The Search For Smaller Tumors

By Christine Gorman

Mammograms have saved the lives of tens of thousands of women over the past 20 years. Though mammograms are not perfect, their ability to detect small tumors gives doctors and their patients the option of treating the cancer while it is in an early, more curable stage. And yet by the time even a small tumor is picked up on a mammogram, odds are it has been growing for five to seven years. What if doctors could find even younger (and therefore presumably easier to treat) breast tumors? That's the question that a group of researchers asked themselves at a conference sponsored by the Department of Defense that ended in Atlanta last week. Their cautious conclusion: with a little help from the biotech industry, they may have found some good strategies for uncovering the tiniest of tumors.

BLOOD TESTS Researchers from the John Wayne Cancer Center in Santa Monica, Calif., are working on developing biological markers that could identify microscopic tumors as they travel through the blood. As many as 20% of women with early breast cancer whose tumor has not, as far as anyone can tell, spread to the lymph nodes have a recurrence of the malignancy after their treatment. Current thinking is that they must already have had so-called micrometastases in their bloodstream and that a blood test might eventually uncover the problem ahead of time. Depending on the result, doctors could then pursue more aggressive treatment.

A "PAP SMEAR" FOR THE BREAST Since most breast tumors seem to originate in the milk ducts, why not just remove fluid from the ducts and check the cells for signs of abnormal growth? (That's basically the strategy doctors and other health-care providers use during a Pap smear to check the cervix for signs of abnormal growth before the cells become dangerous.) If there is a problem, so the theory goes, it could be traced to a particular duct, which would then be carefully monitored for signs of malignancy. One major drawback: seemingly abnormal results can be triggered by changes in the breast during pregnancy, breast feeding, certain stages of the menstrual cycle, and menopause.

BETTER BREAST SCANS Researchers at the University of Chicago and elsewhere are developing computer programs that can point out questionable areas on mammograms that might easily be missed. Other scientists are looking at the possibility that a different type of scan, magnetic resonance imaging, can help spot tumors in areas of the breast that are difficult for a mammogram to penetrate.

This research is so preliminary that no one knows yet which strategies will pan out or even if it's a good idea to look for microcancers. After all, it's quite possible that the body successfully destroys small clumps of tumor cells all the time. Being able to identify them could therefore subject women to needless worry and possibly unnecessary treatment. In addition, it's not always easy to draw the line between normal tissue that happens to be growing a little funny and cells that are destined to become lethal.

For now, at least, mammograms (combined with self-exams) are the best bet for early detection. If you're a healthy woman, 40 or older, be sure to get a mammogram once a year and check your breasts every month. But also keep an eye out for research news that could change the nature of your next breast exam.