According to a study published in the International Journal of Cancer, testing for serum levels of three markers-CA-125, IL-18, and FGF-2-more accurately detects ovarian cancer than testing for CA-125 alone.
Due to a lack of definitive symptoms, the majority of women with ovarian cancer are not diagnosed until their cancer has reached an advanced stage and is considered incurable. For this reason, ovarian cancer has been referred to as the “silent killer.”
Several methods of screening for ovarian cancer have been explored, but none have been uniformly successful. These include transvaginal ultrasound, measurement of serum CA-125, and genetic testing for BRCA1 and BRCA2.
CA-125 is a substance produced by several types of cells, including ovarian cancer cells. Women with ovarian cancer frequently have high CA-125 levels, and changes in level of CA-125 may be used to monitor response to treatment.
Though CA-125 can help identify women with ovarian cancer, the test is not perfect. CA-125 testing misses some women with ovarian cancer (false-negative test) and incorrectly classifies some women without ovarian cancer (false-positive test).
In an attempt to improve the accuracy of serum tests for ovarian cancer, researchers evaluated a combination of three serum markers-CA-125, IL-18, and FGF-2. The researchers evaluated levels of IL-18 and FGF-2 in serum from women with and without ovarian cancer, and explored how accurately these markers, in combination with CA-125, identified the presence or absence of ovarian cancer. The study involved 47 women with ovarian cancer and 25 women without ovarian cancer.
- Serum levels of IL-18 and FGF-2 were significantly higher in women with ovarian cancer than in women without ovarian cancer.
- Compared to testing for CA-125 alone, testing for the combination of three markers identified a similar proportion of the women with ovarian cancer. Among the 45 women with ovarian cancer, the CA-125 test correctly classified 37 women as having cancer, and the combination of three tests correctly classified 35 women as having cancer.
- The combination of three tests more accurately classified the women without cancer. Among the 25 women without ovarian cancer, the CA-125 test correctly classified 15 women as cancer-free, and the combination of three tests correctly classified 20 women as cancer-free.
Although larger studies will be needed to confirm these results, the researchers conclude that testing for this combination of three markers produces fewer false-positive results than testing for CA-125 alone. Reducing the number of false-positive results would help some women avoid unnecessary anxiety and diagnostic tests.
Reference: Le Page C, Ouellet V, Madore J et al. From Gene Profiling to Diagnostic Markers: IL-18 and FGF-2 Complement CA125 as Serum-Based Markers in Epithelial Ovarian Cancer. International Journal of Cancer. 2006;118:1750-1758.