Profiles of genomic instability in high-grade serous ovarian cancer predict treatment outcome.

PURPOSE: High-grade serous cancer (HGSC) is the most common cancer of the ovary and is characterized by chromosomal instability. Defects in homologous recombination repair (HRR) are associated with genomic instability in HGSC, and are exploited by therapy targeting DNA repair. Defective HRR causes uniparental deletions and loss of heterozygosity (LOH). Our purpose is to profile LOH in HGSC and correlate our findings to clinical outcome, and compare HGSC and high-grade breast cancers. EXPERIMENTAL DESIGN: We examined LOH and copy number changes using single nucleotide polymorphism array data from three HGSC cohorts and compared results to a cohort of high-grade breast cancers. The LOH profiles in HGSC were matched to chemotherapy resistance and progression-free survival (PFS). RESULTS: LOH-based clustering divided HGSC into two clusters. The major group displayed extensive LOH and was further divided into two subgroups. The second group contained remarkably less LOH. BRCA1 promoter methylation was associated with the major group. LOH clusters were reproducible when validated in two independent HGSC datasets. LOH burden in the major cluster of HGSC was similar to triple-negative, and distinct from other high-grade breast cancers. Our analysis revealed an LOH cluster with lower treatment resistance and a significant correlation between LOH burden and PFS. CONCLUSIONS: Separating HGSC by LOH-based clustering produces remarkably stable subgroups in three different cohorts. Patients in the various LOH clusters differed with respect to chemotherapy resistance, and the extent of LOH correlated with PFS. LOH burden may indicate vulnerability to treatment targeting DNA repair, such as PARP1 inhibitors.

Urinary MMP-2 and MMP-9 predict the presence of ovarian cancer in women with normal CA125 levels.

OBJECTIVE: To determine whether urinary matrix metalloproteinases (MMPs) predict the presence of ovarian cancer in patients with CA125 levels below the normal threshold of 35U/mL, a critical group of patients for whom no ovarian cancer biomarker is currently available. To determine whether these noninvasive biomarkers provide clinically useful information in the general ovarian cancer patient population as well. METHODS: ELISA analyses and substrate gel electrophoresis detected the levels and activity of urinary MMP-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex, and MMP-9 dimer in all ovarian cancer patients (n=97), those with CA125 <35U/mL (n=26) and controls (n=81). RESULTS: In patients with CA125 <35U/mL, receiver-operating characteristic (ROC) area under curve (AUC) analysis demonstrated that either urinary MMP-2 or MMP-9 or NGAL significantly discriminated between controls and ovarian cancer patients with normal CA125. Multivariate logistic regression revealed that the combination of urinary MMP-2 and MMP-9 provided the best diagnostic accuracy when multiplexed. When further multiplexed with age, the diagnostic accuracy of these biomarkers increased to a significant AUC of 0.820. These findings were consistent among the general ovarian cancer population studied as well, where the combination of urinary MMP-2 and MMP-9 multiplexed with age resulted in a highly significant AUC of 0.881. Pearson chi-square analysis revealed that higher urinary levels of either MMP-2 or MMP-9 were strongly associated with the increasing percentage of women with ovarian cancer independent of CA125 levels. CONCLUSION: This study demonstrates the potential utility of urinary MMP-2 and MMP-9 to differentiate between ovarian cancer patients with normal CA125 levels and controls and suggests that urinary MMP-2 and MMP-9 may be a clinically useful aid in the diagnosis of advanced or recurrent ovarian cancer.