NEW YORK (Reuters Health) - Annual screening with a technique called
transvaginal ultrasound, coupled with a blood test for CA125, a protein that can
be elevated in the setting of ovarian cancer, does not reliably detect ovarian
cancer early, at a more curable stage, according to a new study.
"We and other groups confirm that the current method of ovarian screening, which
is a combination of ultrasound scans and (blood) markers, is ineffective," Dr.
Emma R. Woodward from Birmingham Women's Hospital, UK, told Reuters Health.
"Therefore, for women at high risk of developing ovarian cancer, the only real
option at present to prevent ovarian cancer death is to have the ovaries removed
as a preventive measure."
The early diagnosis of ovarian cancer is difficult and the disease is often not
detected until it has reached an advanced stage.
In a "look-back" study, Woodward and colleagues assessed the effectiveness of
ovarian cancer screening with the CA125 blood test plus transvaginal ultrasound,
which involves placing an ultrasound probe into the vagina to detect
abnormalities in the ovaries, in 341 women with a family history of ovarian
cancer.
Out of 1,084 surveillance ultrasounds, 929 (86 percent) were normal and 155 (14
percent) were abnormal, the investigators report. Only 18 (2 percent) of 875
surveillance CA125 tests were abnormal.
Fifty-seven women (17 percent) had their ovaries removed as a preventive measure
and 30 of the remaining women had "exploratory" surgery following abnormal
surveillance ultrasound or CA125 testing.
Only four women developed ovarian cancer, the investigators report. Only one was
detected at surgery for abnormal screening results and it was classified as
advanced. In the other three cases, the women developed symptoms between
screenings.
Based on these findings Woodward suggests that, for those women who are not at
high risk for ovarian cancer, "ovarian cancer screening should not be offered
unless it is within a clinical trial aimed at developing new methods for ovarian
screening."
"By entering such a screening program, healthy women may have exploratory
surgery because of false-positive findings, thereby putting themselves at risk
of potential surgical complications," Woodward pointed out.
"Furthermore, the few women who do develop ovarian cancer are unlikely to be
diagnosed at an early stage when the disease is curable."
SOURCE: BJOG: An International Journal of Obstetrics and Gynecology, December
2007.
