Preferential Radio Frequency Ablation (PRFA) is a research project where Unilabs´ Mammography Department at Capio St Göran´s Hospital works closely in collaboration with the breast surgeon Lars Löfgren at the hospital and with professor Hans Wiksell at the Department of Molecular Medicine and Surgery, Karolinska Institute in Stockholm. Professor Wiksell is a civil engineer working with clinical applications of acoustic and electromagnetic energy.
PRFA is a heat induced enzymatic destruction of breast cancer tumors. The cancer is selectively heated for 10 minutes to 70 – 90 º C so the cancer cells die. The surrounding fibrous and fatty tissue will be left unharmed. This procedure is done by the mammography doctor, Karin Thorneman, with ultrasound. The tumor is identified with ultrasound and a thin electrode is inserted into the middle of the cancer. Here it remains while the electrode is heated until the ultrasound image of the cancer shows only an oedema at the spot where the cancer used to be. Then the electrode is retracted.
The patients that are welcome to participate in this study have a solitary well-defined invasive breast cancer that is smaller than 20 mm in diameter. It should not be an invasive lobular cancer since the cells in such a cancer most often form long strands of cancer cells and not a well-defined lesion. The tumor grade should be grade 1-2, but not grade 3. There should not be more than one tumor and not cancer in situ in the surroundings.
First the tumor has to be diagnosed with mammography and ultrasound. Needle biopsy is then performed to find out what kind of malignancy this is. Also the grade and several receptors like ER, PR, Her 2, Ki 67 are controlled. If the patient is suitable for the research project, she will be asked to participate. If she agrees a pre-PRFA MRI of the breasts and a contrast enhanced ultrasound (CEUS) studying the cancer is then made.
The project consists of three different parts.
The first sub-project took place in the operation room. The patient was sedated and then the PRFA was made by the radiologist right before the breast cancer surgery was made. 33 patients were included in the study, 2 were excluded before surgery because of uncertainty concerning the ultrasound images. In the remaining 31 patients 3 did not get the needle in the center of the tumor and 2 cancers were bigger than the pre-operative diagnoses had shown. But the remaining 26 patients had a successful ablation.
In the second on-going project 50 patients shall be recruited. These patients undergo the usual pre-operative program with mammography, ultrasound, needle biopsy for tumor type, grade and receptors. They also undergo CEUS and MRI. The PRFA takes place in the ultrasound room at the Mammography department. Dr Lars Löfgren gives the fully awake patient local anesthesia and Dr Karin Thorneman performs the PRFA while professor Wiksell is monitoring the equipment. Within one hour the patient will leave the department and go home or to their job. Three weeks later mammography, ultrasound, CEUS, MRI and needle biopsy will be performed and then the patient will undergo surgery for breast cancer including sentinel node. So far every patient has been cancer free in this group.
The third study involves a very interesting group and that is the elderly women that either have some sort of condition that do not make them suitable for anesthesia and surgery or they may refuse surgery. In the western world women are getting older and more active than before and this group will get larger. Up till now women that have not undergone surgery in this age group have been treated with anti-hormonal therapy such as Tamoxifen. The results are not as good as the surgical treatment. PRFA is a very interesting alternative in this age group. In this trial no breast surgery will be done. So far 3 elderly women with cerebral-cardiac vascular diseases (CCVD) have participated in the study. Before the PRFA took place the usual pre-operative tests were made. Three months, six months and one year after the PRFA mammography, ultrasound, needle biopsy, CEUS and MRI were made. There are so far no signs of any viable cancer cells in any of these women.
The results in the PRFA research projects are very promising. It seems that PRFA in the future can be an alternative to breast cancer surgery in women with solitary breast cancers.
This method is faster for the woman without any surgical scarring and it is cheaper than surgery. Only local anesthesia will be needed and the women who have participated in this study do not think this method is painful.
Still more research on a greater number of women during a longer time period has to be done before PRFA can be an every day treatment.
Karin Leifland MD Ph D
Head of Mammography
Unilabs
Sweden
Additional links:
Fighting Breast Cancer on Your Lunch Break - most viewed story on Ivanhoe.com (week of October7, 2011)
Swedish breast-cancer treatment shows promise - abc News (Monday, October 03, 2011)