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Transvaginal Ultrasound Screening May Help Detect Ovarian Cancer at Earlier Stages

Researchers at the University of Kentucky Medical Center in Lexington have been investigating a procedure called transvaginal ultrasound that may be effective in detecting ovarian cancer at an early stage. Because there are currently no reliable tests to screen for ovarian cancer, most tumors are detected in late stages when the chances of survival are generally low. According to Dr. Beth Karlan, director of gynecologic oncology at Cedar Sinai Medical Center in Los Angeles, the transvaginal ultrasound provides a clearer picture of the ovaries than conventional abdominal ultrasound.

In a study of 14,469 women with no symptoms of ovarian cancer, researchers detected 17 ovarian cancers (of 180 tumors found) with transvaginal ultrasound. Women who had abnormal findings on the first screening underwent additional tests over a period of four to six weeks to make sure the abnormality was not a transient cyst. Those who had persistent abnormalities were then required to undergo a series of blood and ultrasound tests to determine whether there was a need for surgery. After surgery, researchers determined that 11 of the cancers were Stage I (early stage), three were Stage II, and three were Stage III (late stage). Although the total number of ovarian cancers detected was relatively small, the majority of tumors were detected at an early stage, when they are most likely to respond positively to treatment.

To perform a transvaginal ultrasound, gynecologists insert an ultrasound probe, slightly larger than a tampon, into the vagina. According to Dr. Karlan, the transvaginal ultrasound is anatomically closer to the ovaries in many women than abdominal ultrasound and allows physicians to more accurately see what the ovaries look like. Abdominal ultrasound requires the ultrasound waves to pass through the abdomen, causing the image to be less clear. In general, the closer the ultrasound probe is to the area being imaged, the clearer the image will turn out. Women in the study reported that transvaginal ultrasound was also more comfortable than conventional abdominal ultrasound that requires a distended bladder.

Though the study does not definitively confirm that transvaginal ultrasound reduces the risk of dying from ovarian cancer, researchers believe the exam may help reduce the number of late-stage diagnoses. It is estimated that nearly 15,000 women die from the disease each year, 70% of whom are not diagnosed until the cancer has spread beyond the ovaries.

Early detection of ovarian cancer is the key to survival. Some symptoms of ovarian cancer include:

  • Pelvic or abdominal pain or discomfort
  • Vague, but persistent, gastrointestinal upsets such as gas, nausea and indigestion
  • Frequency and/or urgency of urination in the absence of an infection
  • Unexplained changes in bowel habits
  • Unexplained weight gain or weight loss, particularly weight gain in the abdominal region
  • Pelvic and/or abdominal swelling, bloating, and/or feeling of fullness
  • Pain during intercourse
  • Ongoing fatigue
  • Abnormal post-menopausal bleeding

If diagnosed and treated before the cancer has spread outside the ovary, the five-year survival rate is 95%. However, only 25% of all ovarian cancers are presently detected at this early stage.

Additional Resources and References

Updated: July 23, 2001