Breast Cancer Study Turns to Noninvasive Surgery

W A S H I N G T O N, Oct. 30, 2000 -- Vicki Freeman lay perfectly still inside atube-like machine as ultrasound waves beamed deep into hercancerous breast. Little bursts of heat signaled the beams werecooking her tumor to death — without a mark or cut to her skin.

Freeman is one of the first women to try a novel medicalexperiment to see if this “focused ultrasound therapy” might oneday offer a noninvasive alternative to breast cancer surgery.

It will take years of study to prove whether cooking tumorsworks. But as women already clamor for less disfiguring breastsurgery, pilot experiments at Houston’s M.D. Anderson Cancer Centerand Boston’s Brigham & Women’s Hospital signal the latest in agrowing trend: research on ways to make cancer removal not justless invasive, but to quit cutting patients altogether.

“If you think about surgery, it’s sort of medieval,” says Dr.Darrell Smith, a Harvard University radiologist conducting Brigham& Women’s study. “We’re trying to get more elegant in the way wedo this. It’s kind of Star Trek in a way.”

Minimal Tumor Removal?

Yet it raises a serious safety question: Are doctors trying tomake tumor removal too minimal, particularly for diseases likebreast cancer where surgery can work very well? After all,scientists already know that some younger women undergoinglumpectomies get too little tissue cut out for cosmetic reasons,leaving them more vulnerable to cancer’s return than if they hadproperly sized lumpectomies. Plus, if nonsurgical methods do provesafe, they’ll require more complicated machinery — and thus will bemore expensive — than a simple lumpectomy.

But some radiologists insist noninvasive technologies shouldeliminate just as much tumor as a surgeon’s knife. A small Harvardstudy, to be unveiled at a radiology meeting next month, suggestsfocused ultrasound can successfully cook away benign breast tumorscalled fibroadenomas, bolstering hopes for the new cancerexperiments.

And while breast cancer offers an easy-to-study target, theultimate goal is to one day help harder-to-treat brain, liver orsoft-tissue cancer, or other disorders like uterine fibroids, wheresurgery isn’t optimal.

“We know from basic science and animal research that it canwork. Now we have to show it’s feasible,” says M.D. Anderson’s Dr.Marc Fenstermacher, who treated Freeman.

To do that, Fenstermacher and Smith will test 30 women destinedfor surgical removal of small breast tumors. Patients lie inside aspecially outfitted MRI, or magnetic resonance imaging, machine.Guided by the MRI’s continual sharp picture of the tumor, doctorsposition ultrasound focusing equipment called transducers, builtinto the MRI table, to beam into the tumor. On the MRI, the tumorlights up as 10-second blasts heat it to more than 140 degrees.

About a week later, study participants undergo a regularlumpectomy to see if the tumor really is dead and if enough tissuearound it is free of cancer cells — an important safeguard for afirst study. If it works safely, doctors eventually will seek Foodand Drug Administration permission to test focused ultrasoundwithout a lumpectomy.

“It meant I wasn’t really benefitting myself ... but I hope I’mhelping other women down the road,” says Freeman, who praised thepain-free ultrasound.

Not Burning But Altering

How does it work? Hold a magnifying glass in sunlight. The lenscan focus enough light to burn, say, a leaf directly underneath — but that’s the only hot spot, Smith explains. Similarly, thetransducers act like a lens to focus heat from high-intensityultrasound waves just on the tumor, leaving other breast tissueunharmed.

Ultrasound kills not by burning but by altering cancer cells’proteins, much like boiling an egg stops a chick’s development.It’s not the only nonsurgical method under study, but it’scompletely noninvasive.

In contrast, the University of California, Los Angeles, islooking for volunteers to try freezing breast cancer using aneedle-like probe stuck into the tumor, alternately freezing andthawing it until the cancer cells’ membranes burst. Otherscientists are experimenting with probes that deliverradio frequency waves to burn liver or breast tumors, and withinjectable drugs that sensitize certain tumors to cancer-killinglight beams.

“The fundamental question: Which [method] gives us the bestkilling, best cosmetic result and most economical result?” saysUCLA’s Dr. Helena Chang, who leads the freezing experiment.

If such methods ultimately do work, doctors caution they’re onlyfor tumor eradication — they won’t replace the chemotherapy andradiation many patients need after a tumor is removed.