Comparison of different definitions of pathologic complete response in operable breast cancer: a pooled analysis of three prospective neoadjuvant studies of JBCRG

Comparison of proportions and prognostic impact of pathological complete response between evaluations of representative specimen and total specimen in primary breast cancer after neoadjuvant chemoradiotherapy: an ancillary study of JCOG0306

BACKGROUND

In JCOG0306 trial, a phase II study to examine the efficacy of neoadjuvant chemotherapy followed by radiation therapy (NAC-RT) to primary breast cancer, pathological complete response (pCR) was evaluated from specimens of the representative cross-section including the tumor center that had been accurately marked [representative specimen (RS) method]. In this ancillary study, we examined if the RS method was comparable to the conventional total specimen (TS) method, which is widely employed in Japan, to identify the pCR group showing excellent prognosis.

METHODS

We obtained long-term follow-up data of 103 patients enrolled in JCOG0306 trial. As histological therapeutic effect, pCR (ypT0 and ypT0/is) and quasi-pCR [QpCR, ypT0/is plus Grade 2b (only a few remaining invasive cancer cells)] were evaluated with RS and TS methods. Concordance of pCR between these two methods and associations of the pCR with prognosis were examined.

RESULTS

ypT0, ypT0/is, and QpCR were observed in 28 (27.2%), 39 (37.9%), and 45 (43.7%) patients with RS method, whereas these were 20 (19.4%), 25 (24.3%) and 40 (38.9%) with TS method, respectively. Between RS and TS methods, concordance proportions of ypT0 and ypTis were 92.2% and 86.4%, respectively. Risk of recurrence of ypT0/is group was lower than that of non-ypT0/is group (HR 0.408, 95% CI [0.175-0.946], P = 0.037) and risk of death of ypT0/is group was lower than that of non-ypT0/is group (HR 0.251, 95% CI [0.073-0.857], P = 0.027). The ypT0 and ypT0/is groups with RS method showed excellent prognosis similarly with those with TS method, and RS method was able to differentiate the OS and RFS between pCR and non-pCR than TS method significantly even if pCR was classified ypT0 or ypT0/is. With TS method, QpCR criteria stratified patients into the better and worse prognosis groupsmore clearly than pCR criteria of ypT0 or ypT0/is.

CONCLUSIONS

RS method was comparable to TS method for the evaluation of pCR in the patients who received NAC-RT to primary breast cancer provided the tumor center was accurately marked. As pCR criteria with RS method, ypT0/is appeared more appropriate than ypT0.

TP53 signature predicts pathological complete response after neoadjuvant chemotherapy for breast cancer: Observational and confirmational study using prospective study cohorts

The TP53 signature is considered a predictor of neoadjuvant chemotherapy (NAC) response and prognostic factor in breast cancer. The objective of this study was to confirm TP53 signature can predict pathological complete response (pCR) and prognosis in cohorts of breast cancer patients who received NAC in prospective studies. Development cohorts (retrospective [n = 37] and prospective [n = 216] cohorts) and validation cohorts (NAC administered prospective study cohorts [n = 407] and retrospective perioperative chemotherapy (PC)-naïve, hormone receptor (HrR)-positive cohort [PC-naïve_HrR+ cohort] [n = 322]) were used. TP53 signature diagnosis kit was developed using the development cohorts. TP53 signature predictability for pCR and the relationship between recurrence-free survival (RFS), overall survival (OS), and the TP53 signature were analyzed. The pCR rate of the mutant (mt) signature group was significantly higher than that of the wild-type (wt) signature group (odds ratio, 5.599; 95 % confidence interval = 1.876-16.705; P = 0.0008). The comparison of the RFS and OS between the HrR+ and HER2- subgroup of the NAC cohort and of the PC-naïve_HrR+ cohort indicated that the RFS and OS benefit of NAC was greater in the mt signature group than in the wt signature group. From post hoc analyses, the RFS and OS benefit from adding capecitabine to FEC+T as NAC might be observed only in the mt signature group. The TP53 signature can predict the pCR after NAC, and the RFS and OS benefit from NAC may be greater in the mt signature group than in the wt signature group.

Real-world evidence of neoadjuvant chemotherapy for breast cancer treatment in a Brazilian multicenter cohort: Correlation of pathological complete response with overall survival

OBJECTIVES

We aimed to evaluate the pCR rate in patients receiving NAC for the treatment of breast cancer (BC) in a multicenter cohort in Brazil. Additionally, we aimed to use RWD to assess the impact of pCR on OS and DFS.

METHODS

This was a retrospective, multicenter cohort study that included female patients over 18 years of age who were diagnosed with nonmetastatic breast cancer and received NAC. OS and DFS at five years were estimated by the Kaplan‒Meier method. Additionally, we conducted a multivariate analysis to identify factors that were significantly associated with pCR and OS.

RESULTS

From 2011 to 2020, 1891 patients were included in the study, and 421 (22,3%) achieved pCR (ypT0 ypN0). Considering the presence of residual DCIS, pCR was achieved in 467 patients (23,5%). The pCR rate varied between the subtypes: HER-2+ (p = 0,016) and clinical stage IIIA and IIIB (p < 0,001). Among HER-2+ patients, those who received trastuzumab had a significantly higher pCR rate than those who did not receive trastuzumab (p < 0.0001). Similarly, patients with TNBC who received treatment with platinum-based regimens also showed higher pCR rates (p < 0.0001). OS was grouped according to pCR status, and the OS rate was 88,3% in the pCR group and 58.1% in the non-pCR group (p < 0.0001). The five-year DFS was 92.2% in the pCR group and 64.3% in the non-pCR group (p < 0.0001).

CONCLUSION

The pCR rate and its prognostic value varied across BC subtypes. In our study, pCR could be used as a surrogate of favorable clinical outcome, as it was associated with higher OS and DFS rates.

Dose-Dense Docetaxel-Cyclophosphamide and Epirubicin-Cisplatin(ddDCEP): Analysis of an Alternative Platinum-Containing Regimen in 116 Patients with Early Triple Negative Breast Cancer

We assessed the efficacy, tolerability, and cost-effectiveness of a novel neoadjuvant regimen comprising docetaxel-cyclophosphamide alternating with epirubicin-cisplatin (ddDCEP) administered biweekly for 16 weeks in 116 patients with early triple-negative breast cancer. This regimen achieved a high pathological complete response (ypT0/TisN0) rate of 55.2% and favorable survival outcomes (30-month event-free survival, 91.2%; overall survival, 97%). Febrile neutropenia was observed in 4.3% of patients, and 98% completed at least six of eight cycles. ddDCEP was more cost-effective than contemporary carboplatin-based regimens. This novel approach offers an economically viable and effective alternative to current chemoimmunotherapy regimens, and merits further investigation.

Low neutrophil-to-lymphocyte ratio and pan-immune-inflammation-value predict nodal pathologic complete response in 1274 breast cancer patients treated with neoadjuvant chemotherapy: a multicenter analysis

Background

Systemic inflammatory markers draw great interest as potential blood-based prognostic factors in several oncological settings.

Objectives

The aim of this study is to evaluate whether neutrophil-to-lymphocyte ratio (NLR) and pan-immune-inflammation value (PIV) predict nodal pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in node-positive (cN+) breast cancer (BC) patients.

Design

Clinically, cN+ BC patients undergoing NAC followed by breast and axillary surgery were enrolled in a multicentric study from 11 Breast Units.

Methods

Pretreatment blood counts were collected for the analysis and used to calculate NLR and PIV. Logistic regression analyses were performed to evaluate independent predictors of nodal pCR.

Results

A total of 1274 cN+ BC patients were included. Nodal pCR was achieved in 586 (46%) patients. At multivariate analysis, low NLR [odds ratio (OR) = 0.71; 95% CI, 0.51-0.98; p = 0.04] and low PIV (OR = 0.63; 95% CI, 0.44-0.90; p = 0.01) were independently predictive of increased likelihood of nodal pCR. A sub-analysis on cN1 patients (n = 1075) confirmed the statistical significance of these variables. PIV was significantly associated with axillary pCR in estrogen receptor (ER)-/human epidermal growth factor receptor 2 (HER2)+ (OR = 0.31; 95% CI, 0.12-0.83; p = 0.02) and ER-/HER2- (OR = 0.41; 95% CI, 0.17-0.97; p = 0.04) BC patients.

Conclusion

This study found that low NLR and PIV levels predict axillary pCR in patients with BC undergoing NAC.

Registration

Eudract number NCT05798806.

Association of Residual Ductal Carcinoma In Situ With Breast Cancer Recurrence in the Neoadjuvant I-SPY2 Trial

Importance

Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in breast cancer strongly correlates with overall survival and has become the standard end point in neoadjuvant trials. However, there is controversy regarding whether the definition of pCR should exclude or permit the presence of residual ductal carcinoma in situ (DCIS).

Objective

To examine the association of residual DCIS in surgical specimens after neoadjuvant chemotherapy for breast cancer with survival end points to inform standards for the assessment of pathologic complete response.

Design, Setting, and Participants

The study team analyzed the association of residual DCIS after NAC with 3-year event-free survival (EFS), distant recurrence-free survival (DRFS), and local-regional recurrence (LRR) in the I-SPY2 trial, an adaptive neoadjuvant platform trial for patients with breast cancer at high risk of recurrence. This is a retrospective analysis of clinical specimens and data from the ongoing I-SPY2 adaptive platform trial of novel therapeutics on a background of standard of care for early breast cancer. I-SPY2 participants are adult women diagnosed with stage II/III breast cancer at high risk of recurrence.

Interventions

Participants were randomized to receive taxane and anthracycline-based neoadjuvant therapy with or without 1 of 10 investigational agents, followed by definitive surgery.

Main Outcomes and Measures

The presence of DCIS and EFS, DRFS, and LRR.

Results

The study team identified 933 I-SPY2 participants (aged 24 to 77 years) with complete pathology and follow-up data. Median follow-up time was 3.9 years; 337 participants (36%) had no residual invasive disease (residual cancer burden 0, or pCR). Of the 337 participants with pCR, 70 (21%) had residual DCIS, which varied significantly by tumor-receptor subtype; residual DCIS was present in 8.5% of triple negative tumors, 15.6% of hormone-receptor positive tumors, and 36.6% of ERBB2-positive tumors. Among those participants with pCR, there was no significant difference in EFS, DRFS, or LRR based on presence or absence of residual DCIS.

Conclusions and Relevance

The analysis supports the definition of pCR as the absence of invasive disease after NAC regardless of the presence or absence of DCIS.

Trial Registration

ClinicalTrials.gov Identifier NCT01042379.

Development of a novel nomogram-based online tool to predict axillary status after neoadjuvant chemotherapy in cN+ breast cancer: A multicentre study on 1,950 patients

BACKGROUND

Type of axillary surgery in breast cancer (BC) patients who convert from cN + to ycN0 after neoadjuvant chemotherapy (NAC) is still debated. The aim of the present study was to develop and validate a preoperative predictive nomogram to select those patients with a low risk of residual axillary disease after NAC, in whom axillary surgery could be minimized.

PATIENTS AND METHODS

1950 clinically node-positive BC patients from 11 Breast Units, treated by NAC and subsequent surgery, were included from 2005 to 2020. Patients were divided in two groups: those who achieved nodal pCR vs. those with residual nodal disease after NAC. The cohort was divided into training and validation set with a geographic separation criterion. The outcome was to identify independent predictors of axillary pathologic complete response (pCR).

RESULTS

Independent predictive factors associated to nodal pCR were axillary clinical complete response (cCR) after NAC (OR 3.11, p < 0.0001), ER-/HER2+ (OR 3.26, p < 0.0001) or ER+/HER2+ (OR 2.26, p = 0.0002) or ER-/HER2- (OR 1.89, p = 0.009) BC, breast cCR (OR 2.48, p < 0.0001), Ki67 > 14% (OR 0.52, p = 0.0005), and tumor grading G2 (OR 0.35, p = 0.002) or G3 (OR 0.29, p = 0.0003). The nomogram showed a sensitivity of 71% and a specificity of 73% (AUC 0.77, 95%CI 0.75-0.80). After external validation the accuracy of the nomogram was confirmed.

CONCLUSION

The accuracy makes this freely-available, nomogram-based online tool useful to predict nodal pCR after NAC, translating the concept of tailored axillary surgery also in this setting of patients.

Eribulin-based neoadjuvant chemotherapy for triple-negative breast cancer patients stratified by homologous recombination deficiency status: a multicenter randomized phase II clinical trial

Purpose

To investigate clinical usefulness of eribulin-based neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) patients.

Methods

Patients in group A (aged < 65 years with homologous recombination deficiency, HRD, score ≥ 42, or those at any age with germline BRCA mutation, gBRCAm) were randomized to 4 cycles of paclitaxel plus carboplatin (group A1) or eribulin plus carboplatin (group A2), followed by 4 cycles of anthracycline. Patients in group B (aged < 65 years with HRD score < 42, or aged ≥ 65 years without gBRCAm) were randomized to 6 cycles of eribulin plus cyclophosphamide (group B1) or eribulin plus capecitabine (group B2); non-responders to the first 4 cycles of the eribulin-based therapy received anthracycline. Primary endpoint was pCR rate (ypT0-is, ypN0; centrally confirmed). Main secondary endpoint was safety.

Results

The full analysis set comprised 99 patients. The pCR rate was 65% (90% CI, 46%–81%) and 45% (27%–65%) in groups A1 and A2, respectively, and 19% (8%–35%) in both groups B1 and B2. No major difference was seen in secondary endpoints, but peripheral neuropathy incidence was 74% in group A1, whereas it was 32%, 22%, and 26% in groups A2, B1, and B2, respectively.

Conclusions

In patients aged < 65 years with high HRD score or gBRCAm, weekly paclitaxel plus carboplatin and eribulin plus carboplatin followed by anthracycline resulted in a pCR rate of > 60% and > 40%, respectively, suggesting potential usefulness of patient stratification using HRD; pCR tended to be low in patients with HRD-negative tumors. Neurotoxicity was less frequent with the eribulin-based regimen. Trial registration:The study has been registered with the University Hospital Medical Information Network Clinical Trials Registry (http://www.umin.ac.jp/ctr/index-j.htm) with unique trial number UMIN000023162. The Japan Breast Cancer Research Group trial number is JBCRG-22.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06184-w.

Androgen receptor expression is useful to predict the therapeutic effect in HER2-positive breast carcinoma

PURPOSE

Although HER2-positive (HER2+) invasive breast carcinomas (BC) have a different clinical therapeutic responsiveness according to estrogen and progesterone receptor expression, the relationship with androgen receptors (AR), which are the same family of steroid hormones, is poorly understood. We investigated the relationship between AR expression in HER2 BCs and therapeutic responsiveness and prognosis in this study.

METHODS

We evaluated patients with HER2 (H) + invasive BC undergoing surgery after neoadjuvant chemotherapy (± HER2-targeted therapies) from 2007-2017, classified as hormone receptor-positive (Allred score: 2-8) (luminal B: LH) and receptor-negative groups (Allred: score 0) (non-luminal: NLH). AR expression was assessed by immunostaining pre-neoadjuvant chemotherapy biopsy specimens, positive with Allred score ≥ 4. The pathological complete response, disease-free survival, and overall survival rates were compared between AR-positive and AR-negative groups.

RESULTS

We classified 82 patients with HER2 + invasive BC into LH (n = 45, 54.9%) and NLH groups (n = 37, 45.1%), and AR + was observed in 43 patients (52.4%) (LH: 23, 51.1%; NLH: 20, 54.1%; p = 0.79). Quasi-pathological complete response was observed in 40 patients (48.8%) (LH: 18, 40%; NLH: 22, 59.5%; p = 0.08) overall, and in 31 AR + patients (72.1%) (LH: 15, 34.9%; NLH: 16, 37.2%), significantly higher than in the AR - group for both subgroups (p < 0.001). Regarding prognosis, disease-free survival was relatively better in the AR + group in all HER2 + BCs (p = 0.085), and overall survival was significantly better in the AR + group for NLH (p = 0.029).

CONCLUSIONS

High AR expression may be a useful predictor of therapeutic effects and prognosis in both subgroups of HER2 + BCs.

Defining radiologic complete response using a correlation of presurgical ultrasound and mammographic localization findings with pathological complete response following neoadjuvant chemotherapy in breast cancer

PURPOSE

Breast cancer affects a significant number of patients younger than 40 years in the Gulf and breast conservative treatment is highly preferred. Pathological complete response (pCR) following neoadjuvant chemotherapy is increasingly being observed with the new chemotherapy agents. Although MRI is more accurate in such evaluations, digital mammography and high-resolution ultrasound (US) which are less expensive may accurately predict pCR which is the focus of this study.

METHODS

A 6-year retrospective study of 93 breast cancer cases who had neoadjuvant chemotherapy and had presurgical radiological localization was carried out. Forty-five had US localization while 48 underwent mammographic localization when US failed to define any residual mass. Radiologic complete response (rCR) was defined as absence of mass with only postbiopsy clip overlying normal breast parenchyma pattern in US and in mammography (clip sign). Mass or abnormal parenchymal pattern was considered as residual tumor. The pathology reports of pCR or not with background changes were recorded.

RESULTS

Ultrasound localization correctly predicted 42 out of 43 pathologic masses with 98 % accuracy. Mammographic localization correctly predicted 40 out of 43 pCR with 93 % accuracy. The best responders were triple negative and HER2 positive hormone negative breast cancer.

CONCLUSION

The study defines radiologic complete response (rCR) as absence of a mass with the postbiopsy tissue marker overlying a normal-looking breast parenchyma in both ultrasound and mammographic evaluation. A correlation of 93 % was found with pCR. The few false negative cases were associated with overlying dense breast and possibly post treatment reaction. Allocation of a BI-RADS category for rCR is suggested.

A randomized, 3-arm, neoadjuvant, phase 2 study comparing docetaxel + carboplatin + trastuzumab + pertuzumab (TCbHP), TCbHP followed by trastuzumab emtansine and pertuzumab (T-DM1+P), and T-DM1+P in HER2-positive primary breast cancer

Purpose

The standard of care in the neoadjuvant setting for human epidermal growth factor receptor 2 (HER2)-positive breast cancer is dual HER2-targeted therapy. However, a need to minimize treatment-related toxicity and improve pathological complete response (pCR) rates, particularly in luminal HER2-positive disease, exists.

Methods

Neopeaks, a randomized, phase 2 study, compared docetaxel + carboplatin + trastuzumab + pertuzumab (TCbHP; 6 cycles; group A), TCbHP (4 cycles) followed by trastuzumab emtansine + pertuzumab (T-DM1+P; 4 cycles; group B), and T-DM1+P (4 cycles; group C) regimens in HER2‐positive primary breast cancer patients; concurrent hormone therapy with T-DM1+P was administered in case of estrogen receptor positivity (ER+). Based on tumor shrinkage, nonresponders in group C were switched to 5-fluorouracil + epirubicin + cyclophosphamide (FEC; 4 cycles). Primary endpoint was pCR (comprehensive pCR ypN0 [ypT0-TisypN0]).

Results

Of 236 patients enrolled, 204 were randomized to groups A (n = 51), B (n = 52), and C (n = 101). In group C, 80 (79%) patients continued T-DM1+P following favorable response, whereas 21 (21%) nonresponders switched to FEC. pCR rate was numerically higher with the TCbHP →  T-DM1+P regimen (71%) versus the standard TCbHP (57%) and T-DM1+P (57%) regimens. The rate in group C was higher among responders continuing T-DM1+P (63%) versus nonresponders who switched to FEC (38%). pCR rates after initial 4 cycles of T-DM1+P (group C; 57%) and standard TCbHP regimen (57%) were equivalent. pCR rate in patients with ER+ was significantly higher in group B (69%) than groups A (43%) and C (51%), but was comparable in patients with ER− (67–76%). Compared with the T-DM1-based arm, the incidence of adverse events was higher in the taxane-based arms.

Conclusion

In the neoadjuvant setting, the pCR rate with the standard TCbHP →  T-DM1+P regimen was numerically better than the TCbHP regimen alone and significantly better in patients with ER+. Personalization of the T-DM1+P regimen could serve as a reasonable approach to minimize toxicity while maintaining efficacy.

Trial registration ID: UMIN-CTR: UMIN000014649.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05524-6) contains supplementary material, which is available to authorized users.

Changes in background parenchymal enhancement in HER2-positive breast cancer before and after neoadjuvant chemotherapy: Association with pathologic complete response

This study aimed to analyze the relationship between pathologic complete response (pCR) and changes in background parenchymal enhancement (BPE) levels in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer and who received neoadjuvant chemotherapy (NAC).The pre- and post-NAC magnetic resonance imaging results of 51 patients with confirmed unilateral HER2-positive breast cancer were retrospectively analyzed by 2 experienced radiologists. Pre- and post-NAC of contralateral BPE levels were classified into 4 categories (1 = minimal, 2 = mild, 3 = moderate, and 4 = marked). The 4 categories of BPE were defined by the visually estimated enhancement of fibroglandular tissue of the breast. Changes in BPE before and after NAC were compared between the premenopausal and postmenopausal groups and between the pCR and non-pCR groups. The associations between BPE and pCR and between BPE and tumor size were analyzed before and after NAC.Twenty-three patients achieved pCR, and 28 patients achieved non-pCR. Premenopausal patients had significantly higher baseline BPE levels than postmenopausal women (P = .023). The post-NAC BPE levels of premenopausal patients significantly decreased relative to those of postmenopausal patients (P = .027). The baseline BPE levels of the pCR group were not significantly different from those of the non-pCR group (P = .892). However, the decrease in BPE levels in the pCR group was more drastic than that in the non-pCR group (P < .001). Decreased BPE levels were directly associated with pCR and tumor size reduction (P < .05). Women with hormone receptor (HR)-negative tumors were more likely to exhibit pCR than those with HR-positive tumors (P = .007).Decreased BPE of patients with HER2-positive breast cancer may serve as an indicator of NAC effectiveness. Furthermore, women with HR-negative tumors were more likely to exhibit pCR than women with HR-positive tumors.

Chemotherapy may eradicate ductal carcinoma in situ (DCIS) but not the associated microcalcifications

INTRODUCTION

We studied the effect of neoadjuvant chemotherapy (NAC) ± trastuzumab on the ductal carcinoma in situ (DCIS) component in patients with locally advanced breast cancer who achieved pathological complete response (pCR).

METHODS

The diagnostic biopsies of 92 consecutive breast cancer patients that were treated with neoadjuvant chemotherapy (NAC) ± trastuzumab were evaluated for the presence of DCIS. Upon completion of NAC, the surgical specimens were evaluated for complete eradication of both the invasive and non-invasive cancer in the breast. The pretreatment mammograms were evaluated for the presence of microcalcifications and compared to the mammograms that were obtained upon completion of therapy prior to surgery.

RESULTS

Thirty of 92 patients (33%) had a substantial component of DCIS in the pretreatment biopsy. Thirty nine patients (42%) achieved pCR: 22 (56%) following NAC + trastuzumab, 17 (32%) following chemotherapy only. Ten of 30 patients (33%) with DCIS component achieved pCR: 4 received chemotherapy only, in 6 trastuzumab was added. Multiple microcalcifications on the pretreatment mammograms were observed in 3 of 10 patients with DCIS who achieved pCR. No reduction in the area of calcifications was observed following NAC.

CONCLUSIONS

DCIS may be completely eradicated by NAC ± trastuzumab. However, associated microcalcifications probably persist. Patients with locally advanced breast cancer with substantial DCIS may still opt for NAC and breast conservation as the DCIS component may respond and even completely disappear following NAC. Residual widespread microcalcifications after NAC do not necessarily indicate residual cancer. Larger studies are needed to direct the surgical management of these patients.

pCR rates in patients with bilateral breast cancer after neoadjuvant anthracycline-taxane based-chemotherapy - A retrospective pooled analysis of individual patients data of four German neoadjuvant trials

PURPOSE

Patients with bilateral breast cancer (BBC) are usually excluded from participating in clinical trials and little is known about the response and outcome of BBC to neoadjuvant chemotherapy compared to unilateral BC (UBC).

METHODS

We prospectively captured the information on patients with BBC in our database treated within four neoadjuvant chemotherapy trials and collected retrospectively the rate of pathological complete response (pCR) defined as ypT0 ypN0, ypT0/is ypN0, ypT0 ypNX, clinical and histologic parameters. Synchronous carcinoma in the contralateral breast was considered as the non-indicator lesion. Patients with UBC only treated within the same neoadjuvant trials performed the control group.

RESULTS

From the 6727 patients treated within 4 German neoadjuvant trials 119 (1.8%) patients have been identified with the diagnosis of BBC. The pCR rate (ypT0 ypN0) was 12.6% in the non-indicator lesion group versus 10.9% the indicator lesion group versus 20.9% for patients with unilateral disease (p = 0.003). There were more advanced tumor stages and positive axillary lymph nodes in the indicator lesion than in the nonindicator lesion or in UBC. In 52.5% the molecular subtype was identical between indicator and non-indicator lesion with more triple negative and HER2 positive BC in the group of UBC. The disease free survival rate (DFS) was 25.8% for patients with UBC versus 39.6% for patients with BBC.

CONCLUSION

The selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Patients with BBC patients had a lower pCR rate and a lower DFS.

Evaluation of Pathologic Complete Response in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy: Experience in a Single Institution over a 10-Year Period

BACKGROUND

Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) has been associated with favorable clinical outcome in breast cancer patients. However, the possibility that the prognostic significance of pCR differs among various definitions has not been established.

METHODS

We retrospectively evaluated the pathologic response after NAC in 353 breast cancer patients and compared the prognoses after applying the following different definitions of pCR: ypT0/is, ypT0, ypT0/is ypN0, and ypT0 ypN0.

RESULTS

pCR was significantly associated with improved distant disease-free survival (DDFS) regardless of the definition (ypT0/is, p = .002; ypT0, p = .008; ypT0/is ypN0, p < .001; ypT0 ypN0, p = .003). Presence of tumor deposits of any size in the lymph nodes (LNs; ypN ≥ 0(i+)) was associated with worse DDFS (ypT0 ypN0 vs ypT0 ypN ≥ 0(i+), p = .036 and ypT0/is ypN0 vs ypT0/is ypN ≥ 0(i+), p = .015), and presence of isolated tumor cells was associated with decreased overall survival (OS; ypT0/is ypN0 vs ypT0/is ypN0(i+), p = .013). Residual ductal carcinoma in situ regardless of LN status showed no significant difference in DDFS or OS (DDFS: ypT0 vs ypTis, p = .373 and ypT0 ypN0 vs ypTis ypN0, p = .462; OS: ypT0 vs ypTis, p = .441 and ypT0 ypN0 vs ypTis ypN0, p = .758). In subsequent analysis using ypT0/is ypN0, pCR was associated with improved DDFS and OS in triple-negative tumors (p < .001 and p = .003, respectively).

CONCLUSIONS

Based on our study results, the prognosis and rate of pCR differ according to the definition of pCR and ypT0/is ypN0 might be considered a more preferable definition of pCR.

Perfusion Parameters on Breast Dynamic Contrast-Enhanced MRI Are Associated With Disease-Specific Survival in Patients With Triple-Negative Breast Cancer

OBJECTIVE

The aim of this study was to investigate the association between perfusion parameters on MRI performed before treatment and survival outcome (disease-free survival [DFS], disease-specific survival [DSS]) in patients with triple-negative breast cancer (TNBC).

MATERIALS AND METHODS

Sixty-one patients (median age, 50 years; age range, 27-77 years) with TNBC (tumor size on MRI: median, 25.5 mm; range, 11.0-142.0 mm) were included. We analyzed clinical and pathologic variables and MRI parameters. Cox proportional hazards models were used to determine associations with survival outcome.

RESULTS

The median follow-up time was 46.1 months (range, 13.9-58.4 months). Eleven of 61 (18.0%) patients had events (i.e., local, regional, or distant recurrence or contralateral breast cancer) and seven (11.5%) died of breast cancer. Among the pretreatment variables, a larger tumor size on MR images (hazard ratio [HR] = 1.024, p = 0.003) was associated with worse DFS at univariate analysis. In multivariate pretreatment models for DSS, a higher fractional volume of extravascular extracellular space per unit volume of tissue (v_e) value (HR = 1.658, p = 0.038), higher peak enhancement (HR = 1.843, p = 0.018), and a larger tumor size on MR images (HR = 1.060, p = 0.001) were associated with worse DSS. In multivariate posttreatment models, a larger pathologic tumor size (HR for DFS, 1.074 [p = 0.005]; HR for DSS, 1.050 [p = 0.042]) and metastasis in surgically resected axillary lymph nodes (HR for DFS, 5.789 [p = 0.017]; HR for DSS, 23.717 [p = 0.005]) were associated with worse survival outcome.

CONCLUSION

A higher v_e value, higher peak enhancement, and larger tumor size of the primary tumor on pretreatment MRI were independent predictors of worse DSS in patients with TNBC.