Antibody Discovery May Help Detect Ovarian Cancer Early
Ovarian cancer is a formidable challenge to detect and treat, but now scientists have identified an antibody in the blood of infertile women that could eventually be used to screen for the disease in its early stages. Rush University Medical Center researchers detected a significant amount of the antibody on the surface of ovarian cancer cells.
Early detection of ovarian cancer could save lives
While the mortality rates of many other cancers have improved in recent years, the rates for ovarian cancer remain poor. The relative five-year survival rate is 46 percent, with women diagnosed at an early stage of the disease having a much higher five-year survival rate than those who are diagnosed at a later stage. However, the disease is detected early in fewer than 20 percent of women with the disease.
One of the few known risk factors for ovarian cancer is infertility, with women in both groups having autoantibodies to ovarian antigens, substances that cause the immune system to produce antibodies against it. In this latest study, researchers found that infertile women have antibodies to a protein called mesothelin, a known ovarian cancer antigen.
Investigators obtained sera samples from 109 infertile women, 28 with ovarian cancer, 24 with benign ovarian tumors or cysts, and 152 healthy women. Significant levels of antibodies to mesothelin were present in women with ovarian cancer, premature ovarian failure, ovulatory dysfunction, and unexplained infertility, but not in healthy women, women with endometriosis, or women who had benign ovarian disease.
Even though the researchers don’t know why mesothelin antibodies should be linked with ovarian cancer, the finding is “extremely important because at present medical tests are unable to detect ovarian cancer in its early stages,” noted Judith Luborsky, PhD, professor of pharmacology, obstetrics and gynecology and preventive medicine at Rush and the study’s lead author.
Screening for ovarian cancer typically involves a pelvic examination, especially for women who have persistent abdominal discomfort and/or those with a family history of the disease. Two other tests not routinely done—transvaginal ultrasonography and CA125 blood test, are recommended for women with a family history of ovarian cancer, although these screening procedures are imperfect.
A symptoms index can also be helpful in making a diagnosis. Women who have any of the following symptoms more than 12 times per month, occurring only within the past 12 months, are suspect: bloating or increased abdominal size, pelvic or abdominal pain, and difficulty eating or feeling full quickly.
Luborsky also explained that “with the discovery of the mesothelin antibody, we now have what appears to be a biomarker that can potentially be used in screening tests to help us conquer ovarian cancer.” The National Cancer Institute reports that an estimated 21,990 new cases of the disease and 15,460 deaths will occur in 2011.