ORLANDO--Preoperative chemotherapy in breast cancer patients can leave a surgeon in the dark as to the specific amount of normal tissue to remove if the chemotherapy eliminates the tumor or renders it no longer palpable. A simple tattoo outlining the original tumor site can be a great aid in helping surgeons determine the type of surgery to be performed after the therapy.
Dr. Umberto Veronesi, speaking at the 15th Annual International Breast Cancer Conference, presented some caveats for consideration before and during surgery that follows chemotherapy.
In addition to defining the original tumor site, he said, the surgeon must also obtain a clinical evaluation of the extent of regression, a reliable gross evaluation of the residual mass, a reliable frozen section examination, and an assessment of the significance of persistent microcalcifications.
Chemo May Destroy the Tumor
Dr. Veronesi, scientific director at the Instituto Europeo di Oncologia, Milan, uses a tattoo, with the aid of mam-mography, to designate the original tumor site. Chemotherapy may destroy the tumor, leaving it nonpalpable, yet there may still be a foci of viable tumors.
"If you’re not experienced, you may make a mistake," he said. "You need to excise a wide area, which represents the area before chemotherapy." The tattoo leaves no doubt as to the site of the original tumor. However, as a further precaution, the pathologist may need toexamine anywhere from 5 to 15 frozen sections to confirm the extent of tumor regression.
Microcalcifications should be noted, since they do not disappear after chemotherapy. "They instead tend to shrink and aggregate so that the total area they occupied is reduced," Dr. Veronesi explained. This can be an "important index of the regression process and an excellent guide for the operation." He also said that intraoperative x-ray examination may be used to confirm how completely the tumor mass was removed.
The final decision as to the type of surgery that is performed after neoadju-vant therapy should be made in the operating room. Evaluation of the tumor regression, examination of the resection margins, assessment of tumor size in relation to breast size, and assessment of microcalcifications all need to be taken into account, Dr. Veronesi said.
The final caveat concerns chemore-sistant cells. Dr. Veronesi said that 90% of the patients studied experienced chemo-regression. However, in the rest of the women, the tumors did not regress and sometimes progressed.
"In the rare cases of total resistance to chemotherapy, the condition must be discovered as early as possible so that an immediate mastectomy can be performed," he said.
The objectives of neoadjuvant chemotherapy are to reduce the extent of surgery, reduce the risk of local failure, and provide information for chemosensitivity or a chemoresistant rate of response. Keeping in mind the above caveats, Dr. Veronesi feels that preoperative chemotherapy offers an improved therapeutic strategy and, for most patients, will improve results of breast-conserving surgery when that is a viable option.
