By John Otrompke
CHICAGO -- November 9, 2009 -- Most data gathered by needle biopsy of in situ ductal carcinoma patients are of limited value in predicting whether a subsequent breast excision will be successful, except for the amount of necrosis in the sample, according to a study presented here at the American Society for Clinical Pathology (ASCP) 2009 Annual Meeting.
"Necrosis did show a significant association with outcomes," said Nathan F. Clement, MD, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio, Texas, on October 29. "We found that if there's much necrosis within the needle sample, when they did the excision, they were more likely to have a close margin."
"This means the patient likely still has some cancer in the breast," he continued. "If the tumour is going to the edge of whatever was taken out, there's a good chance that when they go to excise that tumour, they may not get it all out."
"For someone who wants to excise a tumour known to have necrosis on core biopsy needs perhaps to take a wider margin, or use radiation or something that might keep them from having an incomplete surgery," said Clement.
For the study, researchers examined 20 specimens from patients who later underwent mastectomy, and 29 who underwent breast conservation surgery, for in situ ductal carcinoma.
The specimens were examined for morphological features that may predict a close margin, defined <=0.2 cm or positive margin upon subsequent excision. Tissue from the core biopsy was compared with tissue from the surgical excision performed later.
Residual carcinoma was found in the excision in 40 out of the 49 cases. Of these, there were 5 cases in which comedo-pattern carcinoma was present in the excision but not in the core biopsy. In 28 cases, a sentinel lymph node biopsy was performed, but only 1 turned out positive.
With the exception of necrotic tissue in the needle sample, none of the other morphologic features were predictive of margin.
"We counted the number of breast ducts involved by cancer, and we counted the number of needle cores used, up to 10, but these didn't predict whether the surgeon would have close margin," said Dr. Clement. "Nuclear grade, which is based on the degree of atypicality of the cell nucleus upon microscope evaluation, also didn't predict close margins."
[Presentation title: High- and Intermediate-Grade Ductal Carcinoma In Situ of the Breast: A Comparison of Pathologic Features in Core Biopsies and Excisions and an Evaluation of Core Biopsy Features That May Predict a Close or Positive Margin in the Excision. Abstract 19]
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