Epithelial-Mesenchymal Transition (EMT) Gene Variants and Epithelial Ovarian Cancer (EOC) Risk

Epithelial-mesenchymal transition (EMT) is a process whereby epithelial cells assume mesenchymal characteristics to facilitate cancer metastasis. However, EMT also contributes to the initiation and development of primary tumors. Prior studies that explored the hypothesis that EMT gene variants contribute to epithelial ovarian carcinoma (EOC) risk have been based on small sample sizes and none have sought replication in an independent population. We screened 15,816 single-nucleotide polymorphisms (SNPs) in 296 genes in a discovery phase using data from a genome-wide association study of EOC among women of European ancestry (1,947 cases and 2,009 controls) and identified 793 variants in 278 EMT-related genes that were nominally (P < 0.05) associated with invasive EOC. These SNPs were then genotyped in a larger study of 14,525 invasive-cancer patients and 23,447 controls. A P-value <0.05 and a false discovery rate (FDR) <0.2 were considered statistically significant. In the larger dataset, GPC6/GPC5 rs17702471 was associated with the endometrioid subtype among Caucasians (odds ratio (OR) = 1.16, 95% CI = 1.07-1.25, P = 0.0003, FDR = 0.19), whereas F8 rs7053448 (OR = 1.69, 95% CI = 1.27-2.24, P = 0.0003, FDR = 0.12), F8 rs7058826 (OR = 1.69, 95% CI = 1.27-2.24, P = 0.0003, FDR = 0.12), and CAPN13 rs1983383 (OR = 0.79, 95% CI = 0.69-0.90, P = 0.0005, FDR = 0.12) were associated with combined invasive EOC among Asians. In silico functional analyses revealed that GPC6/GPC5 rs17702471 coincided with DNA regulatory elements. These results suggest that EMT gene variants do not appear to play a significant role in the susceptibility to EOC.

Common Genetic Variation in Circadian Rhythm Genes and Risk of Epithelial Ovarian Cancer (EOC)

Disruption in circadian gene expression, whether due to genetic variation or environmental factors (e.g., light at night, shiftwork), is associated with increased incidence of breast, prostate, gastrointestinal and hematologic cancers and gliomas. Circadian genes are highly expressed in the ovaries where they regulate ovulation; circadian disruption is associated with several ovarian cancer risk factors (e.g., endometriosis). However, no studies have examined variation in germline circadian genes as predictors of ovarian cancer risk and invasiveness. The goal of the current study was to examine single nucleotide polymorphisms (SNPs) in circadian genes BMAL1, CRY2, CSNK1E, NPAS2, PER3, REV1 and TIMELESS and downstream transcription factors KLF10 and SENP3 as predictors of risk of epithelial ovarian cancer (EOC) and histopathologic subtypes. The study included a test set of 3,761 EOC cases and 2,722 controls and a validation set of 44,308 samples including 18,174 (10,316 serous) cases and 26,134 controls from 43 studies participating in the Ovarian Cancer Association Consortium (OCAC). Analysis of genotype data from 36 genotyped SNPs and 4600 imputed SNPs indicated that the most significant association was rs117104877 in BMAL1 (OR = 0.79, 95% CI = 0.68-0.90, p = 5.59 × 10^-4]. Functional analysis revealed a significant down regulation of BMAL1 expression following cMYC overexpression and increasing transformation in ovarian surface epithelial (OSE) cells as well as alternative splicing of BMAL1 exons in ovarian and granulosa cells. These results suggest that variation in circadian genes, and specifically BMAL1, may be associated with risk of ovarian cancer, likely through disruption of hormonal pathways.

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

BACKGROUND

Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk.

METHODS

In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons.

RESULTS

The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4).

CONCLUSION

These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes.

Two decades beyond BRCA1/2: Homologous recombination, hereditary cancer risk and a target for ovarian cancer therapy

Almost exactly 20 years after their discovery, the BRCA1 and BRCA2 genes have become the target of the first "personalized" therapy available for patients with ovarian cancer. In December 2014, a poly(ADP-ribose) polymerase (PARP) inhibitor was granted expedited approved by the United States Food and Drug Administration for use in advanced ovarian cancer patients with germline BRCA1/2 mutations who have received three or more prior lines of chemotherapy. This review article will discuss (1) the BRCA1 and BRCA2 genes within the larger context of homologous recombination deficiency; (2) the advances in our understanding of hereditary cancer risk and the dramatic shifts that have occurred in the genetic testing landscape since the landmark 2013 Supreme Court ruling invalidating patents on BRCA1 and BRCA2 genetic testing; and (3) the clinical trials leading to the approval of olaparib, the first in human PARP inhibitor.

Differential expression of argininosuccinate synthetase in serous and non-serous ovarian carcinomas

The current standard of care for epithelial ovarian cancer does not discriminate between different histologic subtypes (serous, clear cell, endometrioid and mucinous) despite the knowledge that ovarian carcinoma subtypes do not respond uniformly to conventional platinum/taxane‐based chemotherapy. Exploiting addictions and vulnerabilities in cancers with distinguishable molecular features presents an opportunity to develop individualized therapies that may be more effective than the current ‘one size fits all' approach. One such opportunity is arginine depletion therapy with pegylated arginine deiminase, which has shown promise in several cancer types that exhibit low levels of argininosuccinate synthetase including hepatocellular and prostate carcinoma and melanoma. Based on the high levels of argininosuccinate synthetase previously observed in ovarian cancers, these tumours have been considered unlikely candidates for arginine depletion therapy. However, argininosuccinate synthetase levels have not been evaluated in the individual histologic subtypes of ovarian carcinoma. The current study is the first to examine the expression of argininosuccinate synthetase at the mRNA and protein levels in large cohorts of primary and recurrent ovarian carcinomas and ovarian cancer cell lines. We show that the normal fallopian tube fimbria and the majority of primary high‐grade and low‐grade serous ovarian carcinomas express high levels of argininosuccinate synthetase, which tend to further increase in recurrent tumours. In contrast to the serous subtype, non‐serous ovarian carcinoma subtypes (clear cell, endometrioid and mucinous) frequently lack detectable argininosuccinate synthetase expression. The in vitro sensitivity of ovarian cancer cell lines to arginine depletion with pegylated arginine deiminase was inversely correlated with argininosuccinate synthetase expression. Our data suggest that the majority of serous ovarian carcinomas are not susceptible to therapeutic intervention with arginine deiminase while a subset of non‐serous ovarian carcinoma subtypes are auxotrophic for arginine and should be considered for clinical trials with pegylated arginine deiminase.

Variation in NF-κB signaling pathways and survival in invasive epithelial ovarian cancer

Survival in epithelial ovarian cancer (EOC) is influenced by the host immune response, yet the key genetic determinants of inflammation and immunity that affect prognosis are not known. The nuclear factor-κB (NF-κB) transcription factor family plays an important role in many immune and inflammatory responses, including the response to cancer. We studied common inherited variation in 210 genes in the NF-κB family in 10,084 patients with invasive EOC (5,248 high-grade serous, 1,452 endometrioid, 795 clear cell, and 661 mucinous) from the Ovarian Cancer Association Consortium. Associations between genotype and overall survival were assessed using Cox regression for all patients and by major histology, adjusting for known prognostic factors and correcting for multiple testing (threshold for statistical significance, P < 2.5 × 10(-5)). Results were statistically significant when assessed for patients of a single histology. Key associations were with caspase recruitment domain family, member 11 (CARD11) rs41324349 in patients with mucinous EOC [HR, 1.82; 95% confidence interval (CI), 1.41-2.35; P = 4.13 × 10(-6)] and tumor necrosis factor receptor superfamily, member 13B (TNFRSF13B) rs7501462 in patients with endometrioid EOC (HR, 0.68; 95% CI, 0.56-0.82; P = 2.33 × 10(-5)). Other associations of note included TNF receptor-associated factor 2 (TRAF2) rs17250239 in patients with high-grade serous EOC (HR, 0.84; 95% CI, 0.77-0.92; P = 6.49 × 10(-5)) and phospholipase C, gamma 1 (PLCG1) rs11696662 in patients with clear cell EOC (HR, 0.43; 95% CI, 0.26-0.73; P = 4.56 × 10(-4)). These associations highlight the potential importance of genes associated with host inflammation and immunity in modulating clinical outcomes in distinct EOC histologies.

Thrombocytosis at secondary cytoreduction for recurrent ovarian cancer predicts suboptimal resection and poor survival

OBJECTIVES

A growing body of evidence supports a role for thrombocytosis in the promotion of epithelial ovarian cancer biology. However, studies have only linked preoperative platelet count at time of initial cytoreductive surgery to clinical outcome. Here, we sought to determine the impact of elevated platelet count at time of secondary cytoreductive surgery (SCS) for recurrent disease.

METHODS

Under an IRB-approved protocol, we identified 107 women with invasive epithelial ovarian cancer who underwent SCS between January 1997 and June 2012. We reviewed clinical, laboratory, and pathologic records from this retrospective cohort. The data was analyzed using the chi-squared, Fisher's exact, Cox proportional hazards, and Kaplan-Meier tests. We defined thrombocytosis as a platelet count ≥ 350 × 10(9)/L and optimal resection at SCS as microscopic residual disease.

RESULTS

Thirteen of 107 women (12%) with recurrent ovarian cancer had thrombocytosis prior to SCS. Preoperative thrombocytosis at SCS was associated with failure to undergo optimal resection (p=0.0001). Women with preoperative thrombocytosis at time of SCS demonstrated shorter overall survival (33 months) compared to those with normal platelet counts (46 months, p=0.004). On multivariate analysis, only preoperative platelet count retained significance as an independent prognostic factor (p=0.025) after controlling for age at SCS (p=0.90), disease free interval from primary treatment (0.06), and initial stage of disease (0.66).

CONCLUSIONS

Elevated platelet count at time of SCS is associated with suboptimal resection and shortened overall survival. These data provide further evidence supporting a plausible role for thrombocytosis in aggressive ovarian tumor biology.

Venous thromboembolism during primary treatment of ovarian clear cell carcinoma is associated with decreased survival

OBJECTIVES

To determine the impact of venous thromboembolism (VTE) during primary treatment of ovarian clear cell carcinoma (OCCC) on survival.

METHODS

After Institutional Review Board approval, 74 cases of OCCC were retrieved from our pathology files. Clinical and pathological data were obtained by medical record and pathology review. Standard statistical analyses were performed.

RESULTS

Among 74 patients with OCCC, VTE was diagnosed in 11 (15%) during primary treatment and 7 (9%) at time of cancer recurrence. 56 (76%) patients never developed VTE. Patients with VTE during OCCC primary treatment had shorter progression-free survival (PFS) and overall survival (OS) than OCCC patients without VTE (median PFS 11 vs. 76 months, p=0.01, median OS 19 vs. 90 months, p=0.001). Patients with VTE during OCCC primary treatment had a 3.9-fold increase in risk of recurrence (p=0.007) and a 6.3-fold increase in risk of death (p<0.001). After controlling for cancer stage, VTE during OCCC primary treatment remained an independent prognostic factor for death (HR=3.6, p=0.005). No patient died of VTE.

CONCLUSIONS

VTE during OCCC primary treatment is associated with a significantly higher risk of cancer recurrence and death. This increased risk is not attributable to VTE-related mortality and raises the possibility that a paracrine circuit involving thrombosis might contribute to a more aggressive tumor biology.

Common variants at the 19p13.1 and ZNF365 loci are associated with ER subtypes of breast cancer and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Genome-wide association studies (GWAS) identified variants at 19p13.1 and ZNF365 (10q21.2) as risk factors for breast cancer among BRCA1 and BRCA2 mutation carriers, respectively. We explored associations with ovarian cancer and with breast cancer by tumor histopathology for these variants in mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA).

METHODS

Genotyping data for 12,599 BRCA1 and 7,132 BRCA2 mutation carriers from 40 studies were combined.

RESULTS

We confirmed associations between rs8170 at 19p13.1 and breast cancer risk for BRCA1 mutation carriers [HR, 1.17; 95% confidence interval (CI), 1.07-1.27; P = 7.42 × 10(-4)] and between rs16917302 at ZNF365 (HR, 0.84; 95% CI, 0.73-0.97; P = 0.017) but not rs311499 at 20q13.3 (HR, 1.11; 95% CI, 0.94-1.31; P = 0.22) and breast cancer risk for BRCA2 mutation carriers. Analyses based on tumor histopathology showed that 19p13 variants were predominantly associated with estrogen receptor (ER)-negative breast cancer for both BRCA1 and BRCA2 mutation carriers, whereas rs16917302 at ZNF365 was mainly associated with ER-positive breast cancer for both BRCA1 and BRCA2 mutation carriers. We also found for the first time that rs67397200 at 19p13.1 was associated with an increased risk of ovarian cancer for BRCA1 (HR, 1.16; 95% CI, 1.05-1.29; P = 3.8 × 10(-4)) and BRCA2 mutation carriers (HR, 1.30; 95% CI, 1.10-1.52; P = 1.8 × 10(-3)).

CONCLUSIONS

19p13.1 and ZNF365 are susceptibility loci for ovarian cancer and ER subtypes of breast cancer among BRCA1 and BRCA2 mutation carriers.

IMPACT

These findings can lead to an improved understanding of tumor development and may prove useful for breast and ovarian cancer risk prediction for BRCA1 and BRCA2 mutation carriers.

Indole-3-carbinol synergistically sensitises ovarian cancer cells to bortezomib treatment

BACKGROUND

Bortezomib is a proteasome inhibitor with minimal clinical activity as a monotherapy in solid tumours, but its combination with other targeted therapies is being actively investigated as a way to increase its anticarcinogenic properties. Here, we evaluate the therapeutic potential of co-treatment with bortezomib and indole-3-carbinol (I3C), a natural compound found in cruciferous vegetables, in human ovarian cancer.

METHODS

We examined the effects of I3C, bortezomib and cisplatin in several human ovarian cancer cell lines. Synergy was determined using proliferation assays and isobologram analysis. Cell cycle and apoptotic effects were assessed by flow cytometry. The mechanism of I3C and bortezomib action was determined by RNA microarray studies, quantitative RT-PCR and western blotting. Antitumour activity of I3C and bortezomib was evaluated using an OVCAR5 xenograft mouse model.

RESULTS

I3C sensitised ovarian cancer cell lines to bortezomib treatment through potent synergistic mechanisms. Combination treatment with bortezomib and I3C led to profound cell cycle arrest and apoptosis as well as disruptions to multiple pathways, including those regulating endoplasmic reticulum stress, cytoskeleton, chemoresistance and carcinogen metabolism. Moreover, I3C and bortezomib co-treatment sensitised ovarian cancer cells to the standard chemotherapeutic agents, cisplatin and carboplatin. Importantly, in vivo studies demonstrated that co-treatment with I3C and bortezomib significantly inhibited tumour growth and reduced tumour weight compared with either drug alone.

CONCLUSION

Together, these data provide a novel rationale for the clinical application of I3C and bortezomib in the treatment of ovarian cancer.

Common alleles at 6q25.1 and 1p11.2 are associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers

Two single nucleotide polymorphisms (SNPs) at 6q25.1, near the ESR1 gene, have been implicated in the susceptibility to breast cancer for Asian (rs2046210) and European women (rs9397435). A genome-wide association study in Europeans identified two further breast cancer susceptibility variants: rs11249433 at 1p11.2 and rs999737 in RAD51L1 at 14q24.1. Although previously identified breast cancer susceptibility variants have been shown to be associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers, the involvement of these SNPs to breast cancer susceptibility in mutation carriers is currently unknown. To address this, we genotyped these SNPs in BRCA1 and BRCA2 mutation carriers from 42 studies from the Consortium of Investigators of Modifiers of BRCA1/2. In the analysis of 14 123 BRCA1 and 8053 BRCA2 mutation carriers of European ancestry, the 6q25.1 SNPs (r(2) = 0.14) were independently associated with the risk of breast cancer for BRCA1 mutation carriers [hazard ratio (HR) = 1.17, 95% confidence interval (CI): 1.11-1.23, P-trend = 4.5 × 10(-9) for rs2046210; HR = 1.28, 95% CI: 1.18-1.40, P-trend = 1.3 × 10(-8) for rs9397435], but only rs9397435 was associated with the risk for BRCA2 carriers (HR = 1.14, 95% CI: 1.01-1.28, P-trend = 0.031). SNP rs11249433 (1p11.2) was associated with the risk of breast cancer for BRCA2 mutation carriers (HR = 1.09, 95% CI: 1.02-1.17, P-trend = 0.015), but was not associated with breast cancer risk for BRCA1 mutation carriers (HR = 0.97, 95% CI: 0.92-1.02, P-trend = 0.20). SNP rs999737 (RAD51L1) was not associated with breast cancer risk for either BRCA1 or BRCA2 mutation carriers (P-trend = 0.27 and 0.30, respectively). The identification of SNPs at 6q25.1 associated with breast cancer risk for BRCA1 mutation carriers will lead to a better understanding of the biology of tumour development in these women.

Xeroderma pigmentosum complementation group C single-nucleotide polymorphisms in the nucleotide excision repair pathway correlate with prolonged progression-free survival in advanced ovarian cancer

BACKGROUND

The nucleotide excision repair (NER) pathway is the principal DNA repair pathway for removing bulky platinum DNA adducts. Suboptimal DNA repair may lead to improved response to platinum agents. The objective of this study was to determine whether single-nucleotide polymorphisms (SNPs) in NER pathway genes could be markers of platinum response in ovarian cancer.

METHODS

The authors identified patients with advanced-stage, papillary serous ovarian cancer who underwent primary cytoreductive surgery followed by platinum-based chemotherapy. DNA was isolated from peripheral blood specimens. Twenty-two SNPs within NER genes (xeroderma pigmentosum [XP] complementation group A [XPA], XPB/excision repair cross-complementing rodent repair deficiency, complementation group 3 [ERCC3], XPC, XPD/ERCC2, XPF/ERCC4, XPG/ERCC5, Cockayne syndrome group B protein [CSB]/ERCC8, ERCC1) were genotyped using polymerase chain reaction analysis.

RESULTS

In total, 139 patients with stage III and IV papillary serous ovarian cancer were genotyped. The XPC (reference SNP 3731108 [rs3731108]) adenosine-guanine (AG)/AA genotype versus the GG genotype was associated with prolonged a progression-free survival (PFS) of 21.3 months versus 13.4 months (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.42-0.95; P = .03). The XPC (rs1124303) guanosine-thymidine (GT)/GG genotype versus the TT genotype was associated with a prolonged PFS of 22.8 months versus 14.9 months (HR, 0.47; 95% CI, 0.24-0.94; P = .03). The XPC poly(AT) (PAT) (-/+)/(-/-) genotype versus the (+/+) genotype was associated with a prolonged PFS of 17 months versus 11.6 months (HR, 0.56; 95% CI, 0.36-0.89; P = .01). The XPF/ERCC4 (rs12926685) cytidine-thymidine (CT)/CC genotype versus the TT genotype was associated with a prolonged PFS of 16.7 months versus 12.4 months (HR, 0.63; 95% CI, 0.41-0.95; P = .03). On multivariate analysis adjusting for breast cancer (BRCA) gene and cytoreductive surgery status, the XPC SNPs remained significantly associated with prolonged PFS.

CONCLUSIONS

The current results indicated that XPC is a key component of the NER pathway that participates in DNA damage repair. SNPs in the XPC gene may represent novel markers of ovarian cancer response to platinum-based chemotherapy.

CA125 surveillance increases optimal resectability at secondary cytoreductive surgery for recurrent epithelial ovarian cancer

OBJECTIVE

Recent data suggest that serial CA125 surveillance following remission in asymptomatic patients with epithelial ovarian cancer (EOC) does not impact overall survival. However, earlier detection of recurrence may influence resectability at secondary cytoreductive surgery (SCS). We hypothesized that a shorter time interval between CA125 elevation and SCS correlates with a higher likelihood of optimal resection among eligible patients.

METHODS

We identified patients with recurrent epithelial ovarian cancer who underwent SCS from 1995 to 2009 at our institution. All patients initially underwent primary cytoreductive surgery followed by platinum-based chemotherapy. CA125 elevation was considered the first value two-times the patient's nadir level. Our "study interval" was the time between CA125 elevation and SCS. Optimal SCS was defined as microscopic residual disease (≤0.5cm). Our analysis compared patients who underwent optimal vs. suboptimal SCS.

RESULTS

Seventy-four patients who underwent SCS for recurrent EOC met inclusion criteria. Median disease-free interval prior to SCS was 19 vs. 12months for the optimal and suboptimal SCS groups. More patients undergoing suboptimal SCS had ascites (21% vs. 2%, p=0.01) and carcinomatosis (42% vs. 5%, p<0.0001). Patients who underwent optimal SCS went to the operating room 5.3 vs. 16.4weeks (HR 1.03, 95% CI 1.01-1.06, p=0.04) from the time of their CA125 elevation. Optimal SCS was associated with a longer overall survival (47 vs. 23months, p<0.0001).

CONCLUSIONS

Each week delay after first CA125 elevation correlated with a 3% increased chance of suboptimal resection at SCS. Serial CA125 surveillance for early detection of recurrence may increase rates of optimal SCS and potentially influence overall survival.

Is older age a poor prognostic factor in stage I and II endometrioid endometrial adenocarcinoma?

OBJECTIVE

Prior studies have shown that age ≥70 years is associated with more aggressive non-endometrioid histology and worse survival in endometrial cancer. The purpose of this study is to assess if age is an independent poor prognostic factor in endometrioid histologies.

METHODS

Under an IRB-approved protocol, we identified patients with surgical stage I to II endometrioid endometrial adenocarcinoma from 1995 to 2008 at two institutions. Patients were divided into two groups based on age at diagnosis: Group A (age 50-69 years) and Group B (age≥70 years). All patients underwent hysterectomy, bilateral salpingoophorectomy, +/-pelvic/aortic lymphadenectomy and adjuvant therapy. Prognostic factors were evaluated by univariate and multivariate analyses.

RESULTS

We identified 338 patients with stage IA to IIB endometrioid endometrial adenocarcinoma. The median age in Group A was 59 years (range 50-69) and Group B was 75 years (range 70-92). Patients in Group B were more likely to have hypertension (51% vs. 68%, p=0.006) and coronary artery disease (9% vs. 18%, p=0.03). There were no differences in progression-free or disease-specific survival, however, Group B had a worse overall survival (OS) (50.1 vs. 62.6 months, p=0.03). On univariate analysis, age (p=0.04), grade (p=0.006), and coronary artery disease (p=0.01) were associated with worse OS. After adjusting for grade and coronary artery disease, age was no longer a significant variable for OS (p=0.17).

CONCLUSIONS

After adjusting for other poor prognostic factors, age ≥70 years alone may not be a significant variable affecting overall survival in patients with early stage endometrioid endometrial adenocarcinoma.

Lynch syndrome among gynecologic oncology patients meeting Bethesda guidelines for screening

OBJECTIVE

Lynch syndrome (LS) is characterized by a high lifetime incidence of colorectal cancer and gynecologic malignancies such as endometrial and ovarian cancer. Identification of LS families is important as it allows for heightened cancer screening which decreases colorectal cancer mortality. The original 1996 Bethesda guidelines included two gynecologic populations that should be further evaluated for LS: those with endometrial cancer before the age of 45 years and those with two LS-related cancers (i.e. synchronous endometrial and ovarian cancer). Our study aims to estimate the prevalence of LS in these two populations.

METHODS

We utilized a diagnostic algorithm that included immunohistochemistry for mismatch repair protein expression followed by selective evaluation for microsatellite instability and MLH1 gene promoter methylation.

RESULTS

Among 72 eligible patients, 9 (12%) had molecular findings consistent with LS: 6/50 (12%) in the early-onset endometrial cancer group and 3/22 (14%) in the synchronous primary cancer group. In an additional 3 cases, MLH1 silencing was due to promoter methylation: 1/50 (2%) in the early-onset endometrial cancer group and 2/22 (9%) in the synchronous primary cancer group. Of the 9 women with molecular criteria suggesting LS, only three had pedigrees meeting the Amsterdam criteria.

CONCLUSIONS

A diagnostic algorithm can identify patients with LS and those who warrant further genetic testing. Our findings reinforce the recommendation that women diagnosed with endometrial cancer before the age of 45 years and women with synchronous endometrial and ovarian cancer be screened for LS, irrespective of family history.

Genome-wide loss of heterozygosity and uniparental disomy in BRCA1/2-associated ovarian carcinomas

PURPOSE

The importance of the BRCA gene products in maintaining genomic stability led us to hypothesize that BRCA-associated and sporadic ovarian cancers would have distinctive genetic profiles despite similarities in histologic appearance.

EXPERIMENTAL DESIGN

A whole-genome copy number analysis of fresh, frozen, papillary serous ovarian cancer DNA was done using the Affymetrix 50K Xba Mapping Array using each patient's normal genomic DNA as the matched control. Loss of heterozygosity and copy number abnormalities were summarized to define regions of amplification, deletion, or uniparental disomy (UPD), defined as loss of one allele and duplication of the remaining allele. Genomic abnormalities were compared between BRCA-associated and sporadic tumors.

RESULTS

We compared 6 BRCA-associated with 14 sporadic papillary serous ovarian carcinomas. Genetic instability, measured by percentage of genome altered, was more pronounced in BRCA-associated tumors (median, 86.6%; range, 54-100%) than sporadic tumors (median, 43.6%; range, 2-83%; P = 0.009). We used frequency plots to show the proportion of cases affected by each type abnormality at each genomic region. BRCA-associated tumors showed genome-wide loss of heterozygosity primarily due to the occurrence of UPD rather than deletion. UPD was found in 100% of the BRCA-associated and 50% of the sporadic tumors profiled.

CONCLUSIONS

This study reports on a previously underappreciated genetic phenomenon of UPD, which occurs frequently in ovarian cancer DNA. We observed distinct genetic patterns between BRCA-associated and sporadic ovarian cancers, suggesting that these papillary serous tumors arise from different molecular pathways.

Stage II uterine papillary serous carcinoma: Carboplatin/paclitaxel chemotherapy improves recurrence and survival outcomes

OBJECTIVES

To determine recurrence patterns and survival outcomes of stage II uterine papillary serous carcinoma (UPSC) patients treated by various modalities with an emphasis on carboplatin/paclitaxel-based chemotherapy (CT)+/-radiotherapy (RT).

METHODS

A retrospective, multi-institution study of women with stage II UPSC diagnosed from 1992 to 2006 was performed. All patients underwent comprehensive surgical staging. Treatment included observation (OBS), RT (vaginal brachytherapy, whole pelvic and/or whole abdominal therapy), or >or=3 cycles carboplatin/paclitaxel alone or with RT. Recurrence and survival outcomes were determined.

RESULTS

We identified 55 subjects: 10 treated with OBS, 26 with RT alone and 19 with CT+/-RT. After a median follow-up of 33 mos (range, 10-119), 20 recurrences (36%) were observed. There was an overall difference in recurrence based upon treatment (p=.013). Specifically, all CT+/-RT treated patients had a lower risk of recurrence (11%) compared to patients treated by RT alone (50%) or OBS (50%). No patients treated with both CT+RT (n=12) experienced a recurrence. Treatment with CT was also associated with a decreased risk of recurrence on multivariate analysis (p=.015). Most recurrences were extra-pelvic (70%), occurred within 2 years (85%) and were not salvageable (84%). Five-year progression-free survival was 86% in chemotherapy-treated patients versus 41% in those not receiving chemotherapy (p=.010); overall survival was 88% in chemotherapy-treated patients versus 64% in those not receiving chemotherapy (p=.115).

CONCLUSIONS

Stage II UPSC patients have a significant risk for unsalvageable, extra-pelvic recurrence. However, treatment with platinum/taxane therapy+/-RT appears to reduce this risk and is associated with improved progression free survival outcomes.

ERCC5 is a novel biomarker of ovarian cancer prognosis

PURPOSE

To identify a biomarker of ovarian cancer response to chemotherapy. PATIENTS AND METHODS Study: participants had epithelial ovarian cancer treated with surgery followed by platinum-based chemotherapy. DNA and RNA were isolated from frozen tumors and normal DNA was isolated from matched peripheral blood. A whole-genome loss of heterozygosity (LOH) analysis was performed using a high-density oligonucleotide array. Candidate genomic areas that predicted enhanced response to chemotherapy were identified with Cox proportional hazards methods. Gene expression analyses were performed through microarray experiments. Candidate genes were tested for independent effects on survival using Cox proportional hazards models, Kaplan-Meier survival curves, and the log-rank test.

RESULTS

Using a whole-genome approach to study the molecular determinants of ovarian cancer response to platinum-based chemotherapy, we identified LOH of a 13q region to predict prolonged progression-free survival (PFS; hazard ratio, 0.23; P = .006). ERCC5 was identified as a candidate gene in this region because of its known function in the nucleotide excision repair pathway, the unique DNA repair pathway that removes platinum-DNA adducts. We found LOH of the ERCC5 gene locus and downregulation of ERCC5 gene expression to predict prolonged PFS. Integration of genomic and gene expression data shows a correlation between 13q LOH and ERCC5 gene downregulation.

CONCLUSION

ERCC5 is a novel biomarker of ovarian cancer prognosis and a potential therapeutic target of ovarian cancer response to platinum chemotherapy.

FBXW7 mutation in adult T-cell and B-cell acute lymphocytic leukemias

The FBXW7 (also known as AGO, hCDC4, FBW7 and SEL-10) gene encodes a subunit of an ubiquitin protein ligase which regulates levels of cyclin E, NOTCH and other proteins. Engineered FBXW7 null cells display cell cycle and chromosome stability defects. Mutations of FBXW7 have been found in human colorectal, ovarian, endometrial tumors and T-cell acute lymphocytic leukemias. Prompted by these findings we have examined acute myeloid leukemia, non-Hodgkin's lymphoma, T-cell acute lymphocytic leukemia, B-cell acute lymphocytic leukemia and adult T-cell leukemia DNA for mutations of the FBXW7 gene. Mutations were detected by PCR-SSCP of all coding exons of the three isoforms of FBXW7, shifted bands were direct sequenced. As expected, mutations were found in T-cell acute lymphocytic leukemias. However mutations of FBXW7 were also found in four of 118 B-cell acute lymphocytic leukemias and one of 24 adult T-cell leukemia samples. The nucleotide changes consisted of an insertion, resulting in a frameshift mutation, and missense mutations of highly conserved residues. All mutations affected the FBXW7 target interacting domain. These observations suggest that disruption of FBXW7 has a role in several forms of lymphocytic leukemias and not exclusively T-cell acute lymphocytic leukemia.