Radiofrequency ablation of breast cancer cells reduces need for further
surgery
30 October 2005
Fremont Calif. & Little Rock, Ark. USA. A study of patients undergoing
breast-conserving surgery to remove cancerous cells has found that heating
the surrounding cells of the lumpectomy site by radiofrequency ablation
(RFA) reduced the need for further surgery.
RITA Medical Systems and the University of Arkansas for Medical Sciences
have announced that clinical investigators at the University of Arkansas
Cancer Research Center reported the results of a clinical trial,
Radiofrequency Ablation (RFA)-assisted Lumpectomy, in a paper session at
the American College of Surgeons (ACS) 91st Annual Clinical Congress in San
Francisco. The presentation reviewed the results of a multiphase clinical
trial with 25 patients in which RFA-assisted lumpectomy using RITA's
products was shown to reduce the need for re-excision for inadequate margins
following lumpectomy by 86%.
Professor Suzanne Klimberg MD commented, "Our short-term follow-up has
shown no in-site recurrence of cancer in these patients." Dr. Klimberg
continued, "We believe that RFA-assisted lumpectomy is a technique that may
give women who choose breast-conserving surgery added assurance that they
will not need to endure a second surgical procedure to remove cancer found
during pathology examination of the margins of their lumpectomy specimen
post-surgery." Professor Klimberg is Professor of Surgery and Pathology at
the University of Arkansas for Medical Sciences (UAMS), and the Central
Arkansas Veterans Healthcare Systems, Chief of the Division of Breast
Surgical Oncology at UAMS, Director of the Breast Cancer Program at UAMS'
Arkansas Cancer Research Center, and corresponding author of the clinical
abstract.
In the trial, 25 patients with an average tumor size of 1.8 cm underwent
RFA treatment of their lumpectomy excision site in the operating room
immediately following breast conserving lumpectomy surgery. The excised
lumpectomy specimen was then sent for pathology analysis. Final pathology
results found inadequate margins in 28% of the patients. The inadequate
margins found in those patients who received RFA at the time of surgery were
not re-excised because in a bench trial of 29 mastectomy samples (breast
tissue donated by patients undergoing mastectomy surgery) RFA consistently
demonstrated a complete zone of ablation to a thickness greater than 5
millimeters.
A finding of "inadequate margin" is made during the post-surgery
pathology examination of the lumpectomy specimen when cancer cells are found
close to the perimeter of the specimen, indicating that additional cancer
cells may remain in the lumpectomy site. Typically, a second operation would
be required several days or weeks later to re-excise the inadequate margins
in order to reduce the likelihood of in-site breast cancer recurrence. A
finding of "positive margin" during the pathology examination is made when
cancer cells are found on the perimeter of the lumpectomy specimen. A
finding of "negative margin" during the pathology examination is made when
no cancer cells are found close to the perimeter of the lumpectomy specimen.
Edward M. Copeland, MD, Edward R. Woodward Professor, Department of
Surgery, University of Florida College of Medicine, and a pioneer in breast
conservation therapies for breast cancer commented, "Assuring that
lumpectomy margins are negative is one of the keys to preventing recurrence
of breast cancer following breast conservation treatment. Were
radiofrequency ablation proven to be a safe and cost effective method of
obtaining negative margins, it would be a positive addition to the treatment
armamentarium of the oncologic surgeon."
Mr. Joseph DeVivo, President and CEO of RITA Medical, commented, "We
believe that RFA-assisted lumpectomy holds great promise for women who
choose breast conserving surgery. We expect Dr. Klimberg and her team to add
clinical data to support the use of the RFA-assisted lumpectomy technique.
As part of an ongoing pilot study that followed the clinical trial reported
at the ACS meeting this week, 8 patients out of 16 treated for breast cancer
were found to have inadequate surgical margins after lumpectomy. All 8
patients were spared re-excision because Dr. Klimberg used RFA at the time
of lumpectomy."
Mr. DeVivo concluded, "Our goal is to create a well-defined application
of RFA in the treatment of breast cancer supported by solid clinical data.
As we have previously said, we believe there is a terrific market
opportunity for the application of RFA in the treatment of breast cancer."
RFA-assisted lumpectomy utilizes heat with the intent to create an
additional tumour-free zone around the lumpectomy cavity. During the trial
reported on at ACS this week a RITA RFA probe was deployed 1cm
circumferentially into the walls of the lumpectomy cavity and maintained at
100°C for 15 minutes in 25 patients. In addition
to the in-vivo clinical application of RFA, 29 prophylactic mastectomy
ablations were performed revealing a 5–10mm ablation zone in 72.4%(21/29),
10–20mm in 24.1%(7/29), and greater than 20mm in 3.5%(1/29). Researchers in
the clinical trial reported at ACS this week that they concluded that these
ex-vivo ablations reliably created a minimum 5–10 mm zone of ablation.
An abstract of the presentation at the ACS 91st Annual Clinical Congress
can be found at the American College of Surgeons website,
www.facs.org
Contributing authors of the presentation abstract include Julie Kepple
M.D., oncology fellow, Soheila Korourian M.D., Associate Professor,
Department of Pathology, Ronda S. Henry-Tillman M.D., FACS, Associate
Professor of Surgery and Director of the UAMS Cancer Control Department,
Aaron Margulies M.D. FACS, Instructor of Surgery and Fellow in Diseases of
the Breast, Gal Shafirstein Ph.D., Assistant Professor, Department of
Otolaryngology/Head and Neck Surgery, and V. Suzanne Klimberg M.D., FACS.
Links
UAMS
www.uams.edu
ACRC
www.acrc.uams.edu
RITA Medical Systems, Inc.
www.ritamedical.com
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