Desmoglein 2 is a receptor for adenovirus serotypes 3, 7, 11 and 14

We have identified desmoglein 2 (DSG2) as the primary high-affinity receptor used by adenovirus (Ad) serotypes Ad3, Ad7, Ad11, and Ad14. These serotypes represent important human pathogens causing respiratory tract infections. In epithelial cells, adenovirus binding to DSG2 triggers events reminiscent of epithelial-to-mesenchymal transition, leading to transient opening of intercellular junctions. This improves access to receptors, e.g. CD46 and Her2/neu, that are trapped in intercellular junctions. In addition to complete virions, dodecahedral particles (PtDd), formed by viral penton and fiber in excess during viral replication, can trigger DSG2-mediated opening of intercellular junctions as shown by studies with recombinant Ad3 PtDd. Our findings shed light on adenovirus biology and pathogenesis and have implications for cancer therapy.

Assessing lead time of selected ovarian cancer biomarkers: a nested case-control study

Background

CA125, human epididymis protein 4 (HE4), mesothelin, B7-H4, decoy receptor 3 (DcR3), and spondin-2 have been identified as potential ovarian cancer biomarkers. Except for CA125, their behavior in the prediagnostic period has not been evaluated.

Methods

Immunoassays were used to determine concentrations of CA125, HE4, mesothelin, B7-H4, DcR3, and spondin-2 proteins in prediagnostic serum specimens (1–11 samples per participant) that were contributed 0–18 years before ovarian cancer diagnosis from 34 patients with ovarian cancer (15 with advanced-stage serous carcinoma) and during a comparable time interval before the reference date from 70 matched control subjects who were participating in the Carotene and Retinol Efficacy Trial. Lowess curves were fit to biomarker levels in cancer patients and control subjects separately to summarize mean levels over time. Receiver operating characteristic curves were plotted, and area-under-the curve (AUC) statistics were computed to summarize the discrimination ability of these biomarkers by time before diagnosis.

Results

Smoothed mean concentrations of CA125, HE4, and mesothelin (but not of B7-H4, DcR3, and spondin-2) began to increase (visually) in cancer patients relative to control subjects approximately 3 years before diagnosis but reached detectable elevations only within the final year before diagnosis. In descriptive receiver operating characteristic analyses, the discriminatory power of these biomarkers was limited (AUC statistics range = 0.56–0.75) but showed increasing accuracy with time approaching diagnosis (eg, AUC statistics for CA125 were 0.57, 0.68, and 0.74 for ≥4, 2–4, and <2 years before diagnosis, respectively).

Conclusion

Serum concentrations of CA125, HE4, and mesothelin may provide evidence of ovarian cancer 3 years before clinical diagnosis, but the likely lead time associated with these markers appears to be less than 1 year.

Analysis of epithelial and mesenchymal markers in ovarian cancer reveals phenotypic heterogeneity and plasticity

In our studies of ovarian cancer cells we have identified subpopulations of cells that are in a transitory E/M hybrid stage, i.e. cells that simultaneously express epithelial and mesenchymal markers. E/M cells are not homogenous but, in vitro and in vivo, contain subsets that can be distinguished based on a number of phenotypic features, including the subcellular localization of E-cadherin, and the expression levels of Tie2, CD133, and CD44. A cellular subset (E/M-MP) (membrane E-cadherin(low)/cytoplasmic E-cadherin(high)/CD133(high), CD44(high), Tie2(low)) is highly enriched for tumor-forming cells and displays features which are generally associated with cancer stem cells. Our data suggest that E/M-MP cells are able to differentiate into different lineages under certain conditions, and have the capacity for self-renewal, i.e. to maintain a subset of undifferentiated E/M-MP cells during differentiation. Trans-differentiation of E/M-MP cells into mesenchymal or epithelial cells is associated with a loss of stem cell markers and tumorigenicity. In vivo xenograft tumor growth is driven by E/M-MP cells, which give rise to epithelial ovarian cancer cells. In contrast, in vitro, we found that E/M-MP cells differentiate into mesenchymal cells, in a process that involves pathways associated with an epithelial-to-mesenchymal transition. We also detected phenotypic plasticity that was dependent on external factors such as stress created by starvation or contact with either epithelial or mesenchymal cells in co-cultures. Our study provides a better understanding of the phenotypic complexity of ovarian cancer and has implications for ovarian cancer therapy.

Combining CA 125 and SMR serum markers for diagnosis and early detection of ovarian carcinoma

OBJECTIVES

The serum tumor marker CA 125 is elevated in most clinically advanced ovarian carcinomas. Because these elevations may precede clinical detection by a year or more, CA 125 is potentially useful for early detection as part of an ovarian cancer screening program. However, CA 125 is often not elevated in clinically detected cancer and is frequently elevated in women with benign ovarian tumors. CA 125 may be more useful in conjunction with one or more other tumor biomarkers. Additional markers could play a role if, when used with CA 125, they identify some carcinomas missed by CA 125 (i.e., they improve sensitivity), rule out false positives (i.e., improve specificity), or are able to detect the same cancers earlier.

METHODS

We have evaluated a composite marker (CM) that combines CA 125 and a previously described soluble mesothelin related (SMR) marker in sera from 52 ovarian cancer cases, 43 controls with benign ovarian tumors, and 220 normal risk controls who participated in a screening program, including 25 healthy women having two serum samples collected 1 year apart. CA 125, SMR, and CM were evaluated for their ability to identify clinical disease and for their temporal stability, which assesses their ability to obtain even greater sensitivity when used in a longitudinal screening program.

RESULTS

CM has the best sensitivity, with specificity equal to CA 125. Importantly, CM has temporal stability at least as high as CA 125.

CONCLUSION

The CM may outperform CA 125 alone in a longitudinal screening program as well as in a diagnostic setting.

Genetic system for reversible integration of DNA constructs and lacZ gene fusions into the Escherichia coli chromosome

A plasmid system for site-specific integration into and excision and recovery of gene constructs and lacZ gene fusions from the Escherichia coli chromosome was developed. Plasmid suicide vectors utilizing the origin of replication of R6K plasmids and containing the attP sequence of bacteriophage lambda, multiple cloning site, and antibiotic resistance markers facilitate reversible integration into the E. coli chromosome by site-specific recombination. Additional vectors permit construction of lacZ gene fusions in three possible reading frames for recombination with the bacterial chromosome. These suicide vectors can be propagated in newly constructed E. coli strains that harbor different pir alleles. Two helper plasmids that encode the necessary gene products for integration (Int) and excision (Int and Xis) were also constructed. This plasmid system was shown to be a reliable and efficient means to integrate and subsequently recover plasmids from the E. coli attB site.

Collagen-induced proMMP-2 activation by MT1-MMP in human dermal fibroblasts and the possible role of alpha2beta1 integrins

Culture of human dermal fibroblasts within a three-dimensional matrix composed of native type I collagen fibrils is widely used to study the cellular responses to the extracellular matrix. Upon contact with native type I collagen fibrils human skin fibroblasts activate latent 72-kDa type IV collagenase/ gelatinase (MMP-2) to its active 59- and 62-kDa forms. This activation did not occur when cells were cultured on plastic dishes coated with monomeric type I collagen or its denatured form, gelatin. Activation could be inhibited by antibodies against MT1-MMP, by the addition of TIMP-2 and by prevention of MT1-MMP processing. MT1-MMP protein was detected at low levels as active protein in fibroblasts cultured as monolayers. In collagen gel cultures, an increase of the active, 60-kDa MT1-MMP and an additional 63-kDa protein corresponding to inactive MT1-MMP was detected. Incubation of medium containing latent MMP-2 with cell membranes isolated from fibroblasts grown in collagen gels caused activation of the enzyme. Furthermore, regulation of MT1-MMP expression in collagen cultures seems to be mediated by alpha2beta1 integrins. These studies suggest that activation of the proMMP-2 is regulated at the cell surface by a mechanism which is sensitive to cell culture in contact with physiologically relevant matrices and which depends on the ratio of proenzyme and the specific inhibitor TIMP-2.

Outcome of unexpected adnexal neoplasia discovered during risk reduction salpingo-oophorectomy in women with germ-line BRCA1 or BRCA2 mutations

OBJECTIVE

This study computed the risk of clinically silent adnexal neoplasia in women with germ-line BRCA1 or BRCA2 mutations (BRCA(m+)) and determined recurrence risk.

METHODS

We analyzed risk reduction salpingo-oophorectomies (RRSOs) from 349 BRCA(m+) women processed by the SEE-FIM protocol and addressed recurrence rates for 29 neoplasms from three institutions.

RESULTS

Nineteen neoplasms (5.4%) were identified at one institution, 9.2% of BRCA1 and 3.4% of BRCA2 mutation-positive women. Fourteen had a high-grade tubal intraepithelial neoplasm (HGTIN, 74%). Mean age (54.4) was higher than the BRCA(m+) cohort without neoplasia (47.8) and frequency increased with age (p < 0.001). Twenty-nine BRCA(m+) patients with neoplasia from three institutions were followed for a median of 5 years (1-8 years.). One of 11 with HGTIN alone (9%) recurred at 4 years, in contrast to 3 of 18 with invasion or involvement of other sites (16.7%). All but two are currently alive. Among the 29 patients in the three institution cohort, mean ages for HGTIN and advanced disease were 49.2 and 57.7 (p = 0.027).

CONCLUSIONS

Adnexal neoplasia is present in 5-6% of RRSOs, is more common in women with BRCA1 mutations, and recurs in 9% of women with HGTIN alone. The lag in time from diagnosis of the HGTIN to pelvic recurrence (4 years) and differences in mean age between HGTIN and advanced disease (8.5 years) suggest an interval of several years from the onset of HGTIN until pelvic cancer develops. However, some neoplasms occur in the absence of HGTIN.

Epithelial phenotype confers resistance of ovarian cancer cells to oncolytic adenoviruses

We studied the susceptibility of primary ovarian cancer cells to oncolytic adenoviruses. Using gene expression profiling of cancer cells either resistant or susceptible to viral oncolysis, we discovered that the epithelial phenotype of ovarian cancer represents a barrier to infection by commonly used oncolytic adenoviruses targeted to coxsackie-adenovirus receptor or CD46. Specifically, we found that these adenovirus receptors were trapped in tight junctions and not accessible for virus binding. Accessibility to viral receptors was critically linked to depolarization and the loss of tight and adherens junctions, both hallmarks of epithelial-to-mesenchymal transition (EMT). We showed that specific, thus far little-explored adenovirus serotypes (Ad3, Ad7, Ad11, and Ad14) that use receptor(s) other than coxsackie-adenovirus receptor and CD46 were able to trigger EMT in epithelial ovarian cancer cells and cause efficient oncolysis. Our studies on ovarian cancer cultures and xenografts also revealed several interesting cancer cell biology features. Tumors in situ as well as tumor xenografts in mice mostly contained epithelial cells and cells that were in a hybrid stage where they expressed both epithelial and mesenchymal markers (epithelial/mesenchymal cells). These epithelial/mesenchymal cells are the only xenograft-derived cells that can be cultured and with passaging undergo EMT and differentiate into mesenchymal cells. Our study provides a venue for improved virotherapy of cancer as well as new insights into cancer cell biology.

Coadministration of epithelial junction opener JO-1 improves the efficacy and safety of chemotherapeutic drugs

PURPOSE

Epithelial junctions between tumor cells inhibit the penetration of anticancer drugs into tumors. We previously reported on recombinant adenovirus serotype 3-derived protein (JO-1), which triggers transient opening of intercellular junctions in epithelial tumors through binding to desmoglein 2 (DSG2), and enhances the antitumor effects of several therapeutic monoclonal antibodies. The goal of this study was to evaluate whether JO-1 cotherapy can also improve the efficacy of chemotherapeutic drugs.

EXPERIMENTAL DESIGN

The effect of intravenous application of JO-1 in combination with several chemotherapy drugs, including paclitaxel/Taxol, nanoparticle albumin-bound paclitaxel/Abraxane, liposomal doxorubicin/Doxil, and irinotecan/Camptosar, was tested in xenograft models for breast, colon, ovarian, gastric and lung cancer. Because JO-1 does not bind to mouse cells, for safety studies with JO-1, we also used human DSG2 (hDSG2) transgenic mice with tumors that overexpressed hDSG2.

RESULTS

JO-1 increased the efficacy of chemotherapeutic drugs, and in several models overcame drug resistance. JO-1 treatment also allowed for the reduction of drug doses required to achieve antitumor effects. Importantly, JO-1 coadmininstration protected normal tissues, including bone marrow and intestinal epithelium, against toxic effects that are normally associated with chemotherapeutic agents. Using the hDSG2-transgenic mouse model, we showed that JO-1 predominantly accumulates in tumors. Except for a mild, transient diarrhea, intravenous injection of JO-1 (2 mg/kg) had no critical side effects on other tissues or hematologic parameters in hDSG2-transgenic mice.

CONCLUSIONS

Our preliminary data suggest that JO-1 cotherapy has the potential to improve the therapeutic outcome of cancer chemotherapy.

Evaluation of ovarian cancer remission markers HE4, MMP7 and Mesothelin by comparison to the established marker CA125

OBJECTIVE

Evaluate and compare the effectiveness of CA125, HE4, Mesothelin and MMP7 marker levels to monitor ovarian cancer patients after surgery and chemotherapy. Evaluate the lead time of a rise of marker levels before recurrence.

METHODS

The study consists of 23 patients with advanced stage ovarian/fallopian tube cancer. Blood was drawn after front line surgery and chemotherapy treatment and at 3 month intervals thereafter. One patient had chemoresistant disease, two patients remained in remission and 20 patients had recurring disease and were used for marker evaluation.

RESULTS

In five patients HE4 was the only marker to elevate before recurrence with a lead time of up to 4½ months including one patient who did not have a CA125 response at all. In a further two patients, HE4 increased before CA125 did. In four of these seven patients, HE4 levels were consistently at or above threshold during remission when both CA125 and imaging results were negative. MMP7 elevated before recurrence in one patient who was negative for the other markers. Mesothelin elevated in two patients who were also positive for CA125 and HE4.

CONCLUSIONS

HE4 can predict ovarian cancer recurrence earlier than CA125 and it can be elevated in patients that do not express CA125 at sufficient levels to make a clinical decision. MMP7 and Mesothelin have lower potential as markers for ovarian cancer recurrence to complement CA125. A failure of HE4 levels to normalize at completion of standard therapy may indicate a poor prognosis.

Use of a stochastic simulation model to identify an efficient protocol for ovarian cancer screening

The intervention protocol for an ovarian cancer screening trial should be efficient as well as effective, because it may become the standard of care if the trial demonstrates mortality reduction. To identify an efficient ovarian cancer screening protocol, the effectiveness and cost-effectiveness of selected single modality and multimodal screening strategies were estimated using a stochastic simulation model. Screening was simulated over a 30-year period in a hypothetical cohort of 1 million women aged 50 at the beginning of the period. The net present value of the cost per year of life saved was estimated for six protocols involving transvaginal sonography (TVS) and/or the tumor antigen CA 125. Internal and external validation was performed, and sensitivity analyses were conducted to assess the robustness of the ranking of the strategies. A multimodal strategy involving CA 125 with a threshold for positivity of either elevation above 35 U/ml or doubling since the previous screen, followed by TVS only if CA 125 is positive, was found to be efficient in the sense that no other strategies saved as many years of life at lower cost per year of life saved. Used annually, this strategy cost under $100,000 per year of life saved over a range of assumptions. The model's predictions are consistent with results reported in the literature regarding the performance of TVS and CA 125. The multimodal strategy used annually or every six months was efficient compared to either ultrasound or CA 125 used alone, over a range of assumptions. Simulation of screening may be useful in selecting a screening protocol to be tested in a randomized controlled trial.

Clinical trials: understanding and perceptions of female Chinese-American cancer patients

Under-representation of minority and female participants prompted the U.S. legislature to mandate the inclusion of women and minorities in federally funded research. Recruitment of minorities to participate in clinical trials continues to be challenging. Although Asian Americans constitute one of the major minority groups in the U.S., published literature contains sparse data concerning the participation of Asian Americans in cancer clinical trials. The authors completed qualitative, semistructured interviews with 34 participants: Chinese-American female cancer patients ages 20-85 years or their family members. Interviews were conducted in Cantonese, Mandarin, or English and were audiotaped. Chinese interviews were translated into English, and all interviews were transcribed subsequently into English. A team of five coders individually reviewed then met to discuss the English transcripts. The authors used the constant comparative technique throughout the entire coding process as part of the analysis. Among participants, 62% lacked any knowledge of clinical trials, and many expressed negative attitudes toward clinical trials. Barriers to participation included inadequate resources, language issues, and a lack of financial and social support. Facilitating factors included recommendations by a trusted oncologist or another trusted individual and information in the appropriate language. It is noteworthy that family members played an important role in the cancer experience of these participants. To promote participation, there is a need to increase knowledge of clinical trials among Chinese cancer patients. It also is necessary to examine the applicability of current patient-physician communication and interaction models. In addition, decision-making based on Asian philosophies within the context of Euro-American bioethics requires further study.

Quality assessment and data analysis for microRNA expression arrays

MicroRNAs are small (approximately 22 nt) RNAs that regulate gene expression and play important roles in both normal and disease physiology. The use of microarrays for global characterization of microRNA expression is becoming increasingly popular and has the potential to be a widely used and valuable research tool. However, microarray profiling of microRNA expression raises a number of data analytic challenges that must be addressed in order to obtain reliable results. We introduce here a universal reference microRNA reagent set as well as a series of nonhuman spiked-in synthetic microRNA controls, and demonstrate their use for quality control and between-array normalization of microRNA expression data. We also introduce diagnostic plots designed to assess and compare various normalization methods. We anticipate that the reagents and analytic approach presented here will be useful for improving the reliability of microRNA microarray experiments.

Worry about ovarian cancer risk and use of ovarian cancer screening by women at risk for ovarian cancer

OBJECTIVE

This study examined reports of perceived risk of ovarian cancer, worry, and screening use in a large sample of women. While screening for asymptomatic women is not generally recommended, in 1994 a consensus conference concluded that women with multiple affected relatives are at high risk for ovarian cancer and should be encouraged to participate in screening. The consensus report also suggested that women with a single affected first-degree relative are at elevated risk and while these women were not encouraged to get screening it was suggested that they may choose to pursue screening outside of a randomized trial [NIH Consensus Conference. JAMA 1995;273(6) 491-7].

METHODS

A total of 3257 women participated in this research by completing a mailed survey on ovarian cancer risk, worry, and use of screening. One hundred forty-two of these women were at high risk for this disease due to a strong family history. An additional 144 women were at elevated risk due to a single first-degree affected relative with ovarian cancer.

RESULTS

Family history did predict perceived risk, difficulties due to worry, and use of ovarian cancer screening. However, the group of women most likely to report high levels of perceived risk and to have received screening for ovarian cancer were women with a single affected relative rather than those at high risk, for whom screening is recommended.

CONCLUSIONS

These results suggest that many women need additional education about ovarian cancer risk. Most women overestimated their risk for this disease. Some average-risk women get screening although it is not recommended outside of randomized trials, and a significant percentage of women at high risk fail to get recommended screening.

Integrative proteomic analysis of serum and peritoneal fluids helps identify proteins that are up-regulated in serum of women with ovarian cancer

BACKGROUND

We used intensive modern proteomics approaches to identify predictive proteins in ovary cancer. We identify up-regulated proteins in both serum and peritoneal fluid. To evaluate the overall performance of the approach we track the behavior of 20 validated markers across these experiments.

METHODOLOGY

Mass spectrometry based quantitative proteomics following extensive protein fractionation was used to compare serum of women with serous ovarian cancer to healthy women and women with benign ovarian tumors. Quantitation was achieved by isotopically labeling cysteine amino acids. Label-free mass spectrometry was used to compare peritoneal fluid taken from women with serous ovarian cancer and those with benign tumors. All data were integrated and annotated based on whether the proteins have been previously validated using antibody-based assays.

FINDINGS

We selected 54 quantified serum proteins and 358 peritoneal fluid proteins whose case-control differences exceeded a predefined threshold. Seventeen proteins were quantified in both materials and 14 are extracellular. Of 19 validated markers that were identified all were found in cancer peritoneal fluid and a subset of 7 were quantified in serum, with one of these proteins, IGFBP1, newly validated here.

CONCLUSION

Proteome profiling applied to symptomatic ovarian cancer cases identifies a large number of up-regulated serum proteins, many of which are or have been confirmed by immunoassays. The number of currently known validated markers is highest in peritoneal fluid, but they make up a higher percentage of the proteins observed in both serum and peritoneal fluid, suggesting that the 10 additional markers in this group may be high quality candidates.

Validation and characterization of human kallikrein 11 as a serum marker for diagnosis of ovarian carcinoma

PURPOSE

The serum tumor marker CA 125 is elevated in most clinically advanced ovarian carcinomas, and currently, one of the most promising early detection strategies for ovarian cancer uses CA 125 level in conjunction with imaging. However, CA 125 is elevated in only 50% of early-stage ovarian cancer and is often elevated in women with benign ovarian tumors and other gynecologic diseases. Additional markers may improve on its individual performance if they increase sensitivity and specificity and are less sensitive to other gynecologic conditions. The human kallikrein 11 (hK11) marker has been reported to have favorable predictive value for ovarian cancer, although, by itself, it may be inferior to CA 125.

EXPERIMENTAL DESIGN

We here validate the performance of hK11 on an independent data set and further characterize its behavior in multiple types of controls. We also investigate its behavior when combined with CA 125 to form a composite marker. hK11 had not previously been evaluated on these serum samples. CA 125, hK11, and the composite marker were evaluated for their performance in identifying ovarian cancer and for temporal stability.

RESULTS

hK11 significantly distinguished ovarian cancer cases from healthy controls and is less sensitive to benign ovarian disease than is CA 125.

CONCLUSION

We conclude that hK11 is a valuable new biomarker for ovarian cancer and its temporal stability implies that it may do even better when used in a longitudinal screening program for early detection.

Proteogenomic analysis of chemo-refractory high-grade serous ovarian cancer

To improve the understanding of chemo-refractory high-grade serous ovarian cancers (HGSOCs), we characterized the proteogenomic landscape of 242 (refractory and sensitive) HGSOCs, representing one discovery and two validation cohorts across two biospecimen types (formalin-fixed paraffin-embedded and frozen). We identified a 64-protein signature that predicts with high specificity a subset of HGSOCs refractory to initial platinum-based therapy and is validated in two independent patient cohorts. We detected significant association between lack of Ch17 loss of heterozygosity (LOH) and chemo-refractoriness. Based on pathway protein expression, we identified 5 clusters of HGSOC, which validated across two independent patient cohorts and patient-derived xenograft (PDX) models. These clusters may represent different mechanisms of refractoriness and implicate putative therapeutic vulnerabilities.

Desmoglein-2 as a prognostic and biomarker in ovarian cancer

Greater than 80% of all cancer cases are carcinomas, formed by the malignant transformation of epithelial cells. One of the key features of epithelial tumors is the presence of intercellular junctions, which link cells to one another and act as barriers to the penetration of molecules. This study assessed the expression of desmoglein-2, an epithelial junction protein, as a prognostic and diagnostic biomarker for ovarian cancer. Ovarian cancer sections were stained for DSG2 and signal intensity was correlated to cancer type and grade. DSG2 immunohistochemistry signals and mRNA levels were analyzed in chemo-resistant and chemo-sensitive cases. Ovarian cancer patient serum levels of shed DSG2 were correlated to disease-free and overall survival. Primary ovarian cancer cells were used to study DSG2 levels as they changed in response to cisplatin treatment. DSG2 expression was found to be positively correlated with cancer grade. Ovarian cancer patients with high serum levels of shed DSG2 fared significantly worse in both progression-free survival (median survival of 16 months vs. 26 months, p = .0023) and general survival (median survival of 37 months vs. undefined, p < .0001). A subgroup of primary chemotherapy-resistant cases had stronger DSG2 IHC/Western signals and higher DSG2 mRNA levels. Furthermore, our in vitro studies indicate that non-cytotoxic doses of cisplatin can enhance DSG2 expression, which, in turn, can contribute to chemo-resistance. We suggest that DSG2 can be used in stratifying patients, deciding on where to use aggressive treatment strategies, predicting chemoresistance, and as a companion diagnostic for treatments targeting DSG2.

Phase Ib with expansion study of olaparib plus weekly (Metronomic) carboplatin and paclitaxel in relapsed ovarian cancer patients

OBJECTIVE

Our goals were to: establish the maximum-tolerated dose of olaparib tablets combined with metronomic carboplatin and paclitaxel in patients with relapsed high-grade serous ovarian cancer; evaluate dose-limiting toxicities; and evaluate efficacy at the maximum tolerated dose.

METHODS

In this open-label, single-arm, investigator-initiated trial (ClinicalTrials.gov NCT01650376), patients with high-grade serous ovarian cancer who failed primary platinum and taxane therapy received oral olaparib tablets twice daily days 1-3 each week combined with fixed-dose metronomic carboplatin AUC2 and paclitaxel 60 mg/m² weekly for 3 out of 4 weeks. A 3 × 3 design was used to determine the olaparib maximum tolerated dose. Combination therapy continued until disease progression, but patients with partial or complete response were transitioned to olaparib maintenance therapy. All patients were included in the analysis.

RESULTS

The maximum tolerated dose of olaparib tablets was 150 mg twice daily with metronomic carboplatin and paclitaxel. 54 women were enrolled, 14 in phase Ib and 40 in the expansion phase. The median number of prior therapeutic regimens was 3. Response included 13 complete remission (24%) and 16 partial remission (30%) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) for an overall response rate of 54% (95% CI 40% to 67%). Of 47 patients who underwent BRCA testing, 23 were BRCA mutation (BRCAm) and 24 B RCA wild type (BRCAwt). Progression-free survival for BRCAm was 12.1 months versus 4.8 for BRCAwt (p=0.0001). Median overall survival for BRCAm was 24.1 months versus 10.4 months for BRCAwt (p=0.02). 42 patients (78%) experienced grade 3-4 toxicities with combination therapy; the most common were hematologic. There were no treatment related deaths. Among 14 patients who received maintenance therapy, 7 experienced grade 1-2 non-hematologic toxicities.

CONCLUSIONS

Olaparib 150 mg tablet twice daily can be safely administered in combination with metronomic carboplatin and paclitaxel in pre-treated relapsed ovarian cancer with 24% complete remission. BRCAm patients had statistically significant longer progression-free survival and overall survival than BRCAwt.

TRIAL REGISTRATION NUMBER

NCT01650376.

Current and future developments in screening for ovarian cancer

Over 90% of women diagnosed with localized ovarian cancer survive at least 5 years, but because the disease is often advanced at diagnosis, only half of patients survive that long. Currently, screening is only recommended for women with a strong family history of the disease, for whom prophylactic surgery is appropriate once childbearing is complete. Screening is not recommended for the general population since currently available screening tests seldom detect curable tumors, and often lead to unnecessary surgery. New markers are under investigation that may signal disease earlier and be useful in a marker panel to select women for imaging and/or surgery. A clinical challenge is that definitive diagnosis requires major abdominal surgery, and screening tests often detect benign ovarian conditions. A challenge for translational research in biomarkers for early detection is that access is needed to preclinical blood samples, obtained some months prior to diagnosis, in order to determine if candidate markers can detect disease prior to onset of symptoms.

2-deoxy-2-[F-18]fluoro-D-glucose accumulation in ovarian carcinoma cell lines

PURPOSE

To evaluate 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) accumulation in human ovarian carcinoma cell lines compared with control tumor cell lines known to accumulate FDG.

PROCEDURES

FDG accumulation assays were performed in 15 different ovarian carcinoma cell lines at 1, 2, and 3 hours after incubation with 1 microCi of FDG. Results were compared with FDG accumulation in six different control tumor cell lines. 2-deoxy-2-[F-18]fluoro-D-glucose accumulation was expressed as counts per minute (cpm) in cells and normalized to initial cpm in medium and total protein content of cell lysates.

RESULTS

FDG accumulation in all 15 ovarian carcinoma cell lines was equal to or higher than 0.0005 +/- 8.6 10(-5) cpm in cells/cpm in medium/mug protein at all three different time points. In two ovarian carcinoma cell lines (ES-2, poorly differentiated clear cell carcinoma, and OVCAR-3, poorly differentiated papillary adenocarcinoma), FDG accumulation was not statistically, significantly different compared to the control cell line with the highest FDG accumulation (LS 174T human colorectal adenocarcinoma) at two or more time points (P > or = 0.07). In 2 of 15 (13%) ovarian carcinoma cell lines (OVCAR5 epithelial carcinoma and SKOV3 clear cell carcinoma), FDG accumulation was lower than that in the control cell line with the lowest FDG accumulation (HT-29 human colorectal adenocarcinoma) at one or more time points (P < 0.05).

CONCLUSIONS

Most human ovarian carcinoma cell lines showed comparable FDG accumulations with control cell lines known to accumulate FDG. This study lays the foundations for further comparisons with other ovarian cancer cell lines and for other positron emission tomography tracers.

Reported ovarian cancer screening among a population-based sample in Washington state

OBJECTIVE

To assess the prevalence of reported ovarian cancer screening among a population-based sample of women from Washington state and identify factors that influence the decision to be screened.

METHODS

A population-based sample of 6749 women aged 54-84 years, living in 40 predominately rural communities in Washington state, was surveyed about their utilization of ultrasonography and CA 125 for ovarian cancer screening. We also assessed relevant demographic, family history, psychosocial, and health behavior variables.

RESULTS

After exclusions, data from 4938 respondents were available. Two percent (n = 96) reported having been screened. Multiple logistic regression identified ovarian cancer worry, contact with an obstetrician-gynecologist, and family history of ovarian cancer as independently associated with screening. Based on self-reported family histories, 27 women had pedigrees consistent with high risk of ovarian cancer, but none of those women reported having been screened.

CONCLUSION

Ovarian cancer screening is rare. Women at high risk of it might not be getting recommended screening.