Blood test may help spot ovarian cancer early
Washington: Scientists have developed a new screening strategy for ovarian cancer that can accurately detect the disease before it becomes lethal.
There currently are no established screening strategies for ovarian cancer. The disease often causes no specific symptoms and is difficult to detect in the early stages when it is most responsive to treatment.
Therefore, ovarian cancer is highly lethal because most women have advanced disease when they are diagnosed.
Karen Lu, of The University of Texas MD Anderson Cancer Center in Houston, led a team that tested the potential of a two-stage ovarian cancer screening strategy that incorporates changes in a blood protein called CA125, which is a known tumour marker.
In their 11-year study, 4051 post- menopausal women initially underwent an annual CA125 blood test.
Based on a calculation called the "Risk of Ovarian Cancer Algorithm," women were divided into three groups: those who should receive another CA125 test one year later (low risk), those who should receive a repeat CA125 in three months (intermediate risk), and those who should receive a transvaginal ultrasound and be referred to a gynecologic oncologist (high risk).
An average of 5.8 per cent of women were found to be of intermediate risk each year, meaning that they should receive a CA125 test in three months.
Ten women underwent surgery based on their ultrasound exams, with four having invasive ovarian cancers, two having ovarian tumours of low malignant potential, one having endometrial cancer, and three having benign ovarian tumours.
The specificity of the testing strategy was 99.9 per cent, meaning that only 0.1 per cent of patients without cancer would be falsely identified as having the disease. Importantly, all of the ovarian cancers were early stage.
"We are currently waiting for the results of a larger, randomised study currently being conducted in the United Kingdom that uses the same Risk of Ovarian Cancer Algorithm in a similar population of women. If the results of this study are also positive, then this will result in a change in practice," Lu said.
The strategy is described in a study published in Cancer, a peer-reviewed journal of the American Cancer Society.