Better testing with fine needle aspirates

Fine needle aspirates (FNAs) from breast cancer contain a higher percentage of malignant cells than do surgical biopsy specimens, cytopathologists at Yale University School of Medicine report.

Molecular analysis techniques, such as cDNA microarrays, require high-quality, relatively homogeneous RNA therefore this finding if particularly important says doctors Linda Ernst and David Rimm, New Haven, Connecticut.

Reported in the October 25th issue of Cancer Cytopathology, Ernest and Rimm compared ThinPrep prepared needle wash specimens to surgical excision specimens obtained from five patients with breast cancer. For each specimen five random, cellular X20 microscopic fields were photographed so that malignant and benign cells could be counted.

According to the report, each FNA sample demonstrated a higher percentage of malignant cells than the biopsy specimens, reaching statistical significance in three samples. The proportion of malignant cells averaged 83% for FNAs and 62.3% for surgical excisions (p = 0.0009).

The doctors propose that decreased adhesion of malignant cells compared with benign cells, plus the mechanophysical properties of the FNA procedure, lead to the higher proportion of malignant cells compared with surgical biopsy material.

“The recovery of a higher fraction of malignant cells may provide a superior specimen for advanced molecular diagnostic studies,” they conclude.

(Source: ASCO)