Accuracy of Screenings for Ovarian Cancer Is Still Inconsistent
Because screening for ovarian cancer is still in its infancy, women
should educate themselves about symptoms and risk factors. There is no
single, proven screening technique for ovarian cancer for the general
population. However, there are recommendations for high-risk individuals and
a combination of screening methods are being tested for the general
population.
Women are at high risk of developing ovarian cancer if there is a strong
family history of ovarian cancer or a combination of cancers linked to a
family cancer syndrome, which may include breast, ovarian, uterine and
colorectal cancers. A genetic test is available to help determine if a women
carries a mutated gene, known as BRCA1 or BRCA2, that makes her more likely
to develop ovarian or related cancers. This test may be offered to women who
appear to have a greater than 10% chance of getting such cancers.
The Froedtert & Medical College Cancer Genetics Screening Program includes a
cancer geneticist/counselor and committee of doctors. After a review of
family history and discussions with the patient, a blood test may be
administered and analyzed for the mutated cancer genes. Typically, it will be
offered to patients who have two or more first-degree relatives (mother or
sisters) who developed ovarian cancer or family cancer syndrome cancers by
the age of 50. An early onset or cluster of breast cancers, even in aunts and
cousins, is of particular note. Patients with such a strong family history
usually have a greater than 10% chance of getting ovarian and/or related
cancers. If the test does not show a gene abnormality, it is most likely not
a hereditary condition and the individual is not at high risk of developing
the cancer.
If a gene abnormality is found, there are two approaches. In women who are
older or who do not want more children, the ovaries are removed as a
preventive measure. However, this is not 100% reliable, as primary peritoneal
cancer, which mimics ovarian cancer, is still possible, although rare. In
younger women who may want children, more screenings will be conducted. A
blood test for CA125, the tumor marker for the most common form of ovarian
cancer, will be administered every six months to a year thereafter. In
addition, a transvaginal ultrasound, in which a probe is inserted into the
vagina, will be administered on the same time schedule. A recto-vaginal
pelvic exam will also be conducted every six months to a year thereafter.
Challenges
Unfortunately, the CA125 blood test is unreliable. Younger patients may have
elevated tumor markers because of conditions unrelated to cancer, such as
endometriosis or menstruation irregularities. Older, non-menstruating
patients may show elevated CA125 markers if they have diverticulitis, for
example. And individuals who have the initial, or Stage 1, ovarian cancer,
display elevated CA125 markers only about half the time. It is far from a
perfect test, and used alone, is not beneficial. An ongoing study is checking
the efficacy of transvaginal ultrasound with the CA125 test.
Past studies of ovarian cancer screening tests typically found a small number
of cancers, but usually in patients who had advanced symptoms already and who
were beyond the curable stage. Some studies have found that false-positive
screening results led to more women having unnecessary surgeries than the
number of true-positive results detected by the test. Various blood tests are
currently under study, and a screening for lysophosphitidic acid (LPA) shows
promise in identifying early-stage ovarian cancer.
Stage 1 ovarian cancer is curable, but most ovarian cancer cases are
discovered in Stage 3 in which the cancer has spread beyond the ovaries and pelvic area. Cure at an advanced stage is more elusive than in Stage 1. Stage 1
ovarian cancer symptoms are non-specific, making them difficult to identify.
However, high-risk individuals and even the general population can benefit by
knowing them. Symptoms include: an abdomen that is growing in size for no
apparent reason; pelvic pain, pressure or bloating; heartburn; and a bladder
that is not functioning as well.
Until a better screening method is developed, women should learn the symptoms
of ovarian cancer, determine if they are at high risk for the disease, and
follow-up accordingly. If they are not at high risk, they should at least
have an annual pelvic exam of the recto-vaginal areas.
Kenny Bozorgi, MD
Former Assistant Professor of Obstetrics & Gynecology
Medical College of Wisconsin and Froedtert Hospital
Article Created: 2000-07-13
Article Updated: 2000-07-14
MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.
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