Prognostic Impact of EGFR and CK5/6 as Basal-Markers in Triple-Negative breast Cancers

摘要

Background: Triple-negative breast cancer (TNBC) is defined by the loss of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2neu) . It is a high risk group of breast cancer that lacks the benefit of specific therapies and is classified into aggressive basal subtype and less aggressive non-basal subtype. Objective: To examine the expression of basal markers; including epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6) among triple-negative breast cancer cases and correlate the results with those of Ki-67expression and with the clinic pathological parameters and survival for determining prognosis and therapeutic strategies Materials and Methods: A total of 97 TNBC cases from January 2012 to July 2015based on ER, PR, and the HER2neu negativities were included in the study. The tissue specimens were stained by immune histochemistry for detection of EGFR, CK5/6 and Ki-67. Statistical analysis was done using the SPSS software version 21 for comparison between basal and non-basal TNBC. Results: About 75out of the whole cohort (77.3%) of studied TNBC specimens showed positive basal markers EGFR and or CK5/6 together with high proliferation rate detected by Ki-67 and poor prognostic parameters including overall survival (OS) and progression free survival (PFS). Conclusion: The “Triple-negative” status cannot be used alone as a surrogate for the “basal expression”. Basal subtypes of TNBC show more aggressive behavior and could better predict breast cancer survival.