Researchers have identified an effective, minimally invasive, 2-step screening strategy for postmenopausal women in the general population with average risk of developing ovarian cancer.
The 2-stage screening strategy includes (1) calculating risk of ovarian cancer using the patient’s age and measurements of cancer antigen 125 (CA-125) over time, followed by (2) a recommendation for follow-up for a CA-125 test for those found to be at a low to intermediate risk, or a transvaginal ultrasound (TVS) if at high risk. This strategy was very accurate, with only a small number of false positives.
Ovarian Cancer is Deadly; Early Detection is Critical
Why would this be considered a breakthrough? Ovarian cancer is responsible for more deaths than any other cancer of the female reproductive system in the U.S. The overall 5-year survival rate is only 44.2% which can be partially explained by the unequal distribution of stage at diagnosis.
- There are only 15% of cases diagnosed at an early localized stage, where cancer is confined to the ovaries.
- 18% are diagnosed at a regional stage, where cancer has spread to the lymph nodes.
- The majority (61%) are diagnosed at a distant stage, in which cancer has spread to another site.
Regardless of advances in treatment, the survival rates tend to decline with advanced disease; rates are highest for those diagnosed with localized (91%), followed by regional (72%) and distant (27.3%) stage of disease.
These rates demonstrate that treatment is successful if ovarian cancer is detected early enough, but also reflect the lack of effective strategies for early detection of ovarian cancer in the clinical setting.
Detect Ovarian Cancer: Step One
A single-arm prospective study, conducted by Dr. Karen Lu and colleagues, followed 4,051 postmenopausal women between the ages 50 and 74 years with at least one ovary from 2000-2011. The researchers used the Risk of Ovarian Cancer Algorithm (ROCA) to quantify the risk of a particular woman having a change-point in CA-125 levels (due to ovarian cancer). CA-125 is a known biomarker for ovarian cancer because it is found to be concentrated when cancer is present in the ovary. CA-125 levels are measured from a blood test, and the normal value is less than 35 Units /milliliter (U/ml).