Rae Lynn Baldwin

Improved survival in women with BRCA-associated ovarian carcinoma†

The objective of this study was to determine the clinical characteristics, treatment response, and frequency of p53 overexpression in Ashkenazi Jewish women with hereditary ovarian carcinoma.

Comparative hybridization of an array of 21 500 ovarian cDNAs for the discovery of genes overexpressed in ovarian carcinomas

Comparative hybridization of cDNA arrays is a powerful tool for the measurement of differences in gene expression between two or more tissues. We optimized this technique and employed it to discover genes with potential for the diagnosis of ovarian cancer. This cancer is rarely identified in time for a good prognosis after diagnosis. An array of 21,500 unknown ovarian cDNAs was hybridized with labeled first-strand cDNA from 10 ovarian tumors and six normal tissues. One hundred and thirty-four clones are overexpressed in at least five of the 10 tumors. These cDNAs were sequenced and compared to public sequence databases. One of these, the gene HE4, was found to be expressed primarily in some ovarian cancers, and is thus a potential marker of ovarian carcinoma.

Prognostic DNA Methylation Biomarkers in Ovarian Cancer

Purpose: Aberrant DNA methylation, now recognized as a contributing factor to neoplasia, often shows definitive gene/sequence preferences unique to specific cancer types. Correspondingly, distinct combinations of methylated loci can function as biomarkers for numerous clinical correlates of ovarian and other cancers. Experimental Design: We used a microarray approach to identify methylated loci prognostic for reduced progression-free survival (PFS) in advanced ovarian cancer patients. Two data set classification algorithms, Significance Analysis of Microarray and Prediction Analysis of Microarray, successfully identified 220 candidate PFS-discriminatory methylated loci. Of those, 112 were found capable of predicting PFS with 95% accuracy, by Prediction Analysis of Microarray, using an independent set of 40 advanced ovarian tumors (from 20 short-PFS and 20 long-PFS patients, respectively). Additionally, we showed the use of these predictive loci using two bioinformatics machine-learning algorithms, Support Vector Machine and Multilayer Perceptron. Conclusion: In this report, we show that highly prognostic DNA methylation biomarkers can be successfully identified and characterized, using previously unused, rigorous classifying algorithms. Such ovarian cancer biomarkers represent a promising approach for the assessment and management of this devastating disease.

Peritoneal serous papillary carcinoma, a phenotypic variant of familial ovarian cancer: implications for ovarian cancer screening.

OBJECTIVE Our purpose was to report the cancers arising during a familial ovarian cancer screening program and investigate the tumors clonality and association with BRCA1 and BRCA2 mutations. STUDY DESIGN Program participants with a diagnosis of ovarian cancer or peritoneal serous papillary carcinoma were identified and their demographic characteristics, ultrasonographic findings, CA 125 results, operative reports, and pathology slides reviewed. Immunohistochemical analysis of p53, bcl-2, HER-2/neu, and nm23 H1 expression was performed on tumor tissues from multiple metastatic sites, and germline BRCA1 and BRCA2 mutations were identified. RESULTS Three stage I ovarian cancers and 7 cases of peritoneal serous papillary carcinoma were diagnosed from among 1261 program participants. Ultrasonographic abnormalities triggered surgical exploration in all 3 cases of stage I disease. Elevated levels of CA 125 were the harbinger in 2 of 7 cases of peritoneal serous papillary carcinoma, abnormal ultrasonographic findings prompted diagnosis in 2 of 7 cases, and 3 of 7 women had abdominal symptoms 5, 6, and 16 months after screening. Results of immunohistochemical studies suggested multifocal disease in 5 of 7 patients with peritoneal serous papillary carcinoma. At least 3 of the patients with peritoneal serous papillary carcinoma carry BRCA1 185delAG mutations. CONCLUSION Multifocal peritoneal serous papillary carcinoma may be a phenotypic variant of familial ovarian cancer, and screening strategies for these women cannot rely on ultrasonography and CA 125 testing to detect early disease.

Cancer Incidence in a Population of Jewish Women at Risk of Ovarian Cancer

PURPOSE To evaluate the incidence and clinical characteristics of ovarian and other cancers in a cohort of women at risk of developing ovarian cancer. PATIENTS AND METHODS The Gilda Radner Ovarian Cancer Detection Program in Los Angeles, CA, was established in 1991 to study the efficacy of screening in the early detection of ovarian cancer. We present findings from a historical cohort of 290 Jewish women who were offered BRCA testing for three common founder mutations (BRCA1 185delAG and 5382insC and BRCA2 6174delT). RESULTS In 10 years, 17 cancers were observed (1,111 per 100,000 per year), including six breast and eight ovarian or related cancers. A high proportion of cancers of peritoneal origin was observed. The majority (86%) of women with incident breast or ovarian/peritoneal cancer carried a mutation in the BRCA1 gene. The overall cancer incidence among carriers of mutations in the BRCA1 gene was estimated to be 5,450 per 100,000 per year, corresponding to a cumulative incidence of 47.5% at 10 years. In contrast, the cumulative incidence of cancer among noncarriers was 2.5% (P < 10(-8)). After adjustment for sampling, the risks to BRCA1 mutation carriers at 10 years were estimated to be 21% for ovarian/peritoneal/tubal cancer, 16% for breast cancer, and 36% for all cancers. CONCLUSION The excess risk of breast and ovarian cancer in Jewish women with a family history of ovarian cancer is largely attributable to mutations in BRCA1. Intensive surveillance by use of CA-125 and ultrasound does not seem to be an effective means of diagnosing early-stage ovarian cancer in this high-risk cohort.

Gene expression in epithelial ovarian carcinoma

We analysed the mRNA levels corresponding to 12 600 transcripts in primary cultures of ovarian epithelial cells derived from nine normal ovaries and 21 epithelial ovarian carcinoma. The class distinction and hierarchical clustering of expression data revealed a clear distinction in gene expression between normal and carcinoma-derived ovarian epithelial cells. Comparison of expression levels revealed 111 genes with mean expression values of >2.5-fold higher in carcinoma cells. Similarly, 62 genes were expressed at >2.5-fold higher levels in normal ovarian epithelial cells. For a few selected genes, we demonstrate that the pattern of differential expression observed in cultured epithelial cells is present in the normal ovaries and epithelial ovarian carcinoma. Use of cultured epithelial cells represents a novel strategy to study gene expression in a cell-type specific manner.

Altered expression of transforming growth factor-β ligands and receptors in primary and recurrent ovarian carcinoma

Resistance to the potent growth inhibitory effects of transforming growth factor‐β (TGF‐β) is a characteristic of many malignancies. TGF‐β insensitivity has been attributed to alterations in the number and function of the TGF‐β receptors as well as disturbances of downstream signal transduction. Paradoxically, increased levels of TGF‐β ligand have been demonstrated in several types of malignant tumors. TGF‐β also may play a role in ovarian carcinogenesis; however, the nature of this interaction has yet to be defined completely.

The fragile histidine triad gene: a molecular link between cigarette smoking and cervical cancer.

Purpose: Smoking is an epidemiologic risk factor for cervical cancer. The fragile histidine triad (FHIT) gene is a tumor suppressor gene that is altered in 80% of tobacco-associated lung cancers. We hypothesized that reduced FHIT protein expression, homozygous deletions (HD) or hemizygous deletions (HemiD) and microsatellite alterations (MA) at the FHIT/FRA3B locus occur more commonly in cervical cancers of smokers than nonsmokers. Experimental Design: Archival tissues of 58 patients with stage IA1 to IB2 squamous cell carcinoma of the cervix were identified. FHIT protein expression was studied with immunohistochemistry. Laser capture microdissection was used to isolate tumor and normal DNA. HD/HemiD of FHIT exons 4 and 5 were analyzed by monoplex real-time PCR. MA at FHIT/FRA3B were studied with multiplex nested PCR with three fluorescently labeled microsatellite markers (D3S1300, D3S1312, and D3S1480). Results: Eighteen of 26 tumors from smokers (69%) and 13 of 32 nonsmokers (41%; P < 0.05) showed loss of FHIT protein expression. Thirty-seven stage IB tumors yielded sufficient DNA for analyses. HD or HemiD of both exons tested occurred in 8 of 17 smokers (47%) and 2 of 20 nonsmokers (10%; P < 0.05). MA at more than two sites were found in 11 of 17 tumors of smokers (65%) and 6 of 20 nonsmokers (30%; P < 0.05). Mean composite genomic FHIT alteration scores were significantly higher for tumors of smokers versus nonsmokers (0.67 versus 0.40; P < 0.02). Conclusion: Loss of FHIT expression, HD, HemiD, and MA at the FHIT/FRA3B locus occur significantly more commonly in cervical cancers of smokers. These findings suggest that the tumor suppressor gene FHIT may represent a molecular target in cigarette smoking–associated cervical carcinogenesis.

Cytotoxic effects of TGF-α-Pseudomonas exotoxin A fusion protein in human pancreatic carcinoma cells

The epidermal growth factor (EGF) receptor is overexpressed in human pancreatic cancers and cultured cell lines. TP40 is a chimeric protein composed of transforming growth factor-α (TGF-α) linked to a modified Pseudomonas exotoxin A (PE40) that exerts growth inhibitory effects on cells bearing a high number of EGF receptors. Therefore, we compared the effect of TP40 on the growth of Chinese hamster ovary (CHO) cells expressing varying levels of the EGF receptor and on the growth of two human pancreatic cancer cell lines. The growth of CHO cells devoid of endogenous EGF receptors was minimally altered by high concentrations of TP40, even following a 72-h incubation period. In contrast, in CHO cells expressing ∼95,000 and 438,000 EGF receptors per cell, one-half maximal growth inhibition occurred at 5 and 3 ng/ml TP40, respectively. Following a 72-h incubation in T3M4 and COLO 357 human pancreatic cancer cells, one-half maximal growth inhibition occurred at 0.2 and 0.4 ng/ml TP40, respectively. This effect was significantly greater than that of native Pseudomonas exotoxin A. These findings indicate that human pancreatic cancer cells are markedly sensitive to the growth inhibitory effects of TP40 and raise the possibility that TP40 may have a therapeutic role in this disorder.

Molecular advances in gynecologic oncology.

Cancer is a genetic disease, and inherited or acquired genetic defects contribute to the initiation and progression of cancer. Improved molecular techniques have lead to the identification of many of these genetic mutations in gynecologic malignancies. The molecular characterization of cancer has provided a better understanding of tumor formation and the clinical behavior of different tumor types, with important implications for developing screening tests and prognostic markers. Applications of these findings have led to novel targeted gene therapies that correct the critical genetic defects seen in gynecologic cancers. Future research will focus on the clinical translation of these genetic alterations as targets of cancer prevention, screening, and treatment.