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Clinical Study

Oncology 2011;81:30–38 DOI: 10.1159/000330766

Clinical and Pathological Features of Breast Cancer Associated with the Pathological Complete Response to Anthracycline-Based Neoadjuvant Chemotherapy

Serkan Keskin   a Mahmut Muslumanoglu   d Pinar Saip   a Hasan Karanlık   b Murat Guveli   c Esmehan Pehlivan   e Fatma Aydoğan   a Yesim Eralp   a Adnan Aydıner   a Ekrem Yavuz   e Vahit Ozmen   d Abdullah Igci   d Erkan Topuz   a  

Departments of a   Medical Oncology, b   General Surgery and c   Radiation Oncology, Institute of Oncology, and Departments of d   General Surgery and e   Pathology, University of Istanbul, Istanbul , Turkey

months. Progression-free survival was significantly im-proved in patients achieving pCR (p = 0.001). Conclusions: pCR is associated with a better outcome regardless of clinical and pathological parameters in breast cancer patients who receive NAC. The probability of pCR was higher in ER-nega-tive, LVI-negative tumors and in patients treated with se-quential taxane-containing chemotherapy.

Copyright © 2011 S. Karger AG, Basel

Introduction

A pathologic complete response (pCR) is defined as the disappearance of all invasive cancer in the breast after completion of neoadjuvant chemotherapy (NAC). Theo-retically, if CR is reflective of chemosensitivity in occult distant metastatic sites, patients who have pCR in both the primary breast tumor and axillary lymph nodes after NAC should have the longest disease-free survival rates. In previous studies, pCR after NAC correlated with im-proved long-term, disease-free and overall survival [1–5] .

NAC has the same advantages: induction of tumor shrinkage that may render inoperable tumors amenable to surgery, the rate of breast conservation surgery can be increased by 10–20%, and tumor response to NAC can be

Key Words

Anthracycline � Clinicopathologic parameters � Neoadjuvant chemotherapy � Pathological complete response � Survival

Abstract

Objective: Patients with breast cancer with a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) have a better prognosis than patients with residual disease. The aim of the current study was to identify predic-tors of pCR. Methods: This retrospective study included 388 patients treated with anthracycline-based NAC. Clinicopath-ological parameters were compared between the patients with and without pCR in breast and axilla. Results: Treat-ment consisted of FAC/FEC in 230 patients (59%), TAC in 39 (10%) patients and AC followed by docetaxel in 119 (31%). In all, 36 (9.3%) patients had pCR. In univariate analysis, age, tumor size, lymph node involvement, tumor grade (p = 0.077, n = 265), ER and HER-2 status (n = 213), lymphovascular inva-sion (LVI), type of chemotherapy and taxane-containing che-motherapy were associated with pCR. In multivariate analy-sis, ER negativity (p = 0.003), the absence of LVI (p = 0.009) and taxane-containing NAC (p = 0.026) were found to be sig-nificant indicators of pCR. Median follow-up time was 69

Received: April 19, 2011 Accepted after revision: June 2, 2011 Published online: September 9, 2011

Oncology

Dr. Serkan Keskin Istanbul Universitesi Onkoloji Enstitusu, Capa TR–34093 Istanbul (Turkey) Tel. +90 212 414 24 34E-Mail drkeskin76   @   hotmail.com

© 2011 S. Karger AG, Basel0030–2414/11/0811–0030$38.00/0

Accessible online at:www.karger.com/ocl

The Role of pCR for Breast Cancer Oncology 2011;81:30–38 31

directly monitored and exactly assessed by both clinician and patient, resulting in an in vivo measure for the che-mosensitivity of the tumor that can also be used as a sur-rogate marker for clinical outcome of the disease [6] .

A major clinical challenge is to identify the subset of patients (at the time of diagnosis) who would benefit from these more prolonged, often more toxic and more expen-sive regimens. There are several clinical and pathological variables that are consistently associated with a better re-sponse to NAC. These include the estrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER-2) receptor status, histological or nuclear grade, high pro-liferative activity and tumor size [1, 2, 7, 8] . Other prog-nostic and predictive factors have been studied in an ef-fort to explain this phenomenon, with some of them being more relevant than others: expression of other members of the epithelial growth factor receptor family, S-phase fraction, DNA ploidy, p53 gene mutations, cyclin E, p27 dysregulation, the presence of tumor cells in the circulation or bone marrow, and perineural and lympho-vascular invasion (LVI) [9–13] . However, no similar mul-tivariate predictor exists to estimate the probability of pCR to NAC. In order to identify patients most likely to benefit from NAC, it would be useful to be able to iden-tify predictors of pCR prior to treatment initiation.

The aim of this study was to determine the incidence of pCR in the breast and axillary lymph nodes, the clini-copathological factors associated with it, and the clinical course of patients who have such a response.

Patients and Methods

A sequential and prospectively maintained database of the In-stitute of Oncology (University of Istanbul) was retrospectively searched for patients with histologically confirmed locally ad-vanced invasive breast carcinoma who received NAC. Three hun-dred and eighty-eight patients who had received anthracycline-based NAC from January 2000 to August 2010 were included in this retrospective study. Patients were only eligible if the diagno-sis had been confirmed histologically (by core biopsy) prior to the start of NAC, and if breast surgery and axillary dissection had been performed following NAC. Exclusion criteria were male gen-der, systemic metastasis, no anthracycline-based NAC, bilateral disease or no definitive surgery.

Study variables included age, histology, T stage, lymph node status, clinical stage, menopausal status, tumor grade, ER, pro-gesterone receptor (PgR) and HER-2 status, LVI, necrosis, micro-calcifications, type of chemotherapy, pathological response in the breast and axillary lymph nodes, surgical details, and informa-tion regarding recurrence, disease-free and overall survival and the last status. This retrospective study was approved by the In-stitutional Review Board of the Institute of Oncology, University of Istanbul.

Staging and Pathological Review Clinical stage at diagnosis was based on the staging criteria

proposed by the American Joint Committee on Cancer in 2003 [14] . The staging workup included a complete history and physical examination, complete blood cell and platelet counts, blood chemistry analysis, carcinoembryonic antigen and CA 15.3 levels, electrocardiography, chest radiography, abdominal ultrasonog-raphy and bone scan at presentation. The local evaluation com-prised clinical and ultrasonographic assessment of tumor and nodes and bilateral mammography. Further investigations were only carried out if clinically indicated.

Initial biopsy specimens of all patients were used to confirm invasive carcinoma, categorize the histological type according to the World Health Organization classification system [15] and to define histological grade according to the modified Bloom-Rich-ardson grading system [16] . ER, PgR and HER-2 receptor status was assessed on the diagnostic core biopsy specimen prior to the start of NAC.

The core biopsy specimens (either fixed in 10% formalin solu-tion or Hollande’s solution) were embedded in paraffin. Slides derived from these blocks (5 � m thick) were stained with hema-toxylin and eosin. Grading was also performed on these slides. Afterwards, immunohistochemical staining with anti-ER (SP1; NeoMarkers, Fremont, Calif., USA), anti-PgR (SP2; NeoMarkers) and anti-HER-2 receptor (CBE-356; Novocastra, Newcastle, UK) is performed on 3- � m-thick slides derived from the same blocks. Tumors were defined as positive if ER or PgR staining of any in-tensity were detected on 6 1% of tumor cells. HER-2 immunohis-tochemical staining was categorized as follows: +/+++ = negative and +++/+++ = positive and for tumor staining. If ++/+++, then silver in situ hybridization (Ventana Medical Systems, Oro Valley, Ariz., USA) was performed to detect amplification according to the HER-2/Chr 17 ratio.

Treatment Modalities All patients had to have received an anthracycline-based NAC

regimen, which included: (1) FAC/FEC: 600 mg/m 2 fluorouracil on day 1, 60 mg/m 2 doxo-

rubicin (epirubicin 90 mg/m 2 ) on day 1, 600 mg/m 2 cyclophos-phamide on day 1, every 21 days for 6 cycles.

(2) 4AC + 4T: 60 mg/m 2 doxorubicin and 600 mg/m 2 cyclophos-phamide on day 1, respectively, every 21 days for 4 cycles, fol-lowed by 100 mg/m 2 docetaxel on day 1, every 21 days for 4 cycles.

(3) TAC: 75 mg/m 2 docetaxel on day 1, 60 mg/m 2 doxorubicin on day 1, 600 mg/m 2 cyclophosphamide on day 1, every 21 days for 6 cycles.

(4) Trastuzumab: after a 8 mg/kg loading dose, 6 mg/kg trastu-zumab were given on day 1, every 21 days for 1 year. Patients were scheduled to undergo surgery 3–4 weeks after

NAC. All patients were given radiotherapy 2–4 weeks after sur-gery. Patients undergoing mastectomy were given 50 Gy to the chest wall and 46–50 Gy to adjacent lymphatic regions. Patients undergoing breast-conserving surgery were given breast radio-therapy. The range of doses given to the breast was 46–50 Gy fol-lowed by boosts to the tumor bed (10–14 Gy).

Tamoxifen (20 mg/day), anastrozole (1 mg/day) or letrozole (2.5 mg/day) was given to ER- and/or PgR-positive patients for 5 years according to the standard practice at that time. Trastuzu-mab was administered in 27 patients who had HER-2-positive tu-

Keskin et al. Oncology 2011;81:30–3832

mors; however, 20 HER-2-positive patients did not receive trastu-zumab because they began therapy before the introduction of trastuzumab.

Response Patients were reviewed after each NAC cycle for clinical re-

sponse. Clinical response was classified according to criteria of the World Health Organization. CR was defined as no residual palpable disease; partial response as 1 50% tumor shrinkage; sta-ble disease as a decrease ! 50% or an increase ! 25%; progressive disease as an increase 6 25% or the appearance of new lesions.

pCR was evaluated based on the specimen resected after NAC. Pathological specimens with no residual invasive carcinoma cells in the original tumor or lymph nodes were classified as pCR. Tu-mors with residual carcinoma in situ were included in the pCR group.

Follow-Up and Survival Following surgery or radiotherapy, the patients were reviewed

every 3 months for 2 years, then every 6 months until 5 years. Thereafter, they were assessed clinically and with mammography annually. Progression-free survival was calculated from the time of surgery to the time of local or distant metastases or the last follow-up. Patients who died before experiencing disease recur-rence were considered censored at their date of death for the anal-ysis of progression-free survival. Overall survival was calculated from the time of surgery to the date of death from any cause or the last follow-up. The median follow-up time was calculated as the median observation time among all patients and among pa-tients still alive at their last follow-up.

Statistical Analyses Patient characteristics were tabulated or described by their

medians and ranges overall by pCR group. The � 2 test was used to compare pCR rates among levels of the considered variables. Survival distributions were estimated with the Kaplan-Meier

method, and the log-rank statistic was used to test for differences between groups. Cox’s proportional hazard regression models were used to assess the prognostic significance of clinical and his-topathological characteristics of the tumor on the evaluated out-comes. Factors that were significant at p ̂ 0.05 in univariate analysis were entered into the multiple regression models. Results from Cox’s models were expressed as hazard ratios with 95% con-fidence intervals (CIs). All analyses were performed using the SPSS 15.0 statistical software package (SPSS, Chicago, Ill., USA), with p ! 0.05 considered to be significant.

Results

Between January 2000 and August 2010, 410 patients received surgery following NAC for locally advanced in-vasive breast cancer. Twenty-two cases were excluded from the analyses ( fig.  1 ). Therefore, 388 patients were analyzed. Overall, 61 (16%) patients underwent conserva-tive surgery and 327 (84%) underwent mastectomy. In 36 (9.3%) patients, residual invasive disease was absent after NAC. The median age of the patients was 47 years (range, 22–80 years). Baseline characteristics are summarized in table 1 . The predominant tumor type was invasive ductal carcinoma (IDC; 76%), and the majority of the patients had stage IIIB disease (39%). Most of the tumors were hormone receptor (ER and/or PgR) positive (55%). HER-2 receptor status was available in 213 patients, 29% of whom were found to be positive. The majority of patients were premenopausal (51%); positive for clinical lymph nodes (95%) and ER (51%); negative for PgR (44%), and hadT 3–4 tumor (71%); histologic grade III (44%) and nuclear grade III (30%), and absence of LVI (37%), necrosis (47%) and microcalcifications (43%). Treatment consisted of FAC/FEC in 230 (59%) patients, TAC in 39 (10%) and 4AC + 4T in 119 (31%) patients; 158 patients (41%) received tax-ane-containing chemotherapy; radiotherapy was admin-istered to 340 patients (87%).

In univariate analysis, factors associated with pCR were younger age ( p = 0.017), primary tumor size in stable disease (p = 0.002), absence of lymph node involvement (p = 0.009), nuclear grade (p = 0.048), positive HER-2(p = 0.002), negative ER (p ! 0.001), negative hormone receptor status (p = 0.009), negative LVI (p = 0.003), NAC including docetaxel (p ! 0.001) and taxane-containing NAC (p = 0.001; table 2 ). Differences in pCR rate accord-ing to the menopausal status, histology, histological grade, PgR status, necrosis and microcalcifications were not statistically significant.

A multivariate analysis was performed using the vari-ables, and absence of clinical lymph node involvement, ER negativity, absence of LVI and taxane-containing

Original sample size(n = 410)

Eligible(n = 388)

Patient with pCR(n = 36, 9.3%)

Patient with RD(n = 352, 90.7%)

Ineligible (n = 22)Unsatisfactory data (n = 12)

Other previous tumors (n = 3)Bilateral tumors (n = 5)

Male breast cancer (n = 2)

Fig. 1. Diagram of the study. RD = Residual disease.

The Role of pCR for Breast Cancer Oncology 2011;81:30–38 33

NAC were found to be independent significant prognos-ticators of pCR ( table 3 ).

Correlation between pCR and Survival The median follow-up was 69 months (range 4–168).

Distant metastases were found in 1 (2.8%) and 116 (33%) patients with and without pCR, respectively. Local re-lapse was not seen in patients with pCR, whereas 50 (14%) patients without pCR had local relapse. Overall, 139 of 388 (36%) patients had local recurrence and/or distant metastases). Of the patients with and without pCR, 1 and 35 (10%) patients succumbed to the disease, respectively. pCR following NAC was not associated with improved overall survival (p = 0.305; fig. 2 ). There was a statistically significant increase in progression-free sur-vival in patients achieving pCR (p = 0.001; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2409783/figure/fig2/; fig. 3 ).

Discussion

In our study, the percentage of patients with pCR (9.3%) was similar to that noted in other studies (range, 6–30%) [8, 16–20] . In our patients with pCR, outcome was better than in those without pCR. None of the 36 pa-tients with pCR had local recurrence, whereas 36% of the patients without pCR progressed: 14% had local recur-rence and 33% distant metastases. These results were also reflected in patients with pCR (breast and/or axilla). In this group, 20 of 108 patients with pCR (breast and/or axilla; 19%) had local and/or distant metastases, in con-trast to 42% (113/269) of the patients without pCR (data not shown; p ! 0.001).

The results of this retrospective study indicate that the incidence of recurrence (local and distant) in patients with breast cancer who achieve a pCR after NAC is small-er (2.8%) than the recurrence rates reported in previous studies, which range from 12 to 13.7% [16, 21, 22] . This ef-fect may be due to the small number of patients with pCR. It has been reported that patients achieving pCR following NAC have a better long-term outcome than those who fail to respond to NAC [1, 4] . It has, therefore, been assumed that pCR is a valid surrogate marker of long-term surviv-al and cure in patients with locally advanced breast cancer treated with NAC [1] . The primary aim of the current study was to identify factors predictive of pCR.

Age before therapy, clinical T stage, clinical lymph node status, clinical stage, nuclear grade, HER-2, ER, hormone receptor status, LVI, type of chemotherapy and

Table 1. Patient characteristics (n = 388)

Characteristics P atients

n %

Age ≤35 years>35 years

64324

1684

Menopausal status PremenopausalPostmenopausal

198190

5149

Histology DuctalLobularDuctal + lobularOtherUnknown

29424461212

766

1233

Clinical stage before NAC T1–2T3–4

114274

2971

Lymph node NegativePositive

19369

595

Clinical stage IIBIIIAIIIBIIIC

40150151

47

10393912

Histological grade IIIIIUnknown

94171123

244432

Nuclear grade IIIIIUnknown

113117158

293041

HER-2 status NegativePositiveUnknown

15063

175

391645

ER status before NAC NegativePositiveUnknown

137197

54

355114

PgR status before NAC NegativePositiveUnknown

169140

79

443620

ER and/or PgR statusbefore NAC

NegativePositiveUnknown

111215

62

295516

LVI NoYesUnknown

143137108

373528

Necrosis NoYesUnknown

18244

162

471142

Microcalcifications NoYesUnknown

16838

182

431047

Type of NAC FEC/FACTAC4AC + 4T

23039

119

591031

Taxen treatment NoYes

230158

5941

Radiotherapy NoYesUnknown

22340

26

687

7Type of surgery Breast conservation

Mastectomy61

3271684

Keskin et al. Oncology 2011;81:30–3834

taxane-containing chemotherapy were significant pre-dictors of pCR in univariate analysis. However, in a mul-tivariate model, clinical lymph node status, ER, LVI and taxane-containing CT were the only significant indepen-dent predictors of pCR.

In our study, there was a significant difference be-tween patients with pCR and without pCR between older ( 6 35 years) and younger patients ( ! 35 years). In patients younger ! 35 years, pCR was more frequent, but this dif-ference was absent in patients with a higher cutoff point

Table 2. Univariate analysis of factors predicting pCR in breast cancer patients following NAC

Factors p CR Total p value(�2)ye s no

Age ≤35 years>35 years

11 (17%)25 (8%)

53 (83%)299 (92%)

64324 0.017

Menopausal status PremenopausalPostmenopausal

23 (12%)13 (7%)

175 (88%)177 (93%)

198190 NS

Histology IDCILC

30 (10%)2 (8%)

264 (90%)22 (92%)

29424 NS

Clinical stage before NAC T1T2T3T4

4 (36%)14 (14%)

8 (7%)10 (6%)

7 (64%)89 (86%)

100 (93%)156 (94%)

11103108166 0.002

T1–2T3–4

18 (16%)18 (7%)

96 (84%)256 (93%)

114274 0.004

Clinical lymph node involvement NegativePositive

5 (26%)31 (8%)

14 (74%)338 (92%)

19369 0.009

Clinical stage IIBIIIAIIIBIIIC

7 (18%)13 (9%)15 (10%)

1 (2%)

33 (82%)137 (91%)136 (90%)

46 (98%)

4015015147 NS

Histologic grade IIIII

4 (4%)18 (11%)

90 (96%)153 (89%)

94171 0.077

Nuclear grade IIIII

6 (6%)15 (13%)

107 (94%)102 (87%)

113117 0.048

HER-2 status NegativePositive

12 (8%)15 (24%)

138 (92%)48 (76%)

15063 0.002

ER status before CT NegativePositive

25 (18%)8 (4%)

112 (82%)189 (96%)

137197 <0.001

PgR status before CT NegativePositive

21 (12%)11 (8%)

148 (88%)129 (92%)

169140 NS

ER and/or PgR status before NAC NegativePositive

18 (16%)15 (7%)

93 (84%)200 (93%)

111215 0.009

LVI NoYes

16 (11%)3 (2%)

127 (89%)134 (98%)

143137 0.003

Necrosis NoYes

12 (7%)3 (7%)

170 (93%)41 (93%)

18244 NS

Microcalcifications NoYes

14 (8%)2 (5%)

154 (92%)36 (95%)

16838 NS

Type of NAC FEC/FACTAC4AC + 4T

12 (5%)0

24 (20%)

218 (95%)39 (100%)95 (80%)

23039119 <0.001

Taxan treatment NoYes

12 (5%)24 (15%)

218 (95%)134 (85%)

230158 0.001

The Role of pCR for Breast Cancer Oncology 2011;81:30–38 35

for age (50 years; data not shown). Also, patient age was not a prognosticator of pCR of breast tumors previously [2] . However, Gajdos et al. [3] and Huober et al. [23] re-ported tumor response to be inversely related to age.

The histological type was not significantly associated with pCR in this study. Although pCR to NAC was lower for invasive lobular breast carcinoma (ILC) than IDC (10 vs. 8%, respectively), this difference did not reach statisti-cal significance, possibly due to the small number of pa-tients with pCR. Our findings are in agreement with those reported by Montagna et al. [1] ; in their study, pa-tients with ILC were less likely to have pCR (0 vs. 10.9%; p = 0.06) compared with IDC patients. However, in sev-eral other studies, the incidence of pCR was lower in pa-

tients with ILC histology [24–27] . The low response rate of ILC to chemotherapy could be related to their particu-lar biological profile when compared with IDC; ILCs have higher hormone receptor levels and bcl-2 expression and lower Ki-67 scores and HER-2 expression [1] .

In this study, tumor size and presence of clinical lymph node involvement at baseline are clinical features that might identify patients at higher risk. Smaller tumor size and node negativity were correlated with a higher rate of pCR; consequently, in patients with a larger tumor size and node positivity pCR was less frequent. In this study, clinical node status was found to be an independent prog-nosticator. In addition, only 26% of the patients with clin-ical stage T 1–2 had local and/or distant metastases, which is in contrast to the 78% in T 3–4 (p = 0.014; data not shown). Our results are in accord with previous studies [1, 2] . Theoretically, the ability to achieve pCR might in-dicate high tumor chemosensitivity and therefore eradi-cation of all distant invasive micrometastases, thus re-sulting in low recurrence rates. It might be argued, how-ever, that with more advanced disease, there is a higher probability of micrometastatic clones, a subgroup of which may be resistant to conventional agents or have tu-mor features different from those in primary tumors [1] .

In this study, we showed that receptor status was a pre-dictor for pCR. Of the 36 patients with pCR in whom ER/

Table 3. Multivariate analysis of factors predicting pCR in breast cancer patients following NAC

Factor Hazard ratio 95% CI p value

Clinical lymph node status(negative vs. positive) 4.8 0.9–25.8 0.062

ER (negative vs. positive) 6.4 1.8–22.2 0.003LVI (negative vs. positive) 5.9 1.5–22.8 0.009Taxan-containing NAC 3.8 1.1–12.5 0.026

1.0

0.8

0.6

0.4

Prog

ress

ion-

free

sur

viva

l

0.2

00 24 48 72

Months after surgery96 120 144 168

+ + ++++++++

+++

++++++++

++++++++++

++++++++

+++++

+++++++++

++++++++++++++++ +++ ++ +

+

pCR

pCR

NoYes

95% Cl

72–9276–97

Follow-up (median)

6966

Events, n

1381

+ Censored

p = 0.001

No pCR

1.0

0.8

0.6

0.4Ove

rall

surv

ival

0.2

00 24 48 72

Months after surgery96 120 144 168

++++++++++++++++++++++++++++++++++ +++++++ ++ ++

+++ +

+ + +++++ ++ +++ +

+++++++++++

+++++ +++ ++ ++++++++++++

++pCR

pCR

NoYes

95% Cl

127–148138–173

Follow-up (median)

7166

Events, n

351

+ Censored

p = 0.305

No pCR

Fig. 2. Progression-free survival analysis. Fig. 3. Overall survival analysis.

Colo

r ver

sion

ava

ilabl

e on

line

Colo

r ver

sion

ava

ilabl

e on

line

Keskin et al. Oncology 2011;81:30–3836

PgR status was assayed before treatment, 76% had ER, 66% had PgR, and 55% had hormone receptor-negative tumors. Hormone receptor negativity (ER and/or PgR) was a significant predictor of pCR in univariate analysis but not in multivariate analysis. Previously published data suggest that steroid receptor negativity predicts che-mosensitivity. In a study by Guarneri et al. [2] , response to NAC was superior in hormone receptor-negative tu-mors than in ER-positive tumors. Other studies have also shown a statistically significant correlation between pCR and hormone receptor negativity [17, 28, 29] , but the lack of response (apoptosis) of ER-positive cells to chemother-apy remains to be established. However, in vitro studies suggest that ER signaling can increase bcl-2 levels and induce anthracycline resistance [8] .

It has been demonstrated that breast cancer is a het-erogeneous disease, and different subtypes have been de-scribed. The patients with HER-2-positive breast cancer have a worse outcome before and after trastuzumab ther-apy. However, it has been shown that HER-2-positivetumors have a good response to anthracycline-basedchemotherapy. All of our patients were treated with an-thracycline-based NAC. In our HER-2-overexpressing tumors, the pCR rate was superior to that in HER-2-neg-ative tumors (24 vs. 8%, respectively). However, in 45% of patients, HER-2 receptor was unknown, and 31% of HER-2-positive patients were not treated with trastuzumab. The pCR rates were 37 and 25%, respectively (p 1 0.05), in patients with and without trastuzumab treatment. This unexpected finding might be due to the small sam-ple size and the retrospective nature of the study. Our findings are similar to those reported by Fernández-Mo-rales et al. [30] , who found that patients with HER-2-neg-ative breast cancer were less likely to have pCR compared with those with HER-2-positive breast cancer (13.9 vs. 28.6%, respectively), in agreement with studies reporting a higher incidence of pCR in patients with HER-2-posi-tive breast cancer [2, 31] . The low response rate of HER-2-negative breast cancers to chemotherapy may be as-cribed to their particular biological profile compared with HER-2-positive breast cancers.

With respect to histological and nuclear grades, a higher nuclear grade was a significant predictor of pCR. Presence of a higher histological grade shows a non-sig-nificant trend for pCR (p = 0.077). However, neither his-tological nor nuclear grade were significant predictors of pCR in multivariate analyses, whereas other investigators found grade to be an independent predictor of pCR in multivariate analyses [32–34] . However, Uematsu et al. [35] found that grade was not an important predictor of

breast cancer chemosensitivity. These discordant results may be due to the small number of patients with pCR, a large number of patients with unknown grade and the heterogeneous patient populations. Another major limi-tation of most of these studies (including the present) is their retrospective nature.

One study showed that absence of LVI in post-NAC surgical specimens correlated with pathological response [35] . Another study reported that grade of LVI was sig-nificantly associated with tumor recurrence and tumor-related death [36] . Therefore, it is important to assess LVI in surgical specimens after NAC to be able to predict pathological response and outcome in patients after NAC.

Interestingly, none of patients who received the TAC regimen had pCR. The limited number of patients may be the reason for this result. In a phase III, randomized GeparTrio trial, pCR following TAC was 5.3% [37] . In the National Surgical Adjuvant Breast and Bowel Project Protocol B-27 study, addition of docetaxel to an anthra-cycline-based regimen, particularly when added sequen-tially, resulted in higher clinical and pathological re-sponse rates [38] . In this study, preoperative docetaxel added to AC significantly increased the proportion of pa-tients having pCR compared with preoperative AC alone (26 vs. 13%, respectively; p ! 0.001). Finally, taxanes have produced increases in response rates in the neoadjuvant setting. In addition, sequential administration of taxanes to AC (not concurrently) increased pCR and progression-free survival (p = 0.079; data not shown).

Conclusion

In conclusion, the current study provides clinical and pathological prognosticators of response to NAC in breast cancer. We demonstrated that achievement of pCR after NAC is correlated with a significantly improved out-come. Additionally, this analysis confirms that age, ER, hormone receptor, HER-2 receptor status, tumor size, clinical lymph node involvement, LVI and type of chemo-therapy were associated with the probability of achieving pCR. Chemotherapy consisting of doxorubicin and cy-clophosphamide followed by docetaxel was found to in-dicate a better outcome for pCR.

Disclosure Statement

All authors state that they have no conflicts of interest.

The Role of pCR for Breast Cancer Oncology 2011;81:30–38 37

References

1 Montagna E, Bagnardi V, Rotmensz N, Viale G, Pruneri G, Veronesi P, Cancello G, Bal-duzzi A, Dellapasqua S, Cardillo A, Luini A, Zurrida S, Gentilini O, Mastropasqua MG, Bottiglieri L, Iorfida M, Goldhirsch A, Col-leoni M: Pathological complete response af-ter preoperative systemic therapy and out-come: relevance of clinical and biologic base-line features. Breast Cancer Res Treat 2010; 124: 689–699.

2 Guarneri V, Broglio K, Kau SW, Cristofanil-li M, Buzdar AU, Valero V, Buchholz T, Me-ric F, Middleton L, Hortobagyi GN, Gonza-lez-Angulo AM: Prognostic value of patho-logic complete response after primary chemotherapy in relation to hormone recep-tor status and other factors. J Clin Oncol 2006; 24: 1037–1044.

3 Gajdos C, Tartter PI, Estabrook A, Gistrak MA, Jaffer S, Bleiweiss IJ: Relationship of clinical and pathologic response to neoadju-vant chemotherapy and outcome of locally advanced breast cancer. J Surg Oncol 2002; 80: 4–11.

4 Ionta MT, Atzori F, Deidda MC, Pusceddu V, Palmeri S, Frau B, Murgia M, Barca M, Mi-nerba L, Massidda B: Long-term outcomesin stage IIIB breast cancer patients who achieved less than a pathological complete response ( ! pCR) after primary chemothera-py. Oncologist 2009; 14: 1051–1060.

5 Penault-Llorca F, Abrial C, Raoelfils I, Chol-let P, Cayre A, Mouret-Reynier MA, Thivat E, Mishellany F, Gimbergues P, Durando X: Changes and predictive and prognostic value of the mitotic index, Ki-67, cyclin D1, and cyclo-oxygenase-2 in 710 operable breast cancer patients treated with neoadjuvant chemotherapy. Oncologist 2008; 13: 1235–1245.

6 Rody A, Karn T, Gatje R, Ahr A, Solbach C, Kourtis K, Munnes M, Loibl S, Kissler S, Ruckhaberle E, Holtrich U, von Minckwitz G, Kaufmann M: Gene expression profiling of breast cancer patients treated with docetaxel, doxorubicin, and cyclophospha-mide within the GeparTrio trial: HER-2, but not topoisomerase II alpha and microtubule-associated protein tau, is highly predictive of tumor response. Breast 2007; 16: 86–93.

7 Burcombe RJ, Makris A, Richman PI, Daley FM, Noble S, Pittam M, Wright D, Allen SA, Dove J, Wilson GD: Evaluation of ER, PgR, HER-2 and Ki-67 as predictors of response to neoadjuvant anthracycline chemotherapy for operable breast cancer. Br J Cancer 2005; 92: 147–155.

8 Alvarado-Cabrero I, Alderete-Vazquez G, Quintal-Ramirez M, Patino M, Ruiz E: Inci-dence of pathologic complete response in women treated with preoperative chemo-therapy for locally advanced breast cancer: correlation of histology, hormone receptor status, Her2/Neu, and gross pathologic find-ings. Ann Diagn Pathol 2009; 13: 151–157.

9 Gonzalez-Angulo AM, Morales-Vasquez F, Hortobagyi GN: Overview of resistance to systemic therapy in patients with breast can-cer. Adv Exp Med Biol 2007; 608: 1–22.

10 Makris A, Powles TJ, Dowsett M, Allred C: p53 protein overexpression and chemosensi-tivity in breast cancer. Lancet 1995; 345: 1181–1182.

11 Alkarain A, Slingerland J: Deregulation of p27 by oncogenic signaling and its prognos-tic significance in breast cancer. Breast Can-cer Res 2004; 6: 13–21.

12 Cristofanilli M, Budd GT, Ellis MJ, Stopeck A, Matera J, Miller MC, Reuben JM, Doyle GV, Allard WJ, Terstappen LW, Hayes DF: Circulating tumor cells, disease progression, and survival in metastatic breast cancer. N Engl J Med 2004; 351: 781–791.

13 Gasparini G, Weidner N, Bevilacqua P, Maluta S, Dalla Palma P, Caffo O, Barbares-chi M, Boracchi P, Marubini E, Pozza F: Tu-mor microvessel density, p53 expression, tu-mor size, and peritumoral lymphatic vessel invasion are relevant prognostic markers in node-negative breast carcinoma. J Clin On-col 1994; 12: 454–466.

14 Singletary SE, Allred C, Ashley P, Bassett LW, Berry D, Bland KI, Borgen PI, Clark GM, Edge SB, Hayes DF, Hughes LL, Hutter RV, Morrow M, Page DL, Recht A, Theriault RL, Thor A, Weaver DL, Wieand HS, Greene FL: Staging system for breast cancer: revisions for the 6th edition of the AJCC Cancer Stag-ing Manual. Surg Clin North Am 2003; 83: 803–819.

15 The World Health Organization Histologi-cal Typing of Breast Tumors – Second Edi-tion. The World Organization. Am J Clin Pathol 1982; 78: 806–816.

16 Robbins P, Pinder S, de Klerk N, Dawkins H, Harvey J, Sterrett G, Ellis I, Elston C: Histo-logical grading of breast carcinomas: a study of interobserver agreement. Hum Pathol 1995; 26: 873–879.

17 Osako T, Horii R, Matsuura M, Ogiya A, Domoto K, Miyagi Y, Takahashi S, Ito Y, Iwase T, Akiyama F: Common and discrimi-native clinicopathological features between breast cancers with pathological complete response or progressive disease in response to neoadjuvant chemotherapy. J Cancer Res Clin Oncol 2010; 136: 233–241.

18 Fisher B, Bryant J, Wolmark N, Mamounas E, Brown A, Fisher ER, Wickerham DL, Be-govic M, DeCillis A, Robidoux A, Margolese RG, Cruz AB Jr, Hoehn JL, Lees AW, Dimi-trov NV, Bear HD: Effect of preoperative chemotherapy on the outcome of women with operable breast cancer. J Clin Oncol 1998; 16: 2672–2685.

19 Charfare H, Limongelli S, Purushotham AD: Neoadjuvant chemotherapy in breast cancer. Br J Surg 2005; 92: 14–23.

20 Bonadonna G, Veronesi U, Brambilla C, Fer-rari L, Luini A, Greco M, Bartoli C, Coop-mans de Yoldi G, Zucali R, Rilke F, et al: Pri-mary chemotherapy to avoid mastectomy in tumors with diameters of three centimeters or more. J Natl Cancer Inst 1990; 82: 1539–1545.

21 Sarid D, Ron IG, Sperber F, Stadler Y, Kahan P, Kovner F, Ben-Yosef R, Marmor S, Grin-berg Y, Maimon N, Weinstein J, Yaal-Hahoshen N: Neoadjuvant treatment with paclitaxel and epirubicin in invasive breast cancer: a phase II study. Clin Drug Investig 2006; 26: 691–701.

22 Gonzalez-Angulo AM, McGuire SE, Buch-holz TA, Tucker SL, Kuerer HM, Rouzier R, Kau SW, Huang EH, Morandi P, Ocana A, Cristofanilli M, Valero V, Buzdar AU, Hor-tobagyi GN: Factors predictive of distant metastases in patients with breast cancer who have a pathologic complete response af-ter neoadjuvant chemotherapy. J Clin Oncol 2005; 23: 7098–7104.

23 Huober J, von Minckwitz G, Denkert C, Tesch H, Weiss E, Zahm DM, Belau A, Khan-dan F, Hauschild M, Thomssen C, Hogel B, Darb-Esfahani S, Mehta K, Loibl S: Effectof neoadjuvant anthracycline-taxane-based chemotherapy in different biological breast cancer phenotypes: overall results from the GeparTrio study. Breast Cancer Res Treat 2010; 124: 133–140.

24 Cocquyt VF, Blondeel PN, Depypere HT, Praet MM, Schelfhout VR, Silva OE, Hurley J, Serreyn RF, Daems KK, Van Belle SJ: Dif-ferent responses to preoperative chemother-apy for invasive lobular and invasive ductal breast carcinoma. Eur J Surg Oncol 2003; 29: 361–367.

25 Wenzel C, Bartsch R, Hussian D, Pluschnig U, Altorjai G, Zielinski CC, Lang A, Haid A, Jakesz R, Gnant M, Steger GG: Invasive duc-tal carcinoma and invasive lobular carcino-ma of breast differ in response following neoadjuvant therapy with epidoxorubicin and docetaxel + G-CSF. Breast Cancer Res Treat 2007; 104: 109–114.

26 Mathieu MC, Rouzier R, Llombart-Cussac A, Sideris L, Koscielny S, Travagli JP, Con-tesso G, Delaloge S, Spielmann M: The poor responsiveness of infiltrating lobular breast carcinomas to neoadjuvant chemotherapy can be explained by their biological profile. Eur J Cancer 2004; 40: 342–351.

27 Tubiana-Hulin M, Stevens D, Lasry S, Guine-bretiere JM, Bouita L, Cohen-Solal C, Cherel P, Rouesse J: Response to neoadjuvant che-motherapy in lobular and ductal breast car-cinomas: a retrospective study on 860 pa-tients from one institution. Ann Oncol 2006; 17: 1228–1233.

Keskin et al. Oncology 2011;81:30–3838

28 von Minckwitz G, Sinn HP, Raab G, Loibl S, Blohmer JU, Eidtmann H, Hilfrich J, Merkle E, Jackisch C, Costa SD, Caputo A, Kaufmann M: Clinical response after two cycles com-pared to HER2, Ki-67, p53, and bcl-2 in inde-pendently predicting a pathological com-plete response after preoperative chemother-apy in patients with operable carcinoma of the breast. Breast Cancer Res 2008; 10:R30.

29 Prisack HB, Karreman C, Modlich O, Au-dretsch W, Danae M, Rezai M, Bojar H:Predictive biological markers for responseof invasive breast cancer to anthracycline/cyclophosphamide-based primary (radio-)chemotherapy. Anticancer Res 2005; 25: 4615–4621.

30 Fernández-Morales LA, Segui MA, Andreu X, Dalmau E, Saez A, Pericay C, Santos C, Montesinos J, Gallardo E, Arcusa A, Saigi E: Analysis of the pathologic response to pri-mary chemotherapy in patients with locally advanced breast cancer grouped according to estrogen receptor, progesterone receptor, and HER2 status. Clin Breast Cancer 2007; 7: 559–564.

31 Pu RT, Schott AF, Sturtz DE, Griffith KA, Kleer CG: Pathologic features of breast can-cer associated with complete response to neoadjuvant chemotherapy: importance of tumor necrosis. Am J Surg Pathol 2005; 29: 354–358.

32 Tan MC, Al Mushawah F, Gao F, Aft RL, Gil-landers WE, Eberlein TJ, Margenthaler JA: Predictors of complete pathological response after neoadjuvant systemic therapy for breast cancer. Am J Surg 2009; 198: 520–525.

33 Zhu L, Li YF, Chen WG, He JR, Peng CH, Zhu ZG, Li HW: HER2 and topoisomerase II � : possible predictors of response to neoad-juvant chemotherapy for breast cancer pa-tients. Chin Med J (Engl) 2008; 121: 1965–1968.

34 Shien T, Akashi-Tanaka S, Miyakawa K, Hojo T, Shimizu C, Seki K, Ando M, Kohno T, Taira N, Doihara H, Katsumata N, Fuji-wara Y, Kinoshita T: Clinicopathological fea-tures of tumors as predictors of the efficacy of primary neoadjuvant chemotherapy for operable breast cancer. World J Surg 2009; 33: 44–51.

35 Uematsu T, Kasami M, Watanabe J, Taka-hashi K, Yamasaki S, Tanaka K, Tadokoro Y, Ogiya A: Is lymphovascular invasion degree one of the important factors to predict neo-adjuvant chemotherapy efficacy in breast cancer? Breast Cancer 2010, E-pub ahead of print.

36 Tamura N, Hasebe T, Okada N, Houjoh T, Akashi-Tanaka S, Shimizu C, Shibata T, Sa-sajima Y, Iwasaki M, Kinoshita T: Tumor his-tology in lymph vessels and lymph nodes for the accurate prediction of outcome among breast cancer patients treated with neoadju-vant chemotherapy. Cancer Sci 2009; 100: 1823–1833.

37 von Minckwitz G, Kummel S, Vogel P, Ha-nusch C, Eidtmann H, Hilfrich J, Gerber B, Huober J, Costa SD, Jackisch C, Loibl S, Meh-ta K, Kaufmann M: Neoadjuvant vinorel-bine-capecitabine versus docetaxel-doxoru-bicin-cyclophosphamide in early nonre-sponsive breast cancer: phase III randomized GeparTrio trial. J Natl Cancer Inst 2008; 100: 542–551.

38 Rastogi P, Anderson SJ, Bear HD, Geyer CE, Kahlenberg MS, Robidoux A, Margolese RG, Hoehn JL, Vogel VG, Dakhil SR, Tamkus D, King KM, Pajon ER, Wright MJ, Robert J, Paik S, Mamounas EP, Wolmark N: Preop-erative chemotherapy: updates of National Surgical Adjuvant Breast and Bowel Project Protocols B-18 and B-27. J Clin Oncol 2008; 26: 778–785.