Scientists have developed a new screening strategy for ovarian cancer, which could detect the disease in its early stages, according to a study published in the journal Cancer.
Researchers from the University of Texas MD Anderson Cancer Center in Houston have created a "two-stage" ovarian cancer screening method that measures changes in a blood protein called CA125, a protein known as a marker for tumors.
The scientists say that if this new screening strategy is accepted for clinical trial, it could help save the lives of thousands of women in the US alone.
The study, conducted over an 11-year period, analyzed 4,051 post-menopausal women. All women underwent an annual CA125 blood test at the baseline of the study.
The researchers then used a calculation called the "Risk of Ovarian Cancer Algorithm" to divide the women into three groups. These were:
- Women who should receive another CA125 test 1 year later (low risk)
- Women who should receive a repeat CA125 test in 3 months (intermediate risk)
- Women who should receive a transvaginal ultrasound and be referred to a gynecologic oncologist (high risk).
Findings of the screening revealed that, on average during each year of the study, 5.8% of the women were at intermediate risk.
Around 0.9% of the women were referred to receive a transvaginal ultrasound and review by a gynecologic oncologist annually. From this, ten of the women had surgery.
Four had invasive ovarian cancers, while two women had ovarian tumors of "low malignant potential," one had endometrial cancer, and three had benign ovarian tumors.
The researchers say that these results show a "positive predictive value of 40% for predicting invasive ovarian cancer."
The specificity of the screening method was 99.9%. This means that the percentage of patients who could be falsely identified as having the cancer would be just 0.1%.
The study authors say these findings show that the new screening strategy achieves "high specificity with very few false-positive results" in post-menopausal women.
Dr. Karen Lu of the University of Texas and lead author of the study, says:
"The results from our study are not practice-changing at this time. However, our findings suggest that using a longitudinal (or change over time) screening strategy may be beneficial in post-menopausal women with an average risk of developing ovarian cancer."
Dr. Lu adds that the researchers are currently awaiting the results of a larger, randomized UK study that uses the same "Risk of Ovarian Cancer Algorithm" method in a similar population of women.
"If the results of this study are also positive, then this will result in a change in practice," she adds.
However, Abi Begho, healthcare projects manager at Ovarian Cancer Action in the UK, says this new screening method may not be accurate in detecting the sensitivity of ovarian cancer cases - the proportion of positive cases correctly identified.
"While the specificity of this screening strategy is very good, the research was not designed to detect sensitivity," says Begho.
"They did measure the sensitivity to be 60%, so there is room for improvement, but the researchers did note that no cases of invasive ovarian cancer were missed so the sensitivity could be better than actually reported."
According to the National Cancer Institute, there will be 22,240 new cases of ovarian cancer in the US this year, with 14,030 deaths from the disease.
At present, there are no effective methods for detecting ovarian cancer in its early stages. One problem is that early symptoms of ovarian cancer, such as abdominal pain and feeling bloated and full, are sometimes mistakenly diagnosed as other ailments. Because of this, the majority of women are diagnosed when they are in the late stages of the disease.
Other studies have reported potential new screening methods, which could be used to detect the early stages of ovarian cancer. Medical News today recently reported that US researchers are in the process of developing a breakthrough screening method - training dogs to sniff out ovarian cancer by detecting the odorous compounds found in the disease.