Hormone receptor status and pathologic response of HER2-positive breast cancer treated with neoadjuvant chemotherapy and trastuzumab.
BACKGROUND
The aim of this study was to compare the extent of pathologic response in patients with HER2-positive (HER2+) breast cancer treated with standard neoadjuvant chemotherapy, with or without trastuzumab (H), according to hormone receptor (HR) status.


METHODS
We included 199 patients with HER2+ breast cancer from three successive cohorts of neo-adjuvant chemotherapy on the basis of paclitaxel (Taxol) (P) administered weekly (w) or three weekly (3-w), followed by 5-fluorouracil (F), doxorubicin (A) or epirubicin (E), and cyclophosphamide (C). Residual cancer burden (RCB) was determined from pathologic review of the primary tumor and lymph nodes and was classified as pathologic complete response (pCR) or minimal (RCB-I), moderate (RCB-II), or extensive (RCB-III) residual disease.


RESULTS
In HR-positive (HR+) cancers, a higher rate of pathologic response (pCR/RCB-I) was observed with concurrent H + 3-wP/FEC (73%) than with 3-wP/FEC (34%, P = 0.002) or wP/FAC (47%; P = 0.02) chemotherapy alone. In HR-negative (HR-) cancers, there were no significant differences in the rate of pathologic response (pCR/RCB-I) from 3-wP/FAC (50%), wP/FAC (68%), or concurrent H + 3-wP/FEC (72%).


CONCLUSIONS
Patients with HR+/HER2+ breast cancer obtained significant benefit from addition of trastuzumab to P/FEC chemotherapy; pathologic response rate was similar to that seen in HR-/HER2+ breast cancers.
Peintinger
F
F
Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA.
Buzdar
A U
AU
Kuerer
H M
HM
Mejia
J A
JA
Hatzis
C
C
Gonzalez-Angulo
A M
AM
Pusztai
L
L
Esteva
F J
FJ
Dawood
S S
SS
Green
M C
MC
Hortobagyi
G N
GN
Symmans
W F
WF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002986:Clinical Trials as Topic; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018365:Neoplasm, Residual / Q000517:prevention & control*; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D017239:Paclitaxel / Q000008:administration & dosage; D016032:Randomized Controlled Trials as Topic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D003520:Cyclophosphamide; D004317:Doxorubicin; D015251:Epirubicin; D005472:Fluorouracil; D017239:Paclitaxel; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D000068878:Trastuzumab