Postmenopausal Bleeding: Possible Causes

By Frederick R. Jelovsek, M.D.

The most common presenting symptom of endometrial (uterine) cancer is abnormal uterine bleeding. Most of the time it is categorized as postmenopausal bleeding since the age range of endometrial cancer is usually over age 50. On the other hand, of all postmenopausal bleeding, only 5-10% is due to cancer or its precursors. Traditionally, a D&C in the hospital was the gold standard method to rule out cancer. It was replaced by endometrial biopsy over the last 15-20 years. Now there has been a recent trend to avoiding endometrial biopsy, an invasive and somewhat painful procedure, by using vaginal probe ultrasound to initially evaluate women with postmenopausal bleeding. If the thickness of the endometrial stripe is less than 5 mm, the chances of cancer are less than 1%. What is not clear is whether the strategy of doing an ultrasound first is cost-effective since over half the patients will still need a biopsy.

- A. Weber and others, Vaginal ultrasonography versus endometrial biopsy in women with postmenopausal bleeding, Am J Obstet Gynecol 1997;177:924-9, did a study to try to determine whether an endometrial biopsy should be the primary procedure or ultrasound. Any strategy of diagnostic work-up depends upon the diagnostic accuracy and the costs of each procedure. Accuracy estimates will have a range from various studies and costs will vary at each doctor's office or hospital. For example, endometrial biopsy may only be accurate 62-82% of the time and non-diagnostic the rest of the time. Vaginal ultrasound may vary in cost from $60-$100 or more. The most optimal strategy will thus be very dependent upon which numbers are used in the calculation. In this study, the authors varied the numbers and tested many different combinations.

Their conclusion was that the algorithm using vaginal ultrasound as the initial procedure usually was the most cost effective, $218-$231 versus $238-$246 for biopsy first algorithm. They even present formulae so practitioners can calculate the best strategy based upon local costs and estimates of diagnostic accuracy.

I was impressed that there actually was very little difference between the two approaches. Either one could be used depending upon convenience and cost. The strategy using vaginal ultrasound first is less painful for almost 50% of women so it makes sense to adopt that approach (first do no harm).