The Gynecologic Oncology Group experience in ovarian cancer

Pharmacotherapeutic treatment options for recurrent epithelial ovarian cancer

INTRODUCTION

Almost 80% of epithelial ovarian cancer present in advanced stage at diagnosis and despite excellent response to surgery and chemotherapy, more than 70% cancers recur. Subsequent therapies become decreasingly effective in controlling the disease, with each successful therapy being effective for a shorter duration. As a result, there is a need for novel therapeutic strategies to effectively treat recurrence.

AREAS COVERED

In this extensive literature review of high-quality articles, we have focused on surveillance strategy to detect recurrence early, classification of recurrence based on timeline, role of surgery, chemotherapy, and targeted agents such as anti-angiogenetic drugs, PARP inhibitors, and immune checkpoint inhibitors in platinum-sensitive and platinum-resistant disease, respectively.

EXPERT OPINION

Recurrent ovarian cancers (ROC) are represented by a heterogenous group of patient population in terms of platinum-free interval (PFI), histology, molecular characteristics and immune recognition. In today's era of precision medicine, chemotherapy should be combined with appropriate targeted agent in a multipronged approach to prolong survival and provide better quality of life outcomes by minimizing side effects.

An Integrated Genomic-Based Approach to Individualized Treatment of Patients With Advanced-Stage Ovarian Cancer

Purpose

The purpose of this study was to develop an integrated genomic-based approach to personalized treatment of patients with advanced-stage ovarian cancer. We have used gene expression profiles to identify patients likely to be resistant to primary platinum-based chemotherapy and also to identify alternate targeted therapeutic options for patients with de novo platinum-resistant disease.

Patients and Methods

A gene expression model that predicts response to platinum-based therapy was developed using a training set of 83 advanced-stage serous ovarian cancers and tested on a 36-sample external validation set. In parallel, expression signatures that define the status of oncogenic signaling pathways were evaluated in 119 primary ovarian cancers and 12 ovarian cancer cell lines. In an effort to increase chemotherapy sensitivity, pathways shown to be activated in platinum-resistant cancers were subject to targeted therapy in ovarian cancer cell lines.

Results

Gene expression profiles identified patients with ovarian cancer likely to be resistant to primary platinum-based chemotherapy with greater than 80% accuracy. In patients with platinum-resistant disease, we identified expression signatures consistent with activation of Src and Rb/E2F pathways, components of which were successfully targeted to increase response in ovarian cancer cell lines.

Conclusion

We have defined a strategy for treatment of patients with advanced-stage ovarian cancer that uses therapeutic stratification based on predictions of response to chemotherapy, coupled with prediction of oncogenic pathway deregulation, as a method to direct the use of targeted agents.

Current and future potential roles of the platinum drugs in the treatment of ovarian cancer

The discovery of cisplatin more than two decades ago was the most important therapeutic advance in the treatment of ovarian cancer. Today, cisplatin or carboplatin in combination with paclitaxel is the most commonly used first-line treatment for patients with advanced ovarian cancer. Although platinum drugs remain a critical component of chemotherapy in this type of cancer, cumulative toxicities can limit their use. These toxicities include nephrotoxicity, neurotoxicity and ototoxicity with cisplatin and myelosuppression with carboplatin. Although these adverse events can often be managed, the interventions themselves can complicate and add to the costs of treatment. Importantly, acquired resistance to traditional platinum drugs often develops in patients with ovarian cancer and can limit the usefulness of these drugs. Research into new platinum drugs has focused on identifying compounds with improved tolerability profiles and, importantly, those which can circumvent mechanisms of platinum resistance. New platinum drugs currently under development that are showing promise in ovarian cancer include oxaliplatin, nedaplatin, satraplatin, BBR3464 and ZD0473. If the encouraging in vitro activity shown by new compounds, such as ZD0473 and BBR3464, translates into efficacy in the clinic, they may offer an extended spectrum of activity which includes patients with ovarian cancer resistant to the classical platinum drugs.