Surgery By Radio Waves

by Margaret Chiffriller

A non-surgical lumpectomy procedure is being developed at UC Davis Cancer Center. Instead of cutting out a tumor, the experimental technique uses radio wave energy to kill cancer cells in the breast.

Although it is experimental in breast cancer treatments, the technique is not new. Radio wave therapy, or radiofrequency ablation, has been used for years in the treatment of liver and bone cancers. Researchers are also studying the therapy as a treatment for lung and prostate cancers.

Radio wave therapy has shown favorable results in trials with breast cancer patients at Stanford University, the University of Texas M.D. Anderson Cancer Center in Houston, and the Weill Cornell Breast Center in New York.

A study published in the July, 2001, issue of Radiology, reported on 24 breast cancer patients with liver metastases who were treated with radio frequency ablation. Single lesions were treated in 16 patients, and multiple lesions were treated in 8 patients. Complete necrosis was achieved in 92% of the liver lesions. New metastases developed in 58 per cent of the patients during follow-up. The remaining 42% of patients developed no new metastases.

Vijay Khatri, assistant professor of surgery at UC Davis Cancer Center, John McGahan, professor of radiology, and Bijan Bijan, assistant professor of radiology, are leading a pilot study to evaluate the technique's effectiveness in Stage 1 breast cancer tumors. The investigators are ready to enroll about 30 Sacramento-area women with very small, early stage breast tumors in the study.

To perform radiofrequency ablation, doctors first locate the tumor using ultrasound. Next a thin metal probe is introduced into the tumor through the skin. Tiny wires at the tip of the probe vibrate, generating a frictional heat that kills all of the cells touched by the probe. Patients walk away after the procedure with only a tiny cut visible on the skin. The dead cancer cells from the tumor eventually form a scar inside the breast.

Because the technique is experimental, all of the women will undergo a conventional lumpectomy or mastectomy following the radio wave treatment. After this conventional surgery, researchers will carefully examine the excised breast tissue to confirm that all cancer was eradicated by the radio wave treatment.

If the pilot trial finds radio wave treatment to be effective in killing the tumor cells, the technique could offer advantages over lumpectomy. "There are two potential advantages of the new technique," Khatri said. "First, you don't have to make a big incision. Second, you kill only the tumor and a very thin layer of tissue surrounding it. In a lumpectomy, you take out much more tissue. So the cosmetic results should be much better."

Khatri, McGahan and Bijan received a $90,000 grant from the UC Davis Health System to carry out the study.

Other breast cancer research currently underway at UC Davis Cancer Center includes:

*a trial of a minimally invasive probe that uses light and electrical current to immediately assess malignancy in suspicious breast lesions, potentially eliminating the need for biopsy;

*a digital mammography trial, comparing the accuracy of digital to standard film mammography;

*and a sentinel node biopsy study that explores the safety and effectiveness of removing only one lymph node for biopsy in women with breast cancer. Standard practice has been to remove a dozen or more lymph nodes to determine if cancer has spread.

UC Davis Cancer Center, a program of the University of California, Davis, is a nationally recognized research and treatment center at the front line of the war against cancer. With more than 209 scientists engaged in cancer research and treatment and more than $32 million in cancer research funding, the center is able to offer patients the most advanced therapies--and consequently the greatest hope for recovery.