By Peggy O'Farrell
The Cincinnati Enquirer

Women are getting mixed messages on mammography: On the one hand, health officials and advocates keep telling them to get a mammogram annually once they reach 40. And on the other, a Danish study trumpeted the message that mammography isn't especially effective at saving lives, raising doubts worldwide about the scan.

Breast cancer accounts for a third of cancer cases among women in the United States. About 40,000 women - and 400 men - die of breast cancer each year.

New screening options are being explored. Some researchers are studying magnetic resonance imaging (MRI), ultrasound and other methods to see how effective they are.

Meanwhile, experts say, mammography meets the three A's required for effective screening: affordability, accessibility and accuracy.

"Mammography is the only imaging tool with proven efficacy in the detection of breast cancer," says Dr. Mary Mahoney, a radiologist and the director of the Breast Imaging Center at the Barrett Cancer Center.

Mammography is an X-ray that shows abnormalities within breast tissue. It can't distinguish between benign or malignant tissues, but it does tell doctors whether a more sophisticated scan or biopsy is necessary. Some radiology centers offer computer-assisted diagnosis on mammograms, in which a computer gives a second "read" on the image to pick up anything the radiologist might overlook.

Mammograms aren't perfect, Dr. Mahoney acknowledges. They're not very effective in women with very dense breast tissue and they aren't always effective in women who have a lot of fibrocystic tissue. Sometimes, doctors do overlook suspicious indicators that mean cancer.

But for the money - usually $60 to $80 - mammograms are a good investment.

"Going to a football game or other sporting event is that expensive," says Dr. Hugh Hawkins, a radiologist with ProScan in Madisonville.

But a study by two Danish researchers printed in the Lancet in 2000 set off a debate over how effective mammography is in increasing survival rates - not in detecting breast cancer. The researchers looked at data from seven previous studies and concluded mammography isn't warranted because there was no evidence that it reduced mortality. The study concluded that mammograms have no impact on treatment outcomes whether a lesion is caught early or at an advanced stage, and that, in some cases, the screenings might lead to more aggressive treatment than a patient really needs to eradicate cancer.

"There's been a lot of hoopla about that" study, says Dr. Blake Cady, a surgical oncologist and director of the Breast Health Center at Women and Infants' Hospital in Providence, R.I. Screening mammography helps determine three of the four criteria by which doctors judge how serious a cancer is: the size of the lesion, the stage of the lesion and whether or not it has spread to the lymph nodes.

Given that, Dr. Cady says, "it's inconceivable that screening doesn't work."

Doctors can detect cancer at a smaller size - on average, about 1.5 centimeters, several studies say, and as small as half a centimeter in some cases - and at a less invasive stage with mammography than without it.

Breast cancer mortality has decreased since mammography became widely available, but experts disagree about whether it's because mammograms helped doctors detect cancer earlier or because treatment has improved.

Screenings for other cancers - notably melanoma, colorectal cancer and cervical cancer - have resulted in significant decreases in mortality, Dr. Cady says. Given those results, he says, it's "illogical" to say mammography can't have the same impact.

First step

It's important to note that mammography doesn't diagnose breast cancer. It simply tells doctors whether they need to take a closer look. If an abnormality shows up on a mammogram, a doctor may order an ultrasound - a technique that uses sound waves to help "map out" the size and shape of an abnormality - and then a biopsy.

There are other screening options for women with dense breast tissue and a high risk of developing breast cancer.

A five-year study released in September showed that ultrasound can detect cancers that mammograms miss in women with dense breasts. The study, which appears in this month's issue of Radiology, found that ultrasound increased cancer diagnoses by 42 percent after mammography. Study authors did not suggest that ultrasound should replace mammography as a screening tool, only that it can be an effective "second look."

Susan Hagness, an electrical engineer at the University of Wisconsin-Madison, is looking at ways to detect breast cancer with ultra wideband microwaves, which produce clearer images than X-rays. Computer models show the method can detect malignancies as small as 2 millimeters, but the method is not available clinically.

At the Mayo Clinic in Rochester, Minn., researchers are working with a technique called magnetic resonance elastography, which uses a combination of sound waves and magnetic resonance imaging (MRI) to evaluate breast tissue "mechanics" that might signal malignancies.

Another study at the Mayo Clinic found that MRI is more effective in detecting breast cancer in women with very dense breasts than mammography.

Imaging techniques, such as MRI, ultrasound and positron emission tomography (PET) scans are more likely to be used to determine how large a malignancy is and how far, if at all, it has spread. Most experts agree the methods are too expensive and too hard to access to be effective for routine screening.

Various methods

How various screening methods are used:

Ultrasound sends high-frequency sound waves through the breast and converts them into an image. Ultrasound can determine whether a lump is solid or fluid-filled, but it can't determine malignancy. It's usually used as a complement to other tests.

Magnetic resonance imaging (MRI) uses magnetic fields, not radiation, to create images of the body. The test is expensive and the equipment relatively rare, so MRI is not considered practical for screening. But MRI can pinpoint where a malignancy originates, which can help guide treatment from a breast-conservation standpoint and whether cancer is contained to a single spot or whether it has spread.

Positron emission tomography (PET) scans detect metabolic activity in cells. Radioactive material is injected into the patient. "Hot spots" indicate active cells that might be cancer. The technology is too rare and expensive to be used for routine screening, but PET scans can identify whether a tumor still exists after treatment, whether cancer has spread to the lymph nodes and how cancer is responding to treatment.

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