Clinical response after two cycles compared to HER2, Ki-67, p53, and bcl-2 in independently predicting a pathological complete response after preoperative chemotherapy in patients with operable carcinoma of the breast.
BACKGROUND
To investigate the predictive value of clinical and biological markers for a pathological complete remission after a preoperative dose-dense regimen of doxorubicin and docetaxel, with or without tamoxifen, in primary operable breast cancer.


METHODS
Patients with a histologically confirmed diagnosis of previously untreated, operable, and measurable primary breast cancer (tumour (T), nodes (N) and metastases (M) score: T2-3(> or = 3 cm) N0-2 M0) were treated in a prospectively randomised trial with four cycles of dose-dense (bi-weekly) doxorubicin and docetaxel (ddAT) chemotherapy, with or without tamoxifen, prior to surgery. Clinical and pathological parameters (menopausal status, clinical tumour size and nodal status, grade, and clinical response after two cycles) and a panel of biomarkers (oestrogen and progesterone receptors, Ki-67, human epidermal growth factor receptor 2 (HER2), p53, bcl-2, all detected by immunohistochemistry) were correlated with the detection of a pathological complete response (pCR).


RESULTS
A pCR was observed in 9.7% in 248 patients randomised in the study and in 8.6% in the subset of 196 patients with available tumour tissue. Clinically negative axillary lymph nodes, poor tumour differentiation, negative oestrogen receptor status, negative progesterone receptor status, and loss of bcl-2 were significantly predictive for a pCR in a univariate logistic regression model, whereas in a multivariate analysis only the clinical nodal status and hormonal receptor status provided significantly independent information. Backward stepwise logistic regression revealed a response after two cycles, with hormone receptor status and lymph-node status as significant predictors. Patients with a low percentage of cells stained positive for Ki-67 showed a better response when treated with tamoxifen, whereas patients with a high percentage of Ki-67 positive cells did not have an additional benefit when treated with tamoxifen. Tumours overexpressing HER2 showed a similar response to that in HER2-negative patients when treated without tamoxifen, but when HER2-positive tumours were treated with tamoxifen, no pCR was observed.


CONCLUSIONS
Reliable prediction of a pathological complete response after preoperative chemotherapy is not possible with clinical and biological factors routinely determined before start of treatment. The response after two cycles of chemotherapy is a strong but dependent predictor. The only independent factor in this subset of patients was bcl-2.
von Minckwitz
Gunter
G
Dept. of Gynecology and Obstetrics, Goethe University, Frankfurt am Main, Germany. Gunter.vonMinckwitz@germanbreastgroup.de
Sinn
Hans-Peter
HP
Raab
Günter
G
Loibl
Sibylle
S
Blohmer
Jens-Uwe
JU
Eidtmann
Holger
H
Hilfrich
Jörn
J
Merkle
Elisabeth
E
Jackisch
Christian
C
Costa
Serban D
SD
Caputo
Angelika
A
Kaufmann
Manfred
M
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D000077143:Docetaxel; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis*; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008408:Mastectomy / Q000379:methods; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D013629:Tamoxifen / Q000008:administration & dosage; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
D014408:Biomarkers, Tumor; D000077143:Docetaxel; D004317:Doxorubicin; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen; D043823:Taxoids; D016159:Tumor Suppressor Protein p53