Fishman, David A.

Abstract Purpose: Advanced-stage epithelial ovarian cancer has a poor prognosis with long-term survival in less than 30% of patients. When the disease is detected in stage I, more than 90% of patients can be cured by conventional therapy. Screening for early-stage disease with individual serum tumor markers, such as CA125, is limited by the fact that no single marker is up-regulated and shed in adequate amounts by all ovarian cancers. Consequently, use of multiple markers in combination might detect a larger fraction of early-stage ovarian cancers. Experimental Design: To identify potential candidates for novel markers, we have used Affymetrix human genome arrays (U95 series) to analyze differences in gene expression of 41,441 known genes and expressed sequence tags between five pools of normal ovarian surface epithelial cells (OSE) and 42 epithelial ovarian cancers of different stages, grades, and histotypes. Recursive descent partition analysis (RDPA) was performed with 102 probe sets representing 86 genes that were up-regulated at least 3-fold in epithelial ovarian cancers when compared with normal OSE. In addition, a panel of 11 genes known to encode potential tumor markers [mucin 1, transmembrane (MUC1), mucin 16 (CA125), mesothelin, WAP four-disulfide core domain 2 (HE4), kallikrein 6, kallikrein 10, matrix metalloproteinase 2, prostasin, osteopontin, tetranectin, and inhibin] were similarly analyzed. Results: The 3-fold up-regulated genes were examined and four genes [Notch homologue 3 (NOTCH3), E2F transcription factor 3 (E2F3), GTPase activating protein (RACGAP1), and hematological and neurological expressed 1 (HN1)] distinguished all tumor samples from normal OSE. The 3-fold up-regulated genes were analyzed using RDPA, and the combination of elevated claudin 3 (CLDN3) and elevated vascular endothelial growth factor (VEGF) distinguished the cancers from normal OSE. The 11 known markers were analyzed using RDPA, and a combination of HE4, CA125, and MUC1 expression could distinguish tumor from normal specimens. Expression at the mRNA level in the candidate markers was examined via semiquantitative reverse transcription-PCR and was found to correlate well with the array data. Immunohistochemistry was performed to identify expression of the genes at the protein level in 158 ovarian cancers of different histotypes. A combination of CLDN3, CA125, and MUC1 stained 157 (99.4%) of 158 cancers, and all of the tumors were detected with a combination of CLDN3, CA125, MUC1, and VEGF. Conclusions: Our data are consistent with the possibility that a limited number of markers in combination might identify >99% of epithelial ovarian cancers despite the heterogeneity of the disease.

Abstract Purpose: Epithelial ovarian cancers are thought to arise from flattened epithelial cells that cover the ovarian surface or that line inclusion cysts. During malignant transformation, different histotypes arise that resemble epithelial cells from normal fallopian tube, endometrium, and intestine. This study compares gene expression in serous, endometrioid, clear cell, and mucinous ovarian cancers with that in the normal tissues that they resemble. Experimental Design: Expression of 63,000 probe sets was measured in 50 ovarian cancers, in 5 pools of normal ovarian epithelial brushings, and in mucosal scrapings from 4 normal fallopian tube, 5 endometrium, and 4 colon specimens. Using rank-sum analysis, genes whose expressions best differentiated the ovarian cancer histotypes and normal ovarian epithelium were used to determine whether a correlation based on gene expression existed between ovarian cancer histotypes and the normal tissues they resemble. Results: When compared with normal ovarian epithelial brushings, alterations in serous tumors correlated with those in normal fallopian tube (P = 0.0042) but not in other normal tissues. Similarly, mucinous cancers correlated with those in normal colonic mucosa (P = 0.0003), and both endometrioid and clear cell histotypes correlated with changes in normal endometrium (P = 0.0172 and 0.0002, respectively). Mucinous cancers displayed the greatest number of alterations in gene expression when compared with normal ovarian epithelial cells. Conclusion: Studies at a molecular level show distinct expression profiles of different histologies of ovarian cancer and support the long-held belief that histotypes of ovarian cancers come to resemble normal fallopian tube, endometrial, and colonic epithelium. Several potential molecular markers for mucinous ovarian cancers have been identified.

Abstract Epithelial ovarian cancer (EOC) is the leading cause of death among all gynecologic cancers in the United States. Because women who are diagnosed with early stage disease have a better prognosis than women diagnosed with late stage disease, early detection represents a potentially practical approach to reduce the mortality associated with EOC. Unfortunately, no single screening test has proven to be effective for this purpose, and a valid and feasible screening program to detect early stage EOC in the general population has not yet been devised. Consequently, research has focused on coupling two or more screening modalities to improve program validity and feasibility. Serum cancer antigen 125 (CA125) and a soluble isoform of the epidermal growth factor receptor (p110 sEGFR) have been studied individually as biomarkers of ovarian cancer. In this study, we compare serum CA125 levels and sEGFR concentrations in women with EOC to women with benign gynecologic conditions of ovarian and non-ovarian origin. We show that serum sEGFR concentrations are lower in patients with EOC than in women with benign gynecologic conditions, whereas serum CA125 levels are higher in patients to EOC compared with women with benign gynecologic conditions. These data also reveal that age and serum sEGFR concentrations modify the association between CA125 levels and EOC versus benign gynecologic disease. Hence, age- and sEGFR-dependent CA125 cutoff thresholds improve the ability of CA125 to discern EOC patients from women with benign ovarian tumors and non-ovarian gynecologic conditions. Our analyses show that parallel testing with fixed sEGFR and CA125 cutoff thresholds optimizes sensitivity to detect EOC, whereas serial testing with age- and sEGFR-dependent CA125 cutoff thresholds optimizes test specificity, and overall accuracy to discern patients with EOC from women with benign ovarian and non-ovarian gynecologic conditions. The combined use of serologic sEGFR and CA125, thus, has improved utility for screening and diagnosing EOC, which may increase the positive predictive value of a multimodal screening program that incorporates these biomarkers to detect and subsequently differentiate benign from malignant ovarian tumors.