Screening for Ovarian Cancer With Biomarkers: Are We There Yet?
CA-125 is used mainly to monitor patients with ovarian cancer (OC), in part due to the low level of sensitivity when CA-125 is used alone. In an effort to improve the early detection of OC while keeping the number of false positives low (higher specificity), studies of other biomarkers, either alone or in combination with CA-125, are ongoing. In one such study, apolipoprotein A-1, transthyretin and transferrin were combined with CA-125 to detect early-stage mucinous tumors. This panel detected early-stage cancer with a sensitivity of 96 percent.
Another study of multiple markers included CA-125, macrophage colony-stimulating factor, and OVX1. At least one of the serum markers was elevated in 98 percent of patients with stage I ovarian cancer; CA-125 levels alone were elevated in only 67 percent. By the same criteria, 11 percent of healthy individuals and 51 percent of patients with benign pelvic masses had at least one elevated marker value. The authors concluded that “a panel of these three tumor markers can identify early-stage ovarian cancer with extremely high sensitivity and moderate specificity.”
Studies of annual screening have been reported in the U.S. and U.K. with more than 230,000 followed for up to three years. The British group concluded that “the prevalence screen has established that the screening strategies are feasible. The results of ongoing screening are awaited so that the effect of screening on mortality can be determined.”
While not all groups agree that such screening is efficient, continued research with CA-125 and other markers is needed to validate the encouraging work that has been done.
Shawn Berberich contributed to this entry.