Ritu Salani

Secondary cytoreductive surgery for localized, recurrent epithelial ovarian cancer: analysis of prognostic factors and survival outcome.

The objective of this study was to evaluate the role of secondary cytoreductive surgery in the outcome of patients who had recurrent epithelial ovarian carcinoma that was limited to ≤5 recurrence sites within the abdomen or pelvis on preoperative imaging studies and attempt to define selection criteria associated with improved survival, with specific attention to the number of lesions suspicious for recurrent disease.

Amplicon profiles in ovarian serous carcinomas.

Ovarian serous carcinoma is the most common and lethal type of ovarian cancer and its molecular etiology remains poorly understood. As an ongoing effort to elucidate the pathogenesis of ovarian serous carcinomas, we assessed the DNA copy number changes in 33 high‐grade serous carcinomas and 10 low‐grade serous tumors by using a genome‐wide technique, single nucleotide polymorphism array, performed on affinity‐purified tumor cells from fresh surgical specimens. Compared to low‐grade tumors, high‐grade serous carcinomas showed widespread DNA copy number changes. The most frequent alterations were in loci harboring candidate oncogenes: cyclin E1 (CCNE1), AKT2, Notch3 and PIK3CA as well as in novel loci, including 12p13, 8q24, 12p13 and 12q15. Seven amplicons were selected for dual color fluorescence in situ hybridization analysis in ∼90 high‐grade serous carcinomas and 26 low‐grade serous tumors, and a high level of DNA copy number gain (amplification) was found in CCNE1, Notch3, HBXAP/Rsf‐1, AKT2, PIK3CA and chr12p13 occurring in 36.1%, 7.8%, 15.7%, 13.6%, 10.8% and 7.3% of high‐grade serous carcinomas. In contrast, we did not observe high level of ERBB2 amplification in any of the samples. Low‐grade tumors did not show DNA copy number gain in any of the loci, except in 2 (8%) of 24 low‐grade tumors showing low copy number gain in the Notch3 locus. Taken together, our results provide the first comprehensive analysis of DNA copy number changes in highly pure ovarian serous carcinoma. These findings may have important biological and clinical implications.

Assessment of TP53 mutation using purified tissue samples of ovarian serous carcinomas reveals a higher mutation rate than previously reported and does not correlate with drug resistance.

The TP53 mutation frequency in ovarian serous carcinomas has been reported to range between 50% and 80%, but a stringent analysis of TP53 using purified epithelial samples has not yet been performed to accurately assess the mutation frequency and to correlate it with the histologic grade. The purpose of this study was to assess the TP53 mutational profile in a relatively large series of high-grade (53 primary and 18 recurrent) and 13 low-grade ovarian serous tumors using DNA isolated from affinity-purified tumor cells and to correlate it with in vitro drug resistance. All samples were affinity purified, and the tumor DNA was analyzed for TP53 mutations in exons 4–9. In vitro drug resistance assays to carboplatin, cisplatin, paclitaxel, and taxotere were performed on the same tumor samples and correlated with the TP53 mutation status. TP53 mutations were detected in 57 (80.3%) of 71 high-grade carcinomas and in one (7.8%) of 13 low-grade serous tumors (an invasive low-grade serous carcinoma). The mutations were predominantly missense mutations (59.6%). TP53 mutations were associated with high-grade serous carcinomas and recurrent disease (P < 0.0001). There was no statistically significant correlation between TP53 mutation status and drug resistance assays or clinical stage (P > 0.25). The frequency of TP53 mutations using purified tumor DNA from ovarian serous carcinomas was 80.3%, which is much higher than previously reported. Furthermore, we found that TP53 is not directly involved in the development of drug resistance in high-grade ovarian serous carcinomas.

A BTB/POZ protein, NAC-1, is related to tumor recurrence and is essential for tumor growth and survival

Recent studies have suggested an oncogenic role of the BTB/POZ-domain genes in hematopoietic malignancy. The aim of this study is to identify and characterize BTB/POZ-domain genes in the development of human epithelial cancers, i.e., carcinomas. In this study, we focused on ovarian carcinoma and analyzed gene expression levels using the serial analysis of gene expression (SAGE) data in all 130 deduced BTB/POZ genes. Our analysis reveals that NAC-1 is significantly overexpressed in ovarian serous carcinomas and several other types of carcinomas. Immunohistochemistry studies in ovarian serous carcinomas demonstrate that NAC-1 is localized in discrete nuclear bodies (tentatively named NAC-1 bodies), and the levels of NAC-1 expression correlate with tumor recurrence. Furthermore, intense NAC-1 immunoreactivity in primary tumors predicts early recurrence in ovarian cancer. Both coimmunoprecipitation and double immunofluorescence staining demonstrate that NAC-1 molecules homooligomerize through the BTB/POZ domain. Induced expression of the NAC-1 mutant containing only the BTB/POZ domain disrupts NAC-1 bodies, prevents tumor formation, and promotes tumor cell apoptosis in established tumors in a mouse xenograft model. Overexpression of full-length NAC-1 enhanced tumorigenicity of ovarian surface epithelial cells and NIH 3T3 cells in athymic nu/nu mice. In summary, NAC-1 is a tumor recurrence-associated gene with oncogenic potential, and the interaction between BTB/POZ domains of NAC-1 proteins is critical to form the discrete NAC-1 nuclear bodies and essential for tumor cell proliferation and survival.

Limited utility of conventional criteria for predicting unresectable disease in patients with advanced stage epithelial ovarian cancer

OBJECTIVEnTo evaluate the predictive value of conventional criteria for identifying surgically unresectable disease among patients with ovarian cancer undergoing initial operative intervention at tertiary referral centers employing a so-called aggressive approach to surgical cytoreduction.nnnMETHODSnAll patients with advanced epithelial ovarian cancer undergoing primary surgery between August 1997 and August 2006 were identified. Surgical/pathological documentation of disease extent pre/post-cytoreduction was extracted from the medical record retrospectively. All patients meeting conventional criteria for unresectable disease criteria (ascites >1000 mL, omental extension to spleen >1 cm, parenchymal liver disease >1 cm, porta hepatis involvement >1 cm, diaphragmatic disease >1 cm, carcinomatosis >1 cm, and suprarenal adenopathy >1 cm) were selected for further study.nnnRESULTSnA total of 180 consecutive patients had disease meeting conventional criteria for unresectability at =1 site(s). Optimal cytoreduction (residual disease=1 cm) was achieved in 166 patients (92.2%). Optimal resection rates according to the most common individual unresectable disease criteria were as follows: ascites >1000 mL=91.3% (116/127), carcinomatosis >1 cm=91.0% (81/89), and splenic involvement >1 cm=84.9% (45/53). For patients with ascites >1000 mL alone, optimal cytoreduction was achieved in 95.8% (46/48) of cases. Optimal resection rates according to the total number of unresectable disease sites were as follows: 1 site=95.0% (19/20), 2 sites=93.8% (61/65), 3 sites=81.5% (22/27), 4 sites=93.3% (14/15), and 5 sites=80.0% (4/5).nnnCONCLUSIONSnThese data suggest that commonly accepted criteria of surgically unresectable disease for women with advanced ovarian cancer lack the necessary precision to guide clinical management. Pre-operative assessment of resectability should be made by an experienced surgical team prior to deferring the initial attempt at surgical cytoreduction.

Subdividing ovarian and peritoneal serous carcinoma into moderately differentiated and poorly differentiated does not have biologic validity based on molecular genetic and in vitro drug resistance data.

Serous carcinoma of the ovary has been traditionally graded as well-differentiated, moderately differentiated, and poorly differentiated (ie, a 3-tier system). A new 2-tier system grades serous carcinomas into low or high grade. Recent morphologic and molecular studies have shown that invasive well-differentiated serous carcinoma, referred to by us as “invasive low-grade micropapillary serous carcinoma,” is clearly distinct from high-grade serous carcinoma from the standpoint of pathogenesis and clinicopathologic features. As high-grade serous carcinoma is histologically heterogeneous, the goal of this study was to determine, based on molecular and drug resistance data, whether further subclassification of high-grade serous carcinomas into additional grades (moderately and poorly differentiated) has biologic validity. One hundred eleven ovarian and peritoneal high-grade serous carcinomas further subclassified as moderately and poorly differentiated types using the International Federation of Gynecology and Obstetrics (FIGO) grading system were analyzed for TP53 mutations and in vitro extreme drug resistance to 10 chemotherapeutic drugs. Seventy-six and 35 cases were subclassified as moderately and poorly differentiated, respectively. A TP53 mutation was present in 84% of moderately and 70% of poorly differentiated types of high-grade serous carcinomas, respectively (P=0.21), and there were no significant differences in the frequency of extreme drug resistance for each of the 10 drugs tested (P values ranging from 0.14 to >0.99). Although additional investigation is warranted, this study suggests that subclassification of high-grade serous carcinoma into moderately and poorly differentiated is not relevant. Accordingly, they can be simply classified as high-grade serous carcinoma.

Annexin XI Is Associated with Cisplatin Resistance and Related to Tumor Recurrence in Ovarian Cancer Patients

Purpose: Ovarian cancer patients treated with cisplatin-based chemotherapy often develop acquired cisplatin resistance and, consequently, cancer recurrence. The precise nature of chemoresistance remains unclear. In this study, a protein identified to be associated with cisplatin resistance in ovarian cancer cells was investigated in ovarian cancer tissues to address its clinical significance. Experimental Design: Antibody microarrays were used to identify proteins consistently differentially expressed across three pairs of cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. Immunoblotting was used to confirm observed alteration of protein expression. The protein expression was further evaluated by immunohistochemical staining using tissue microarrays containing various human normal and malignant tissues and 164 surgical specimens derived from primary and recurrent ovarian cancer patients who underwent primary debulking surgery followed by standard chemotherapeutic regimen. Results: Annexin XI was down-regulated in all three cisplatin-resistant cell lines as compared with their parent cells. Annexin XI expression was observed in the majority of human normal organs and decreased in some of the most common human malignancies. The expression level of Annexin XI in first recurrent ovarian cancers was much lower than that in primary ovarian cancers (P = 0.0004). Increased Annexin XI immunoreactivity in ovarian cancers seemed to prolong the disease-free interval of patients (P = 0.03). Annexin XI immunoreactivity inversely correlated with in vitro cisplatin resistance in ovarian cancers (P = 0.01). Conclusion: Decreased expression of Annexin XI is characteristic for cisplatin-resistant cancer cells and may contribute to tumor recurrence. Annexin XI may be a potential marker for chemoresistance and earlier recurrence of ovarian cancer patients.

Measurement of cyclin E genomic copy number and strand length in cell-free DNA distinguish malignant versus benign effusions

Purpose: Previous studies have shown that the concentration of cell-free DNA was higher and its strand length longer in body fluids obtained from patients with cancer as compared to patients with benign diseases. We hypothesized that analysis of both DNA copy number and strand length of cell-free DNA from an amplified chromosomal region could improve the diagnosis of malignant diseases in body fluids. Experimental Design: To test this hypothesis, we used ovarian cancer effusion as an example and applied a quantitative real-time PCR to measure the relative copy number and strand length of DNA fragments from one of the most frequently amplified genes, cyclin E, in ovarian serous carcinomas. Results: As compared with nonamplified chromosomal loci, including β-actin, p53, 2p24.1, and 4p15.31, measurement of cyclin E DNA copy number (100 bp) had the best performance in distinguishing malignant (n = 88) from benign (n = 70) effusions after normalization to effusion volume or Line-1 DNA with areas under the receiver operating characteristics curve (AUC) of 0.832 and 0.847, respectively. Different DNA lengths of the cyclin E locus were further analyzed and we found that the AUC was highest by measuring the 400-bp cyclin E locus (AUC = 0.896). The AUC was improved to 0.936 when it was combined with the length integrity index as defined by the relative abundance of 400 bp cyclin E to 100 bp p53 loci. Cyclin E real-time PCR assay had a higher sensitivity (95.6%) than routine cytology examination (73.9%) and was able to diagnose false-negative cytology cases in this study. Conclusions: The above findings indicate that measurement of the DNA copy number and strand length of the cyclin E locus is a useful cancer diagnostic tool.

Surgical management of mesenteric lymph node metastasis in patients undergoing rectosigmoid colectomy for locally advanced ovarian carcinoma

BackgroundWe sought to determine the incidence of mesenteric lymph node metastases in patients undergoing rectosigmoid resection for epithelial ovarian carcinoma and to evaluate the potential contribution of sigmoid mesocolectomy toward achieving complete surgical cytoreduction.MethodsPathology results for patients undergoing rectosigmoid colectomy for epithelial ovarian carcinoma from August 1998 through September 2005 were retrospectively reviewed. Fifty-three patients with pathological documentation of mesenteric lymph nodes were selected for further review. A focused analysis was performed on cases with an adequate surgical sampling of mesenteric lymph nodes (more than one positive or five total mesenteric lymph nodes) to determine the overall incidence of nodal metastases. χ2 analysis was used to identify clinicopathologic factors associated with mesenteric lymphatic spread.ResultsA total of 39 (73.6%) of 53 patients had an adequate mesenteric resection suitable for nodal analysis. In this subgroup, 32 (82.1%) of 39 patients had one or more mesenteric lymph nodes containing metastatic ovarian carcinoma. Invasion beyond the serosa of the rectosigmoid colon was present in 31 (79.5%) of 39 of cases; however, increasing depth of invasion was not associated with risk of mesenteric nodal disease. In addition to bowel wall involvement, the only clinical factor that correlated with mesenteric lymph node involvement was concurrent tumor spread to retroperitoneal lymph nodes (P = .025).ConclusionsLocally advanced ovarian carcinoma involving the rectosigmoid colon is associated with a high incidence of mesenteric nodal metastasis. Standard surgical technique should include a sigmoid mesocolectomy with resection of the associated lymphatic tributaries at the time of rectosigmoid colectomy if the surgical objective is complete cytoreduction of occult nodal disease.

Expression of extracellular matrix proteins in ovarian serous tumors.

The aims of this study were to perform a comprehensive expression analysis of the genes encoding extracellular matrix proteins and to investigate the expression pattern in one of these proteins, syndecan 1, in normal ovarian epithelium as well as benign and malignant ovarian serous tumors. Gene expression of 16 different extracellular matrix proteins was analyzed in ovarian serous tumors based on serial analysis of gene expression database. Semiquantitative reverse transcription-polymerase chain reaction was used to validate the serial analysis of gene expression result from each gene. As compared with normal ovarian surface epithelium, we found overexpression of syndecan 1, collagen type IV alpha 2, elastin microfibril interfase located protein 1, and laminin 5 in ovarian serous carcinomas. Syndecan 1 was selected for further study as it has not been well characterized in ovarian cancer and the syndecan 1 antibody was available for immunohistochemistry. Using a syndecan 1-specific monoclonal antibody, we demonstrated that syndecan 1 was expressed in 30.4% of high-grade serous carcinomas, 29.7% of low-grade carcinomas and serous borderline tumors, but none of benign serous cystadenomas and ovarian surface epithelium. Although both high-grade and low-grade serous carcinomas had a similar percentage of syndecan 1-positive cases, the immunointensity in high-grade carcinoma was significantly higher than that in low-grade carcinomas and serous borderline tumors (P = 0.007). In summary, ovarian carcinomas exhibit up-regulated expression of several extracellular matrix proteins, and syndecan 1 represents a novel tumor-associated marker in ovarian serous carcinomas.