OA: Genomic profiling for copy number changes in plasma of ovarian cancer patients – a new era for cancer diagnostics? | BMC Medicine | Full Text

BMC Medicine Full Text
 Table of Contents

• Abstract
• Background
• Sub-chromosomal changes: novel cancer biomarker concept
• Conclusions
• Declarations
• References

 Abstract

A blood test that can detect human malignancy with high clinical sensitivity and specificity is highly desirable. To achieve this, a tumor marker is needed that correlates with tumor burden and that can be measured with high analytical sensitivity and specificity. Over the past decades, a number of different types of tumor markers have emerged, including proteins such as enzymes, glycoproteins, and oncofetal antigens. Besides proteins, genetic abnormalities such as mutations, amplifications, and circulating tumor DNA have served as tumor markers. Despite the diversity of such biomarkers, their acceptance and implementation into routine clinical practice requires that their use results in improvements in patient outcome. Current tumor markers used in the clinic have limited utility. As such, innovative approaches to identifying tumor markers are highly desirable and one such approach may be to look for sub-chromosomal changes in the blood of patients with ovarian cancer, as is routinely performed in prenatal screening.

Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0667-6

Keywords

Tumor markers NIPT Ovarian cancer Non-invasive

Background

Ovarian cancer is highly lethal. Current efforts to combat this disease include improved therapies and early diagnosis. Although it is known that detection of early disease can lead to prolonged survival, and even cures, most ovarian cancers are diagnosed at an advanced stage, when surgery and chemotherapy are not very effective [1]. Subsequently, new methods for early diagnosis of this cancer are highly desirable.

In an article recently published in BMC Medicine, Cohen and colleagues propose a new technique for early ovarian cancer diagnosis, using a routine non-invasive prenatal testing (NIPT) platform [2]. Before we analyze this paper in some detail, we summarize below some prerequisites that should be taken into account when considering ovarian cancer screening.

Ovarian cancer screening is considered for women 50–75 years of age. In this age group, the prevalence of the disease is approximately 1 in 200 women [3]. It has previously been suggested that a screening method for ovarian cancer should have a positive predictive value of at least 10 % to be viable. Assuming that a test for ovarian cancer screening has a sensitivity of 90 %, thus detecting most early ovarian cancers, a specificity of 90 % will yield a positive predictive value of around 4 %, and a specificity of 95 % will yield a positive predictive value of 8 %. Consequently, the relatively low prevalence of ovarian cancer in the screening population dictates that very high specificity (i.e., > 95 %) is required to yield a viable positive predictive value......