Distinguishing Score 0 From Score 1+in HER2 Immunohistochemistry-Negative Breast Cancer Clinical and Pathobiological Relevance

作者：Lambein Kathleen^*; Van Bockstal Mieke; Vandemaele Lies; Geenen Sofie; Rottiers Isabelle; Nuyts Ann; Matthys Bart; Praet Marleen; Denys Hannelore; Libbrecht Louis

来源：American Journal of Clinical Pathology, 2013, 140(4): 561-566.

DOI：10.1309/AJCP4A7KTAYHZSOE

• HER2
• Immunohistochemistry
• FISH
• Score 0
• Score 1+
• Breast cancer

Objectives: To investigate the clinical and pathobiological significance of distinguishing score 0 and score 1+ within the group of immunohistochemistry (IHC)-negative invasive breast cancers. %26lt;br%26gt;Methods: We studied HER2 status using both IHC and fluorescence in situ hybridization (FISH) in 150 consecutive breast tumors submitted to our laboratory after a negative IHC result in local testing centers. %26lt;br%26gt;Results: We were able to discern a group of score 0 tumors that had a lower HER2 copy number than the group consisting of score 1+ tumors. In contrast with the group of score 1+ tumors, HER2 FISH was consistently negative for both copy number based and ratio-based tumors without equivocal results. %26lt;br%26gt;Conclusions: In a setting with stringent quality assurance, score 0 and score 1+ tumors emerge as distinct and clinically important subgroups within the HER2 IHC-negative population.

• 出版日期2013-10