Immunofluorescence sensitive for intraoperative evaluation of lymph nodes

Intraoperative evaluation of axillary by immunofluorescence (IF) staining on touch imprints is a fast, sensitive, and specific means of identifying nodal disease in patients undergoing surgery for breast cancer, new findings suggest.

“Axillary sentinel lymph nodes (SLN) sampling is now widely accepted as an integral part of breast cancer surgery,” Dr. Satoru Munakata, director of pathology at Sakai Municipal Hospital in Osaka, Japan noted in comments to Reuters Health. “If SLNs are free of metastasis, SLN sampling can prevent unnecessary axillary node dissection, which often causes postoperative arm dysfunction and psychological distress.” However, the researcher further explained, “Intraoperative detection of micrometastasis is often problematic.”In his group’s study of 150 SLNs sampled from 69 breast cancer patients, the intraoperative application of IF with cytokeratin antibodies to touch imprints “increased sensitivity in a short period of time,” compared with that of Pap, immunocytochemical (ICC), and hematoxylin and eosin (H&E) staining, Dr. Munakata said. [Metastatic disease was identified in 24.0%, 17.3%, 21.3%, and 20.7% of 150 lymph nodes using IF, Pap, ICC, and H&E staining, respectively, the team reports in the October 15th issue of the journal Cancer. The sensitivity of IF staining was 94.6% compared with a sensitivity of 70.3%, 86.5%, and 83.5%, respectively, for Pap, ICC, and H&E staining. The specificity of IF staining was 99.1% versus 100% for all other techniques. The accuracy rate for IF staining was 98.0% versus 92.7%, 96.7%, and 96.0% for Pap, ICC, and H&E staining, respectively. “Because the IF method uses touch imprints from multiple sectioned lymph node samples, examination of a single slide has the same value as does examination of multiple frozen tissue sections,” the authors point out.”IF could conquer the technical problems of frozen section cytology,” Dr. Munakata told Reuters Health. “IF requires up to ten minutes for fixation and staining with the use of microwave oven, after the preparation of touch imprint.” The researcher thinks IF staining “is widely applicable to the hospitals and institutions where axillary SLN sampling is in practice.” concluded. (Source: Cancer 2003;98:1562-1568: Reuters Health: Megan Rauscher: October 28, 2003: Oncolink)