Detecting Ovarian Cancer
A box accompanying "Stopping an elusive killer" [June 28], about the early detection of ovarian cancer, exaggerated the benefit of screening for high-risk women.
No major expert group -- including the U.S. Preventive Services Task Force and the American College of Obstetrics and Gynecology -- recommends such screening. Only the American Cancer Society (ACS) suggests that women with a very strong family history of ovarian cancer may be screened with transvaginal sonography. And even the ACS acknowledges that it is not known how helpful such testing is.
Why isn't screening recommended? Because no study has shown screening to reduce the chance of dying from ovarian cancer. Most women with an abnormal ultrasound test do not have ovarian cancer. But to sort out whether an abnormal ultrasound means cancer requires further testing, and this often includes surgery. One published analysis estimates that for every 10,000 women undergoing twice-a-year ultrasound testing, 350 will have a false positive and 65 will undergo surgery unnecessarily because of this.
Steven Woloshin, MD, MS,
Lisa M. Schwartz, MD, MS
VA Outcomes Group
White River Junction, Vt.
Associate Professors of Medicine
Dartmouth Medical School, Hanover, N.H.
The author replies:
Experts understand the need for improved screening. As Sam Mok, director of Harvard Medical School's Laboratory of Gynecologic Oncology at Brigham and Women's Hospital, so elegantly states, "Studies to date indicate that ultrasonography can increase the chances of finding ovarian cancer by about tenfold . . . However, we don't know if this is sufficiently sensitive for early-stage disease."
Still, most experts continue to recommend screening ultrasound for patients in high-risk groups, says David Fishman, director of the National Ovarian Cancer Early Detection Program, because "the ovary is often missed on a physical examination. We need a test to visualize the ovary in these patients especially when we can't palpate it." Fishman says "All the societies would officially recommend ultrasound for these patients, if not for the significant expense."
Several studies show that the diagnostic yield of ultrasound outweigh the risks of false positives. Diagnostics tests like mammography and cervical Pap testing also carry the risk of over-interpretation, which is why their use in the whole population has been debated. But there is little debate that these tests or ultrasonography, for that matter, should be used in high risk groups.
Marc Siegel, MD
Associate Professor of Medicine
New York University Medical School
Dr. Siegel writes: "Currently, there is no blood test. . . . "The closest marker for ovarian cancer, CA-125, is inaccurate."
Not so fast. The U.S. government 10 years ago took the official position that CA-125 should be used along with ultrasound and pelvic exam to screen women with a hereditary ovarian-cancer syndrome.
Recent research shows that rising CA-125 values provide a more accurate test, whereas a single test is less useful. These preliminary results are being evaluated in a 200,000-woman screening trial that could finally yield the level of proof sought by the medical establishment -- but not until 2011, when the trial ends.
Meanwhile, CA-125 is used every day in screening high-risk women like myself (five relatives with ovarian cancer).
Tasting Food Poisoning
As Carole Sugarman notes in "A Taste of Food Poisoning" [July 5], her daughter Anna's experience with salmonellosis was not unique. With 76 million illnesses and 5,000 deaths caused by food-borne illnesses annually, we could be doing much more to reduce the presence of salmonella and even more deadly pathogens in our food, if only Congress would act.
In 2003, the National Academy of Sciences called on the Congress to grant the U.S. Department of Agriculture (USDA) clear authority to establish and enforce standards to reduce the presence of deadly pathogens in meat and poultry. Together with senators Tom Harkin and Arlen Specter, we responded by introducing legislation ("Kevin's Law") to give the USDA this much-needed authority. Named for Kevin Kowalcyk, a 2 1/2-year-old boy who died after ingesting the deadly O157:H7 strain of e.coli, this bill has been pending in Congress for over four years with no action.
To help prevent other Annas and Kevins from suffering, Kevin's Law deserves, at the very least, a hearing.
Rep. Anna G. Eshoo (D-Calif.),
Rep. Phil English (R-Pa.)
Unfortunately, Sugarman's story is not unique. Of the few patients who seek medical treatment, only a fraction provide samples for testing and, of this number, even fewer are sent to state labs. The Association of Public Health Laboratories, a nonprofit organization representing the national interests of state public health labs, has recommended that states require clinical or hospital laboratories to refer samples to state laboratories for testing. Yet only 36 percent of states have such a requirement.
With state regulation and a deeper commitment from hospitals, doctors and patients, the U.S. will continue to make great strides in reducing foodborne outbreaks.
Association of Public Health Laboratories
An item [July 5] made a confusing -- and somewhat misleading -- assertion about the safety of aspartame.
Hundreds of published studies have confirmed aspartame's safety, and a wide range of professional, medical and patient-advocacy groups have endorsed its use as a low-calorie alternative to sugar. As a District-based physician with a focus on nutrition and obesity, I see patients every week whose general health depends in part upon their ability to limit their caloric intakes. FDA-approved sweeteners like aspartame are useful in meeting this challenge.
C. Wayne Callaway, MD