Research summary
August 2008
Combination of tests may improve early detection of ovarian cancer
Researchers have found that the combination of a symptoms questionnaire and the CA125 blood test may improve the early detection of ovarian cancer.
Background
Over 70 per cent of ovarian cancer cases are detected at an advanced stage where the cancer has spread and is difficult to treat successfully. When ovarian cancer is detected early, about 80 to 90 per cent of women will be alive five years after diagnosis. However, there is currently no screening test for the disease.
Earlier research from these authors (published in the journal Cancer, 2007) identified symptoms that when present for less than one year and occurred more than 12 times per month, were significantly associated with ovarian cancer. The symptoms were abdominal/pelvic pain, increased abdominal size/bloating, and difficulty eating/feeling full. The researchers proposed that a symptom index based on these symptoms may be useful in identifying women at risk of ovarian cancer.
Research findings
Current research involving 254 healthy women at high risk of ovarian cancer and 75 women with ovarian cancer investigated the use of a combination of the symptom index described above and the CA125 blood test to detect ovarian cancer.
The researchers found:
- When used alone, the symptom index detected about 45 per cent of women with early-stage ovarian cancer and about 80 per cent of those with advanced disease.
- When used alone, the CA125 test detected about 65 per cent of women with early-stage ovarian cancer and about 90 per cent of those with advanced disease.
- The combination of the symptom index and blood test (where either one or both of the tests were positive) may detect about 80 per cent of women with early-stage ovarian cancer and about 95 per cent of women with advanced disease.
- The symptom index alone identified 50 per cent of women with ovarian cancer who did not have elevated CA125 levels. However, 12 per cent of women without cancer also received a positive symptom index score.
National Breast and Ovarian Cancer Centre comment
Ovarian cancer has previously been referred to as the ‘silent killer’ because it was thought that symptoms did not develop until the disease reached advanced stages. However, research is emerging to show that in some women, the investigation of symptoms may assist in the early detection of ovarian cancer.
This study reinforces the need to investigate symptomatic women and to consider ovarian cancer if symptoms are new, persistent and unexplained. The significance of this study is in the improved early detection of ovarian cancer when a symptoms index and CA125 test are used in combination. However, further investigation, such as a transvaginal ultrasound, would still be necessary as second line assessment before referral for surgery.
This is one of a number of studies currently investigating ways to improve the early detection of ovarian cancer. Other studies involve the development of tests to detect ovarian cancer through the presence of protein biomarkers in the blood. Further research will show which tests may have a role in the diagnosis of ovarian cancer and the screening of women who are at high risk of the disease.
Sources
Goff B, Mandel L, Drescher C, et al. Development of an Ovarian Cancer Symptom Index: Possibilities for Earlier Detection. Cancer. 2007; 109:221-7.
Anderson R, Goff B, Lowe K, et al. Combining a symptoms index with CA125 to improve detection of ovarian cancer. Cancer. Online 25 June 2008.