Gemcitabine reverses cisplatin resistance: demonstration of activity in platinum- and multidrug-resistant ovarian and peritoneal carcinoma

Chemosensitivity of three patient-derived primary cultures of canine pericardial mesothelioma by single-agent and combination treatment

Introduction

Canine mesothelioma is a rare malignant tumor that mostly affects body cavities, such as the pericardial and pleural cavities. Chemotherapy plays a crucial role in the treatment of canine mesotheliomas. We aimed to compare the antitumor effects of single-agent and combination chemotherapeutic agents on patient-derived primary cultures of canine pericardial mesothelioma established in this study. We planned to generate xenograft models for future studies.

Material and methods

Effusion samples were collected from three dogs with histologically diagnosed pericardial mesothelioma and used for primary culture. Cultured cells were characterized by immunostaining for pan-cytokeratin AE1/AE3, vimentin, Wilms' tumor suppressor gene 1 (WT1), and cytokeratin 5 (CK5). To assess the tumorigenic properties of cells in the effusion and generate a xenograft model, the cell suspension was injected into a severe combined immunodeficient (SCID) mouse either subcutaneously (SC) or intraperitoneally (IP). Lastly, chemosensitivity of established primary cultures against four drugs, doxorubicin, vinorelbine, carboplatin, and gemcitabine, by single-agent treatment as well as combination treatment of carboplatin at a fixed concentration, either 10 or 100 μM, and gemcitabine at different concentrations ranging from 0-1000 μM was assessed by cell viability assay.

Results

Primary cultures were successfully generated and characterized by dual positivity for AE1/AE3 and vimentin and positive staining for WT-1 and CK5, confirming the mesothelial origin of the cells. In the xenograft models, SC mouse developed a subcutaneous mass, whereas IP mouse developed multiple intraperitoneal nodules. The masses were histopathologically consistent with mesotheliomas. The chemosensitivity assay revealed that carboplatin had the highest anti-tumor effects among the four tested single-agent treatments. Furthermore, carboplatin at 100 μM combined with gemcitabine at clinically relevant doses demonstrated the augmented anti-tumor effects compared to single-agent treatment.

Discussion and conclusion

Primary cultures and xenograft models generated in this study could be useful tools for in vitro and in vivo studies of canine mesothelioma. Carboplatin is a highly effective chemotherapeutic agent against canine mesothelioma when used as a sole agent and in combination with gemcitabine.

Combining the SMAC mimetic LCL161 with Gemcitabine plus Cisplatin therapy inhibits and prevents the emergence of multidrug resistance in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly lethal gastrointestinal malignancy that has one of the worst prognoses among solid tumors. The combination of Gemcitabine + Cisplatin (GEM/CIS) remains the standard first-line treatment for advanced stage CCA. However, this drug combination yields only a modest objective response rate, and in cases that initially respond to this treatment, drug resistance commonly rapidly develops. To improve the efficiency of GEM/CIS therapy for CCA, a thorough understanding of the mechanism of GEM/CIS resistance in CCA is required. To that end - in this study, we developed several acquired GEM/CIS-resistant CCA cell lines and we screened those cell lines for acquired vulnerability. The screening process revealed that subset of CCA with GEM/CIS resistance acquired vulnerability to the small-molecule second mitochondrial-derived activator of caspases (SMAC) mimetics LCL161 and Birinapant. The observed acquired vulnerability was found to be associated with upregulation of an inhibitor of apoptosis protein 2 (cIAP2), a known target of SMAC mimetics. LCL161 or cIAP2-shRNA downregulated cIAP2 and restored the sensitivity to GEM/CIS in GEM/CIS-resistant CCA cell lines and in in vivo GEM/CIS-resistant xenograft models. A strong synergic effect was observed when LCL161 was added to GEM/CIS. Interestingly, this synergism was also observed in drug-naïve CCA cell lines, xenografts, and patient-derived organoids. This triplet therapy also prevented the emergence of multidrug-resistant CCA in in vitro and in vivo models. Our findings suggest that activation of cIAP2 allows CCA to escape GEM/CIS, and that suppression of cIAP2 reestablishes the apoptotic profile of CCA, thus restoring its vulnerability to GEM/CIS. The results of this study indicate that combining the SMAC mimetic LCL161 with GEM/CIS inhibits and prevents the emergence of multidrug resistance in CCA.

Comprehensive Network Analysis of Dysregulated Genes Revealed MNX1‐AS1/ hsa‐miR‐4697‐3p/ HOXB13 Axis in OC Chemotherapy Response

Poor chemotherapy response is the main obstacle of ovarian cancer (OC) treatment. Platinum‐refractory and ‐resistant patients are associated with a worse outcome than platinum‐sensitive and partially sensitive patients, but the comprehensive similarities and differences among them are not yet clear. In this study, we analyzed the data of patients with different chemotherapy response in The Cancer Genome Atlas. We found a minority of altered genes were overlapped in refractory and resistant groups, as did the enriched pathways and Gene Ontology terms. We noticed that the neural signaling and drug metabolism enzymes were more significantly enriched and the protein–protein interaction supported these results. The transcription analysis highlighted PDX1 as the common and central transcription factor in both refractory and resistant groups. The competing endogenous RNA (ceRNA) network shared no common ceRNA pairs, indicating a major difference in noncoding RNA post‐transcriptional regulation. In the end, we validated the expression, regulation, binding, and effect on chemotherapy response for selected MNX1‐AS1/hsa‐miR‐4697‐3p/HOXB13 in OC cell lines. Our study offered a novel and comprehensive insight into chemotherapy response, and potential targets for improving chemotherapy response in OC.

Targeted nanomedicine in cisplatin-based cancer therapeutics

Since its license in 1978, cisplatin has proved to be one of the most successful chemotherapeutic agents in the world. However, two acute challenges facing cisplatin, resistance and toxicity, have resulted in a bottleneck of clinical application. Targeted nanomedicine shows great promise in delivering cisplatin for maximizing efficacy while minimizing off-target toxicity. This article surveyed the recent progress and challenges of targeted nanomedicine in managing resistance and toxicity of cisplatin in both fundamental and clinical aspects. Particularly, we focused on three major mechanisms counteracting cisplatin sensitivity (decreased intracellular accumulation, increased cisplatin deactivation, and enhanced DNA repair/translesion synthesis) and correspondingly highlighted a few representative approaches to increase cisplatin sensitivity through improving the intracellular concentration of cisplatin and implementing combination therapy. Moreover, the requirements for future advancements in cisplatin delivery systems are rendered with emphasis on (i) understanding of nano-bio interaction and post-accumulation biological effects instead of overwhelmingly improving tumor accumulation, (ii) development of stimuli-responsive and/or actively-targeted nanomedicines, (iii) optimization of combination therapy, (iv) novel combinations targeting tumor microenvironment and immunotherapy. We postulate that cisplatin-based nanomedicines will continuously advance and potentially revolutionize oncological treatment.

Platinum resistance in gynecologic malignancies: Response, disease free and overall survival are predicted by biochemical signature: A metabolomic analysis

OBJECTIVE

Platinum resistance, defined as the lack of response or relapse within six months of platinum-based chemotherapy, is an important determinant of survival in gynecologic cancer. We used quantitative Mass Spectrometry to identify metabolic signatures that predict platinum resistance in patients receiving chemotherapy for gynecologic cancers.

METHODS

In this study 47 patients with adenocarcinoma of the ovary or uterus who were candidates for carboplatin plus paclitaxel submitted blood for quantitation of metabolites and surgical specimens for the isolation 3-dimensional organoids used to measure individual patient platinum resistance, ex vivo. Results were correlated with response, time to progression and survival.

RESULTS

Of 47 patients, 27 (64.3%) achieved complete remission with a mean time to progression of 1.9 years (± 1.5), disease-free survival of 1.7 years (± 1.4) and overall survival of 2.6 years (± 1.6) and a mean cisplatin lethal concentration 50% (LC50) = 1.15 μg/ml (range 0.4-3.1). Cisplatin LC50's correlated with a non-significant decrease in complete remission (RR [95% CI] =0.76 [0.46-1.27]), diminished disease-free survival (median: 1.15 vs. 2.99 years, p = 0.038) and with biochemical signatures of 186 metabolites. Receiver operating curves (ROC) of lipid ratios, branched chain amino acids and the tryptophan to kynurenine ratio identified patients at the highest risk of relapse and death (AUC = 0.933) with a sensitivity of 92.0% and specificity of 86.0% (p < 0.001).

CONCLUSIONS

Metabolic signatures in gynecologic cancer identify patients at the highest risk of relapse and death offering new diagnostic and prognostic tools for management of the advanced gynecologic tumors.

Phase II trial of cisplatin, gemcitabine and pembrolizumab for platinum-resistant ovarian cancer

OBJECTIVE

To evaluate the combination of pembrolizumab, cisplatin and gemcitabine in recurrent platinum-resistant ovarian cancer.

METHODS

Patients received six cycles of chemotherapy with gemcitabine and cisplatin on day 1 and day 8 of a 21-day treatment cycle. Pembrolizumab was administered on day 1 of cycles 3-6 and as maintenance monotherapy in cycles 7-34. Palliative radiation to a non-target symptomatic lesion was allowed. The primary objective was overall response rate by RECIST 1.1 criteria. Secondary objectives included safety, progression-free survival, time to progression, duration of response and overall survival.

RESULTS

An interim analysis for futility was performed at 18 evaluable patients. Overall response rate was 60%, duration of response was 4.9 months and time to progression was 5.2 months. Progression-free survival at 6 and 12 months was 43% and 5%. Median progression-free survival was 6.2 months and median overall survival was 11.3 months. In all patients, CA125 levels reflected response and progression. There were no pseudoprogression events. After receiving palliative radiation during pembrolizumab maintenance, a patient with recurrent ovarian clear cell carcinoma had an exceptional and durable response that is ongoing for greater than 2 years. After consultation with the sponsor, based on the modest duration of response observed at the interim analysis for futility, the decision was made to close the trial to further accrual.

CONCLUSIONS

The addition of pembrolizumab to cisplatin and gemcitabine did not appear to provide benefit beyond chemotherapy alone in patients with recurrent platinum-resistant ovarian cancer.

The systemic treatment of recurrent ovarian cancer revisited

Treatment approaches for relapsed ovarian cancer have evolved over the past decade from a calendar-based decision tree to a patient-oriented biologically driven algorithm. Nowadays, platinum-based chemotherapy should be offered to all patients with a reasonable chance of responding to this therapy. The treatment-free interval for platinum is only one of many factors affecting patients' eligibility for platinum re-treatment. Bevacizumab increases the response to chemotherapy irrespective of the cytotoxic regimen and can be valuable in patients with an urgent need for symptom relief (e.g. pleural effusion, ascites). For patients with recurrent high-grade ovarian cancer, which responds to platinum-based treatment, maintenance therapy with a poly(ADP-ribose) polymerase inhibitor can be offered, regardless of the BRCA mutation status. Here we review contemporary decision-making processes in the systemic treatment of relapsed ovarian cancer.

Mitochondrial determinants of chemoresistance

Chemoresistance constitute nowadays the major contributor to therapy failure in most cancers. There are main factors that mitigate cell response to therapy, such as target organ, inherent sensitivity to the administered compound, its metabolism, drug efflux and influx or alterations on specific cellular targets, among others. We now know that intrinsic properties of cancer cells, including metabolic features, substantially contribute to chemoresistance. In fact, during the last years, numerous reports indicate that cancer cells resistant to chemotherapy demonstrate significant alterations in mitochondrial metabolism, membrane polarization and mass. Metabolic activity and expression of several mitochondrial proteins are modulated under treatment to cope with stress, making these organelles central players in the development of resistance to therapies. Here, we review the role of mitochondria in chemoresistant cells in terms of metabolic rewiring and function of key mitochondria-related proteins.

Ovarian cancer relapse: From the latest scientific evidence to the best practice

Ovarian cancer (OC) is the fifth most common cause of cancer death in women worldwide. Despite treatment options have continued to improve in recent years, the recurrence rate is still high; in fact around 80% of patients relapses within 18 months. Recently, the scientific landscape is agree in asserting that the ovarian cancer is not a single disease but the outcome of patients depends from the molecular and biological characterization of tumor tissue. In this scenario, molecular targeted therapy given alone or in combination with chemotherapy is showing significant results. We review the different options for the treatment of ovarian cancer recurrence, including the role of surgery, in order to try outlining a possible treatment algorithm evaluating the recent scientific literature and the most important trials.

Phase I/Ib study of olaparib and carboplatin in heavily pretreated recurrent high-grade serous ovarian cancer at low genetic risk

Purpose: To investigate maximum tolerated dose (MTD), activity and predictive biomarkers of olaparib with carboplatin in BRCA wild-type (BRCAwt) high grade serous ovarian carcinoma (HGSOC) patients. Methods: A 3+3 dose escalation study examined olaparib capsules (400 mg twice daily [BID], days 1-7) with carboplatin (AUC3-5 on day 1) every 21 days for 8 cycles, followed by olaparib 400 mg BID maintenance. Blood and tumor biopsy samples were collected pre- and on-treatment in the expansion cohort for PAR levels and proteomic endpoints. Results: 30 patients (median 7 prior regimens [2-12], 63% (19/30) platinum-resistant) were enrolled. Dose-limiting toxicity was thrombocytopenia/neutropenia, and infection with carboplatin AUC5 (2/6 patients). MTD was olaparib 400 mg BID + carboplatin AUC4. Grade 3/4 adverse events (>10%) included neutropenia (23%), thrombocytopenia (20%), and anemia (13%). Five of 25 (20%) evaluable patients had partial response (PR; median 4.5 months [3.3-9.5]). Clinical benefit rate (PR + stable disease ≥4 months) was 64% (16/25). A greater decrease in tissue PAR levels was seen in the clinical benefit group versus no benefit (median normalized linear change -1.84 [-3.39- -0.28] vs 0.51 [-0.27- 1.29], p = 0.001) and a DNA repair score by proteomics did not correlate with response. Conclusions: The olaparib and carboplatin combination is tolerable and has clinical benefit in subsets of heavily pretreated BRCAwt HGSOC, independent of platinum sensitivity.

Trabectedin for reversing platinum resistance and resensitization to platinum in patients with recurrent ovarian cancer

Aims: We evaluated trabectedin in patients with platinum-resistant/refractory and partially platinum-sensitive recurrent ovarian cancer and the outcomes after reintroduction of platinum. Methods: Twenty-seven patients (platinum-resistant/refractory n = 24/PPS; n = 3) treated with trabectedin were retrospectively analyzed. Results: Trabectedin resulted in an objective response rate (ORR) of 18.2% with a 59.1% of disease control rate (ORR plus stable disease). The median progression-free and overall survival were 3.0 and 21.3 months, respectively. Subsequently, 17 patients were retreated with platinum and yield an ORR of 41.2% and DCR of 47.0%. The median progression-free and overall survival after platinum rechallenge were 5.0 and 14.7 months, respectively. Conclusion: Our results suggest that trabectedin may contribute to resensitize tumor cells to platinum rechallenge.

Metastatic gynecologic malignancies: advances in treatment and management

Gynecologic cancers comprise of mostly uterine, ovarian, and cervical malignancies and are responsible for 95,000 new cases annually in the United States. Uterine cancer is the most common and the number of new cases and mortality has been increasing. Cervical cancer has decreased due to screening, early detection, and treatment of pre-invasive cancers. However, ovarian cancer remains the most lethal because of advanced stage at diagnosis and drug resistance. The metastatic spread pattern differs amongst these cancers, with uterine and cervical cancer found mostly in the primary organ and ovarian cancer disseminating throughout the peritoneum and upper abdomen at presentation. The primary treatment of ovarian cancer typically involves surgery followed by systemic therapy for more advanced disease. Previously, systemic chemotherapy with platinums, taxanes, doxorubicin, topotecan, and gemcitabine has been the standard in either upfront or recurrent setting. With molecular and genetic breakthroughs, we now have over eight new indications and five novel biologic therapies including antiangiogenics, poly ADP ribose polymerase inhibitors, and immunotherapies approved over the last 3 years. In this review, we will examine the biology of gynecologic cancer metastasis and focus on new treatment options for these cancers with a focus on ovarian cancer.

A retrospective evaluation of activity of gemcitabine/platinum regimens in the treatment of recurrent ovarian cancer

BACKGROUND

While many of these agents have been compared in prospective clinical trials, the gemcitabine/platinumbased regimens have not been compared in a prospective, randomized clinical trial. While bothgemcitabine/carboplatin and gemcitabine/cisplatin have a similar ORR in separate clinical trials, the tworegimens have never been directly been compared. With overlapping dose-limiting toxicity of thrombocytopenia, the gemcitabine/carboplatin regimen has been challenging to employ in the clinical setting in previously treated ovarian cancer patients and is often associated with treatment delays and/or dose reductions. Gemcitabine/cisplatin can also be a challenge due to its dose limiting neuropathy and renal toxicity, especially in previously treated patients. In the absence of any prospective, head to head comparison this retrospective study was embarked upon to compare the response rate and toxicity profiles of gemcitabine/cisplatin verses gemcitabine/carboplatin for the treatment of platinum-sensitive verses platinum-resistant recurrent ovarian cancer.

METHODS

This was a retrospective chart review study that identified patients that had received either gemcitabine/cisplatin or gemcitabine/carboplatin for treatment of recurrent ovarian cancer and compared documented hematological and non-hematological toxicity and response based on RECIST (v1.1). Data was evaluated based upon platinum sensitivity/resistance as well.

RESULTS

A total of 93 patients were identified that had received a gemcitabine/platinum regimen with 48 with recurrent ovarian cancer that were included in the study. There were 21 patients in the gemcitabine/cisplatin arm and 27 patients identified in the gemcitabine/carboplatin arm. Objective response rate (ORR) was greater in platinum-sensitive patients that received gemcitabine/carboplatin compared to gemcitabine/cisplatin (8 (67%) vs 2 (25%), p < 0.05). Conversely, ORR was greater in platinum-resistant patients treated with gemcitabine/cisplatin (4 (57%) vs 1 (25%), NS). Mean time to progression was greater in gemcitabine/cisplatin patients (7.2 vs 5.1 months, p < 0.03). Patients treated with gemcitabine/carboplatin discontinued due to toxicity at a greater rate (8 (33%) vs 5 (24%)). Specifically gemcitabine/carboplatin had a greater incidence (85%) of grade 2 or greater leukopenia, thrombocytopenia, and neutropenia compared to gemcitabine/cisplatin (19%) However, there was no significant difference in dose reductions, treatment delays, or granulocyte-colony stimulating factor (G-CSF) administration between regimens.

CONCLUSIONS

Gemcitabine/cisplatin appears to have greater efficacy in platinum-resistant patients, while gemcitabine/carboplatin seems to have greater efficacy in platinum-sensitive patients. Overall, gemcitabine/carboplatin was associated with a greater incidence of myelosuppression and discontinuation due to toxicity. Similar to findings in endometrial cancer, gemcitabine/cisplatin may have benefit specifically in platinum-resistant ovarian cancer.

Effects of sequential paclitaxel-carboplatin followed by gemcitabine-based chemotherapy compared with paclitaxel-carboplatin therapy administered to patients with advanced epithelial ovarian cancer: A retrospective, STROBE-compliant study

We aimed to compare the efficacy of paclitaxel and carboplatin followed by gemcitabine-based combination chemotherapy with paclitaxel-carboplatin for treating advanced epithelial ovarian cancer in this retrospective, STROBE-compliant study. Patients' tolerance to treatment was also assessed.We retrospectively analyzed the records of 178 women who underwent initial optimal debulking surgery between January 2003 and December 2011 to treat FIGO stage IIIc epithelial ovarian cancer. Patients in arm 1 (n = 88) received 4 cycles of paclitaxel and carboplatin followed by 2 to 4 cycles of gemcitabine-based combination chemotherapy. Patients in arm 2 (n = 90) received 6 to 8 cycles of paclitaxel and carboplatin. The granulocyte-colony stimulating factor was administered prophylactically to all patients.The median follow-up for both arms was 62 months. Medianprogression-free survival (PFS) between arms 1 and 2 (28 and 19 months [P = 0.003]) as well as 5-year OS (34.1% and 18.9% [P = 0.021]) differed significantly. The neurotoxicity rate was significantly higher in arm 2 than in arm 1 (45.2% vs 27.1%, P = 0.026). There was no significant difference between study arms in hematological toxicity.The sequential regimen significantly improved PFS and 5-year OS with tolerable toxicity compared with the single regimen, and offers an alternative for treating patients with advanced epithelial ovarian cancer.

Gemcitabine, navelbine, and doxorubicin as treatment for patients with refractory or relapsed T-cell lymphoma

T-cell lymphoma (TCL) is resistant to conventional chemotherapy. We retrospectively evaluated the therapeutic efficiency and toxicity of gemcitabine, navelbine, and doxorubicin (GND) in patients with refractory or relapsed TCL. From 2002 to 2012, 69 patients with refractory or relapsed TCL received GND treatment in our hospital. The treatment protocol comprised gemcitabine (800 mg/m², group 1; 1000 mg/m², group 2) on days 1 and 8, navelbine (25 mg/m²) on day 1, and doxorubicin (20 mg/m²) on day 1, repeated every 3 weeks. The overall response rate (ORR) was 65.2%. The median overall survival (OS) was 36 months. The 5-year estimated OS rate was 32.4%. The GND regimen was well tolerated. Subgroup analysis demonstrated that the ORR and CR for group 1 were similar. A longer median OS was observed for group 1. Significant difference in grades 3-4 toxicities was observed between groups 1 and 2 (P = 0.035). Our study indicated that gemcitabine (800 mg/m²) on days 1 and 8 every 21 days was favorable for pretreated TCL patients.

Defective hCNT1 transport contributes to gemcitabine chemoresistance in ovarian cancer subtypes: overcoming transport defects using a nanoparticle approach

Nucleoside analogs are used as chemotherapeutic options for the treatment of platinum-resistant ovarian cancers. Human concentrative nucleoside transporter 1 (hCNT1) is implicated in sensitizing solid tumors to nucleoside analogs although its role in determining drug efficacy in ovarian cancers remains unclear. Here we examined the functional expression of hCNT1 and compared its contributions toward gemcitabine efficacy in histological subtypes of ovarian cancer. Radioactivity analysis identified hCNT1-mediated (3)H-gemcitabine transport in ovarian cancer cells to be significantly reduced compared with that of normal ovarian surface epithelial cells. Biochemical and immunocytochemical analysis identified that unlike normal ovarian cells which expressed high levels of hCNT1 at the apical cell surface, the transporter was either diminished in expression and/or mislocalized in cell lines of various subtypes of ovarian cancer. Retroviral expression of hCNT1 selectively rescued gemcitabine transport in cell lines representing serous, teratocarcinoma, and endometrioid subtypes, but not clear cell carcinoma (CCC). In addition, exogenous hCNT1 predominantly accumulated in intracytoplasmic vesicles in CCC suggesting defective cellular trafficking of hCNT1 as a contributing factor to transport deficiency. Despite diminution of hCNT1 transport in the majority of ovarian cancers and apparent trafficking defects with CCC, the chemotherapeutic efficacy of gemcitabine was broadly enhanced in all subtypes when delivered via engineered nanoparticles (NPs). Additionally, by bypassing the transport requirement, the delivery of a gemcitabine-cisplatin combination in NP formulation increased their synergistic interactions. These findings uncover hCNT1 as a putative determinant for nucleoside analog chemoresistance in ovarian cancer and may help rationalize drug selection and delivery strategies for various histological subtypes of ovarian cancer.

Treatment options in recurrent ovarian cancer: latest evidence and clinical potential

Ovarian cancer (OC) is the fifth most common cause of cancer death in women. Although significant progress has been made in the treatment of OC, the majority of patients experience disease recurrence and receive second-line and sometimes several lines of treatment. Here we review the options available for the treatment of recurrent disease and discuss how different agents are selected, combined and offered in a rationale sequence in the context of multidisciplinary care. We reviewed published work between 1990 and 2013 and meeting abstracts related to the use of chemotherapy and surgery in patients with recurrent ovarian cancer. We discuss treatment regimens, efficacy endpoints and safety profiles of the different therapies. Platinum-based drugs are the most active agents and are selected on the basis of a probability of response to retreatment. Nonplatinum-based chemotherapy regimens are usually given in the 'platinum-resistant' setting and have a modest effect on outcome. Molecular targeted therapy of ovarian cancer given alone or integrated with chemotherapy is showing promising results. Many patients are now receiving more than one line of therapy for recurrent disease, usually platinum based until platinum resistance emerges. The sequential use of chemotherapy regimens and the incorporation of molecularly targeted treatments, either alone or in combination with chemotherapy, have over the last decade significantly extended the median survival of patients with ovarian cancer.

Prognostic impact of human leukocyte antigen class I expression and association of platinum resistance with immunologic profiles in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is one of the most deadly carcinomas in females. Immune systems can recognize EOCs; however, a defect of human leukocyte antigen (HLA) class I expression is known to be a major mechanism for escape from immune systems, resulting in poor prognosis. The purpose of this study is to identify novel correlations between immunologic responses and other clinical factors. We investigated the expression of immunologic components in 122 cases of EOCs for which surgical operations were performed between 2001 and 2011. We immunohistochemically stained EOC specimens using an anti-pan HLA class I monoclonal antibody (EMR8-5) and anti-CD3, -CD4, and -CD8 antibodies, and we analyzed correlations between immunologic parameters and clinical factors. In multivariate analysis that used the Cox proportional hazards model, independent prognostic factors for overall survival in advanced EOCs included low expression level of HLA class I [risk ratio (RR), 1.97; 95% confidence interval (CI), 1.01-3.83; P = 0.046] and loss of intraepithelial cytotoxic T lymphocyte (CTL) infiltration (RR, 2.11; 95% CI, 1.06-4.20; P = 0.033). Interestingly, almost all platinum-resistant cases showed a significantly low rate of intraepithelial CTL infiltration in the χ(2) test (positive vs. negative: 9.0% vs. 97.7%; P < 0.001). Results from a logistic regression model revealed that low CTL infiltration rate was an independent factor of platinum resistance in multivariate analysis (OR, 3.77; 95% CI, 1.08-13.12; P = 0.037). Platinum-resistant EOCs show poor immunologic responses. The immune escape system of EOCs may be one of the mechanisms of platinum resistance.

A phase II study of gemcitabine, carboplatin and bevacizumab for the treatment of platinum-sensitive recurrent ovarian cancer

PURPOSE

The doublet gemcitabine and carboplatin is effective for the treatment of recurrent ovarian cancer, while multi-agent chemotherapy with bevacizumab may add additional benefit. This phase II study tested the efficacy and safety of a biweekly gemcitabine, carboplatin, and bevacizumab combination in patients with platinum-sensitive recurrent ovarian, peritoneal, or tubal cancer (ROC).

PATIENTS AND METHODS

Eligible patients received concurrent gemcitabine 1000 mg/m(2), carboplatin area under the curve 3, and bevacizumab 10 mg/kg administered intravenously on days 1 and 15 every 28 days for six cycles or up to 24 cycles if clinical benefit occurred. The primary end points were progression-free survival (PFS) by RECIST, and safety; the secondary end points were objective response rates and overall survival.

RESULTS

Overall, 45 patients were enrolled. The median PFS was 13.3 months (95% CI, 11.3 to 15.3). The objective response rate was 69%. Grade 4 hematologic toxicities included neutropenia (27%) and thrombocytopenia (2%). Grades 3 and 4 non-hematologic toxicities included fatigue (18%), pain (9%), and nausea/vomiting (4%). There were 2 episodes of cerebrovascular accidents, 2 noted DVTs, and no episodes of bowel perforation. Median OS was 36.1 months (95% CI, 26.7 to 45.5).

CONCLUSION

Biweekly gemcitabine, carboplatin, and bevacizumab were an effective regimen in recurrent ovarian cancer, with comparable toxicity to recently reported day 1 gemcitabine, carboplatin, bevacizumab, and day 8 gemcitabine. Response rate and PFS are improved from reported outcomes of the gemcitabine carboplatin doublet. The degree to which biweekly dosing may present a more rationale schedule for this triplet should be evaluated further.

Gemcitabine as a molecular targeting agent that blocks the Akt cascade in platinum-resistant ovarian cancer

BACKGROUND

Gemcitabine (2', 2' -difluorodeoxycytidine) is one of many nonplatinum drugs that exhibit activity in recurrent, platinum-resistant ovarian cancer. However, the molecular mechanisms by which Gemcitabine treatment inhibits the proliferation of platinum-resistant ovarian cancer cells still remain unclear. We investigated whether Gemcitabine increases the efficacy of Cisplatin in platinum-resistant ovarian cancer models in vitro and in vivo.

METHODS

We used Cisplatin-resistant Caov-3 cells, A2780CP cells and Cisplatin-sensitive A2780 cells to examine the sensitivity of the cell viability of Cisplatin and Gemcitabine using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and the sensitivity of the invasive activity of Cisplatin and Gemcitabine using an invasion assay with Matrigel. We examined the Akt kinase activity and matrix metalloproteinase 9 (MMP9) expression following Cisplatin and Gemcitabine treatment using a Western blot analysis and the mRNA expression of vascular endothelial growth factor (VEGF) using semi-quantitative RT-PCR. Moreover, we evaluated the effects of Cisplatin and Gemcitabine on the intra-abdominal dissemination of ovarian cancer in vivo.

RESULTS

Gemcitabine significantly inhibited Cisplatin-induced Akt activation in the Caov-3 and A2780CP cells, but not in the A2780 cells. In the presence of Gemcitabine, Cisplatin-induced growth inhibition and apoptosis were significantly enhanced in the Caov-3 and A2780CP cells. Co-treatment with Cisplatin and Gemcitabine almost completely inhibited invasion of both types of cells through the Matrigel; however, neither Cisplatin nor Gemcitabine alone inhibited the invasion of both types of cells. Gemcitabine inhibited not only the Cisplatin-induced activation of Akt, but also the MMP9 and mRNA expression of VEGF. Moreover, treatment with Gemcitabine increased the efficacy of Cisplatin-induced growth inhibition of the intra-abdominal dissemination and production of ascites in the athymic nude mice inoculated with Caov-3 cells.

CONCLUSIONS

We herein demonstrated that Gemcitabine inhibits the Akt kinase activity and angiogenetic activity following treatment with Cisplatin in platinum-resistant ovarian cancer cells. These results provide a rationale for using Gemcitabine in clinical regimens containing molecular targeting agents against platinum-resistant ovarian cancers.

The safety and efficacy of cisplatin plus gemcitabine in recurrent ovarian cancer

BACKGROUND

The activity and synergy for the combination treatment of cisplatin and gemcitabine has been identified in a variety of human tumor cells, including ovarian cancer cells, and has been widely approved for the treatment of non-small cell lung cancer, pancreatic cancer and biliary tract cancer. As the gastrointestinal symptoms with cisplatin therapy are commonly considered to negatively affect the quality of life of patients more than those experienced with carboplatin therapy, carboplatin is generally preferred over cisplatin in combination therapy. This study evaluated the safety and efficacy of cisplatin plus gemcitabine in patients with recurrent ovarian cancer.

METHODS

Patients with recurrent ovarian, peritoneal or fallopian tube cancer, who had failed with multiple other chemotherapy agents, including platinum, received cisplatin (30 mg/m(2)) plus gemcitabine (750 mg/m(2)) on days 1 and 8 of every 28 days for between 1 and 4 cycles.

RESULTS

In total, 18 patients were treated with cisplatin and gemcitabine between 2006 and 2011. There were 1 complete and 5 partial responses, producing an overall response rate of 33.4 %. Median overall survival was 11.0 months. Grade 4 neutropenia and thrombocytopenia were seen in 11.1 and 22.2 % of patients, respectively. Non-hematological toxicity was less than Grade 1.

CONCLUSIONS

Non-hematological toxicity with combined cisplatin and gemcitabine therapy was considered tolerable and did not impede patient quality of life. However, this drug combination should be monitored for hematologic toxicity.

Complete remission of platinum-refractory primary Fallopian tube carcinoma with third-line gemcitabine plus cisplatin: A case report and review of the literature

Primary Fallopian tube carcinoma (PFTC) is a rare but highly aggressive disease. Currently, treatments are similar to those used in epithelial ovarian carcinoma (EOC), however, there are distinct differences between the two diseases. PFTC tends to recur in the retroperitoneal nodes and distant sites more often than EOC. Limited literature with regard to effective agents in platinum-resistant and -refractory (Pt-R) disease exists, particularly after two lines of consecutive treatment. In this case report, a 47-year-old female with PFTC exhibited recurrence in the liver after postoperative chemotherapy. The patient received paclitaxel and cisplatin combination as first-line chemotherapy and topotecan as a second-line treatment, which is considered platinum-refractory. After the second-line treatment failed, this patient received a gemcitabine plus cisplatin combination as third-line chemotherapy for a total of 6 cycles. The liver metastases regressed rapidly and completely. The patient's progression-free survival (PFS) was 10 months and overall survival (OS) was 45 months. In conclusion, gemcitabine and cisplatin combination is an effective regimen for refractory PFTC even after the failure of two previous lines of consecutive chemotherapy and this warrants further independent investigation.

Role of gemcitabine in the treatment of ovarian cancer

The US FDA has recently approved the combination of carboplatin and gemcitabine as a second-line therapy for recurrent platinum-sensitive ovarian cancer. This article briefly reviews the pharmacokinetics and mechanism of action of gemcitabine and its synergistic effect with platinum. An overview of the literature on the role of gemcitabine in the treatment of epithelial ovarian cancer is also presented.

Evidence for different mechanisms of 'unhooking' for melphalan and cisplatin-induced DNA interstrand cross-links in vitro and in clinical acquired resistant tumour samples

Background

DNA interstrand cross-links (ICLs) are critical lesions produced by several cancer chemotherapy agents including platinum drugs and nitrogen mustards. We have previously shown in haematological (multiple myeloma) and solid tumours (ovarian cancer) that clinical sensitivity to such agents can result from a defect in DNA ICL processing leading to their persistence. Conversely, enhanced repair can result in clinical acquired resistance following chemotherapy. The repair of ICLs is complex but it is assumed that the ‘unhooking’ step is common to all ICLs.

Methods

Using a modification of the single cell gel electrophoresis (Comet) assay we measured the formation and unhooking of melphalan and cisplatin-induced ICLs in cell lines and clinical samples. DNA damage response in the form of γ-H2AX foci formation and the formation of RAD51 foci as a marker of homologous recombination were also determined. Real-time PCR of 84 genes involved in DNA damage signalling pathways was also examined pre- and post-treatment.

Results

Plasma cells from multiple myeloma patients known to be clinically resistant to melphalan showed significant unhooking of melphalan-induced ICLs at 48 hours, but did not unhook cisplatin-induced ICLs. In ovarian cancer cells obtained from patients following platinum-based chemotherapy, unhooking of cisplatin-induced ICLs was observed at 48 hours, but no unhooking of melphalan-induced ICLs. In vitro, A549 cells were proficient at unhooking both melphalan and cisplatin-induced ICLs. γ-H2AX foci formation closely followed the formation of ICLs for both drugs, and rapidly declined following the peak of formation. RPMI8226 cells unhooked melphalan, but not cisplatin-induced ICLs. In these cells, although cross-links form with cisplatin, the γ-H2AX response is weak. In A549 cells, addition of 3nM gemcitabine resulted in complete inhibition of cisplatin-induced ICL unhooking but no effect on repair of melphalan ICLs. The RAD51 foci response was both drug and cell line specific. Real time PCR studies highlighted differences in the damage response to melphalan and cisplatin following equi-ICL forming doses.

Conclusions

These data suggest that the mechanisms by which melphalan and cisplatin-induced ICLs are ‘unhooked’ in vitro are distinct, and the mechanisms of clinical acquired resistance involving repair of ICLs, are drug specific.

Vosaroxin : a novel antineoplastic quinolone

INTRODUCTION

The antineoplastic quinolone derivative vosaroxin (SNS-595, Sunesis, South San Francisco, CA, USA) was first described in 2002. It represents a novel class of anticancer drugs and is currently in a Phase III clinical trial for relapsed and refractory acute myeloid leukemia (AML). AML is the most common form of acute leukemia in adults and is increasing in incidence due to the aging of the American population. Despite advances in diagnosis, prognostic prediction, and treatment in younger age groups, there has been little improvement in survival among patients over 60 years of age, who make up the majority of those affected.

AREAS COVERED

The development of vosaroxin, its mechanism of action, pharmacology, and metabolism, and the preclinical and clinical data to date will be covered.

EXPERT OPINION

Despite its structural dissimilarity, vosaroxin has mechanisms of action similar to the anthracyclines and anthracenediones already in use for the treatment of AML. However, unlike these agents, vosaroxin is not a P-gp substrate, appears to be unaffected by overexpression of P-gp or TP53 mutations, and may be useful in the treatment of AML, especially in the elderly.

Feasibility of intravenous gemcitabine and an intraperitoneal platinum agent in the treatment of ovarian cancer

The goal of this study is to determine the feasibility of intravenous gemcitabine and an intraperitoneal platinum agent in the treatment of patients with ovarian cancer. We performed a retrospective chart review of patients with primary, persistent or recurrent ovarian cancer, who received intravenous gemcitabine and an intraperitoneal platinum agent. Patients received gemcitabine (750 mg/m²) intravenous on days 1 and 8 and cisplatin (100 or 60 mg/m²) intraperitoneal on day 1 every 21 - 28 days. An alternate regimen was composed of gemcitabine (750 mg/m²) intravenous and carboplatin (AUC 5) intraperitoneal on day 1 every 21 days. Dose reductions occurred at the discretion of the prescribing physician.Intravenous gemcitabine and an intraperitoneal platinum agent were administered to 12 patients with advanced primary or recurrent ovarian cancer. Myelosuppression was the most common toxicity. Grade 3 or 4 thrombocytopenia, neutropenia and anemia occurred in 7, 8 and 2 patients respectively. Dose reductions were required in 7 of 12 patients. 10 of 12 patients received 6 cycles of the regimen. Treatment was discontinued prior to 6 cycles in 2 of 12 patients secondary to progression in one case and to grade 4 neutropenia and thrombocytopenia in another.The combination of intravenous gemcitabine and an intraperitoneal platinum agent appears to be a feasible regimen in patients with ovarian cancer. The most common toxicity was myelosuppression, which resulted in dose reductions in almost half of the patients.

Combination of gemcitabine and cisplatin is highly active in women with endometrial carcinoma: results of a prospective phase 2 trial

BACKGROUND

The treatment of patients with advanced or recurrent endometrial cancer remains problematic, because chemotherapy and hormonal therapy have yielded low response rates and limited progression-free survival. Because the combination of gemcitabine and cisplatin demonstrated synergism in preclinical studies, the authors attempted to determine the efficacy and toxicity of this combination in women with advanced or recurrent endometrial cancer.

METHODS

A prospective, single-institution, phase 2 study was performed in women with histologically documented International Federation of Gynecology and Obstetrics (FIGO) stage III or IV or recurrent endometrioid endometrial carcinoma. Gemcitabine at a dose of 1000 mg/m2 and cisplatin at a dose of 35 mg/m2 were administered intravenously on Days 1 and 8 of each 21-day cycle; because of myelosuppression, the protocol was revised to gemcitabine at a dose of 900 mg/m2 and cisplatin at a dose of 30 mg/m2. Patients were treated until disease progression, unacceptable toxicity, or complete response.

RESULTS

A total of 21 patients were enrolled and received a median of 5 courses of therapy (range, 1-9 courses). The median age at the time of study enrollment was 62 years (range, 41-75 years). Of 20 evaluable patients, 2 (10%) had a confirmed complete response, 8 (40%) had a partial response, 6 (30%) had stable disease, and 4 (20%) developed progressive disease. The median progression-free survival was 7.5 months (range, 2.3-33.6 months), and the median overall survival was 18.2 months (range, 2.5-49.4 months). The development of toxicity mandated dose reductions in 16 of 20 patients (80%). Eighteen patients experienced grade 3 or 4 toxic effects (graded according to the Common Terminology Criteria for Adverse Events [version 3.0]).

CONCLUSIONS

The objective response rate of 50% noted with gemcitabine and cisplatin combination chemotherapy merits the further development of this regimen in women with advanced or recurrent endometrial cancer.

Clinical trials and progress with paclitaxel in ovarian cancer

Paclitaxel is a front-line agent for ovarian cancer chemotherapy, along with the platinum agents. Derived from the Pacific yew tree, Taxus brevifolia, paclitaxel has covered significant ground from the initial discovery of its antineoplastic properties to clinical applications in many forms of human cancers, including ovarian cancer. Although much has been published about the unique mechanism of action of this agent, several issues remain to be resolved. Finding the appropriate dosage schedule for paclitaxel in chemo-naïve and recurrent ovarian cancer, defining the role of paclitaxel in maintenance chemotherapy, and elucidating the mechanisms of taxane resistance are areas of intense research. Newer forms of taxanes are being manufactured to avoid troublesome adverse effects and to improve clinical efficacy. These issues are reviewed in detail in this paper with an emphasis on clinically relevant evidence-based information.

Inhibition of carboplatin-induced DNA interstrand cross-link repair by gemcitabine in patients receiving these drugs for platinum-resistant ovarian cancer

BACKGROUND

The potential of gemcitabine to interact with carboplatin was explored in a phase II trial in platinum-resistant ovarian cancer. Peripheral blood lymphocytes were sampled after drug administration to measure DNA interstrand cross-link formation and repair.

PATIENTS AND METHODS

Forty patients received carboplatin target area under concentration-time curve (AUC 4) followed by gemcitabine 1,000 mg/m(2) with a second dose of gemcitabine on day 8. Peripheral blood lymphocytes were obtained in 12 patients before and at intervals during the first cycle of chemotherapy. DNA cross-link formation and repair (unhooking) were measured by the single-cell gel electrophoresis (comet) assay following ex vivo incubation.

RESULTS

The global response rate was 47% (Response Evaluation Criteria in Solid Tumors rate, 29%; CA125 rate, 63%). Delays in treatment were seen in 24% of cycles largely due to myelosuppression; 15% of day 8 administration was omitted. Peak carboplatin-induced DNA cross-linking was seen by 24 hours. Significant reduction was seen in the repair of in vivo carboplatin-induced DNA cross-links following administration of gemcitabine.

CONCLUSION

An enhanced activity of carboplatin in platinum-resistant ovarian cancer may be due to synergy with gemcitabine through inhibition of repair of DNA cross-links. Future studies should explore coadministration of these drugs, as this may be a more effective schedule.

The combination of monthly carboplatin and weekly paclitaxel is highly active for the treatment of recurrent ovarian cancer

OBJECTIVES

To evaluate the response rate and toxicity of a regimen comprised of monthly carboplatin and weekly paclitaxel for recurrent ovarian cancer.

METHODS

We performed a retrospective chart review of patients with recurrent ovarian cancer treated between 2001 and 2006 at a single institution with carboplatin AUC 5 (day 1), and paclitaxel 80 mg/m(2) (days 1, 8, 15) of a 28-day cycle. Primary endpoints were response rate, progression-free survival and overall survival.

RESULTS

Twenty patients were treated with this regimen from 2001 to 2006. Stage ranged from stages IC to IV. All received intravenous platinum and taxane as their initial therapy. Histologic subtypes included papillary serous (17), carcinosarcoma (1), and clear cell (2). The median number of prior regimens was 1 (range 1-3). The overall response rate was 85.0% (15 complete responses, 2 partial responses). Patients with tumors categorized as platinum sensitive had a response rate of 93.3% (14/15) and those with tumors deemed platinum resistant had a response rate of 60.0% (3/5). The median survival has not yet been reached after a median follow-up of 28 months. Neutropenia was the only grade 3/4 toxicity, occurring in 7 patients (35.0%). Platinum hypersensitivity reactions occurred in 5 patients (25.0%) who all successfully continued treatment using a carboplatin desensitization protocol.

CONCLUSIONS

A monthly carboplatin and weekly paclitaxel regimen is highly active for women with recurrent platinum-sensitive and platinum-resistant epithelial ovarian cancer. The regimen is well tolerated. This pilot series demonstrates the potential for this regimen as treatment of choice among doublet first salvage regimens for patients with recurrent epithelial ovarian cancer, thus warranting multi-institutional study.

Treatment of recurrent epithelial ovarian cancer

Epidemiologic analysis reveals that the mortality rate from ovarian cancer is continuously decreasing due to the improvement of surgery and chemotherapy. However, the prognosis of ovarian cancer patients is still unsatisfactory overall considering that only 30% of patients are alive after five years. In fact, although surgery and first-line systemic chemotherapy induces complete and partial response in up to 80% of patients with about a 25% pathological complete remission rate, recurrences occur in the majority of patients. The role of surgery in recurrent disease has been recently studied and many patients can receive an optimal secondary cytoreduction. Most of the recurrent patients are subject to a number of treatment regimens that, although palliative in nature, are also able to prolong survival. Important results have been obtained in particular in platinum-sensitive recurrent disease where a platinum-based chemotherapy is able to prolong progression-free survival and overall survival. Overall, our armamentarium for the treatment of progressive or recurrent ovarian cancer is significantly richer than in the past, and in many patients it is possible to achieve our goal of controlling the chronic behavior of the disease.

Role of gemcitabine in ovarian cancer treatment

Newer agents and combinations are needed in order to improve current results in ovarian cancer treatment. Gemcitabine is a novel agent that has shown promising activity as a single agent in the treatment of platinum-resistant ovarian cancer and a favorable toxicity profile. Because of its clinical and preclinical synergism with platinum analogues, Gemcitabine has been combined with Carboplatin as a convincing approach in the treatment of platinum-sensitive recurrent ovarian cancer patients. Further combination of Gemcitabine and other agents, including paclitaxel, are also feasible and have been actively studied in order to establish the role of Gemcitabine in the management of treated and untreated ovarian cancer patients.

Prognostic factors associated with response in platinum retreatment of platinum-resistant ovarian cancer

The goal of this study was to determine the factors associated with response to platinum retreatment in patients with platinum-resistant ovarian cancer. A review of patients with epithelial ovarian cancer retreated with cisplatin or carboplatin between 2002 and 2004 was performed. The platinum-free interval (PFI) and treatment-free interval (TFI) were determined for each patient. Response was based on serial CA125 levels using a modification of the Rustin criteria. Patients with clinical benefit ([CB] those who attained at least stable disease) were compared to patients with disease progression (PD). An analysis was performed to determine factors associated with CB in platinum-resistant patients retreated with platinum. Of 48 patients identified, 37 were evaluable included in this analysis. CB was observed in 27 (73%) while disease progression was noted in 10 (27%) women. The PFI was longer in those women who achieved CB (12.3 vs 6.9 months; P = 0.02). The TFI was 7.1 months for patients benefited from platinum retreatment vs 3.5 months for those with disease progression (P = 0.06). There was no statistically significant difference in the number of cytotoxic agents between the time of platinum retreatment and the prior platinum regimen (2 vs 1.5 months; P = 0.61). A prolonged PFI was associated with an improved chance of achieving CB with platinum retreatment. There was no association between the response to platinum retreatment and the number of intervening cytotoxic agents utilized. Further prospective study is warranted to define the optimal timing of platinum retreatment.

Gemcitabine and pegylated liposomal doxorubicin alternating with cisplatin plus cyclophosphamide in platinum refractory/resistant, paclitaxel-pretreated, ovarian carcinoma

OBJECTIVES

This phase II study conducted to investigate the efficacy and toxicity of the combination of gemcitabine (GEM) and pegylated liposomal doxorubicin (LDOX) alternating with cisplatin (CDDP) and cyclophosphamide (CTX) in platinum-resistant/refractory, paclitaxel pretreated epithelial ovarian cancer (EOC).

PATIENTS AND METHODS

Forty-eight patients with CDDP-resistant/refractory and paclitaxel pretreated patients were treated with 8 cycles of GEM 800 mg/m2 days 1 and 8 and LDOX 30 mg/m2 day 1, alternating with CDDP 60 mg/m2 and CTX 600 mg/m2 every 3 weeks.

RESULTS

Objective responses were observed in 37.5% of patients (4 complete and 11 partial responses) with measurable disease (n=40). CA125 response occurred in 30 (71.4%) of patients with elevated CA125 (n=42). After a median follow-up of 23 months, the median progression-free survival (PFS) was 6.9 months (95% confidence interval, CI: 5.2-8.5), while the median overall survival (OS) was 18.2 months (95% CI: 12.7-23.6). A progression-free interval (PFI) of 0-3 months was associated with lower objective responses (10% versus 46.6%, p=0.06). Chemotherapy was well tolerated. The most frequent toxicities were myelosuppression, neurotoxicity, nephrotoxicity, nausea/vomiting, fatigue and palmar-plantar erythrodysesthesia (PPE). Overall 31 (65%) patients received G-CSF and 13 (27%) antibiotics because of neutropenia and/or febrile neutropenia.

CONCLUSION

This alternating combination chemotherapy is feasible for patients with platinum-resistant EOC and is associated with encouraging outcomes and a favorable toxicity profile.

Randomized phase III trial of gemcitabine compared with pegylated liposomal doxorubicin in patients with platinum-resistant ovarian cancer

PURPOSE

Ovarian cancer (OC) patients experiencing progressive disease (PD) within 6 months of platinum-based therapy in the primary setting are considered platinum resistant (Pt-R). Currently, pegylated liposomal doxorubicin (PLD) is a standard of care for treatment of recurrent Pt-R disease. On the basis of promising phase II results, gemcitabine was compared with PLD for efficacy and safety in taxane-pretreated Pt-R OC patients.

PATIENTS AND METHODS

Patients (n = 195) with Pt-R OC were randomly assigned to either gemcitabine 1,000 mg/m2 (days 1 and 8; every 21 days) or PLD 50 mg/m2 (day 1; every 28 days) until PD or undue toxicity. Optional cross-over therapy was allowed at PD or at withdrawal because of toxicity. Primary end point was progression-free survival (PFS). Additional end points included tumor response, time to treatment failure, survival, and quality of life.

RESULTS

In the gemcitabine and PLD groups, median PFS was 3.6 v 3.1 months; median overall survival was 12.7 v 13.5 months; overall response rate (ORR) was 6.1% v 8.3%; and in the subset of patients with measurable disease, ORR was 9.2% v 11.7%, respectively. None of the efficacy end points showed a statistically significant difference between treatment groups. The PLD group experienced significantly more hand-foot syndrome and mucositis; the gemcitabine group experienced significantly more constipation, nausea/vomiting, fatigue, and neutropenia but not febrile neutropenia.

CONCLUSION

Although this was not designed as an equivalency study, gemcitabine and PLD seem to have a comparable therapeutic index in this population of Pt-R taxane-pretreated OC patients. Single-agent gemcitabine may be an acceptable alternative to PLD for patients with Pt-R OC.

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.

Biweekly gemcitabine and cisplatin in platinum-resistant/refractory, paclitaxel-pretreated, ovarian and peritoneal carcinoma

OBJECTIVES

Synergism between gemcitabine and cisplatin is supported by preclinical and clinical data. The present study explores the efficacy of a biweekly regimen in platinum-resistant/refractory, paclitaxel-pretreated ovarian and peritoneal cancer.

METHODS

50 paclitaxel-pretreated patients with platinum-resistant/refractory ovarian or peritoneal carcinoma who had previously received paclitaxel chemotherapy, were treated with six cycles of gemcitabine 1000 mg/m(2) followed by cisplatin 40 mg/m(2) on days 1 and 15, repeated every 4 weeks.

RESULTS

The median platinum-free interval (PFI) was 4 months while the median number of previous treatment lines was 2. Chemotherapy was well tolerated. Objective responses were observed in 31.5% of evaluable patients (n=35). CA125 response was observed in 68% of patients with elevated CA125 (n=41). Median overall survival (OS) was 13.2 months (95% Confidence Interval, CI: 10.2-16.2) while progression-free survival (PFS) was 4.9 months (95%CI: 3.5-6.4). A PFI of less than 3 months was associated with lower objective response rates (15.8% versus 50%, p=0.03).

CONCLUSIONS

Biweekly gemcitabine and cisplatin is feasible for patients with platinum-resistant ovarian or peritoneal cancer and is associated with a favorable toxicity profile. In a population with recent exposure to platinum, a PFI of less than 3 months was the major factor influencing response to chemotherapy.

The current treatment of recurrent ovarian cancer

Contemporary management of recurrent ovarian, primary peritoneal, and fallopian tube cancers has continued to evolve and now offers women the hope of extended survival with an improved quality of life. Platinum continues to be the single most active agent in the treatment of ovarian cancer, but acquired resistance to platinum often emerges. Fortunately, a number of novel agents and treatment strategies have been developed to meet the goals of ameliorating symptoms while extending survival. Classically, patients have been treated based upon the interval from last platinum administration during front-line therapy until time of recurrence. This review focuses upon the current treatment strategies used for platinum-refractory, platinum-resistant, and platinum-sensitive patients. The incorporation of targeted biologic agents is also discussed, along with the role of secondary cytoreduction. It is hoped that the results of future and ongoing clinical trials will offer further advances in the treatment of this devastating disease.

Effect of culture conditions on the chemosensitivity of ovarian cancer cell lines

The aim of this study was to define the chemosensitivity profile of a series of human ovarian cancer cell lines representing the human primary ovarian tumours under altered culture conditions and to compare the results with those from tumour-derived cells. In this study, we used a standardized ATP-based tumour chemosensitivity assay to measure the activity of cytotoxics in the seven ovarian carcinoma cell lines and ovarian tumour-derived cells. The use of adherence-free polypropylene plates and a serum-free medium slowed down cell proliferation in all cell lines tested, mimicking the slow growth rate of solid tumours in this type of plastic. The seeding density was optimized for each cell line and was in the range of 2000-4000 cells/well. Heterogenous sensitivity to different cytotoxics was observed in the seven ovarian cancer cell lines tested in the ATP-based tumour chemosensitivity assay. The human ovarian carcinoma cell line, OVCA433, was found to be the most resistant cell line and 75% of the drugs showed an Index(SUM) above 300. Our results suggest that the use of appropriate culture conditions i.e. a serum-free culture environment, adherence-free growth and optimum seeding density can induce cell lines to behave more like tumour-derived cells in response to cytotoxic agents. On the basis of the comparison of chemosensitivity profiles of tumour-derived cells and cell lines derived from the corresponding tumour, a panel of cell lines can be selected. Such a panel could be used to screen and develop anticancer drugs.

Ovarian cancer: a focus on management of recurrent disease

Surgery and chemotherapy form the cornerstone of the treatment for ovarian cancer. Currently, the standard of care for primary ovarian cancer is platinum and taxane-based therapy. Even among women with advanced and suboptimal disease (i.e. tumors greater than 1 cm) following surgery, the clinical efficacy of chemotherapy is noteworthy. Despite the favorable response characteristics, however, most women with advanced-stage ovarian cancer will relapse, including about 50% of women who have no evidence of disease after primary therapy. A multitude of treatment options are available at the time of recurrence, but there is no clear consensus about how these patients should be managed. Options include surgery, chemotherapy, hormones, and sometimes, radiation therapy. The sequence, combinations of treatment, and manner in which any or all of these options should be employed in an individual patient, which heretofore have not been standardized, are the subjects of ongoing clinical investigations.