Nibrin is a marker of clinical outcome in patients with advanced serous ovarian cancer treated in the phase III OVA-301 trial

MRE11-RAD50-NBS1 complex alterations and DNA damage response: implications for cancer treatment

Genome instability is a hallmark of cancer cells and can be accelerated by defects in cellular responses to DNA damage. This feature of malignant cells opens new avenues for tumor targeted therapy. MRE11-RAD50-NBS1 complex plays a crucial role in sensing and repair of DNA damage. Through interacting with other important players of DNA damage response, MRE11-RAD50-NBS1 complex is engaged in various DNA damage repair pathways. Mutations in any member of this complex may lead to hypersensitivity to genotoxic agents and predisposition to malignancy. It is assumed that the defects in the complex may contribute to tumorigenesis and that treatments targeting the defect may be beneficial to cancer patients. Here, we summarized the recent research findings of the role of MRE11-RAD50-NBS1 complex in tumorigenesis, cancer treatment and discussed the potential approaches of targeting this complex to treat cancer.

Starvation tactics using natural compounds for advanced cancers: pharmacodynamics, clinical efficacy, and predictive biomarkers

The high mortality associated with oncological diseases is mostly due to tumors in advanced stages, and their management is a major challenge in modern oncology. Angiogenesis is a defined hallmark of cancer and predisposes to metastatic invasion and dissemination and is therefore an important druggable target for cancer drug discovery. Recently, because of drug resistance and poor prognosis, new anticancer drugs from natural sources targeting tumor vessels have attracted more attention and have been used in several randomized and controlled clinical trials as therapeutic options. Here, we outline and discuss potential natural compounds as salvage treatment for advanced cancers from recent and ongoing clinical trials and real-world studies. We also discuss predictive biomarkers for patients' selection to optimize the use of these potential anticancer drugs.

Objective response rate is a possible surrogate endpoint for survival in patients with advanced, recurrent ovarian cancer

OBJECTIVE

Evaluate literature to assess response rate as a surrogate endpoint of survival in ovarian cancer (OC).

METHODS

Systematic review consistent with PRISMA criteria, identified randomized, controlled trials reporting overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) in recurrent OC. MEDLINE® and Embase® searches (year 2000-March 23, 2015) were augmented by bibliographic screening. Proposed surrogate measures (independent variables) were ORR and disease control rate. True clinical outcomes (dependent variables) were median OS and PFS. Analyses were performed on unweighted and weighted data using correlation analysis, linear regression, and surrogate threshold effect (STE). Smaller STE indicates greater predictive precision with magnitude of STE dependent on variance of prediction.

RESULTS

Thirty-nine studies were included for review, representing 9223 platinum-sensitive and resistant patients. Objective response rate (r=0.82; P<0.001) was a better predictor than disease control rate (r=0.58; P<0.001) and strongly correlated with PFS (r=0.85; P<0.0001). Weighted-regression analysis demonstrated that for each 10% increase in ORR, PFS increased by 1.20months and OS by 2.83months. Regression analysis of treatment effects (odds ratio of response, hazard ratio of survival) suggests that a 10% increase in odds ratio of ORR would result in 2.5% reduction in the hazard ratio of OS. Based on weighted data, STE indicated that an ORR of ≥1% is needed to achieve nonzero OS benefit.

CONCLUSION

This systematic review supports ORR as a possible surrogate clinical trial endpoint for OS in recurrent OC with at least second-line therapy.

Trabectedin therapy as an emerging treatment strategy for recurrent platinum-sensitive ovarian cancer

Epithelial ovarian cancer (OC) is a common gynecologic malignancy in women. The standard treatment for OC is maximal cytoreductive surgical debulking followed by platinum-based chemotherapy. Despite the high response rate to primary therapy, approximately 85% of patients will develop recurrent ovarian cancer (ROC). This review identifies the clinical use of trabectedin in the treatment algorithm for ROC, with specific emphasis on platinum-sensitive ROC, for which trabectedin in combination with pegylated liposomal doxorubicin has been approved as a treatment protocol. The main mechanisms of action of trabectedin at the cellular level and in the tumor microenvironment is also discussed as bases for identifying biomarkers for selecting patients who may largely benefit from trabectedin-based therapies.

Clinical utility of trabectedin for the treatment of ovarian cancer: current evidence

Among the pharmaceutical options available for treatment of ovarian cancer, attention has been increasingly focused on trabectedin (ET-743), a drug which displays a unique mechanism of action and has been shown to be active in several human malignancies. Currently, single agent trabectedin is approved for treatment of patients with advanced soft tissue sarcoma after failure of anthracyclines and ifosfamide, and in association with pegylated liposomal doxorubicin for treatment of patients with relapsed partially platinum-sensitive ovarian cancer. This review aims at summarizing the available evidence about the clinical role of trabectedin in the management of patients with epithelial ovarian cancer. Novel perspectives coming from a better understanding of trabectedin mechanisms of action and definition of patients subgroups likely susceptible to benefit of trabectedin treatment are also presented.

The prognostic value of CXCR4 in ovarian cancer: a meta-analysis

OBJECTIVE

Recent reports have shown that C-X-C chemokine receptor 4 (CXCR4) is expressed in ovarian cancer and plays an important role in metastasis. However, the prognostic value of CXCR4 in ovarian cancer remains controversial and has not been emphasized. The aim of this study is to evaluate the prognostic significance of CXCR4 in ovarian cancer by performing a meta-analysis.

METHODS

We systematically searched for studies evaluating the relationship between CXCR4 expression and the outcome of ovarian cancer patients. Only articles in which CXCR4 expression was detected by immunohistochemical staining were included. Hazard ratios (HRs) and relative risk (RR) with 95% confidence intervals (CIs) were pooled as effect size (ES) across studies for overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 729 patients from 7 studies (6 articles) were included in this meta-analysis. Our results showed that high CXCR4 expression was significantly associated with poor prognosis in terms of OS (ES, 2.81; 95% CI, 1.16-6.80; p = 0.022) and PFS (ES, 8.48; 95% CI, 2.13-33.70; p = 0.002) in ovarian cancer patients. The association between high CXCR4 expression and poor ovarian cancer prognosis in OS was also statistically significant in subgroups of Asian and III-IV patients constituting 70%.

CONCLUSIONS

The present meta-analysis indicated that high CXCR4 expression was associated with poor prognosis in ovarian cancer. More studies, especially larger scale and well-matched researches, are warranted to clarify the prognostic effect of CXCR4 on the outcome of ovarian cancer.