William A. Cliby

Overexpression of a kinase-inactive ATR protein causes sensitivity to DNA-damaging agents and defects in cell cycle checkpoints.

ATR, a phosphatidylinositol kinase‐related protein homologous to ataxia telangiectasia mutated (ATM), is important for the survival of human cells following many forms of DNA damage. Expression of a kinase‐inactive allele of ATR (ATRkd) in human fibroblasts causes increased sensitivity to ionizing radiation (IR), cis‐platinum and methyl methanesulfonate, but only slight UV radiation sensitivity. ATRkd overexpression abrogates the G2/M arrest after exposure to IR, and overexpression of wild‐type ATR complements the radioresistant DNA synthesis phenotype of cells lacking ATM, suggesting a potential functional overlap between these proteins. ATRkd overexpression also causes increased sensitivity to hydroxyurea that is associated with microtubule‐mediated nuclear abnormalities. These observations are consistent with uncoupling of certain mitotic events from the completion of S‐phase. Thus, ATR is an important component of multiple DNA damage response pathways and may be involved in the DNA replication (S/M) checkpoint.

Prospective assessment of lymphatic dissemination in endometrial cancer: a paradigm shift in surgical staging.

OBJECTIVE To prospectively assess pelvic and para-aortic lymph node metastases in endometrial cancer with lymphatic dissemination, emphasizing the examination of para-aortic metastases relative to the inferior mesenteric artery (IMA). METHODS Over 36 months, 422 consecutive patients were managed by predefined surgical guidelines differentiating low-risk patients from patients at risk for dissemination requiring systematic lymphadenectomy. Low risk was defined as grade 1 or 2 endometrioid type with myometrial invasion (MI) < or = 50% and primary tumor diameter (PTD) < or = 2 cm. Pelvic and para-aortic lymph nodes were submitted separately, with nodes identified from all 8 pelvic and 4 para-aortic node-bearing basins. Surgical quality assessments examined median node counts (primary surrogate for quality) and nodes harvested above and below the IMA and excised gonadal veins (secondary surrogates). RESULTS Lymphadenectomy was not required in 27% of patients (all low risk) and in 33% (n=112) of endometrioid cases. However, 22 patients (20%) of this latter cohort had lymphadenectomy and all lymph nodes were negative. Sixty-three (22%) of 281 patients undergoing lymphadenectomy had lymph node metastases: both pelvic and para-aortic in 51%, only pelvic in 33%, and isolated to the para-aortic area in 16%. Therefore, 67% of patients with lymphatic dissemination had para-aortic lymph node metastases. Furthermore, 77% of patients with para-aortic node involvement had metastases above the IMA, whereas nodes in the ipsilateral para-aortic area below the IMA and ipsilateral common iliac basin were declared negative in 60% and 71%, respectively. Gonadal veins were excised in 25 patients with para-aortic node metastases; 7 patients (28%) had documented metastatic involvement of gonadal veins or surrounding soft tissue. CONCLUSIONS The high rate of lymphatic metastasis above the IMA indicates the need for systematic pelvic and para-aortic lymphadenectomy (vs sampling) up to the renal vessels. The latter should include consideration of excision of the gonadal veins. Conversely, lymphadenectomy does not benefit patients with grade 1 and 2 endometrioid lesions with MI < or = 50% and PTD < or = 2 cm.

Aggressive surgical effort and improved survival in advanced-stage ovarian cancer

OBJECTIVE: Residual disease after initial surgery for ovarian cancer is the strongest prognostic factor for survival. However, the extent of surgical resection required to achieve optimal cytoreduction is controversial. Our goal was to estimate the effect of aggressive surgical resection on ovarian cancer patient survival. METHODS: A retrospective cohort study of consecutive patients with International Federation of Gynecology and Obstetrics stage IIIC ovarian cancer undergoing primary surgery was conducted between January 1, 1994, and December 31, 1998. The main outcome measures were residual disease after cytoreduction, frequency of radical surgical resection, and 5-year disease-specific survival. RESULTS: The study comprised 194 patients, including 144 with carcinomatosis. The mean patient age and follow-up time were 64.4 and 3.5 years, respectively. After surgery, 131 (67.5%) of the 194 patients had less than 1 cm of residual disease (definition of optimal cytoreduction). Considering all patients, residual disease was the only independent predictor of survival; the need to perform radical procedures to achieve optimal cytoreduction was not associated with a decrease in survival. For the subgroup of patients with carcinomatosis, residual disease and the performance of radical surgical procedures were the only independent predictors. Disease-specific survival was markedly improved for patients with carcinomatosis operated on by surgeons who most frequently used radical procedures compared with those least likely to use radical procedures (44% versus 17%, P < .001). CONCLUSION: Overall, residual disease was the only independent predictor of survival. Minimizing residual disease through aggressive surgical resection was beneficial, especially in patients with carcinomatosis. LEVEL OF EVIDENCE: II-2

Detection of epithelial ovarian cancer using 1H-NMR-based metabonomics

Currently available serum biomarkers are insufficiently reliable to distinguish patients with epithelial ovarian cancer (EOC) from healthy individuals. Metabonomics, the study of metabolic processes in biologic systems, is based on the use of 1H‐NMR spectroscopy and multivariate statistics for biochemical data generation and interpretation and may provide a characteristic fingerprint in disease. In an effort to examine the utility of the metabonomic approach for discriminating sera from women with EOC from healthy controls, we performed 1H‐NMR spectroscopic analysis on preoperative serum specimens obtained from 38 patients with EOC, 12 patients with benign ovarian cysts and 53 healthy women. After data reduction, we applied both unsupervised Principal Component Analysis (PCA) and supervised Soft Independent Modeling of Class Analogy (SIMCA) for pattern recognition. The sensitivity and specificity tradeoffs were summarized for each variable using the area under the receiver‐operating characteristic (ROC) curve. In addition, we analyzed the regions of NMR spectra that most strongly influence separation of sera of EOC patients from healthy controls. PCA analysis allowed correct separation of all serum specimens from 38 patients with EOC (100%) from all of the 21 premenopausal normal samples (100%) and from all the sera from patients with benign ovarian disease (100%). In addition, it was possible to correctly separate 37 of 38 (97.4%) cancer specimens from 31 of 32 (97%) postmenopausal control sera. SIMCA analysis using the Coomans plot demonstrated that sera classes from patients with EOC, benign ovarian cysts and the postmenopausal healthy controls did not share multivariate space, providing validation for the class separation. ROC analysis indicated that the sera from patients with and without disease could be identified with 100% sensitivity and specificity at the 1H‐NMR regions 2.77 parts per million (ppm) and 2.04 ppm from the origin (AUC of ROC curve = 1.0). In addition, the regression coefficients most influential for the EOC samples compared to postmenopausal controls lie around δ3.7 ppm (due mainly to sugar hydrogens). Other loadings most influential for the EOC samples lie around δ2.25 ppm and δ1.18 ppm. These findings indicate that 1H‐NMR metabonomic analysis of serum achieves complete separation of EOC patients from healthy controls. The metabonomic approach deserves further evaluation as a potential novel strategy for the early detection of epithelial ovarian cancer.

Phase I Trial of Intraperitoneal Administration of an Oncolytic Measles Virus Strain Engineered to Express Carcinoembryonic Antigen for Recurrent Ovarian Cancer

Edmonston vaccine strains of measles virus (MV) have shown significant antitumor activity in preclinical models of ovarian cancer. We engineered MV to express the marker peptide carcinoembryonic antigen (MV-CEA virus) to also permit real-time monitoring of viral gene expression in tumors in the clinical setting. Patients with Taxol and platinum-refractory recurrent ovarian cancer and normal CEA levels were eligible for this phase I trial. Twenty-one patients were treated with MV-CEA i.p. every 4 weeks for up to 6 cycles at seven different dose levels (10(3)-10(9) TCID(50)). We observed no dose-limiting toxicity, treatment-induced immunosuppression, development of anti-CEA antibodies, increase in anti-MV antibody titers, or virus shedding in urine or saliva. Dose-dependent CEA elevation in peritoneal fluid and serum was observed. Immunohistochemical analysis of patient tumor specimens revealed overexpression of measles receptor CD46 in 13 of 15 patients. Best objective response was dose-dependent disease stabilization in 14 of 21 patients with a median duration of 92.5 days (range, 54-277 days). Five patients had significant decreases in CA-125 levels. Median survival of patients on study was 12.15 months (range, 1.3-38.4 months), comparing favorably to an expected median survival of 6 months in this patient population. Our findings indicate that i.p. administration of MV-CEA is well tolerated and results in dose-dependent biological activity in a cohort of heavily pretreated recurrent ovarian cancer patients.

Multi-Institutional Reciprocal Validation Study of Computed Tomography Predictors of Suboptimal Primary Cytoreduction in Patients With Advanced Ovarian Cancer

PURPOSE Identify features on preoperative computed tomography (CT) scans to predict suboptimal primary cytoreduction in patients treated for advanced ovarian cancer in institution A. Reciprocally cross validate the predictors identified with those from two previously published cohorts from institutions B and C. PATIENTS AND METHODS Preoperative CT scans from patients with stage III/IV epithelial ovarian cancer who underwent primary cytoreduction in institution A between 1999 and 2005 were retrospectively reviewed by radiologists blinded to surgical outcome. Fourteen criteria were assessed. Crossvalidation was performed by applying predictive model A to the patients from cohorts B and C, and reciprocally applying predictive models B and C to cohort A. RESULTS Sixty-five patients from institution A were included. The rate of optimal cytoreduction ( 1 cm residual disease) was 78%. Diaphragm disease and large bowel mesentery implants were the only CT predictors of suboptimal cytoreduction on univariate (P < .02) and multivariate analysis (P < .02). In combination (model A), these predictors had a sensitivity of 79%, a specificity of 75%, and an accuracy of 77% for suboptimal cytoreduction. When model A was applied to cohorts B and C, accuracy rates dropped to 34% and 64%, respectively. Reciprocally, models B and C had accuracy rates of 93% and 79% in their original cohorts, which fell to 74% and 48% in cohort A. CONCLUSION The high accuracy rates of CT predictors of suboptimal cytoreduction in the original cohorts could not be confirmed in the cross validation. Preoperative CT predictors should be used with caution when deciding between surgical cytoreduction and neoadjuvant chemotherapy.

Ataxia Telangiectasia Mutated (ATM) and ATM and Rad3-related Protein Exhibit Selective Target Specificities in Response to Different Forms of DNA Damage

The ataxia telangiectasia mutated (ATM) and ATR (ATM and Rad3-related) protein kinases exert cell cycle delay, in part, by phosphorylating Checkpoint kinase (Chk) 1, Chk2, and p53. It is well established that ATR is activated following UV light-induced DNA damage such as pyrimidine dimers and the 6-(1,2)-dihydro-2-oxo-4-pyrimidinyl-5-methyl-2,4-(1H,3H)-pyrimidinediones, whereas ATM is activated in response to double strand DNA breaks. Here we clarify the activation of these kinases in cells exposed to IR, UV, and hyperoxia, a condition of chronic oxidative stress resulting in clastogenic DNA damage. Phosphorylation on Chk1(Ser-345), Chk2(Thr-68), and p53(Ser-15) following oxidative damage by IR involved both ATM and ATR. In response to ultraviolet radiation-induced stalled replication forks, phosphorylation on Chk1 and p53 required ATR, whereas Chk2 required ATM. Cells exposed to hyperoxia exhibited growth delay in G1, S, and G2 that was disrupted by wortmannin. Consistent with ATM or ATR activation, hyperoxia induced wortmannin-sensitive phosphorylation of Chk1, Chk2, and p53. By using ATM- and ATR-defective cells, phosphorylation on Chk1, Chk2, and p53 was found to be ATM-dependent, whereas ATR also contributed to Chk1 phosphorylation. These data reveal activated ATM and ATR exhibit selective substrate specificity in response to different genotoxic agents.

Current management strategies for ovarian cancer

Epithelial ovarian cancer originates in the layer of cells that covers the surface of the ovaries. The disease spreads readily throughout the peritoneal cavity and to the lymphatics, often before causing symptoms. Of the cancers unique to women, ovarian cancer has the highest mortality rate. Most women are diagnosed as having advanced stage disease, and efforts to develop new screening approaches for ovarian cancer are a high priority. Optimal treatment of ovarian cancer begins with optimal cytoreductive surgery followed by combination chemotherapy. Ovarian cancer, even in advanced stages, is sensitive to a variety of chemotherapeutics. Although improved chemotherapy has increased 5-year survival rates, overall survival gains have been limited because of our inability to eradicate all disease. Technologic advances that allow us to examine the molecular machinery that drives ovarian cancer cells have helped to identify numerous therapeutic targets within these cells. In this review, we provide an overview of ovarian cancer with particular emphasis on recent advances in operative management and systemic therapies.

Expression of p16 and Retinoblastoma Determines Response to CDK4/6 Inhibition in Ovarian Cancer

Purpose: PD-0332991 is a selective inhibitor of the CDK4/6 kinases with the ability to block retinoblastoma (Rb) phosphorylation in the low nanomolar range. Here we investigate the role of CDK4/6 inhibition in human ovarian cancer. Experimental Design: We examined the effects of PD-0332991 on proliferation, cell-cycle, apoptosis, and Rb phosphorylation using a panel of 40 established human ovarian cancer cell lines. Molecular markers for response prediction, including p16 and Rb, were studied using gene expression profiling, Western blot, and array CGH. Multiple drug effect analysis was used to study interactions with chemotherapeutic drugs. Expression of p16 and Rb was studied using immunohistochemistry in a large clinical cohort of ovarian cancer patients. Results: Concentration-dependent antiproliferative effects of PD-0332991 were seen in all ovarian cancer cell lines, but varied significantly between individual lines. Rb-proficient cell lines with low p16 expression were most responsive to CDK4/6 inhibition. Copy number variations of CDKN2A, RB, CCNE1, and CCND1 were associated with response to PD-0332991. CDK4/6 inhibition induced G0/G1 cell cycle arrest, blocked Rb phosphorylation in a concentration-and time-dependent manner, and enhanced the effects of chemotherapy. Rb-proficiency with low p16 expression was seen in 97/262 (37%) of ovarian cancer patients and was independently associated with poor progression-free survival (adjusted relative risk 1.49, 95% CI 1.00–2.24, P = 0.052). Conclusions: PD-0332991 shows promising biologic activity in ovarian cancer cell lines. Assessment of Rb and p16 expression may help select patients most likely to benefit from CDK4/6 inhibition in ovarian cancer. Clin Cancer Res; 17(6); 1591–602. ©2011 AACR.

The National Cancer Database report on advanced-stage epithelial ovarian cancer: Impact of hospital surgical case volume on overall survival and surgical treatment paradigm

OBJECTIVE To examine the effect of hospital procedure volume and other prognostic variables on overall survival outcome and likelihood of receiving standard recommended care among patients with advanced-stage epithelial ovarian cancer. METHODS The National Cancer Data Base (NCDB) was searched for patients undergoing primary treatment for FIGO Stage IIIC/IV epithelial ovarian cancer from 1996 to 2005. The average annual surgical procedure volume was derived for each reporting hospital. Quartile ranking discriminated four groups of hospitals based on annual surgical volume: low (<9), intermediate (9-20), high (21-35), and very high (>35). Cox proportional hazards modeling was used to determine the impact on overall survival of hospital surgical volume adjusted for treatment, FIGO/AJCC stage, ethnicity, age, payer status, household income, and tumor grade. Binomial multivariate logistic regression modeling was used to assess differences in patient demographic, tumor, and treatment variables between high/very high volume hospitals and low/intermediate volume hospitals. RESULTS A total of 45,929 patients were identified. After adjusting for other factors, overall survival was significantly correlated with hospital case volume: very high (reference); high (HR 0.98, 95% CI=0.92-1.04); intermediate (HR 1.08, 95% CI=1.01-1.15); and low (HR 1.14, 95% CI=1.07-1.22). Compared to low and intermediate volume hospitals, patients treated at very high and high-volume hospitals were less likely to receive neo-adjuvant chemotherapy (OR=0.33, 95% CI=1.18-1.50) or surgery alone (OR=0.77, 95% CI=0.73-0.82) instead of initial surgery and adjuvant chemotherapy. CONCLUSIONS Hospital ovarian cancer surgical volume >or=21 cases/year is associated with a higher likelihood of patients with Stage IIIC/IV epithelial ovarian cancer receiving standard treatment (surgery followed by adjuvant chemotherapy). Even after adjusting for treatment paradigm and other factors, hospital volume >or=21 cases/year was significantly predictive of improved overall survival outcome.