Ultrasound screening may catch ovarian cancer early

A new study suggests that ovarian cancer screening with a technique called transvaginal ultrasonography (TVS) may catch ovarian cancer early, at a more curable stage.
TVS involves using an ultrasound probe placed in the vagina to direct sound waves through the vaginal wall towards the ovaries to detect abnormalities. The new study shows that TVS screening is able to detect ovarian cancers at an earlier stage, perhaps increasing their chances of survival.
The early diagnosis of ovarian cancer is difficult and the disease is often not detected until it has reached an advanced stage. Compared with other gynecologic cancers, ovarian cancer carries a very poor prognosis.
Dr. John R. van Nagell, from the University of Kentucky in Lexington, and colleagues assessed the value of annual TVS screening for ovarian cancer in 25,327 women who were seen between 1987 and 2005.
To be eligible for the study, the women had to be at least 50 years old with no cancer-related symptoms or at least 25 years old with a family history of ovarian cancer.
Overall, 364 women (1.4 percent) had a persistent ovarian tumor on TVS, the authors report in the journal Cancer. Malignant cases included 35 primary invasive ovarian cancers, 9 ovarian tumors of low malignant potential, and 7 "metastatic" cancers that had already spread beyond the ovaries. Most of the contained or "non-metastatic" ovarian tumors were early stage I tumors.
During an average follow-up of about 5 years, 38 women were alive and well, 4 had died of their cancer, and 2 had died from other causes.
The 2-year survival rate in annually TVS screened women approached 90 percent and the 5-year survival rate in screened women was a little over 77 percent.
TVS screening was highly sensitive and specific in detecting ovarian cancer. However, "false-negative" results were obtained in nine women, including three who died of their disease, the investigators note.
Summing up, the researchers say early detection of ovarian cancer could potentially improve treatment efficacy and reduce deaths. "The protective effect of annual sonographic screening on ovarian cancer mortality observed in the current trial should only increase as more specific biomarkers are added to TVS in screening algorithms," they conclude.
SOURCE: Cancer, May 1, 2007.