Ovarian cancer

Contemporary quality of life issues affecting gynecologic cancer survivors

Regardless of cancer origin or age of onset, the disease and its treatment can produce short- and long-term sequelae (ie, sexual dysfunction, infertility, or lymphedema) that adversely affect quality of life (QOL). This article outlines the primary contemporary issues or concerns that may affect QOL and offers strategies to offset or mitigate QOL disruption. These contemporary issues are identified within the domains of sexual functioning, reproductive issues, lymphedema, and the contribution of health-related QOL in influential gynecologic cancer clinical trials.

Phase II evaluation of phenoxodiol in combination with cisplatin or paclitaxel in women with platinum/taxane-refractory/resistant epithelial ovarian, fallopian tube, or primary peritoneal cancers

INTRODUCTION

Chemoresistance is a major limitation in the treatment of ovarian cancer. Phenoxodiol is a novel biomodulator capable of reversing chemoresistance in vitro and in vivo. In this study, we determined the safety and efficacy of intravenous phenoxodiol in combination with cisplatin or paclitaxel in women with platinum/taxane-refractory/resistant ovarian cancers.

METHODS

Thirty-two patients were randomized to 1 of 2 treatment arms according to their previous responses: (1) platinum refractory/resistant, cisplatin (40 mg/m intravenous) weekly on day 2 + phenoxodiol (3 mg/kg) weekly on days 1 and 2 and (2) taxane refractory/resistant, paclitaxel (80 mg/m IV) weekly on day 2 and phenoxodiol (3 mg/kg) weekly on days 1 and 2. Patients continued on treatment until complete response, disease progression, unacceptable toxicity, or voluntary withdrawal.

RESULTS

There were no treatment-related deaths. There was only one treatment-related hospitalization and 2 grade 4 toxicities. In the cisplatin arm, there were 3 partial responses, 9 patients (56%) achieved stable disease, 4 (25%) progressed, and the overall best response rate was 19%. In the paclitaxel arm, there was one complete response and 2 partial responses, 8 patients (53%) achieved stable disease, 4 patients (27%) progressed, and the overall best response rate was 20%.

DISCUSSION

The combination of IV phenoxodiol with cisplatin or paclitaxel was well tolerated in this study. Cisplatin-phenoxodiol was particularly active and warrants further study in patients with platinum-resistant ovarian cancer.

Prevalence of epithelial ovarian cancer stem cells correlates with recurrence in early-stage ovarian cancer

Epithelial ovarian cancer stem cells (EOC stem cells) have been associated with recurrence and chemoresistance. CD44 and CK18 are highly expressed in cancer stem cells and function as tools for their identification and characterization. We investigated the association between the number of CD44+ EOC stem cells in ovarian cancer tumors and progression-free survival. EOC stem cells exist as clusters located close to the stroma forming the cancer stem cell “niche”. 17.1% of the samples reveled high number of CD44+ EOC stem cells (>20% positive cells). In addition, the number of CD44+ EOC stem cells was significantly higher in patients with early-stage ovarian cancer (FIGO I/II), and it was associated with shorter progression-free survival (P = 0.026). This study suggests that quantification of the number of EOC stem cells in the tumor can be used as a predictor of disease and could be applied for treatment selection in early-stage ovarian cancer.

Modulation of drug resistance in ovarian adenocarcinoma by enhancing intracellular ceramide using tamoxifen-loaded biodegradable polymeric nanoparticles

PURPOSE

To modulate intracellular ceramide levels and lower the apoptotic threshold in multidrug-resistant ovarian adenocarcinoma, we have examined the efficacy and preliminary safety of tamoxifen coadministration with paclitaxel in biodegradable poly(ethylene oxide)-modified poly(epsilon-caprolactone) (PEO-PCL) nanoparticles.

EXPERIMENTAL DESIGN

In vitro cytotoxicity and proapoptotic activity of paclitaxel and tamoxifen, either as single agent or in combination, was examined in wild-type (SKOV3) and MDR-1-positive (SKOV3TR) human ovarian adenocarcinoma cells. Subcutaneous SKOV3 and SKOV3TR xenografts were established in female nu/nu mice, and this model was used to evaluate the antitumor efficacy and preliminary safety. Paclitaxel (20 mg/kg) and tamoxifen (70 mg/kg) were administered i.v. either as a single agent or in combination in aqueous solution and in PEO-PCL nanoparticles.

RESULTS

In vitro cytotoxicity results showed that administration of paclitaxel and tamoxifen in combination lowered the IC50 of paclitaxel by 10-fold in SKOV3 cells and by >3-fold in SKOV3TR cells. The combination paclitaxel/tamoxifen co-therapy showed even more pronounced effect when administered in nanoparticle formulations. Upon i.v. administration of paclitaxel/tamoxifen combination in PEO-PCL nanoparticle formulations, significant enhancement in antitumor efficacy was observed. Furthermore, the combination paclitaxel/tamoxifen therapy did not induce any acute toxicity as measured by body weight changes, blood cell counts, and hepatotoxicity.

CONCLUSIONS

The results of this study show that combination of paclitaxel and tamoxifen in biodegradable PEO-PCL nanoparticles can serve as an effective clinically translatable strategy to overcome multidrug resistance in ovarian cancer.

Design, synthesis and applications of hyaluronic acid-paclitaxel bioconjugates

Paclitaxel (1a), a well known antitumor agent adopted mainly for the treatment of breast and ovarian cancer, suffers from significant disadvantages such as low solubility, certain toxicity and specific drug-resistance of some tumor cells. To overcome these problems extensive research has been carried out. Among the various proposed strategies, the conjugation of paclitaxel (1a) to a biocompatible polymer, such as hyaluronic acid (HA, 2), has also been considered. Coupling a bioactive compound to a biocompatible polymer offers, in general, many advantages such as better drug solubilization, better stabilization, specific localization and controlled release. Hereafter the design, synthesis and applications of hyaluronic acid-paclitaxel bioconjugates are reviewed. An overview of HA-paclitaxel combinations is also given.

Paclitaxel and ceramide co-administration in biodegradable polymeric nanoparticulate delivery system to overcome drug resistance in ovarian cancer

The objective of this study was to overcome drug resistance upon systemic administration of combination paclitaxel (PTX) and the apoptotic signaling molecule C(6)-ceramide (CER) in biodegradable poly(ethylene oxide)-modified poly(epsilon-caprolactone (PEO-PCL) nanoparticles. Subcutaneous sensitive (wild-type) and multidrug resistant (MDR-1 positive) SKOV-3 human ovarian adenocarcinoma xenografts were established in female Nu/Nu mice. PTX and CER were administered intravenously either as a single agent or in combination in aqueous solution and in PEO-PCL nanoparticles to the tumor-bearing mice. There was significant (p< 0.05) tumor growth suppression in both wild-type SKOV-3 and multidrug resistant SKOV-3(TR) models upon single dose co-administration of PTX (20 mg/kg) and CER (100 mg/kg) in nanoparticle formulations as compared to the individual agents and administration in aqueous solutions. For instance, in SKOV-3 wild-type model, more than 4.3-fold increase (p < 0.05) in tumor growth delay and 3.6-fold (p < 0.05) increase in tumor volume doubling time (DT) were observed with the combination treatment in nanoparticles as compared to untreated animals. Similarly, 3-fold increase (p < 0.05) in tumor growth delay and tumor volume DT was observed in SKOV-3(TR) model. Body weight changes and blood cells counts were used as measures of safety and, except for an increase in platelet counts (p < 0.05) in PTX + CER treated animals, there was no difference between various treatment strategies. The results of this study show that combination of PTX and CER in biodegradable polymeric nanoparticles can serve as a very effective therapeutic strategy to overcome drug resistance in ovarian cancer.

Quality of Life Considerations in Gynecologic Cancer

Quality of life (QOL) is a fundamental consideration for patients with life threatening diseases. Major evolving paradigms are discussed: improved QOL with laparoscopic surgery, the impact on QOL of intraperitoneal chemotherapy for optimally cytoreduced ovarian cancer, combination therapy, sexuality, and survivorship. The goals of treatment for many patients with gynecologic tumors remain largely palliative, and patient reported QOL is the primary outcome determining the utility of treatment. Particularly in this area, QOL endpoints are increasingly important in clinical trials. The QOL issues facing gynecologic cancer patients, the use of validated QOL instruments, recent advances in the evaluation of interventions, and changes in concepts related to QOL are reviewed.

Molecular prognostic markers in ovarian cancer: toward patient-tailored therapy

In ovarian cancer the ceiling seems to be reached with chemotherapeutic drugs. Therefore a paradigm shift is needed. Instead of treating all patients according to standard guidelines, individualized molecular targeted treatment should be aimed for. This means that molecular profiles of the distinct ovarian cancer subtypes should be established. Until recently, most studies trying to identify molecular targets were single-marker studies. The prognostic role of key components of apoptotic and prosurvival pathways such as p53, EGFR, and HER2 has been extensively studied because resistance to chemotherapy is often caused by failure of tumor cells to go into apoptosis. However, it is more than likely that different ovarian cancer subtypes with extensive molecular heterogeneity exist. Therefore, exploration of the potential of specific tumor-targeted therapy, based on expression of a prognostic tumor profile, may be of interest. Recently, new profiling techniques, such as DNA and protein microarrays, have enabled high-throughput screening of tumors. In this review an overview of the current status of prognostic marker and molecular targeting research in ovarian cancer, including microarray studies, is presented.

Recurrent Ovarian Cancer

Ovarian cancer is increasingly recognized as a chronic disease whose treatment is often characterized by administration of multiple, sequential active agents, each of which may or may not be accompanied by a tumor response. Despite the large proportion of patients who relapse and undergo longer-term treatment, the question of optimal treatment duration has not been fully addressed to date. For patients who progress on therapy, the answer is straightforward: they are switched to another active agent, presumably having a different mechanism of action from previous therapies with, ideally, limited overlapping toxicities. However, for patients who remain in partial response or who have stable disease, the answer is less apparent and less clear. The majority of oncologists believe that treatment beyond 6 cycles of a given therapy does not provide any additional benefit to patients. There are some data to support that treatment strategy. However, with the advent of new, less toxic agents, treatment to progression should be further explored. Agents that are potentially well suited for extended treatment intervals may include such properties as absence of cumulative toxicity, non-cross-resistance, positive benefit on quality of life, and convenient schedule. A number of active agents in ovarian cancer (platinum, paclitaxel, topotecan, liposomal doxorubicin, docetaxel, gemcitabine, and etoposide) will be reviewed in the context of what is known about cumulative toxicity, potential adverse effects on patients' quality of life, and evidence addressing the potential benefits of longer-term treatment.

ATM-dependent CHK2 activation induced by anticancer agent, irofulven

Irofulven (6-hydroxymethylacylfulvene, HMAF, MGI 114) is one of a new class of anticancer agents that are semisynthetic derivatives of the mushroom toxin illudin S. Preclinical studies and clinical trials have demonstrated that irofulven is effective against several tumor types. Mechanisms of action studies indicate that irofulven induces DNA damage, MAPK activation, and apoptosis. In this study we found that in ovarian cancer cells, CHK2 kinase is activated by irofulven while CHK1 kinase is not activated even when treated at higher concentrations of the drug. By using GM00847 human fibroblast expressing tetracycline-controlled, FLAG-tagged kinase-dead ATR (ATR.kd), it was demonstrated that ATR kinase does not play a major role in irofulven-induced CHK2 activation. Results from human fibroblasts proficient or deficient in ATM function (GM00637 and GM05849) indicated that CHK2 activation by irofulven is mediated by the upstream ATM kinase. Phosphorylation of ATM on Ser(1981), which is critical for kinase activation, was observed in ovarian cancer cell lines treated with irofulven. RNA interference results confirmed that CHK2 activation was inhibited after introducing siRNA for ATM. Finally, experiments done with human colon cancer cell line HCT116 and its isogenic CHK2 knockout derivative; and experiments done by expressing kinase-dead CHK2 in an ovarian cancer cell line demonstrated that CHK2 activation contributes to irofulven-induced S phase arrest. In addition, it was shown that NBS1, SMC1, and p53 were phosphorylated in an ATM-dependent manner, and p53 phosphorylation on serine 20 is dependent on CHK2 after irofulven treatment. In summary, we found that the anticancer agent, irofulven, activates the ATM-CHK2 DNA damage-signaling pathway, and CHK2 activation contributes to S phase cell cycle arrest induced by irofulven.

Quality of life in patients receiving treatment for gynecologic malignancies: Special considerations for patient care

Advances in the treatment of gynecologic cancer have extended the duration of survival of many patients. However, these patients frequently experience a variety of treatment- and disease-related side effects that diminish their quality of life (QOL) during and after treatment; among these are pain, nausea and vomiting, anemia, fatigue, peripheral neuropathy, emotional distress, and sexual dysfunction. Given the gains in survival time, patient care is being expanded to include enhancement or preservation of QOL in addition to early diagnosis and disease treatment, thus treating the whole person. In parallel with this evolution in cancer care, supportive measures are being increasingly recognized as crucial to effective patient management. This paper reviews some of the potential causes of diminished QOL in gynecologic cancer patients and basic treatment strategies for their control, with a focus on short-term QOL issues. It is important that clinicians monitor QOL during the course of the disease and its treatment, utilize procedures and therapeutic agents that take patient preferences and QOL into account, and proactively prevent and treat relevant symptoms.

3D QSAR studies of the interaction between beta-tubulin and microtubule stabilizing antimitotic agents (MSAA). A combined pharmacophore generation and pseudoreceptor modeling approach applied to taxanes and epothilones

Based on the conformer of paclitaxel extracted from the experimental tubulin structure, a pharmacophoric model has been generated and used to find the chemical features common to the taxane and epothilone classes of compounds. This original alignment has been translated into the experimental tubulin binding site obtaining an assembly subsequently submitted to the pseudoreceptor modeling approach. As a result, an original 3D QSAR model, able to evaluate, at a quantitative level, the relationships between the molecular structures and biological data of the studied compounds, has been obtained.

Management of treatment-related toxicity in advanced ovarian cancer

Recognition of recurrent ovarian cancer as a disease with significant secondary responses and remissions has led to an increase in the need for oncologists to plan for the long-term therapy of patients. However, many of the currently available front-line and salvage agents used in advanced ovarian cancer are associated with cumulative and/or irreversible toxicities that pose challenges in long-term planning. The irreversible effects associated with some of these therapies may render patients less tolerant to subsequent treatments and lead to a cycle of diminishing treatment options with each remission and disease relapse. Additionally, the potential for patients to experience cumulative toxicity must be carefully weighed against the goals of prolonging the disease-free interval and improving patient quality of life. A number of agents are available in the treatment armamentarium (platinum, paclitaxel, gemcitabine, etoposide, liposomal doxorubicin, and topotecan), many, but not all of which are associated with cumulative toxicity. For instance, cumulative neurotoxicity associated with cisplatin as first-line therapy may diminish the option for retreatment with platinum at first relapse. In contrast, the main toxicity associated with topotecan is noncumulative, manageable myelosuppression. In this review, the major toxicities associated with the predominant chemotherapy agents used in advanced ovarian cancer are discussed along with selected management approaches in the context of long-term treatment planning and sequencing.