The effect of neoadjuvant chemotherapy on hormone receptor status, HER2/neu and prolactin in breast cancer.
OBJECTIVE
Histological and immunohistochemical findings may vary in cases of breast cancer. Possible changes in tumor markers between biopsies performed before and after neoadjuvant chemotherapy are controversial and pose a challenge when a clinical decision is needed. The objectives of the present study were: (i) to compare the immunohistochemical expression of estrogen, progesterone and prolactin receptors and HER-2/neu in breast cancer before and after neoadjuvant chemotherapy; and (ii) to correlate the expression of these tumor markers with partial tumor response to neoadjuvant chemotherapy.


METHODS
Immunohistochemical staining for breast tumor markers was performed in 90 cases of breast cancer. Statistical analysis was carried out using Fisher's exact test, McNemar's test, Spearman's correlation and the Kappa index with linear weighting (k).


RESULTS
Agreement between markers before and after neoadjuvant chemotherapy was fair to moderate (k = 0.37-0.51). The immunohistochemical expression of HER-2/neu and prolactin receptors showed a significant, albeit weak correlation before and after neoadjuvant chemotherapy (HER-2/neu, rho = 0.34; P = 0.0009; k = 0.35 [95% CI, 0.19-0.51]). Prolactin status changed in 28/90 cases (P = 0.001; McNemar's test), whereas no changes were found in estrogen or progesterone receptors. No association was found between tumor marker expression and tumor response.


CONCLUSIONS
It seems prudent to reevaluate immunohistochemical markers such as HER-2/neu after neoadjuvant chemotherapy, since the findings will guide the strategy for implementation of adjuvant systemic treatment. No correlation was found between the tumor markers analyzed in the present study and partial tumor response to neoadjuvant chemotherapy.
Universidade Federal de Ciências da Saúde de Porto Alegre, Hospital Nossa Senhora da Conceição, Grupo Hospitalar Conceição, Porto Alegre, Brazil. jose.pedrini@hotmail.com
José Luiz
JL
Pedrini
Ricardo
R
Francalacci Savaris
Mario
M
Casales Schorr
Eduardo
E
Cambruzi
Melina
M
Grudzinski
Cláudio Galleano
CG
Zettler
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology* / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy*; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy; D018275:Carcinoma, Lobular / Q000188:drug therapy; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*; D011981:Receptors, Prolactin / Q000187:drug effects / Q000378:metabolism*
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011981:Receptors, Prolactin