Source: Medicine (Baltimore)  |  Posted 5 years ago

By Alison Palkhivala

MONTREAL, CANADA -- September 19, 2006 -- Immunohistochemical staining using anti cytokeratin 5/6 and E-cadherin can help determine the type of atypical lesion found with large core needle biopsy following suspicious mammography scans and can help predict surgical findings.

In an effort to improve the diagnostic ability of large core needle biopsy, Dr. Antoine and her colleagues re-evaluated 68 patients with atypical lesions diagnosed via this biopsy technique between 1999 and 2005. They reviewed the pathology slides using anti cytokeratin 5/6 and E-cadherin stains to determine if they could identify any pathological markers that would help predict surgical outcomes.

According to lead author Martine Antoine, MD, pathologist, Tenon Hospital, Paris, France, large core needle biopsies using stereotactic or ultrasound guidance and performed under local anesthesia are becoming a popular way of looking for signs of carcinoma in patients with suspicious mammography findings. This is a beneficial alternative to surgical biopsy, she said.

However, she added, a significant number of patients with atypical lesions identified using large core biopsy go to surgery with a histological underestimation of cancer.

Dr. Antoine presented the results of her study in a poster session held here on September 17[^]th[] at the 26[^]th[] International Congress of the International Academy of Pathology (IAP).

Overall, 10% of patients had received an underestimation of their disease based on biopsy, a low rate that Dr. Antoine attributes to the homogeneity of her sample. Among these were 5 patients with atypical ductal hyperplasia, and 2 with mixed atypia. Six of these patients were found at surgery to have ductal carcinoma in situ (DCIS), and 1 was found to have invasive ductal carcinoma.

With immunohistochemical analysis, 2 cases of atypical ductal hyperplasia were reclassified as simple hyperplasia, and 1 case of atypical lobular hyperplasia was reclassified as mixed atypia.

The only variable that predicted the risk of finding a malignant lesion at surgery was the presence of atypical ductal hyperplasia versus atypical lobular hyperplasia ([]P[] = .05), she said. Other variables that were investigated but not found to be predictive were age, personal and familial history of breast cancer, size of radiological lesion, American College of Radiology (ACR) classification, complete or incomplete removal of calcification, and number of foci involved.

The authors concluded that immunohistochemical staining using anti cytokeratin 5/6 and E-cadherin can help determine the patient's precise type of atypical lesion, which in turn can help predict surgical outcomes. This form of pathological investigation can also help identify patients with simple hyperplasia. These findings should help limit the number of patients who undergo surgery unnecessarily, Dr. Antoine concluded.

[Presentation title: Is Type of Epithelial Atypia on Large Core Needle Biopsy Predictive of Carcinoma on Surgical Excision? Poster 62]