Abstract ED06-02: Circulating ovarian cancer biomarkers and early detection

Abstract

Abstract Ovarian cancer is considered a rare disease (affecting fewer than 200,000 people) but at the same time it is the ninth most common cancer in the United States and the fifth leading cause of cancer-related deaths in women. The American Cancer Society estimates that in 2013, about 22,240 new cases of ovarian cancer will be diagnosed and 14,030 women will die of ovarian cancer in the U.S. The mortality rates for ovarian cancer have not improved in forty years since the “War on Cancer” was declared. However, other cancers have shown a marked reduction in mortality, due to the availability of early detection tests and improved treatments. Unfortunately, this is not the case with ovarian cancer, which is still the most lethal gynecological malignancy accounting for more deaths than endometrial and cervical cancer combined. The lifetime incidence for ovarian malignancies is one in 72 (1.39%) and the lifetime risk of death from ovarian cancer is one in 96 (1.04%) for US women. The symptoms of ovarian cancer can be vague and are not always gynecologic. They often mimic those of many other more common conditions, including digestive problems and thus women continue to be diagnosed with advanced-stage disease when survival rates are unacceptable (5-year survival is less than 45%). Therefore, preventive strategies, including improvements in early detection of disease as well as in preventing disease recurrence, are crucial to improving prognosis. Ovarian cancer prevention can be defined by two main strategies: 1) early detection of cancer in at-risk patients and 2) prevention of recurrent disease in patients with an established diagnosis of cancer. If one could detect early-stage disease, women would require a less morbid operation, may not require adjuvant chemotherapy and have a 5-year survival approaching 90%. However, only 20% of ovarian cancer cases are caught before the cancer has spread. More importantly, despite herculean efforts, there are still no highly sensitive or specific screening assays for detection of early-stage disease. Therefore, new tools such as serum biomarkers and medical imaging are required to affect a paradigm shift from the detection of late- to early-stage ovarian cancer. An ideal screening test for ovarian cancer must have a high sensitivity in order to correctly diagnose all women with the disease and a high specificity to avoid too many false-positive results. A blood test with 75% sensitivity and 98% specificity when combined with an imaging modality such as transvaginal ultrasonography (TVU) achieves a specificity of 99.6% resulting in an acceptable positive predictive value for surgery. Such a screening test would greatly improve care if the test detected most ovarian cancers in early stage disease. Current screening methods include pelvic examination, CA-125 levels, TVU, or a combination of modalities and allow for the detection of only 30 to 45% of cases in early-stage disease. Recent developments in the biology of ovarian cancer and “omics”-based research have identified a number of potential biomarkers. This talk will examine the current status of a potentially promising circulating biomarkers and detection approaches with the goal towards improving early detection of ovarian cancer. Citation Format: Andrew K. Godwin. Circulating ovarian cancer biomarkers and early detection. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr ED06-02.