Immunohistochemiluminescence detection: a quantitative tool in breast cancer HER-2 status evaluation

• Published in: Disease markers Vol. 34; no. 5; pp. 373 - 377
• Main Authors: de Melo Rêgo, Moacyr Jesus Barreto, Cordeiro, Marina Ferraz, Cavalcanti, Carmelita de Lima Bezerra, de Carvalho Junior, Luiz Bezerra, Beltrão, Eduardo Isidoro Carneiro
• Format: Journal Article
• Language: English
• Published: IOS Press 01.01.2013
• Subjects: Other
• ISSN: 0278-0240; 1875-8630
• DOI: 10.3233/DMA-130981

Her-2 status evaluation in breast cancer has prognostic and treatment response value but its interobserver variation among pathologists is a problem since it is not quantitatively assayed. This study presents an immunohistochemiluminescence method to quantify Her-2 in breast cancer. Anti-Her-2 antibody was conjugated to acridinium ester (AE) and used to evaluate/quantify Her-2 status in breast Invasive Ductal Carcinoma (IDC, n = 50) comparing with traditional immunohistochemistry. Anti-HER-2-AE results were expressed in Relative Lights Units (RLU) and showed to be able to distinguish and quantify the differences between the three groups of Her-2 status. 3+ Her-2 status presented the highest RLU (246,982 × 10 3 ± 2.061 × 10 3 ) compared to 2+ (76,146 × 10 3 ± 0.290 × 10 3 ), negative (27,415 × 10 3 ± 1.445 × 10 3 ) and normal tissues (27,064 × 10 3 ± 2.060). Status differences were significant between 3+ and 2+ ( p = 0.0025); 2+ and negative ( p = 0.0003), and +3 and +1 ( p = 0.0001) beside this, normal breast control RLU was 27,064 × 10 3 ± 2,060 × 10 3 , similar to negative cases. Results showed that anti-HER-2-AE conjugate was effective in breast tumors Her-2 status evaluation, allowing its quantitative establishment to consequently decrease the subjectivity in prognostic and predictive information intrinsic to this test.