Up date in the management of advanced ovarian carcinoma

Suppression of ARID1A associated with decreased CD8 T cells improves cell survival of ovarian clear cell carcinoma

Objective

AT-rich interactive domain 1A (ARID1A) plays an important role as a tumor suppressor gene in ovarian clear cell carcinoma (OCCC), but the clinical application of ARID1A remains unclear. The aim of this study was to analyze clinicopathological parameters, molecular interactions and immune-infiltration in patients with low ARID1A expression and to provide candidate target drugs.

Methods

We investigated the clinicopathologic parameters, specific gene sets/genes, and immunological relevance according to ARID1A expression in 998 OCCC patients from 12 eligible studies (using meta-analyses); 30 OCCC patients from the Hanyang University Guri Hospital (HYGH) cohort; and 52 OCCC patients from gene set enrichment (GSE) 65986 (25 patients), 63885 (9 patients), and 54809 (6 patients and 12 healthy people) of the Gene Expression Omnibus (GEO). We analyzed network-based pathways based on gene set enrichment analysis (GSEA) and performed in vitro drug screening.

Results

Low ARID1A expression was associated with poor survival in OCCC from the meta-analysis, HYGH cohort and GEO data. In GSEA, low ARID1A expression was related to the tumor invasion process as well as a low immune-infiltration. In silico cytometry showed that CD8 T cells were decreased with low ARID1A expression. In pathway analysis, ARID1A was associated with angiogenic endothelial cell signaling. In vitro drug screening revealed that cabozantinib and bicalutamide effectively inhibited specific hub genes, such as vascular endothelial growth factor-A and androgen receptor, in OCCC cells with low ARID1A expression.

Conclusions

Therapeutic strategies making use of low ARID1A could contribute to better clinical management/research for patients with OCCC.

Patterns of Recurrence and Clinical Outcome of Patients With Stage IIIC to Stage IV Epithelial Ovarian Cancer in Complete Response After Primary Debulking Surgery Plus Chemotherapy or Neoadjuvant Chemotherapy Followed by Interval Debulking Surgery: An Italian Multicenter Retrospective Study

OBJECTIVE

The objective of this retrospective study was to assess the clinical outcome of patients with advanced epithelial ovarian cancer in complete response after primary debulking surgery (PDS) or neoadjuvant chemotherapy followed by interval debulking surgery (IDS]).

METHODS

The authors reviewed the hospital records of 384 patients who underwent PDS (n = 322) or IDS (n = 62) and who were in complete response after primary treatment.

RESULTS

Optimal (residual disease [RD] < 1 cm) and complete (no gross RD) cytoreduction rates were higher after IDS than after PDS (71.0% vs 55.9%; P = 0.001 and 51.6% vs 35.7%, respectively; P = 0.02). Tumor recurred in 73.0% of the 322 complete responders after PDS versus 87.1% of the 62 complete responders after IDS (P = 0.01). The IDS group showed a higher recurrence rate within 6 months (11.3% vs 3.1%: P = 0.01) and a trend to higher recurrence rate between 6 and 12 months (30.6% vs 19.9%). Tumor recurred in 57.4% of the 115 completely cytoreduced patients after PDS versus 87.5% of the 32 completely cytoreduced patients after IDS (P = 0.001). The IDS group showed a trend to higher recurrence rate within 6 months (6.2% vs 1.7%) and a higher recurrence rate between 6 and 12 months (37.5% vs 15.6%; P = 0.01). Two-year, 5-year, and 7-year progression-free survival were 65.8%, 40.8%, and 39.3% for completely cytoreduced patients after PDS versus 43.8%, 12.5%, and 12.5% for completely cytoreduced patients after IDS (P = 0.001); and 2-year, 5-year, and 7-year overall survival were 96.4%, 69.3%, and 50.4% for the former versus 87.1%, 41.8%, and 32.6% for the latter (P = 0.001).

CONCLUSIONS

The clinical outcome of completely cytoreduced patients was significantly better for PDS group than for IDS group, and therefore, the achievement of no gross RD after surgery seemed to have a different prognostic relevance for the 2 groups.

Dieckol, isolated from the edible brown algae Ecklonia cava, induces apoptosis of ovarian cancer cells and inhibits tumor xenograft growth

PURPOSE

Ecklonia cava is an abundant brown alga and has been reported to possess various bioactive compounds having anti-inflammatory effect. However, the anticancer effects of dieckol, a major active compound in E. cava, are poorly understood. In the present study, we investigated the anti-tumor activity of dieckol and its molecular mechanism in ovarian cancer cells and in a xenograft mouse model .

METHODS

MTT assay, PI staining, and PI and Annexin double staining were performed to study cell cytotoxicity, cell cycle distribution, and apoptosis. We also investigated reactive oxygen species (ROS) production and protein expression using flow cytometry and Western blot analysis, respectively. Anti-tumor effects of dieckol were evaluated in SKOV3 tumor xenograft model.

RESULTS

We found that the E. cava extract and its phlorotannins have cytotoxic effects on A2780 and SKOV3 ovarian cancer cells. Dieckol induced the apoptosis of SKOV3 cells and suppressed tumor growth without any significant adverse effect in the SKOV3-bearing mouse model. Dieckol triggered the activation of caspase-8, caspase-9, and caspase-3, and pretreatment with caspase inhibitors neutralized the pro-apoptotic activity of dieckol. Furthermore, treatment with dieckol caused mitochondrial dysfunction and suppressed the levels of anti-apoptotic proteins. We further demonstrated that dieckol induced an increase in intracellular ROS, and the antioxidant N-acetyl-L-cysteine (NAC) significantly reversed the caspase activation, cytochrome c release, Bcl-2 downregulation, and apoptosis that were caused by dieckol. Moreover, dieckol inhibited the activity of AKT and p38, and overexpression of AKT and p38, at least in part, reversed dieckol-induced apoptosis in SKOV3 cells.

CONCLUSION

These data suggest that dieckol suppresses ovarian cancer cell growth by inducing caspase-dependent apoptosis via ROS production and the regulation of AKT and p38 signaling.

Inhibition of PI3K/Akt/mTOR signaling pathway enhances the sensitivity of the SKOV3/DDP ovarian cancer cell line to cisplatin in vitro

The activation of the PI3K/AKT/mTOR pathway plays a key role in ovarian cancer tumorigenesis, progression and chemotherapy resistance. This study aimed to explore the possible mechanism that PI-103, a dual inhibitor of phosphatidylinositide 3-kinase and mTOR, enhances the sensitivity of SKOV3/DDP ovarian cancer cell line to cisplatin chemotherapy. The results showed that PI-103 could significantly increase the sensitivity of SKVO3/DDP cells to cisplatin through inhibiting the activation of PI3K/Akt/mTOR signaling pathway and inducing cell cycle arrest and apoptosis.

Tectorigenin sensitizes paclitaxel-resistant human ovarian cancer cells through downregulation of the Akt and NFκB pathway

Paclitaxel (Taxol) is currently used as the front-line chemotherapeutic agent for several cancers including ovarian carcinoma; however, the drug frequently induces drug resistance through multiple mechanisms. The new strategy of using natural compounds in combination therapies is highly attractive because those compounds may enhance the efficacy of chemotherapy. In this study, we found that tectorigenin, an isoflavonoid isolated from flower of Pueraria thunbergiana, enhanced the growth-inhibitory effect of paclitaxel in paclitaxel-resistant ovarian cancer cells (MPSC1(TR), A2780(TR) and SKOV3(TR)) as well as their naive counterparts. The combination of tectorigenin with paclitaxel resulted in a synergistic apoptosis compared with either agent alone through activation of caspases-3, -8 and -9. Treatment with tectorigenin inhibited the nuclear translocation of NFκB and the expression of NFκB-dependent genes such as FLIP, XIAP, Bcl-2, Bcl-xL and COX-2, which are known to be associated with chemoresistance. In addition, the tectorigenin-paclitaxel combination inhibited the phosphorylation of IκB and IKK and the activation of Akt in paclitaxel-resistant cancer cells. Moreover, tectorigenin-paclitaxel-induced cell growth inhibition was enhanced by pretreatment with the Akt inhibitor LY294002 or overexpression of the dominant negative Akt (Akt-DN), but reduced by overexpression of constitutively activated Akt (Akt-Myr). Furthermore, we found that Akt-Myr, at least in part, reversed tectorigenin-paclitaxel-induced nuclear translocation of NFκB and the phosphorylation of IκB and IKK. These data suggest that tectorigenin could sensitize paclitaxel-resistant human ovarian cancer cells through inactivation of the Akt/IKK/IκB/NFκB signaling pathway, and promise a new intervention to chemosensitize paclitaxel-induced cytotoxicity in ovarian cancer.

Expression of hypoxia-inducible factor 1alpha gene affects the outcome in patients with ovarian cancer

We conducted study to determine whether and how the expression of the hypoxia-inducible factor 1alpha (HIF-1alpha) gene relates to outcome in patients with epithelial ovarian cancer. A total of 66 patients with epithelial ovarian cancer, who underwent primary surgery followed by platinum-based chemotherapy, were entered into this study. We confirmed the expression of HIF-1alpha and the vascular endothelial growth factor (VEGF) by immunohistochemistry. To determine the quantity of HIF-1alpha and VEGF expression, messenger RNA of each gene was measured by real-time reverse transcription-polymerase chain reaction. The cutoff values were determined by the receiver-operating characteristic curve according to survival. The protein expressions of HIF-1alpha and VEGF were strongly observed in the cancer cells. The cutoff value of HIF-1alpha and VEGF gene expression was 6.0 and 3.0, respectively. The expression of HIF-1alpha did not relate to clinical stage, but tumor with low VEGF expression was observed more frequently in stage I patients. The response rate to chemotherapy did not differ between high and low expression of both genes. The overall survival for patients with high expression of HIF-1alpha was significantly lower, but disease-free survival did not differ between high and low expression of HIF-1alpha, whereas both overall and disease-free survival for patients with high expression of VEGF were significantly lower. Multivariate analysis revealed that FIGO stage and HIF-1alpha expression were independent prognostic factors but that VEGF was not. The present study suggested that the expression level of HIF-1alpha could be an independent prognostic factor in epithelial ovarian cancer.

Surveillance procedures for patients treated for epithelial ovarian cancer: a review of the literature

Epithelial ovarian cancer is the leading cause of death from gynecological cancer in the Western countries. Approximately 20%–30% of patients with early-stage disease and 50%–75% of those with advanced disease who obtain a complete response following first-line chemotherapy will ultimately develop recurrent disease, which more frequently involves the pelvis and abdomen. Few formal guidelines exist regarding the surveillance of these patients, and there is no agreement in the literature about the type and timing of examinations to perform. Moreover, the objective of follow-up is unclear as recurrent epithelial ovarian cancer continues to be a therapeutic dilemma and quite all the relapsed patients will eventually die of their disease. The follow-up of asymptomatic patients generally include complete clinical history, serum cancer antigen (CA)125 assay, physical examination, and often ultrasound examination, whereas additional radiologic imaging techniques are usually performed when symptoms or signs appear.18Fluoro-2-deoxy-glucose (18FDG)–positron emission tomography (PET) has a sensitivity of 90% and a specificity of 85% approximately for the detection of recurrent disease, and this examination appears to be particularly useful for the diagnosis of recurrence when CA125 levels are rising and conventional imaging is inconclusive or negative. Recently, technologic advances have led to novel combined18FDG-PET/computed tomography (CT) devices, which perform contemporaneous acquisition of both18FDG-PET and CT images. The role of18FDG-PET/CT for the detection of recurrent ovarian cancer is very promising, and this technique may be especially useful for the selection of patients with late recurrent disease who may benefit from secondary cytoreductive surgery.

Post-operative sequential high-dose chemotherapy with haematopoietic stem cell support as front-line treatment in advanced ovarian cancer: a phase II multicentre study

In spite of multimodal management including aggressive surgery and chemotherapy, the prognosis of advanced ovarian cancer (AOC) remains poor. Multicycle high-dose chemotherapy (HDC) with haematopoietic stem cell (HSC) support has been shown to be a promising procedure in various cancers including AOC. We conducted a phase II multicentre study to evaluate feasibility, toxicity and efficacy of post-operative front-line sequential HDC with HSC support in AOC. Thirty four patients with stage IIIC/IV received a post-operative sequential combination of high-dose cyclophosphamide/epirubicin (D1, D21) with HSC harvesting, high-dose carboplatin (D42, D98) followed by HSC infusion, and dose-dense paclitaxel (D63, D77, D119, D133). Rh-G-CSF (filgrastim) was administered following all cycles. Primary endpoint was pathological complete response rate (pCR). Thirty patients received at least 7 of the scheduled 8 cycles. Haematological toxicity was significant but manageable. Grade 3/4 extra-haematopoietic toxicities were relatively uncommon and reversible. No toxicity-related death was observed. The observed pCR was 37% and did not reach the initial endpoint. Post-operative front-line sequential HDC in AOC is feasible and safe in a multicentre setting. The observed pCR does not support a clear advantage over conventional treatment. This approach remains an experimental strategy to further optimise and validate.

Consolidation and maintenance treatments for patients with advanced epithelial ovarian cancer in complete response after first-line chemotherapy: A review of the literature

Most patients with advanced epithelial ovarian cancer experience objective responses to paclitaxel/platinum-based chemotherapy, but responses are generally short-lived and the clinical outcome is still unsatisfactory. Therefore, the strategy to consolidate and to prolong the duration of response is very attractive. Different consolidation or maintenance treatments have been attempted, such as whole abdomen radiotherapy, intraperitoneal chromic phosphate, radioimmunotherapy, intraperitoneal chemotherapy, high-dose chemotherapy with haematopoietic support, prolonged administration of the first-line regimen, second-line single-agent chemotherapy, and biological agents. Clinical studies have given conflicting, inconclusive, and generally disappointing results. A recent US randomised trial appeared to show that the prolonged administration of single-agent paclitaxel (175 mg/m2 every 3 weeks) significantly improved the progression-free survival of complete responders to paclitaxel/platinum-based chemotherapy. Alternative less toxic, and probably more effective schedules of administration of chemotherapy (i.e. weekly paclitaxel) might assure a better balance between quality of life and anti-tumor activity in patients previously exposed to chemotherapy.

High-dose chemotherapy with autologous haemopoietic support for advanced ovarian cancer in first complete remission: retrospective analysis from the Solid Tumour Registry of the European Group for Blood and Marrow Transplantation (EBMT)

The majority of advanced ovarian cancer patients achieve an objective response following chemotherapy; however, only 20-30% are in remission after 5 years. Intraperitoneal or high-dose chemotherapy (HDC) may prolong disease-free and overall survival (OS) in patients with platinum-sensitive, small volume disease. To better define the subsets of patients who might benefit from HDC, we performed a retrospective analysis on 91 patients in 1st complete remission (CR) treated from 21 centres of the EBMT group. At a median follow-up of 48 months, median time-to-progression (TTP) and OS were 21.2 and 44.4 months, respectively. Tumour grade, stage, residual disease, disease status before HDC, type and year of transplant, source of haemopoietic progenitors and use of haemopoietic growth factors (HGF) after transplant were analysed for TTP and OS. The only significant parameter was the use of HGF: median OS for patients receiving or not receiving HGF was 46.2 vs 17.8 months, respectively (P: 0.035); this difference was maintained after multivariate analysis (P: 0.02). Our analysis does not identify any subgroup of patients in 1st CR who can benefit from HDC; however, median survival of patient with no residual disease has not been reached. The role of HGF after HDC deserves further investigation.

Relationship Between Time Interval From Primary Surgery to the Start of Taxane- Plus Platinum-Based Chemotherapy and Clinical Outcome of Patients With Advanced Epithelial Ovarian Cancer: Results of a Multicenter Retrospective Italian Study

Purpose

To assess whether the interval from primary surgery to the start of taxane- plus platinum-based chemotherapy has any impact on the clinical outcome of advanced ovarian cancer patients.

Patients and Methods

The study was conducted on 313 patients who underwent surgery followed by taxane- plus platinum-based chemotherapy. The median follow-up of survivors was 30.7 months (range, 6 to 109 months).

Results

The 25%, 50%, and 75% quantiles of intervals from surgery to the start of chemotherapy were 11, 21, and 31 days, respectively. After the sixth cycle, 102 patients achieved a pathologic complete response at second-look surgery and 98 obtained a clinical complete response but were not submitted to second-look surgery. Taking into consideration the best assessed response, a complete (either clinical or pathologic) response was found in 200 patients. Residual disease (≤ 1 v > 1 cm; P < .0001) and ascites (absent v present; P = .003) were independent predictive factors for achieving a complete response, whereas residual disease (P = .001) and stage (IIc to III v IV; P = .04) were independent prognostic variables for survival. Conversely, statistical analyses failed to detect significant differences in complete response rates and survival among patients with an interval from surgery to chemotherapy shorter than 11 days, 12 to 21 days, 22 to 31 days, and longer than 31 days.

Conclusion

The interval from surgery to the start of taxane- plus platinum-based chemotherapy seems to have neither a predictive value for response to treatment nor a prognostic relevance for survival of advanced ovarian cancer patients.

A Novel Assay to Assess Primary Human Cancer Infectibility by Replication-Selective Oncolytic Adenoviruses

Purpose: Replication-selective oncolytic adenoviruses hold promise for cancer treatment, but the predictive use of cell lines, dissociated tumor tissue, and animal models for efficacy against primary cancers are unclear. To further evaluate cytotoxicity and the potential for efficacy of replication-competent adenoviruses we therefore developed a novel methodology using primary human cancer specimens ex vivo; ovarian, colon, rectal, and breast carcinomas were included.

Experimental Design: Tissue culture conditions were developed to maintain viability of adenocarcinomas ex vivo for 48 hours postsurgery. Explants were infected by replication-competent (wild type 5 and E1A mutant dl922-947) and replication-defective (dl312) adenoviruses; early (E1A) and late (hexon) viral gene expression, αv integrins, coxsackievirus and adenovirus receptor (CAR) and tissue viability were assessed by immunohistochemistry and histopathology. Viral replication was verified by replication assays on selected samples.

Results: Viral gene expression varied dramatically among cancer specimens (n = 41). With Ad5, hexon expression was high in 8 of 11 tested specimens, whereas E1A levels were detectable in 16 of 27 tumor explants. Viral gene expression, distribution, and cytopathic effects were greater postinfection with dl922-947. Specimens that supported early gene expression (E1A) also supported viral replication in 13 of 14 tested cases, determined by recovery of infectious units. As predicted, the replication-defective adenovirus dl312 was not associated with viral gene expression.

Conclusions: Primary human tumor tissue remained viable when cultured ex vivo enabling evaluation of viral mutants in tissue with intact morphology. This assay may have great use in determining treatment-sensitive cancers and assess specific oncolytic mutants in individual cases.

Second-line therapy of advanced ovarian cancer with GnRH analogs

Ovarian cancer is still the first cause of death among female malignancies. The standard treatment adopted in ovarian cancer is a radical surgical treatment or cytoreduction, followed by six courses of platinum-based chemotherapy; second-line regimens are associated with severe side effects. GnRH analogs could represent an alternative therapeutical approach. The aim of our study was to evaluate the role of GnRH analogs in the management of platinum-resistant ovarian cancers. We enrolled 12 patients affected by advanced ovarian cancer, previously treated with six courses of platinum-paclitaxel. In second-line therapy, we used leuprolide on 1, 8, and 28 days of treatment. CA 125 levels were recorded for each patient. One case of clinical partial response was obtained (8.3%). Stable disease was diagnosed in three patients (25%). Progression was recorded in eight cases (66.7%). Progression-free survival was 6 months. The treatment was well tolerated by patients. The high tolerability and the results obtained with leuprolide versus platinum in second-line therapy might permit a better use of the analogs for advanced ovarian cancer.

The predictive and prognostic value of serum CA 125 half-life during paclitaxel/platinum-based chemotherapy in patients with advanced ovarian carcinoma

OBJECTIVES

Serum CA 125 kinetics during early chemotherapy has a strong predictive and prognostic relevance for patients with advanced ovarian carcinoma who received a first-line platinum-based regimen, whereas the ability of serum CA 125 assay to reflect the response to paclitaxel-based chemotherapy has not yet been defined. The aim of the present paper is to calculate the serum CA 125 half-life during first-line paclitaxel/platinum-based chemotherapy in patients with advanced ovarian carcinoma and to correlate this kinetic parameter with the response to treatment, progression-free survival and overall survival.

METHODS

This retrospective investigation assessed 71 patients with stages IIc-IV ovarian carcinoma who underwent initial surgery followed by paclitaxel/platinum-based chemotherapy and who had serum CA 125 > 35 U/ml before the first cycle of chemotherapy. Only epithelial ovarian cancers were included.

RESULTS

The 25%, 50%, and 75% quantiles of serum CA 125 half-life during early chemotherapy were 10, 14, and 20 days, respectively. Taking the value corresponding to the 50% quantile (i.e., 14 days) as cutoff limit, serum CA 125 half-life was an independent prognostic factor for the chance of achieving a complete response to treatment as well as for progression-free survival and overall survival. In detail, patients with serum antigen half-life <== 14 days had a 3.362 times as great probability to achieve a complete response and a 3.113 times as low probability to die when compared to those with a longer half-life.

CONCLUSIONS

Serum CA 125 assay represents a reliable biochemical tool for the management of advanced ovarian carcinoma patients who receive a first-line paclitaxel/platinum-based chemotherapy.

Pathogenesis of malignant ascites in ovarian cancer patients

Peritonitis carcinomatosa, indicating the presence of malignant cells in the peritoneal cavity, is a well- known complication of malignant disease. The collection of intraperitoneal fluid in a patient with ovarian cancer is most likely due to intraperitoneal spread of disease. The recognition of small quantities of intraperitoneal fluid may have staging and prognostic significance, while symptomatic large collections may reflect end-stage disease, which permits only palliative therapeutic options. In this paper we dis- cussed the pathogenesis of malignant ascites in ovarian cancer patients and suggested potential new treatment approaches.

First-line chemotherapy with epidoxorubicin, paclitaxel, and carboplatin for the treatment of advanced epithelial ovarian cancer patients

OBJECTIVE

A combination of carboplatin (CBDCA) and paclitaxel (TAX) is the standard treatment in advanced ovarian cancer (AOC) patients. Epidoxorubicin (EDX) is an active treatment in AOC and exhibits nonoverlapping toxicities with CBDCA and TAX; moreover, when added to platinum-based chemotherapy, it improves long-term survival. We have therefore conducted a phase II study to evaluate the tolerability and antitumor activity of an EDX/TAX/CBDCA (ETC) triplet in AOC patients.

METHODS

Patients with histologically confirmed suboptimal stage III-IV ovarian cancer who had not previously received cytotoxic drugs were treated with TAX (175 mg/m(2) in a 3-h iv infusion), CBDCA (AUC 6, Calvert formula), and EDX (75 mg/m(2) iv bolus) all given on day 1 every 28 days for a maximum of six courses on an outpatient basis. EDX dosage was chosen after a pilot phase I study.

RESULTS

Fifty-five patients were registered, of whom 5 were determined ineligible bacause of age. Forty-two of the 50 are evaluable for response; 27 (64%) achieved a clinical complete response (CR) and 9 (21%) a partial response (PR) for a response rate of 86% (95% CI 71-94%). Thirty-three patients underwent a secondary debulking procedure after a median of 6 courses (range 2-6). Pathological CR and PR were observed in 9 (27.3%) and 21 (63.6%), respectively; among patients with persistent disease a successful cytoreduction (<1 cm) was obtained in 53.8% of patients. At a median follow up of 35.6 months (range 0-55.5) median progression-free survival is 19.5 months and median overall survival is 36 months. The most common adverse effects were G3-4 leukopenia and thrombocytopenia which occurred in 59 and 37% of patients, respectively.

CONCLUSIONS

The ETC combination given according to the outlined doses and schedule is highly active in AOC patients with poor prognostic factors and deserves further study.

Role of weekly paclitaxel in the treatment of advanced ovarian cancer

Dose-dense weekly administration of paclitaxel has the potential advantage of allowing a larger percentage of cancer cells to enter the vulnerable phase of their cell cycle when cytotoxic paclitaxel concentrations are present. The lower doses and shorter infusion times used with weekly dosing should also minimize bone marrow suppression and other toxicities associated with standard paclitaxel 3-weekly administration. Clinical studies have confirmed that paclitaxel can be safely delivered on a weekly schedule as a 1-h infusion to patients with advanced ovarian cancer. Weekly administration of paclitaxel also appears to be better tolerated than 3-weekly administration. Single-agent weekly paclitaxel is associated with response rates of 20-65%. Combination therapy with weekly paclitaxel has mainly involved carboplatin and response rates with such regimens range from 60-88%. Triple-drug combination therapy has produced response rates of 42-67.5%. Such therapy has included weekly paclitaxel in combination with carboplatin/cisplatin plus topotecan, and carboplatin plus doxorubicin. In an attempt to avoid problems with high corticosteroid doses, dexamethasone doses of 10 and 8 mg have been used successfully in premedication regimens for weekly paclitaxel in ovarian cancer.

Phase I trial of intraperitoneal injection of the E1B-55-kd-gene-deleted adenovirus ONYX-015 (dl1520) given on days 1 through 5 every 3 weeks in patients with recurrent/refractory epithelial ovarian cancer

PURPOSE

Resistance to chemotherapy in ovarian cancer is frequently associated with mutations in the p53 gene. The adenovirus dl1520 (ONYX-015) with the E1B 55-kd gene deleted, allowing selective replication in and lysis of p53-deficient tumor cells, has shown preclinical efficacy against p53-deficient nude mouse-human ovarian carcinomatosis xenografts.

PATIENTS AND METHODS

We undertook a phase I trial of intraperitoneal dl1520 in patients with recurrent ovarian cancer. Sixteen women with recurrent/refractory ovarian cancer received 35 cycles (median, two cycles) of dl1520 delivered on days 1 through 5 in four dose cohorts: 1 x 10(9) plaque forming units (pfu), 1 x 10(10) pfu, 3 x 10(10) pfu, and 1 x 10(11) pfu.

RESULTS

The most common significant toxicities related to virus administration were flu-like symptoms, emesis, and abdominal pain. One patient receiving 1 x 10(10) pfu developed common toxicity criteria grade 3 abdominal pain and diarrhea, which was dose-limiting. The maximum-tolerated dose was not reached at 10(11) pfu, and at this dose level patients did not experience significant toxicity. There was no clear-cut evidence of clinical or radiologic response in any patient. Blood samples were taken for adenovirus DNA and neutralizing antibodies. Polymerase chain reaction data indicating presence of virus up to 10 days after the final (day 5) infusion of dl1520 are suggestive of continuing viral replication.

CONCLUSION

This article therefore describes the first clinical experience with the intraperitoneal delivery of any replication-competent/-selective virus in cancer patients.

An adenovirus encoding proapoptotic Bax induces apoptosis and enhances the radiation effect in human ovarian cancer

Overexpression of proapoptotic Bax favors death in cells resistant to ionizing radiation. We hypothesized that expression of Bax via adenoviral-mediated gene delivery could sensitize radiation-refractory cells to radiotherapy. An inducible Bax recombinant adenovirus (Ad/Bax) had been generated using the Cre/loxp system. Human ovarian cancer cell lines and primary, patient-derived cancer cells from ascites were irradiated and infected with the Ad/Bax and an expression-inducing vector, Ad/Cre. Cell death was evaluated by crystal violet staining, fluorescence-activated cell sorter analysis of Annexin V, and colony formation assay (cell lines only). To further characterize the mechanism of death, cell morphology was examined by nuclear staining with Hoechst 33258. Lastly, to evaluate the capacity of the combined treatment to inhibit tumor growth, mice were injected subcutaneously with ovarian cancer cells exposed to Bax, radiation therapy (RT), or both, and tumor size was measured periodically. Infection of the cancer cell lines and primary cells with both Ad/Bax and Ad/Cre significantly enhanced sensitivity to ionizing radiation, achieving high levels of cell killing in short-term assays. In addition, the combination of Bax and radiotherapy reduced the survival fraction of cell lines 2 logs in standard colony-forming assays. Investigation into the involved mechanism suggests that Bax-mediated radiosensitization occurs through both apoptosis and necrosis pathways. Further, mice subcutaneously injected with ovarian tumor cells previously treated with radiation, or with radiation and irrelevant viruses, consistently developed tumor nodules. In addition, approximately 80% of injections were followed by tumor formation after treatment with Ad/Bax and Ad/Cre alone. In contrast, tumor formation was completely inhibited after combined treatment with Ad/Bax and Ad/Cre and radiation. Augmentation of the effect of radiotherapy on human ovarian cancer cells and primary cancer cells from patients via a recombinant adenovirus encoding Bax is feasible.