Oncotype Dx (ODx) recurrence score (RS) is used in early breast cancer to guide the use of adjuvant therapy. In addition to RS the test produces results of reverse transcriptase-polymerase chain reaction (RT-PCR) of Estrogen receptors (ER), Progesterone receptors (PgR) and Human epidermal growth factor receptor 2 (HER2-neu). Our goal was to determine the correlation between immunohistochemistry (IHC) and RT-PCR testing of ER, PgR and HER2-neu and to correlate the results of ODx RS with tumors' grade, age and PgR status. 113 patients with ER+, HER2-neu- breast cancers that underwent ODx testing were analyzed for receptors correlation and concordance rates by the 2 methods. A total of 104 patients had ER+/PgR+ tumors and 9 patients had ER+/PgR- tumors by IHC, the average RS were 17.5 ± 9.1 and 31.2 ± 8.7 (P < 0.001) respectively. The Spearman correlation coefficient between IHC and ODx results were 0.5 (95% CI 0.34-0.62) for ER and 0.78 (95% CI 0.7-0.84) for PgR. The concordance rate between IHC and ODx was 98.2% for ER, 89.4%.for PgR and 99.1% for HER2-neu. Most of the discordant cases (9 out of 13) were low positive (1-10%) by IHC and negative by RT-PCR. In addition higher tumor grade was associated with a higher ODx RS. Our data show that the IHC results were highly concordant with RT-PCR for ER, PgR and Her2-neu. In addition low positive (1-10%) ER/PgR might indicate a real negative status. Our study shows that ER+/PgR- breast cancers are associated with a significantly higher ODx RS. Copyright © 2020 Elsevier Inc. All rights reserved.
Maher A Sughayer, Sallam Alhassoon, Haytham M Sughayer. Comparison of Estrogen receptors, Progesterone receptors and HER2-neu immunohistochemistry results in breast cancer with those of Oncotype Dx. Annals of diagnostic pathology. 2020 Aug;47:151556
PMID: 32592992
View Full Text