Clinical Efficacy of Ovarian Cancer Screening

Tumor evolution and chemoresistance in ovarian cancer

Development of novel strategies to overcome chemoresistance is central goal in ovarian cancer research. Natural history of the cancer development and progression is being reconstructed by genomic datasets to understand the evolutionary pattern and direction. Recent studies suggest that intra-tumor heterogeneity (ITH) is the main cause of treatment failure by chemoresistance in many types of cancers including ovarian cancer. ITH increases the fitness of tumor to adapt to incompatible microenvironment. Understanding ITH in relation to the evolutionary pattern may result in the development of the innovative approach based on individual variability in the genetic, environment, and life style. Thus, we can reach the new big stage conquering the cancer. In this review, we will discuss the recent advances in understanding ovarian cancer biology through the use of next generation sequencing (NGS) and highlight areas of recent progress to improve precision medicine in ovarian cancer.

The effect of CA125 on metastasis of ovarian cancer: old marker new function

CA125 has been used extensively to screen for neoplasms, especially in ovarian cancer. The serum CA125 level can be used as a better prognosis evaluation and it may dynamic monitoring the disease progression. We explored the effect of CA125 on ovarian cancer cell migration and its underlying mechanism. Transwell assays showed that exposure to 0.2 μg/ml or 0.4 μg/ml CA125 for 48 h increased migration of A2780 and OVCAR-3 ovarian cancer cells. This effect of CA125 was blocked addition of 200 ng/ml DKK-1, a Wnt pathway inhibitor. Conversely, addition of CA125 reversed the inhibitory effect of Wnt inhibition in A2780 cells pretreated with DKK-1. Examination of CA125 levels in serum from 97 ovarian cancer patients revealed no relationship between a patient's age or CA125 level currently used clinically for ovarian cancer diagnosis and metastasis. However, using receiver operating characteristic (ROC) curves, we identified a new cut-off value for the serum CA125 concentration (82.9 U/ml) that is predictive of metastasis. The area under the curve is 0.632. This new cut-off value has the potential to serve as a clinically useful indicator of metastasis in ovarian cancer patients.

Ten Important Considerations for Ovarian Cancer Screening

The unique intricacies of ovarian cancer screening and perspectives of different screening methods are presented as ten considerations that are examined. Included in these considerations are: (1) Deciding on the number of individuals to be screened; (2) Anticipating screening group reductions due to death; (3) Deciding on the duration and frequency of screening; (4) Deciding on an appropriate follow-up period after screening; (5) Deciding on time to surgery when malignancy is suspected; (6) Deciding on how screen-detected ovarian cancers are treated and by whom; (7) Deciding on how to treat the data of enrolled participants; (8) Deciding on the most appropriate way to assign disease-specific death; (9) Deciding how to avoid biases caused by enrollments that attract participants with late-stage disease who are either symptomatic or disposed by factors that are genetic, environmental or social; and (10) Deciding whether the screening tool or a screening process is being tested. These considerations are presented in depth along with illustrations of how they impact the outcomes of ovarian cancer screening. The considerations presented provide alternative explanations of effects that have an important bearing on interpreting ovarian screening outcomes.

Subtypes of Ovarian Cancer and Ovarian Cancer Screening

Ovarian cancer is the foremost cause of gynecological cancer death in the developed world, as it is usually diagnosed at an advanced stage. In this paper we discuss current issues, the efficacy and problems associated with ovarian cancer screening, and compare the characteristics of ovarian cancer subtypes. There are two types of ovarian cancer: Type I carcinomas, which are slow-growing, indolent neoplasms thought to arise from a precursor lesion, which are relatively common in Asia; and Type II carcinomas, which are clinically aggressive neoplasms that can develop de novo from serous tubal intraepithelial carcinomas (STIC) and/or ovarian surface epithelium and are common in Europe and the USA. One of the most famous studies on the subject reported that annual screening using CA125/transvaginal sonography (TVS) did not reduce the ovarian cancer mortality rate in the USA. In contrast, a recent study in the UK showed an overall average mortality reduction of 20% in the screening group. Another two studies further reported that the screening was associated with decreased stage at detection. Theoretically, annual screening using CA125/TVS could easily detect precursor lesions and could be more effective in Asia than in Europe and the USA. The detection of Type II ovarian carcinoma at an early stage remains an unresolved issue. The resolving power of CA125 or TVS screening alone is unlikely to be successful at resolving STICs. Biomarkers for the early detection of Type II carcinomas such as STICs need to be developed.