Letters to the Editors

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Authors' reply

We would like to respond to the letter from Dr Parker and colleagues[[1]]. The thrust of our comments was whether to retain ovaries at the time of hysterectomy[[2]]. Our commentary emphasized that we felt that it was important to make women aware of the risks of ovarian cancer and the opportunity to decrease this if they were already undergoing laparotomy for a gynecological reason. Our emphasis, as stated several times in our comments, was purely related to the peri- or postmenopausal woman already undergoing a planned procedure.

We agree that benign ovarian cysts in postmenopausal women do not require surgical intervention. However, this is not the issue. The very appropriately quoted study from Dorum and colleagues shows that ovarian cysts are common among postmenopausal women[[3]]. That no ovarian cancer was found is no surprise as they performed autopsies on only 234 women. The ovarian cancer incidence is about 50/100 000 postmenopausal women and it would have been a pure chance to detect one[[4]]. But, although ovarian cysts in postmenopausal women are benign in the majority of cases, it has to be appreciated that no currently available test is perfect, offering 100% specificity and sensitivity. Ultrasound often fails to differentiate between benign and malignant lesions, and serum CA-125 levels, although raised in over 80% of ovarian cancers, are raised in only 50% of stage I cases. Although expectant management of postmenopausal women with low-risk ovarian cysts (less than 3% risk of cancer) is usually suggested, guidelines also recommend a follow-up with ultrasound scans and CA-125 measurements every 4 months for 1 year[[5]]. This creates significant stress and anxiety for the woman until the ovarian malignancy is excluded – in many cases by a surgical intervention.

As long as we do not have a reliable early diagnostic test for ovarian cancer, an oophorectomy remains the only means to decrease the incidence of this deadly disease. Therefore, from the gynecological oncological perspective, a bilateral salpingo-oophorectomy should be part of a hysterectomy for benign disease in a peri- or postmenopausal woman.

Ultimately, only a prospective randomized trial comparing oophorectomy versus ovarian preservation at the time of surgery for benign disease is going to give a definitive answer to this controversy. Meanwhile, we wish to ensure that women are given sufficient information prior to planned surgery to best protect themselves against cancer, unnecessary worry about subsequent ovarian masses, and the possible need for further surgery at an older age where they might be less resilient.

None of the comments by Parker and colleagues change any of these arguments.

Department of Gynaecological M. Davy Oncology M. K. Oehler

Royal Adelaide Hospital

South Australia

Author's reply

I would like to reply to the letter of Parker and colleagues[[1]] concerning my commentary discussing the validity of the epidemiological evidence for whether retention of the ovaries improves long-term survival after hysterectomy[[2]]. Among the principal determinants of mortality in elderly women are coronary heart disease, stroke, and cancers of the breast and large bowel. Other outcomes such as pulmonary embolism are common, and caused by supplemental hormones. The claim that a valid prediction of the risk of such outcomes in oophorectimized women can be made, while ignoring menopausal and other relevant factors, is absurd.

I have described the defects of meta-analysis elewhere[[3,], [4]]. If anything, the decision analysis of Parker and colleagues was even more defective: whereas meta-analysis at least purports to synthesize the total evidence across an array of studies, Parker and his colleagues simply selected those studies that they deemed to be the best evidence[[5]]. The rest of us are under no obligation to agree with them, or with the implied claim that a commonly used and validated (i.e. ostensibly ‘objective’) quality grading system[[6]] renders our judgments redundant. Common use is not a criterion of validity. Nor is a system valid simply because a task force decrees that it is[[6]].

Finally, histories of hysterectomy with or without oophorectomy have only been incompletely checked (‘validated’) in a limited number of studies, and hardly checked at all if they occurred in the distant past; the estimation of mortality using relative risk estimates derived from incidence data is questionable; and what is meant by the phrase ‘confidence intervals were also captured by sensitivity analyses, including worst-case scenarios’ is unclear: unless the lowest reported confidence limits were evaluated, the sensitivity analyses were incomplete.

Department of Public Health S. SHAPIRO and Family Medicine

University of Cape Town Medical School

South Africa