title: Predictive Value of IHC4 Score for Pathological Response to Neoadjuvant Chemotherapy in Hormone Receptor-Positive Breast Cancer.
abstract: OBJECTIVE
  This study aimed to explore the value of IHC4 in predicting pathological response after neoadjuvant chemotherapy in patients with hormonal receptor (HR)-positive breast cancer (BC).
  
  
  METHODS
  In this retrospective exploratory study, data for 68 HR-positive BC patients who received neoadjuvant chemotherapy were recorded. IHC4 scores were calculated based on estrogen receptors/progesterone receptors, Ki-67 and HER2 status. Logistic and ordinal regression analyses in addition to likelihood ratio test were used to explore associations of IHC4 scores and other clinico-pathological parameters with pathological complete response (pCR) and pathological stage.
  
  
  RESULTS
  Taking the 25th percentile as the cut-off, a lower IHC4 score was associated with an increased probability of pCR (low; 52.9% vs. High; 21.6%, OR=4.1, 95% CI= 1.28-13.16, p=0.018) and a lower pathological stage (OR =3.9, 95% CI=1.34-11.33, p=0.012). When the IHC4 score was treated as a continuous variable, a lower score was again associated with an increased probability of pCR (OR=1.010, 95% CI=1.001-1.018, p=0.025) and lower pathological stage (OR=1.009, 95% CI= 1.002-1.017, P=0.008). Lower clinical stage was associated with a better pCR rate that was of borderline significance (P=0.056). When clinical stage and IHC4 score were incorporated together in a logistic model, the likelihood ratio test gave a P-value of 0.004 after removal of the IHC4 score and 0.011 after removal of the stage, indicating a more significant predictive value of the IHC4 score for pCR.
  
  
  CONCLUSIONS
  This study suggests that the IHC4 score can predict pathological response to neoadjuvant chemotherapy in HR-positive BC patients. This finding now needs to be validated in a larger cohort of patients.
authors.affiliation: Oncology, King Abdullah Medical City, Makkah, Saudi Arabia E-mail : shereefmohamad@yahoo.com.
authors.forename: Shereef
authors.initials: S
authors.lastname: Elsamany
authors.forename: Soha
authors.initials: S
authors.lastname: Elmorsy
authors.forename: Abdullah
authors.initials: A
authors.lastname: Alzahrani
authors.forename: Ayman
authors.initials: A
authors.lastname: Rasmy
authors.forename: Waleed N
authors.initials: WN
authors.lastname: Abozeed
authors.forename: Amrallah A
authors.initials: AA
authors.lastname: Mohammed
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Sherisher
authors.forename: Mohammed M
authors.initials: MM
authors.lastname: Abbas
authors.forename: Miral
authors.initials: M
authors.lastname: Mashhour
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000473:pathology*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D016015:Logistic Models; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading / Q000379:methods*; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012189:Retrospective Studies; D012529:Saudi Arabia
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human