untapped potential in SV detection for patient stratification.

Molecular stratification of endometrioid ovarian carcinoma predicts clinical outcome.

Endometrioid ovarian carcinoma (EnOC) demonstrates substantial clinical and molecular heterogeneity. Here, we report whole exome sequencing of 112 EnOC cases following rigorous pathological assessment. We detect a high frequency of mutation in CTNNB1 (43%), PIK3CA (43%), ARID1A (36%), PTEN (29%), KRAS (26%), TP53 (26%) and SOX8 (19%), a recurrently-mutated gene previously unreported in EnOC. POLE and mismatch repair protein-encoding genes were mutated at lower frequency (6%, 18%) with significant co-occurrence. A molecular taxonomy is constructed, identifying clinically distinct EnOC subtypes: cases with TP53 mutation demonstrate greater genomic complexity, are commonly FIGO stage III/IV at diagnosis (48%), are frequently incompletely debulked (44%) and demonstrate inferior survival; conversely, cases with CTNNB1 mutation, which is mutually exclusive with TP53 mutation, demonstrate low genomic complexity and excellent clinical outcome, and are predominantly stage I/II at diagnosis (89%) and completely resected (87%). Moreover, we identify the WNT, MAPK/RAS and PI3K pathways as good candidate targets for molecular therapeutics in EnOC.

Hormone receptor expression patterns define clinically meaningful subgroups of endometrioid ovarian carcinoma.

BACKGROUND: Numerous studies have investigated the association between hormone receptor expression and clinical outcome in ovarian carcinoma (OC); however, these have largely focussed on serous OCs, with few studies reporting specifically on endometrioid OCs (EnOC). Where analyses have been stratified by histotype, expression has been assessed using the percentage of positive tumor cells, without accounting for nuclear expression intensity. METHODS: Here we assess the expression levels of progesterone receptor (PR), estrogen receptor alpha (ER) and androgen receptor (AR) using histoscore - a nuclear scoring method incorporating both proportion of positive cells and the intensity of nuclear staining - across a cohort of 107 WT1 negative EnOCs. RESULTS: Hierarchical clustering by PR, ER and AR histoscores identified four EnOC subgroups (PR+/ER+, PR+/ER-, PR-/ER+ and PR-/ER-). EnOC patients in the PR+/ER+ and PR+/ER- groups displayed favorable outcome (multivariable HR for disease-specific survival 0.05 [0.01-0.35] and 0.05 [0.00-0.51]) compared to the PR-/ER+ group. Ten-year survival for stage II PRhigh and PRlow cases was 94.1% and 42.4%. ERhigh EnOC patients (PR+/ER+, PR-/ER+) had higher body mass index compared to ERlow cases (P = 0.015) and high grade serous OC patients (P < 0.001). CONCLUSION: These data demonstrate that endometrioid OC cases with high PR expression display markedly favorable outcome. Stage II EnOCs with high PR expression represent potential candidates for de-escalation of first-line therapy. Future work should seek to characterise the sensitivity of PR and ER positive EnOCs to endocrine therapy.

High EMSY expression defines a BRCA-like subgroup of high-grade serous ovarian carcinoma with prolonged survival and hypersensitivity to platinum.

BACKGROUND: Approximately half of high-grade serous ovarian carcinomas (HGSOCs) demonstrate homologous recombination repair (HR) pathway defects, resulting in a distinct clinical phenotype comprising hypersensitivity to platinum, superior clinical outcome, and greater sensitivity to poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors. EMSY, which is known to be amplified in breast and ovarian cancers, encodes a protein reported to bind and inactivate BRCA2. Thus, EMSY overexpression may mimic BRCA2 mutation, resulting in HR deficiency. However, to our knowledge, the phenotypic consequences of EMSY overexpression in HGSOC patients has not been explored. METHODS: Here we investigate the impact of EMSY expression on clinical outcome and sensitivity to platinum-based chemotherapy using available data from transcriptomically characterized HGSOC cohorts. RESULTS: High EMSY expression was associated with better clinical outcome in a cohort of 265 patients with HGSOC from Edinburgh (overall survival multivariable hazard ratio, 0.58 [95% CI, 0.38-0.88; P = .011] and progression-free survival multivariable hazard ratio, 0.62 [95% CI, 0.40-0.96; P = .030]). Superior outcome also was demonstrated in the Medical Research Council ICON7 clinical trial and multiple publicly available data sets. Patients within the Edinburgh cohort who had high EMSY expression were found to demonstrate greater rates of complete response to multiple platinum-containing chemotherapy regimens (radiological complete response rate of 44.4% vs 12.5% at second exposure; P = .035) and corresponding prolonged time to disease progression (median, 151.5 days vs 60.5 days after third platinum exposure; P = .004). CONCLUSIONS: Patients with HGSOCs demonstrating high EMSY expression appear to experience prolonged survival and greater platinum sensitivity, reminiscent of BRCA-mutant cases. These data are consistent with the notion that EMSY overexpression may render HGSOCs HR deficient.

Clinical and molecular characterization of ovarian carcinoma displaying isolated lymph node relapse.

BACKGROUND: Disease relapse is the primary cause of death from ovarian carcinoma. Isolated lymph node relapse is a rare pattern of ovarian carcinoma recurrence, with a reported median postrelapse survival of 2.5 to 4 years. To date, investigations have not compared isolated lymph node relapse ovarian carcinoma directly to a matched extranodal relapse cohort or performed molecular characterization of cases that subsequently experience isolated lymph node relapse. OBJECTIVE: Here we seek to compare the clinical outcome, tumor-infiltrating lymphocyte burden, and frequency of known prognostic genomic events in isolated lymph node relapse ovarian carcinoma vs extranodal relapse ovarian carcinoma. STUDY DESIGN: Forty-nine isolated lymph node relapse ovarian carcinoma patients were identified and matched to 49 extranodal relapse cases using the Edinburgh Ovarian Cancer Database, from which the clinical data for identified patients were retrieved. Matching criteria were disease stage, histologic subtype and grade, extent of residual disease following surgical debulking, and age at diagnosis. Clinicopathologic factors and survival data were compared between the isolated lymph node relapse and extranodal relapse cohorts. Genomic characterization of tumor material from diagnosis was performed using panel-based high-throughput sequencing and tumor-infiltrating T cell burden was assessed using immunohistochemistry for CD3+ and CD8+ cells. RESULTS: Isolated lymph node relapse cases demonstrated significantly prolonged postrelapse survival and overall survival vs extranodal relapse upon multivariable analysis (HRmulti = 0.52 [0.33-0.84] and 0.51 [0.31-0.84]). Diagnostic specimens from high-grade serous ovarian carcinomas that subsequently displayed isolated lymph node relapse harbored significantly greater CD3+ and CD8+ cell infiltration compared to extranodal relapse cases (P = .001 and P = .009, Bonferroni-adjusted P = .003 and P = .019). Isolated lymph node relapse high-grade serous ovarian carcinoma cases did not show marked enrichment or depletion of cases with BRCA1/2 mutation or CCNE1 copy number gain when compared to their extranodal relapse counterparts (24.4% vs 19.4% and 18.2% vs 22.6%, P = .865 and P = .900). CONCLUSION: Isolated lymph node relapse ovarian carcinoma represents a distinct clinical entity with favorable outcome compared to extranodal relapse. There was no clear enrichment or depletion of BRCA1/2 mutation or CCNE1 gain in the isolated lymph node relapse ovarian carcinoma cohort compared with extranodal relapse cases, suggesting that these known prognostic genomically defined subtypes of disease do not display markedly altered propensity for isolated lymph node relapse. Diagnostic tumor material from isolated lymph node relapse patients demonstrated greater CD3+ and CD8+ cell infiltration, indicating stronger tumor engagement by T cell populations, which may contribute to the more indolent disease course of isolated lymph node relapse.

Endocrine treatment of high grade serous ovarian carcinoma; quantification of efficacy and identification of response predictors.

OBJECTIVES: The role of endocrine therapy (ET) in high grade serous ovarian carcinoma (HGSOC) is poorly defined due to the lack of phase III data and significant heterogeneity of clinical trials performed. In this study, we sought to identify predictive factors of endocrine sensitivity in HGSOC. METHODS: HGSOC patients who received at least four weeks of ET for relapsed disease following one line of chemotherapy at the Edinburgh Cancer Centre were identified. Exclusion criteria were use of endocrine therapy as maintenance therapy or of unknown duration. Duration of therapy and best CA125 response as per modified GCIG criteria were recorded. Oestrogen receptor (ER) histoscore, treatment free interval, prior lines of chemotherapy, and type of ET were evaluated as predictive factors. RESULTS: Of 431 patients identified, 269 were eligible (77.0% letrozole, 18.6% tamoxifen, 2.2% megesterol acetate, 2.2% other). The median duration of therapy was 126 days (range 28-1427 days). 32.7% remained on ET for ≥180 days and 14.1% for ≥365 days. The CA125 response and clinical benefit rates (response or stable disease) were 8.1% and 40.1% respectively. ER histoscore >200 (P = 0.0016) and a treatment free interval of ≥180 days (P < 0.0001) were independent predictive factors upon multivariable analysis. CONCLUSIONS: ET should be considered as a viable strategy to defer subsequent chemotherapy for relapsed HGSOC. Patients with an ER histoscore >200 and a treatment free interval of ≥180 days are most likely to derive benefit.

Expression of glycolytic enzymes in ovarian cancers and evaluation of the glycolytic pathway as a strategy for ovarian cancer treatment.

BACKGROUND: Novel therapeutic approaches are required to treat ovarian cancer and dependency on glycolysis may provide new targets for treatment. This study sought to investigate the variation of expression of molecular components (GLUT1, HKII, PKM2, LDHA) of the glycolytic pathway in ovarian cancers and the effectiveness of targeting this pathway in ovarian cancer cell lines with inhibitors. METHODS: Expression of GLUT1, HKII, PKM2, LDHA were analysed by quantitative immunofluorescence in a tissue microarray (TMA) analysis of 380 ovarian cancers and associations with clinicopathological features were sought. The effect of glycolysis pathway inhibitors on the growth of a panel of ovarian cancer cell lines was assessed by use of the SRB proliferation assay. Combination studies were undertaken combining these inhibitors with cytotoxic agents. RESULTS: Mean expression levels of GLUT1 and HKII were higher in high grade serous ovarian cancer (HGSOC), the most frequently occurring subtype, than in non-HGSOC. GLUT1 expression was also significantly higher in advanced stage (III/IV) ovarian cancer than early stage (I/II) disease. Growth dependency of ovarian cancer cells on glucose was demonstrated in a panel of ovarian cancer cell lines. Inhibitors of the glycolytic pathway (STF31, IOM-1190, 3PO and oxamic acid) attenuated cell proliferation in platinum-sensitive and platinum-resistant HGSOC cell line models in a concentration dependent manner. In combination with either cisplatin or paclitaxel, 3PO (a novel PFKFB3 inhibitor) enhanced the cytotoxic effect in both platinum sensitive and platinum resistant ovarian cancer cells. Furthermore, synergy was identified between STF31 (a novel GLUT1 inhibitor) or oxamic acid (an LDH inhibitor) when combined with metformin, an inhibitor of oxidative phosphorylation, resulting in marked inhibition of ovarian cancer cell growth. CONCLUSIONS: The findings of this study provide further support for targeting the glycolytic pathway in ovarian cancer and several useful combinations were identified.

Enhanced response rate to pegylated liposomal doxorubicin in high grade serous ovarian carcinomas harbouring BRCA1 and BRCA2 aberrations.

BACKGROUND: Approximately 10-15% of ovarian carcinomas (OC) are attributed to inherited susceptibility, the majority of which are due to mutations in BRCA1 or BRCA2 (BRCA1/2). These patients display superior clinical outcome, including enhanced sensitivity to platinum-based chemotherapy. Here, we seek to investigate whether BRCA1/2 status influences the response rate to single-agent pegylated liposomal doxorubicin (PLD) in high grade serous (HGS) OC. METHODS: One hundred and forty-eight patients treated with single-agent PLD were identified retrospectively from the Edinburgh Ovarian Cancer Database. DNA was extracted from formalin-fixed paraffin-embedded (FFPE) archival tumour material and sequenced using the Ion Ampliseq BRCA1 and BRCA2 panel. A minimum variant allele frequency threshold was applied to correct for sequencing artefacts associated with formalin fixation. RESULTS: A superior response rate to PLD was observed in patients with HGS OC who harboured variants likely to affect BRCA1 or BRCA2 function compared to the BRCA1/2 wild-type population (36%, 9 of 25 patients versus 12.1%, 7 of 58 patients; p = 0.016). An enhanced response rate was also seen in patients harbouring only the BRCA1 SNP rs1799950, predicted to be detrimental to BRCA1 function (50%, 3 of 6 patients versus 12.1%, 7 of 58 patients; p = 0.044). CONCLUSIONS: These data demonstrate that HGS OC patients with BRCA1/2 variants predicted damaging to protein function experience superior sensitivity to PLD, consistent with impaired DNA repair. Further characterisation of rs1799950 is now warranted in relation to chemosensitivity and susceptibility to developing ovarian carcinoma.

Baseline clinical predictors of antitumor response to the PARP inhibitor olaparib in germline BRCA1/2 mutated patients with advanced ovarian cancer.

BACKGROUND: The PARP inhibitor olaparib was recently granted Food and Drug Administration (FDA) accelerated approval in patients with advanced BRCA1/2 mutation ovarian cancer. However, antitumor responses are observed in only approximately 40% of patients and the impact of baseline clinical factors on response to treatment remains unclear. Although platinum sensitivity has been suggested as a marker of response to PARP inhibitors, patients with platinum-resistant disease still respond to olaparib. RESULTS: 108 patients with advanced BRCA1/2 mutation ovarian cancers were included. The interval between the end of the most recent platinum chemotherapy and PARPi (PTPI) was used to predict response to olaparib independent of conventional definition of platinum sensitivity. RECIST complete response (CR) and partial response (PR) rates were 35% in patients with platinum-sensitive versus 13% in platinum-resistant (p<0.005). Independent of platinum sensitivity status, the RECIST CR/PR rates were 42% in patients with PTPI greater than 52 weeks and 18% in patients with PTPI less than 52 weeks (p=0.016). No association was found between baseline clinical factors such as FIGO staging, debulking surgery, BRCA1 versus BRCA2 mutations, prior history of breast cancer and prior chemotherapy for breast cancer, and the response to olaparib. METHODS: We conducted an international multicenter retrospective study to investigate the association between baseline clinical characteristics of patients with advanced BRCA1/2 mutation ovarian cancers from eight different cancer centers and their antitumor response to olaparib. CONCLUSION: PTPI may be used to refine the prediction of response to PARP inhibition based on the conventional categorization of platinum sensitivity.

Increased incidence of visceral metastases in scottish patients with BRCA1/2-defective ovarian cancer: an extension of the ovarian BRCAness phenotype.

PURPOSE: To compare the frequency of visceral relapse of BRCA1/2-deficient ovarian cancer to that of nonhereditary controls. PATIENTS AND METHODS: All patients diagnosed in Scotland with epithelial ovarian cancer (EOC) or primary peritoneal cancer (PPC) and a germline BRCA1/2 mutation were identified. Those with previous malignancy were excluded. Each remaining patient who experienced relapse was matched with two nonhereditary controls. RESULTS: Seventy-nine patients with EOC/PPC and germline BRCA1/2 mutations were identified. Fifteen had inadequate clinical data, two had carcinosarcoma, 27 had previous breast cancer, and 16 were in remission. Of the remaining 19 patients who were BRCA1/2 deficient, 14 patients (74%) developed visceral metastases compared with six (16%) of 38 patients in the control group. The percentages of liver, lung, and splenic metastases were 53%, 32%, and 32%, respectively, in the patients compared with 5%, 3%, and 5%, respectively, in the controls. When events occurring outside the matched follow-up period were omitted, the percentages of visceral, liver, lung, and splenic metastases were 58%, 42%, 16%, and 32% in the patients compared with 5%, 0%, 0%, and 3% in controls (P < .001, P < .001, P = .066, and P = .011, respectively). In an independent validation set, the corresponding percentages of visceral, liver, lung, and splenic metastases were 63%, 46%, 13%, and 17% in the patients compared with 11%, 4%, 2%, and 2% in controls (P < .001, P < .001, P = .153, and P = .052, respectively). CONCLUSION: Although sporadic EOC commonly remains confined to the peritoneum, BRCA1/2-deficient ovarian cancer frequently metastasizes to viscera. These data extend the ovarian BRCAness phenotype, imply BRCA1/2-deficient ovarian cancer is biologically distinct, and suggest that patients with visceral metastases should be considered for BRCA1/2 sequencing.

Higher incidence of isolated brain metastases in ovarian cancer patients with previous early breast cancer.

BACKGROUND: The pathogenesis of brain metastasis as a relatively rare complication of epithelial ovarian cancer is poorly understood. Some observations suggest that brain metastases from ovarian cancer are becoming more common and that ovarian cancers, which metastasize to the brain, may have a different biological pattern. METHODS: Data were extracted from the Edinburgh Ovarian Cancer Database on a cohort of patients managed at the Edinburgh Cancer Centre (UK) between 1998 and 2004. The incidence of brain metastases was compared between patients with previous treatment for early breast cancer and patients without previous treatment for early breast cancer. Baseline characteristics, the time to cancer antigen 125 relapse, the time to brain metastasis, and the radiological pattern of relapse were also compared between these patients. RESULTS: We demonstrate a higher incidence of serous histology (P = 0.02) in patients in remission from early breast cancer and that the incidence of brain metastases in this group is 11.6% compared with 1.1% in patients without prior breast cancer (relative risk = 10.5, P < 0.001). Brain metastases were clinically evident after 45.6 months in patients with previous breast cancer compared with 21 months in patients without previous breast cancer (P = 0.008). Among the patients who developed brain metastases, isolated retroperitoneal lymph node recurrence was noticed in patients in remission from early breast cancer but rarely in other patients. CONCLUSIONS: Ovarian cancer patients with a history of early breast cancer have a higher incidence of brain metastases and a different pattern of disease recurrence. We speculate that a higher incidence of breast cancer early onset mutations in patients with previous early breast cancer underlies these observed differences.

Endometrioid epithelial ovarian cancer : 20 years of prospectively collected data from a single center.

BACKGROUND: Clinicopathological features and outcome of women with endometrioid and serous ovarian adenocarcinoma were compared. METHODS: Between 1984 and 2004, baseline and follow-up data were prospectively recorded on 1545 patients with ovarian cancer. Of these, 270 had pure endometrioid tumors; 659 had pure serous adenocarcinoma of the ovary. Response to platinum-based chemotherapy (PBC) overall survival, stage-for-stage median progression-free survival (PFS), and cause-specific median survival were compared. Independent predictors of survival were examined by using multivariate analyses. RESULTS: Median age of diagnosis for patients with endometrioid tumors was younger than those with serous adenocarcinoma of the ovary (60 years vs 62 years; P = .013). They presented more often with early disease (stage I and II; 50% vs 17%; P < .001), had less ascites, and had better performance status both overall and for stage II and III disease. More endometrioid tumors were optimally debulked overall (71% vs 45%; P < .001), but there was no difference according to stage. Objective and CA125 PBC response rates were not significantly different, but median PFS was better for patients with endometrioid tumors (24 months vs 13 months; P < .0001) as was overall median survival (48 months vs 22 months; P < .0001). This relation remained for stage II and III disease and for moderately and poorly differentiated tumors. Patients with concurrent endometrioid ovarian and endometrial malignancies had a survival advantage compared with those with ovarian malignancies alone. Independent predictors of survival after PBC were histological type, debulking status, and disease stage. CONCLUSIONS: Despite similar PBC response rates, endometrioid histology is associated with better survival compared with serous adenocarcinoma of the ovary, even with stage III or poorly differentiated tumors.

Antiestrogen therapy is active in selected ovarian cancer cases: the use of letrozole in estrogen receptor-positive patients.

PURPOSE: To evaluate the efficacy of the aromatase inhibitor letrozole in preselected estrogen receptor (ER)-positive relapsed epithelial ovarian cancer patients and to identify markers that predict endocrine-sensitive disease. EXPERIMENTAL DESIGN: This was a phase II study of letrozole 2.5 mg daily until clinical or marker evidence of disease progression in previously treated ER-positive ovarian cancer patients with a rising CA125 that had progressed according to Rustin's criteria. The primary end point was response according to CA125 and response evaluation criteria in solid tumors (RECIST) criteria. Marker expression was measured by semiquantitative immunohistochemistry in sections from the primary tumor. RESULTS: Of 42 patients evaluable for CA125 response, 7 (17%) had a response (decrease of >50%), and 11 (26%) patients had not progressed (doubling of CA125) following 6 months on treatment. The median time taken to achieve the CA125 nadir was 13 weeks (range 10-36). Of 33 patients evaluable for radiological response, 3 (9%) had a partial remission, and 14 (42%) had stable disease at 12 weeks. Eleven patients (26%) had a PFS of >6 months. Subgroup analysis according to ER revealed CA125 response rates of 0% (immunoscore, 150-199), 12% (200-249), and 33% (250-300); P = 0.028, chi(2) for trend. Expression levels of HER2, insulin-like growth factor binding protein 5, trefoil factor 1, and vimentin were associated with CA125 changes on treatment. CONCLUSIONS: This is the first study of a hormonal agent in a preselected group of ER-positive ovarian cancer patients. A signature of predictive markers, including low HER2 expression, predicts response.