Adjuvant trastuzumab reduces locoregional recurrence in women who receive breast-conservation therapy for lymph node-negative, human epidermal growth factor receptor 2-positive breast cancer

Evaluation of a novel 177Lu-labelled therapeutic Affibody molecule with a deimmunized ABD domain and improved biodistribution profile

PURPOSE

Fusion of Affibody molecules with an albumin-binding domain (ABD) provides targeting agents, which are suitable for radionuclide therapy. To facilitate clinical translation, the low immunogenic potential of such constructs with targeting properties conserved is required.

METHODS

The HER2-targeting Affibody molecule ZHER2:2891 was fused with a deimmunized ABD variant and DOTA was conjugated to a unique C-terminal cysteine. The novel construct, PEP49989, was labelled with 177Lu. Affinity, specificity, and in vivo targeting properties of [177Lu]Lu-PEP49989 were characterised. Experimental therapy in mice with human HER2-expressing xenografts was evaluated.

RESULTS

The maximum molar activity of 52 GBq/µmol [177Lu]Lu-PEP49989 was obtained. [177Lu]Lu-PEP49989 bound specifically to HER2-expressing cells in vitro and in vivo. The HER2 binding affinity of [177Lu]Lu-PEP49989 was similar to the affinity of [177Lu]Lu-ABY-027 containing the parental ABD035 variant. The renal uptake of [177Lu]Lu-PEP49989 was 1.4-fold higher, but hepatic and splenic uptake was 1.7-2-fold lower than the uptake of [177Lu]Lu-ABY-027. The median survival of xenograft-bearing mice treated with 21 MBq [177Lu]Lu-PEP49989 (> 90 days) was significantly longer than the survival of mice treated with vehicle (38 days) or trastuzumab (45 days). Treatment using a combination of [177Lu]Lu-PEP49989 and trastuzumab increased the number of complete tumour remissions. The renal and hepatic toxicity was minimal to mild.

CONCLUSION

In preclinical studies, [177Lu]Lu-PEP49989 demonstrated favourable biodistribution and a strong antitumour effect, which was further enhanced by co-treatment with trastuzumab.

The survival benefit of adjuvant trastuzumab with or without chemotherapy in the management of small (T1mic, T1a, T1b, T1c), node negative HER2+ breast cancer

There is limited data regarding the added benefit of adjuvant systemic therapy in the management of small, node-negative, HER2+ breast cancer. In a multi-institutional retrospective analysis using the American Society of Clinical Oncology CancerLinQ database, we compared survival outcomes among T1a-c N0 HER2+ patients diagnosed between 2010 to 2021 who received locoregional therapy alone or in combination with adjuvant trastuzumab (+/- chemotherapy). Primary outcomes were invasive disease-free survival (iDFS) and overall survival (OS). Of the 1,184 patients, 436 received locoregional therapy alone. We found a statistically significant improvement in iDFS (HR 0.73, P = 0.003) and OS (HR 0.63, P = 0.023) on univariate analysis with adjuvant trastuzumab with or without chemotherapy which remained statistically significant on multivariate analysis. Three-arm univariate analysis found that iDFS was significantly improved with trastuzumab monotherapy (P = 0.003) and combination therapy (P = 0.027) compared to observation. Subgroup data suggests that T1b/c tumors derive the greatest benefit.

Breast conserving surgery combined with radiation therapy offers improved survival over mastectomy in early-stage breast cancer

INTRODUCTION

Landmark trials established equivalent survival regardless of extent of breast surgery in early-stage breast cancer. However, recent studies suggest a survival advantage for breast conserving surgery (BCS) with radiotherapy (BCT). This study assesses the impact of type of surgery on overall survival (OS), breast cancer specific survival (BCSS) and local recurrence (LR) in a modern population-based cohort.

METHODS

Female patients aged ≥18, pT1-2pN0, who had surgery between 2006 and 2016 were identified from Breast Cancer Outcome Unit prospective database. Neoadjuvant chemotherapy patients were excluded. Multivariable Cox regression was used to assess the effect of surgical procedure on OS, BCSS, and LR on cohort with complete data.

RESULTS

BCT was performed in 8422 patients and TM in 4034 patients. The baseline characteristics differed between the groups. Mean follow up was 8.3 years. BCT was associated with increased OS HR 1.37, p < 0.001, BCSS survival HR 1.49, p < 0.001, and similar LR HR 1.00, p > 0.90.

CONCLUSION

This study supports that in early-stage breast cancer, BCT has improved BCSS compared to TM without an increased risk of LR.

Benefit of postoperative regional nodal irradiation in patients receiving preoperative systemic therapy with docetaxel/carboplatin/trastuzumab/pertuzumab for HER2-positive breast cancer

AIM

The role of regional nodal irradiation (RNI) after preoperative systemic treatment (PST) with targeted therapy for HER2-positive breast cancer remains uncertain. This study aimed to investigate the impact of RNI on locoregional recurrence (LRR) and disease-free survival (DFS) outcomes after docetaxel/carboplatin/trastuzumab/pertuzumab (TCHP) for PST.

METHODS

We retrospectively analyzed 255 patients who were treated with six cycles of TCHP between 2016 and 2019. The patients were divided into four groups based on clinical nodal involvement: group A, with no nodal disease; group B, with axillary lymph node (AXL) level I; group C, with AXL level I with II/III; and group D, with supraclavicular or internal mammary nodes.

RESULTS

The RNI group had more advanced nodal disease (C/D) than the no RNI group (56.9 % vs. 6.8 %). With a median follow-up of 51.3 months, there were two (0.8 %), three (1.2 %), and 15 (5.9 %) local, regional, and distant metastases, respectively. LRR did not differ significantly according to the RNI (2.6 % vs. 1.0 %, p = 0.651). Group D had the most frequent distant metastases (17.5 %; p = 0.005). The 4-year DFS rate was 92.7 %, and DFS did not improve significantly after RNI (p = 0.074). When stratified by clinical nodal groups and pathological axillary response, RNI had no effect on LRR/DFS outcomes.

CONCLUSION

With a rare incidence of LRR, RNI did not significantly affect LRR or DFS in patients with HER2-positive breast cancer after with PST-TCHP. However, intensive systemic treatment is required for advanced diseases (C/D). Selective de-intensified RNI and intensified systemic treatment should be investigated in future studies.

Radionuclide Therapy of HER2-Expressing Xenografts Using [177Lu]Lu-ABY-027 Affibody Molecule Alone and in Combination with Trastuzumab

ABY-027 is a scaffold-protein-based cancer-targeting agent. ABY-027 includes the second-generation Affibody molecule Z_HER2:2891, which binds to human epidermal growth factor receptor type 2 (HER2). An engineered albumin-binding domain is fused to Z_HER2:2891 to reduce renal uptake and increase bioavailability. The agent can be site-specifically labeled with a beta-emitting radionuclide ¹⁷⁷Lu using a DOTA chelator. The goals of this study were to test the hypotheses that a targeted radionuclide therapy using [¹⁷⁷Lu]Lu-ABY-027 could extend the survival of mice with HER2-expressing human xenografts and that co-treatment with [¹⁷⁷Lu]Lu-ABY-027 and the HER2-targeting antibody trastuzumab could enhance this effect. Balb/C nu/nu mice bearing HER2-expressing SKOV-3 xenografts were used as in vivo models. A pre-injection of trastuzumab did not reduce the uptake of [¹⁷⁷Lu]Lu-ABY-027 in tumors. Mice were treated with [¹⁷⁷Lu]Lu-ABY-027 or trastuzumab as monotherapies and a combination of these therapies. Mice treated with vehicle or unlabeled ABY-027 were used as controls. Targeted monotherapy using [¹⁷⁷Lu]Lu-ABY-027 improved the survival of mice and was more efficient than trastuzumab monotherapy. A combination of therapies utilizing [¹⁷⁷Lu]Lu-ABY-027 and trastuzumab improved the treatment outcome in comparison with monotherapies using these agents. In conclusion, [¹⁷⁷Lu]Lu-ABY-027 alone or in combination with trastuzumab could be a new potential agent for the treatment of HER2-expressing tumors.

Routine and interval detection of locoregional breast cancer recurrences and risk of subsequent distant metastasis

PURPOSE

Follow-up for breast cancer survivors consists of after care and surveillance. The benefits of routine surveillance visits remain debatable. In this study we compared the severity of locoregional recurrences (LRRs) and the subsequent risk of a distant metastasis (DM) between LRRs detected at routine and interval visits.

METHODS

Women diagnosed with early breast cancer between 2003 and 2008 in one of the 15 participating hospitals, and who developed a LRR as first event after primary treatment, were selected from the Netherlands Cancer Registry (Cohort A). Chi-squared tests were used to compare the severity of routine- and interval-detected local recurrences (LRs) and regional recurrences (RRs), using tumor size, tumor grade, and number of positive lymph nodes. Data on the development of a subsequent DM after a LRR were available for a subset of patients (Cohort B). Cohort B was used to estimate the association between way of LRR-detection and risk of a DM.

RESULTS

Cohort A consisted of 109 routine- and 113 interval-LRR patients. The severity of routine-detected LRs or RRs and interval-detected LRs or RRs did not significantly differ. Cohort B consisted of 66 routine- and 61 interval-LRR patients. Sixteen routine- (24%) and 17 (28%) interval-LRR patients developed a DM. After adjustment, way of LRR-detection was not significantly associated with the risk of a DM (hazard ratio: 1.22; 95% confidence interval: 0.49-3.06).

CONCLUSION

The current study showed that routine visits did not lead to less severe LRRs and did not decrease the risk of a subsequent DM.

The role of tumor phenotype in the surgical treatment of early-stage breast cancer

BACKGROUND

We investigated whether tumor phenotype influences surgical decision-making, and how that may impact overall survival (OS) for early-stage breast cancer.

METHODS

Women aged 18-69 with cT0-2/cN0/cM0 breast cancer in the National Cancer Database (2010-2017) were included. A generalized logistic model was used to identify factors associated with surgery type. A Kaplan-Meier curve was used to visualize unadjusted OS, and the log-rank test was used to test for differences in OS between surgery types.

RESULTS

Of 597,149 patients, 58% underwent lumpectomy with radiation (BCT), 25% unilateral mastectomy (UM), and 17% bilateral mastectomy (BM). After adjustment, HER2+ and triple-negative (TN) tumors were less likely to undergo UM than BCT, versus hormone receptor-positive tumors (OR = 0.881, 95% CI = 0.860-0.903; OR = 0.485, 95% CI = 0.470-0.501). UM and BM had worse 5-year OS versus BCT (UM: 0.926, vs BM: 0.952, vs BCT: 0.960).

CONCLUSIONS

BCT is increasingly used to treat HER2+ and TN tumors. More extensive surgery is not associated with better survival outcomes, regardless of tumor phenotype.

Affibody-Mediated PNA-Based Pretargeted Cotreatment Improves Survival of Trastuzumab-Treated Mice Bearing HER2-Expressing Xenografts

Treatment of patients with human epidermal growth factor receptor 2 (HER2)-expressing tumors using the monoclonal antibody trastuzumab increases survival. The Affibody-based peptide nucleic acid (PNA)-mediated pretargeted radionuclide therapy has demonstrated efficacy against HER2-expressing xenografts in mice. Structural studies suggest that Affibody molecules and trastuzumab bind to different epitopes on HER2. The aim of this study was to test the hypothesis that a combination of PNA-mediated pretargeted radionuclide therapy and trastuzumab treatment of HER2-expressing xenografts can extend survival compared with monotherapies. Methods: Mutual interference of the primary pretargeting probe Z_HER2:342-SR-HP1 and trastuzumab in binding to HER2-expressing cell lines was investigated in vitro. Experimental therapy evaluated the survival of mice bearing HER2-expressing SKOV-3 xenografts after treatment with vehicle, trastuzumab only, pretargeting using Affibody-PNA chimera Z_HER2:342-SR-HP1 and complementary probe ¹⁷⁷Lu-HP2, and combination of trastuzumab and pretargeting. The ethical permit limited the study to 90 d. The animals' weights were monitored during the study. After study termination, samples of liver and kidneys were evaluated by a veterinary pathologist for toxicity signs. Results: The presence of a large molar excess of trastuzumab had no influence on the affinity of Z_HER2:342-SR-HP1 binding to HER2-expressing cells in vitro. The affinity of trastuzumab was not affected by a large excess of Z_HER2:342-SR-HP1 The median survival of mice treated with trastuzumab (75.5 d) was significantly longer than the survival of mice treated with a vehicle (59.5 d). Median survival of mice treated with pretargeting was not reached by day 90. Six mice of 10 in this group survived, and 2 had complete remission. All mice in the combination treatment group survived, and tumors in 7 mice had disappeared at study termination. There was no significant difference between animal weights in the different treatment groups. No significant pathologic alterations were detected in livers and kidneys of treated animals. Conclusion: Treatment of mice bearing HER2-expressing xenografts with the combination of trastuzumab and Affibody-mediated PNA-based radionuclide pretargeting significantly increased survival compared with monotherapies. Cotreatment was not toxic for normal tissues.

Treatment of small (T1mic, T1a, and T1b) node-negative HER2+ breast cancer - a review of current evidence for and against the use of anti-HER2 treatment regimens

INTRODUCTION

Since the advent of anti-HER2 therapies, evidence surrounding adjuvant treatment of small (T1mic, T1a, and T1b), node-negative, HER2-positive breast cancer (HER2+BC) has remained limited. Practices vary widely between institutions with little known regarding the added benefit of systemic therapy, including cytotoxic chemotherapy and HER2-directed treatments. Our group has set out to perform an extensive review of available literature on this topic.

AREAS COVERED

In this review, we examined HER2 biology, anti-HER therapies, outcome definitions, and available prospective and retrospective data surrounding the use of adjuvant therapy in those with small, node-negative, HER2+BC. For outcomes, we primarily explored breast cancer-specific survival (BCSS), invasive disease-free survival (iDFS), and overall survival (OS). We also investigated the incidence of adverse events with a particular focus on symptomatic and asymptomatic declines in left ventricular ejection fraction.

EXPERT OPINION

Retrospective data will likely be the main driver for future treatment decisions. Given what we know, high risk T1b and T1c subgroups derive measurable added benefit from HER2-guided combination therapies but it's not clear whether these benefits outweigh known risks associated with this combination therapy. For tumors ≤0.5cm (T1mic and T1a), treatment remains highly controversial with limited evidence available through retrospective analysis that suggest over-treatment may be occurring.

Postmastectomy Radiotherapy Improves Survival Benefits in De Novo Stage IV Breast Cancer: A Propensity-Score Matched Analysis

Purpose The role of postmastectomy radiotherapy (PMRT) in patients with de novo stage IV breast cancer is unclear. This study aimed to evaluate the value of PMRT for metastatic breast cancer who underwent a modified radical mastectomy. Methods: Data on de novo stage IV breast cancer patients who received modified radical mastectomy between 2010 and 2015 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) analysis based on age, T stage, N stage, breast subtype, and chemotherapy was conducted to balance baseline clinical characteristics. The prognostic roles of PMRT on cancer-specific survival (CSS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox proportional hazard models. Results: A total of 1944 patients were enrolled before PSM. After PSM, 1458 patients were included. PMRT improved the prognosis of CSS and OS. Multivariate Cox analysis showed that PMRT was independently prognostic for CSS (HR 0.739, 95% CI. 0.619-0.884, P = 0.001) and OS (HR 0.744, 95%CI 0.628-0.8810, P = 0.001). Further subgroup analyses found that survival superiority was observed in T3-4 or N + subgroup (both P < 0.001 for CSS and OS), and Her2-/HR + breast subtype (HR 0.703, 95%CI 0.558-0.888 for CSS, and HR 0.712, 95%CI 0.573-0.885 for OS), especially in patients with bone metastasis but without brain metastasis. Conclusion: PMRT improved survival in de novo stage IV breast cancer patients in selected T3-4 or N + subgroup and Her2-/HR + breast subtype. However, these findings need to be validated by further studies before being incorporated into clinical practice.

Triple Negative Breast Cancer: A Mountain Yet to Be Scaled Despite the Triumphs

Metastatic progression and tumor recurrence pertaining to TNBC are certainly the leading cause of breast cancer-related mortality; however, the mechanisms underlying TNBC chemoresistance, metastasis, and tumor relapse remain somewhat ambiguous. TNBCs show 77% of the overall 4-year survival rate compared to other breast cancer subtypes (82.7 to 92.5%). TNBC is the most aggressive subtype of breast cancer, with chemotherapy being the major approved treatment strategy. Activation of ABC transporters and DNA damage response genes alongside an enrichment of cancer stem cells and metabolic reprogramming upon chemotherapy contribute to the selection of chemoresistant cells, majorly responsible for the failure of anti-chemotherapeutic regime. These selected chemoresistant cells further lead to distant metastasis and tumor relapse. The present review discusses the approved standard of care and targetable molecular mechanisms in chemoresistance and provides a comprehensive update regarding the recent advances in TNBC management.

Controversies of radiotherapy in human epidermal growth factor receptor (HER)-2 positive breast cancer patients

Tumor biology plays a crucial role in the systemic treatment, specifically in HER2-positive tumors. Distinct biological behavior of breast cancer subtypes is associated with different rates of locoregional recurrence (LRR). HER2- positive breast cancer patients treated with surgery in combination with radiation, without trastuzumab have poor outcome, including high LRR. The efficacy of radiotherapy in HER-2-positive breast cancer appears to be associated with the expression of estrogen receptors. In patients with HER-2-positive breast cancer, studies conducted before the introduction of trastuzumab indicated higher benefit of adjuvant radiation in patients with hormone receptor-positive tumors compared to patients with tumors not expressing hormone receptors. The introduction of agents targeting HER-2 has transformed the management of these patients, resulting in improved outcomes. The data of clinical studies show that the administration of trastuzumab as part of a multimodality approach (with radiation based on standard guidelines) results in improved outcomes, including lower locoregional recurrence. The risk of cardiac toxicity associated with radiation to the heart and administration of potential cardiotoxic trastuzumab is not clear. In patients treated concomitantly with regional lymph node irradiation and anti-HER-2 agents after prior anthracycline-based chemotherapy minimizing the dose to the myocardium, e.g. respiratory gating or proton beam radiotherapy, have been suggested.

Trastuzumab Provides a Comparable Prognosis in Patients With HER2-Positive Breast Cancer to Those With HER2-Negative Breast Cancer: Post Hoc Analyses of a Randomized Controlled Trial of Post-Mastectomy Hypofractionated Radiotherapy

BACKGROUND AND PURPOSE

We investigated the locoregional effect of trastuzumab, and determined whether patients with human epidermal growth factor receptor (HER)2-positive breast cancer (BC) treated with trastuzumab could achieve comparable efficacy to that of patients with HER2-negative BC.

MATERIALS AND METHODS

This was post hoc analyses of data of 793 BC patients from a randomized controlled trial comparing post-mastectomy hypofractionated radiotherapy with conventional fractionated radiotherapy. Survival rates were analyzed by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

Patients were classified into three groups: HER2-negative (HER2-; n = 547), HER2-positve with trastuzumab (HER2+ + T; n = 136), and HER2-positive without trastuzumab (HER2+ - T; n = 110). The HER2+ + T group had significantly lower locoregional recurrence (LRR, 6.0% vs. 13.9%), distant metastasis (DM, 17.4% vs. 33.8%) and higher disease-free survival (DFS, 81.2% vs. 61.9%) at 5 years than that of the HER2+ - T group (P <.05). The HER2- group had significantly lower LRR (6.8% vs. 13.9%), DM (22.4% vs. 33.8%) and higher DFS (76.1% vs. 61.9%) at 5 years than that of the HER2+ - T group (P <.05). The difference in LRR, DM and DFS at 5 years was not significant between the HER2+ + T group and HER2- group (P >.05). Different annual LRR patterns was found among groups according to HR status.

CONCLUSION

Trastuzumab reduces LRR in patients with locally advanced HER2-positive BC who have received post-mastectomy radiotherapy. It provides comparable DFS to that with patients with HER2-negative BC.

Breast-conserving Surgery Without Radiation Therapy for Invasive Cancer

Radiotherapy (RT) after breast-conserving surgery (BCS) halves the risk of local recurrence, and it is considered the standard of care for the vast majority of patients with early invasive breast cancer. However, the majority of patients treated with BCS will not recur locally, even in the absence of RT. Over the past several decades, the improved and widespread use of systemic therapy has significantly decreased the rate of local recurrence. This has stimulated interest in identifying favorable patient subsets not requiring RT. Randomized controlled trials have shown in women aged ≥ 70 years with stage I estrogen receptor-positive (ER⁺) tumors, RT can be safely omitted. To better identify patients with favorable prognosis, ongoing trials have incorporated biological markers and genomic assays. Despite great research efforts to de-escalate locoregional treatment, real-world data indicate that omission of RT in low-risk patients is inconsistent. Better decision-making is warranted to reduce overtreatment and financial toxicity.

Contrast-Enhanced Mammography for Screening Women after Breast Conserving Surgery

Simple Summary

Breast cancer survivors are at risk for recurrence, and the early detection of recurrence improves survival. Therefore, imaging surveillance is performed for women who have breast-conserving surgery. The aim of our retrospective study was to compare routine mammography with contrast-enhanced mammography in the screening (asymptomatic) post-treatment setting. We confirmed that when screening women with breast conservation surgery, contrast-enhanced mammography had a higher cancer detection rate (15.4/1000) and positive predictive value of biopsies (42.9%) than full-field digital mammography (6.2/1000 and 37.5%, respectively).

Abstract

To investigate the value of contrast-enhanced mammography (CEM) compared to full-field digital mammography (FFDM) in screening breast cancer patients after breast-conserving surgery (BCS), this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved retrospective, single-institution study included 971 CEM exams in 541 asymptomatic patients treated with BCS who underwent screening CEM between January 2013 and November 2018. Histopathology, or at least a one-year follow-up, was used as the standard of reference. Twenty-one of 541 patients (3.9%) were diagnosed with ipsi- or contralateral breast cancer: six (28.6%) cancers were seen with low-energy images (equivalent to FFDM), an additional nine (42.9%) cancers were detected only on iodine (contrast-enhanced) images, and six interval cancers were identified within 365 days of a negative screening CEM. Of the 10 ipsilateral cancers detected on CEM, four were detected on low-energy images (40%). Of the five contralateral cancers detected on CEM, two were detected on low-energy images (40%). Overall, the cancer detection rate (CDR) for CEM was 15.4/1000 (15/971), and the positive predictive value (PPV3) of the biopsies performed was 42.9% (15/35). For findings seen on low-energy images, with or without contrast, the CDR was 6.2/1000 (6/971), and the PPV3 of the biopsies performed was 37.5% (6/16). In the post-BCS screening setting, CEM has a higher CDR than FFDM.

Quantifying the Mitigating Effects of Whole-Breast Radiotherapy and Systemic Treatments on Regional Recurrence Incidence Among Breast Cancer Patients

Background

Despite the potential for residual lymph node metastases after a negative or positive sentinel lymph node biopsy (SLNB), breast cancer patients rarely experience regional recurrences (RRs). This study aimed to quantify the effects of nonsurgical treatments on RR incidence among SLNB-negative (SLNB N0) breast cancer patients.

Methods

All primary SLNB N0-staged breast cancer patients with a diagnosis between 2005 and 2008 and 5-year follow-up data on recurrences were selected from the Netherlands Cancer Registry. The cumulative incidence function (CIF) for RR was calculated as the first event at 5 years, taking into account any other first-event (local or distant recurrence, contralateral breast cancer, or death) as competing risk. Cox regression analysis was used to model the cause-specific hazard of RR developing as the first event to quantify the effect of adjuvant systemic therapy and whole-breast radiotherapy (RT) on RR incidence at 5 years.

Results

The study included 13,512 patients. Of these patients, 162 experienced an RR. The CIF of RR at 5 years was 1.3% (95% confidence interval [CI], 1.1–1.5%), whereas the CIFs for death and other events were 4.4% and 9.5%, respectively. Cox regression analysis showed hazard ratios (HRs) of 0.46 (95% CI 0.33–0.64), 0.31 (95% CI 0.18–0.55), and 0.40 (95% CI 0.24–0.67) respectively for patients treated by RT as a routine part of breast-conserving therapy (BCT), chemotherapy, and hormonal therapy.

Conclusion

RT as routine part of BCT, chemotherapy, and hormonal therapy independently exerted a mitigating effect on the risk for the development of RR. The three methods at least halved the risk.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08356-2) contains supplementary material, which is available to authorized users.

The prognosis comparison of different molecular subtypes of breast tumors after radiotherapy and the intrinsic reasons for their distinct radiosensitivity

Radiotherapy can increase the cell cycle arrest that promotes apoptosis, reduces the risk of tumor recurrence and has become an irreplaceable component of systematic treatment for patients with breast cancer. Substantial advances in precise radiotherapy unequivocally indicate that the benefits of radiotherapy vary depending on intrinsic subtypes of the disease; luminal A breast cancer has the highest benefit whereas human epidermal growth factor receptor 2 (HER2)-positive and triple negative breast cancer (TNBC) are affected to a lesser extent irrespective of the selection of radiotherapy strategies, such as conventional whole-breast irradiation (CWBI), accelerated partial-breast irradiation (APBI), and hypofractionated whole-breast irradiation (HWBI). The benefit disparity correlates with the differential invasiveness, malignance, and radiosensitivity of the subtypes. A combination of a number of molecular mechanisms leads to the strong radioresistant profile of HER2-positive breast cancer, and sensitization to irradiation can be induced by multiple drugs or compounds in luminal disease and TNBC. In this review, we aimed to summarize the prognostic differences between various subtypes of breast tumors after CWBI, APBI, and HWBI, the potential reasons for drug-enhanced radiosensitivity in luminal breast tumors and TNBC, and the robust radioresistance of HER2-positive cancer.

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Adherence to surgical and oncologic standards improves survival in breast cancer patients

BACKGROUND

Adherence to evidence-based standards can lead to improved outcomes for patients with breast cancer. However, adherence rates to standards and their effects on patient outcomes are unknown.

OBJECTIVES

To examine adherence rates to standards compiled by the American College of Surgeons Clinical Research Program and its effects on patient outcomes.

METHODS

Using the National Cancer Database (2004-2015), we identified cohorts of breast cancer patients: clinical T1N0M0 under age of 70 (cT1), clinical T2N0M0 or T3N0M0 (cT2/3), and clinical M0 and pathologic N2 or N3 (pN2/3). Standards included negative margins, any adjuvant therapy, and two or more lymph nodes (LNs) examined (for cT1 or cT2/3 patients) or more than 10 LNs examined (for pN2/3 patients). We performed Kaplan-Meier and Cox proportional hazards analysis.

RESULTS

We identified 318 853 (65.0%) cT1, 164 593 (67.3%) cT2/3, and 77 626 (67.7%) pN2/3 patients who met the standards. More than 90% of patients had negative margins and adjuvant therapy, but less than 80% met LN standards. The median overall survival (OS) was significantly longer for patients who met the standards. Individual components of the standards were predictors of improved OS.

CONCLUSIONS

One-third of patients did not meet the evidence-based standards in their treatment for breast cancer. Efforts to improve the knowledge of and adherence to these standards should be emphasized.

Clinical decision making in postmastectomy radiotherapy in node negative breast cancer

For decades, postmastectomy radiotherapy (PMRT) has been recommended for node positive [N(+)] breast cancer patients; nevertheless, the beneficial effect of PMRT for treatment of node negative [N(−)] disease remains under discussion. Nowadays, the biology of breast cancer and the risk factors (RFs) for locoregional failure (LRF) must be included in the decision on whether or not to carry out PMRT. For these reasons, the present review aims to evaluate the rationale use of PMRT in N(−) patients and discuss which subgroups may further benefit from the treatment in present times where the decision must be personalised, according to the RFs of locoregional recurrence (LRR). To perform the analysis, we ponder that LRR of over 10% should be considered unacceptable due to the fact that LRRs generate great morbidity in patients. For this purpose, we consider that routine RT in these patients is not recommended, although there are subgroups of patients with high LRR, in which PMRT could be beneficial.

Effects of trastuzumab on locoregional recurrence in human epidermal growth factor receptor 2-overexpressing breast cancer patients treated with chemotherapy and radiotherapy

PURPOSE

In the present study, the ability of adjuvant trastuzumab to reduce locoregional recurrence in patients with human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer receiving adjuvant chemotherapy and radiotherapy (RT) was investigated.

MATERIALS AND METHODS

We retrospectively included 520 patients with HER2-overexpressing breast cancer who received surgery followed by adjuvant RT and cytotoxic chemotherapy from 2003 to 2011. Adjuvant trastuzumab was administered to 286 patients. Propensity score matching was conducted to compare trastuzumab-treated and non-treated cohorts.

RESULTS

Median follow-up duration was 7.1 years (range 1.1-14.1 years). Propensity score matching yielded 171 matched pairs of patients with no significantly different clinical factors. An improved 7-year locoregional control (LRC) rate was observed in the trastuzumab-treated cohort compared with the non-treated cohort (95.6% vs. 89.9%, p = 0.014). Based on multivariate analysis, hormone receptor negativity (hazard ratio [HR] = 5.348, p = 0.007), positive lymph node ratio > 0.25 (HR = 2.549, p = 0.040), and lack of adjuvant trastuzumab (HR = 3.401, p = 0.017) were identified as significant risk factors for poor LRC. Adjuvant trastuzumab significantly reduced the locoregional recurrence rate in patients with one or two risk factors (7-year LRC = 95.0% vs. 84.2%, p = 0.007); however, the benefit of adjuvant trastuzumab was non-significant in patients with no risk factors (7-year LRC = 95.8% vs. 97.9%, p = 0.75).

CONCLUSIONS

Adjuvant trastuzumab improved LRC in patients with HER2-overexpressing breast cancer receiving adjuvant RT and cytotoxic chemotherapy, especially in hormone receptor-negative, HER2-enriched subtype, and high positive lymph node ratio breast cancer.

Margins in breast cancer: How much is enough?

The appropriate negative margin width for women undergoing breast-conserving surgery for both ductal carcinoma in situ (DCIS) and invasive carcinoma is controversial. This review examines the available data on the margin status for invasive breast cancer and DCIS, and highlights the similarities and differences in tumor biology and standard treatments that affect the local recurrence (LR) risk and, therefore, the optimal surgical margin. Consensus guidelines support a negative margin, defined as no ink on tumor, for invasive carcinoma treated with breast-conserving therapy. Because of differences in the growth pattern and utilization of systemic therapy, a margin of 2 mm has been found to minimize the LR risk for women with DCIS undergoing lumpectomy and radiation therapy (RT). Wider negative margins do not improve local control for DCIS or invasive carcinoma when they are treated with lumpectomy and RT. Re-excision for negative margins should be individualized, and the routine practice of performing additional surgery to obtain a wider negative margin is not supported by the literature. Cancer 2018;124:1335-41. © 2018 American Cancer Society.

Breast surgery for metastatic breast cancer

BACKGROUND

Metastatic breast cancer is not a curable disease, but women with metastatic disease are living longer. Surgery to remove the primary tumour is associated with an increased survival in other types of metastatic cancer. Breast surgery is not standard treatment for metastatic disease, however several recent retrospective studies have suggested that breast surgery could increase the women's survival. These studies have methodological limitations including selection bias. A systematic review mapping all randomised controlled trials addressing the benefits and potential harms of breast surgery is ideal to answer this question.

OBJECTIVES

To assess the effects of breast surgery in women with metastatic breast cancer.

SEARCH METHODS

We conducted searches using the MeSH terms 'breast neoplasms', 'mastectomy', and 'analysis, survival' in the following databases: the Cochrane Breast Cancer Specialised Register, CENTRAL, MEDLINE (by PubMed) and Embase (by OvidSP) on 22 February 2016. We also searched ClinicalTrials.gov (22 February 2016) and the WHO International Clinical Trials Registry Platform (24 February 2016). We conducted an additional search in the American Society of Clinical Oncology (ASCO) conference proceedings in July 2016 that included reference checking, citation searching, and contacting study authors to identify additional studies.

SELECTION CRITERIA

The inclusion criteria were randomised controlled trials of women with metastatic breast cancer at initial diagnosis comparing breast surgery plus systemic therapy versus systemic therapy alone. The primary outcomes were overall survival and quality of life. Secondary outcomes were progression-free survival (local and distant control), breast cancer-specific survival, and toxicity from local therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted trial selection, data extraction, and 'Risk of bias' assessment (using Cochrane's 'Risk of bias' tool), which a third review author checked. We used the GRADE tool to assess the quality of the body of evidence. We used the risk ratio (RR) to measure the effect of treatment for dichotomous outcomes and the hazard ratio (HR) for time-to-event outcomes. We calculated 95% confidence intervals (CI) for these measures. We used the random-effects model, as we expected clinical or methodological heterogeneity, or both, among the included studies.

MAIN RESULTS

We included two trials enrolling 624 women in the review. It is uncertain whether breast surgery improves overall survival as the quality of the evidence has been assessed as very low (HR 0.83, 95% CI 0.53 to 1.31; 2 studies; 624 women). The two studies did not report quality of life. Breast surgery may improve local progression-free survival (HR 0.22, 95% CI 0.08 to 0.57; 2 studies; 607 women; low-quality evidence), while it probably worsened distant progression-free survival (HR 1.42, 95% CI 1.08 to 1.86; 1 study; 350 women; moderate-quality evidence). The two included studies did not measure breast cancer-specific survival. Toxicity from local therapy was reported by 30-day mortality and did not appear to differ between the two groups (RR 0.99, 95% CI 0.14 to 6.90; 1 study; 274 women; low-quality evidence).

AUTHORS' CONCLUSIONS

Based on existing evidence from two randomised clinical trials, it is not possible to make definitive conclusions on the benefits and risks of breast surgery associated with systemic treatment for women diagnosed with metastatic breast cancer. Until the ongoing clinical trials are finalised, the decision to perform breast surgery in these women should be individualised and shared between the physician and the patient considering the potential risks, benefits, and costs of each intervention.

Molecular Subtypes and Local-Regional Control of Breast Cancer

In the era of personalized medicine, there has been significant progress regarding the molecular analysis of breast cancer subtypes. Research efforts have focused on how classification of subtypes could provide information on prognosis and influence treatment planning. Although much is known about the impact of different molecular subtypes on disease-specific survival, more recent studies have investigated the role of the different molecular subtypes on local-regional recurrence. This is an area of active study, and in recent years there has been significant progress. This article describes outcomes among disease subtypes to aid in optimal surgical decision-making to improve local-regional control.

The Effect of Receptor Status on Mastectomy and Contralateral Prophylactic Mastectomy Rates in Early Stage Invasive Breast Carcinoma

BACKGROUND

There is an established relationship between hormone receptor (HR; estrogen and/or progesterone receptors) status, HER2 status, and locoregional recurrence. The purpose of this study was to analyze how HR and HER2 receptor status have influenced the surgical management trends among patients with early stage breast cancer.

PATIENTS AND METHODS

The National Cancer Database was queried for patients with cT1 to cT3, cN0, and cM0 breast carcinoma from 2004 to 2012. Patients were grouped on the basis of receptor status and surgical management (mastectomy or breast-conserving surgery [BCS]). Multivariable analyses were performed to investigate factors associated with increased odds of receiving mastectomy over BCS. Among a subgroup of patients who underwent ipsilateral mastectomy, analyses were performed to determine any association between contralateral prophylactic mastectomy (CPM) and receptor status.

RESULTS

We found 280,241 patients who met inclusion criteria for analyzing mastectomy or BCS surgical decision. Patients with HER2-positive (HER2⁺) tumors (HR⁺/HER⁺ and HR^-/HER2⁺) were the most likely to undergo mastectomy (odds ratio [OR], 1.212 and 1.499 respectively, compared with HR⁺/HER2^- patients, each P < .001). HR status alone did not affect ipsilateral surgical management as patients with HR⁺/HER2^- and HR^-/HER2^- tumors demonstrated similar mastectomy rates (P = .391). Among the 108,018 who underwent mastectomy, 20% underwent CPM. After adjustment, patients with HR⁺/HER2⁺, HR^-/HER2⁺, and HR^-/HER2^- were all more likely to undergo CPM (OR 1.356, 1.608, and 1.358, respectively compared with HR⁺/HER2^- patients, each P < .001).

CONCLUSION

This analysis indicates that patients with early stage breast cancer are more likely to undergo a mastectomy and CPM if they have HER2⁺ tumors.

Surgical management of breast cancer in China: A 15-year single-center retrospective study of 18,502 patients

The aim of the study was to review the surgical trends in breast cancer treatment in China over the past 15 years and to explore the possible factors related to the choice of surgical modality.The medical records of 18,502 patients with unilateral early stage breast cancer who underwent surgery from January 1999 to December 2013 at our institute were retrospectively reviewed. The utilization of different surgical modalities and the associated clinicopathological factors were analyzed. Furthermore, the prognostic role of surgical modality was also evaluated.The median patient age was 50.0 years. According to the pTNM staging system, 12.5% of the patients were classified as stage 0; 30.2% as stage I; 40.0% as stage II; and 17.3% as stage III. In total, 9.3% of the patients could not be staged. Overall, 67.1% of the breast cancer cases were estrogen receptor (ER) positive. The pattern of breast cancer surgery has changed tremendously over the past 15 years (P < 0.001). The pattern of mastectomy has shifted from radical mastectomy to modified radical mastectomy and simple mastectomy + sentinel lymph node biopsy. A total of 81.7% of the patients underwent mastectomy without immediate reconstruction, 15.2% underwent breast-conserving surgery (BCS), and 3.7% received immediate breast reconstruction after mastectomy. Age, TNM staging, and pathological characteristics greatly affected the choice of surgical modality. The 5-year recurrence-free survival (RFS) rates for the mastectomy, BCS, and reconstruction groups were 87.6%, 93.2%, and 91.7%, respectively (P < 0.001); the RFS rate was likely affected by distant recurrence instead of loco-regional recurrence. We also identified improved RFS over time, stratified by surgical modality and tumor stage. Multivariate Cox-regression analysis revealed that time of treatment, tumor stage, tumor grade, LVI status, and ER status were independent prognostic factors for RFS in our cohort, whereas surgical modality was not.Mastectomy remains the most prevalent surgical modality used to manage early stage breast cancer in China, although the utilization of BCS has increased in the past decade. However, surgical management was not a prognostic factor for RFS. The selection of appropriate patients depended on the assessment of multiple clinicopathological factors, which is essential for making surgical decisions.

Evaluation of Local and Distant Recurrence Patterns in Patients with Triple-Negative Breast Cancer According to Age

BACKGROUND

Triple-negative breast cancer (TNBC) subtype and young patient age are both associated with an increased risk of local recurrence (LR) and distant recurrence (DR). In young women with TNBC, it is unclear whether subtype or patient age is driving prognosis.

METHODS

Patients treated for primary TNBC from 1998 to 2011 were identified from the breast surgery database. Clinicopathologic characteristics, treatment, and outcomes were compared between patients <40 and ≥40 years of age at diagnosis. Multivariate models were used to identify factors independently associated with LR and DR.

RESULTS

Among 1930 patients with TNBC, 289 (15 %) were <40 and 1641 (85 %) were ≥40 years of age at diagnosis. Younger patients were more likely to present with higher stage disease and more likely to receive mastectomy (p < 0.01), axillary node dissection (p < 0.01), and chemotherapy (p < 0.01). At a median follow-up of 74 (0-201.1) months, there was no difference in LR or disease-free survival (DFS) by age group [5-year LR = 3.9 % (95 % confidence interval (CI) 1.5-6.2) vs. 4.5 % (95 % CI 3.5-5.6) and 5-year DFS = 75.3 % (95 % CI 70.2-80.7) vs. 77.7 % (95 % CI 75.6-79.8), p = 0.94] in patients aged <40 and ≥40 years, respectively. On multivariate analysis, larger tumor size, lymphovascular invasion, and nodal positivity were associated with increased risk of DR. Age and type of surgery were not significantly associated with either outcome.

CONCLUSIONS

Young age at diagnosis is not an independent risk factor for LR or DR in patients with TNBC.

Adjuvant Chemotherapy and Trastuzumab Is Safe and Effective in Older Women With Small, Node-Negative, HER2-Positive Early-Stage Breast Cancer

INTRODUCTION

The benefit of adjuvant trastuzumab with chemotherapy is well established for women with higher risk human epidermal growth factor receptor 2-positive (HER2⁺) breast cancer. However, its role in older patients with smaller, node-negative tumors is less clear. We conducted a retrospective, sequential cohort study of this population to describe the impact of trastuzumab on breast cancer outcomes and cardiac safety.

PATIENTS AND METHODS

Women ≥ 55 years with ≤ 2 cm, node-negative, HER2⁺ breast cancer were identified and electronic medical records reviewed. A no-trastuzumab cohort of 116 women diagnosed between January 1, 1999 and May 14, 2004 and a trastuzumab cohort of 128 women diagnosed between May 16, 2006 and December 31, 2010 were identified. Overall survival and distant relapse-free survival were estimated by Kaplan-Meier methods.

RESULTS

The median ages of the trastuzumab and no-trastuzumab cohorts were 62 and 64 years, respectively. More patients in the trastuzumab cohort had grade III (P = .001), lymphovascular invasion (P = .001), or estrogen receptor-negative (P < .001) cancers. The majority of the trastuzumab cohort received chemotherapy versus one-half of the no-trastuzumab cohort (98% vs. 53%; P < .0001). The median follow-up was 4 versus 9 years in the trastuzumab versus no-trastuzumab cohorts; therefore, outcomes at 4 years are reported. Despite the higher-risk tumor features in the trastuzumab group, the 4-year overall survival was 99% in both cohorts; the distant relapse-free survival was 99% versus 97% in the trastuzumab versus no-trastuzumab cohorts. Four (3.1%; 95% confidence interval, 1.0%-7.8%) women in the trastuzumab cohort and 1 in the no-trastuzumab cohort developed symptomatic heart failure. There were no cardiac-related deaths in either arm.

CONCLUSION

Following adjuvant trastuzumab with chemotherapy, selected older women with small, node-negative, HER2⁺ breast cancers have excellent disease control. The rate of cardiac events is low.

Trastuzumab improves locoregional control in HER2-positive breast cancer patients following adjuvant radiotherapy

The benefit of adjuvant trastuzumab in disease-free and overall survival for human epidermal receptor 2-positive (HER2+) breast cancer patients is well established. However, the effect of trastuzumab on locoregional control remains unclear, particularly in patients treated with adjuvant radiotherapy (RT). In this study, we investigated the locoregional benefit of trastuzumab in patients with HER2+ breast cancer after adjuvant RT.Using a single institutional database, we identified 278 patients with stage II/III invasive HER2+ breast tumors receiving adjuvant RT between January 2008 and July 2011. We compared the locoregional outcomes of 134 patients who received trastuzumab to 144 patients without trastuzumab within the same period. Clinical and biological factors that might impact on the locoregional benefit of trastuzumab were also assessed.At the median follow-up of 45 months, trastuzumab significantly lowered the risk of locoregional recurrence (LRR) with a 3-year LRR rate of 2.4% versus 7.5% for the cohort with and without trastuzumab (P = 0.019). Trastuzumab was associated with a more significant locoregional benefit in the hormone receptor-positive (HR+)/HER2+ subgroup, with a 3-year LRR of 0% versus 6.7% in the cohort with and without trastuzumab (P = 0.027). For HR-/HER2+ breast tumor patients, the 3-year LRR rate was still lower for the cohort with trastuzumab (4.7% vs 8.6%). However, statistical significance was not found (P = 0.179). Both univariate and multivariate analyses confirmed that trastuzumab treatment was the only significant predictive factor for LRR (hazard ratio, 4.05; 95% confidence interval, 1.07-15.35; P = 0.039).Adjuvant trastuzumab in addition to RT is associated with significant reduced LRR risk in HER2+ breast cancer.

The effect of trastuzumab-based chemotherapy in small node-negative HER2-positive breast cancer

The prognosis of patients with stage II-III Human Epidermal growth factor Receptor 2 (HER2)-positive breast cancer has significantly improved since the addition of trastuzumab to (neo-)adjuvant chemotherapy. Several reports have shown that small (≤2 cm), node-negative, HER2-positive tumors have a relatively poor prognosis and these patients increasingly receive trastuzumab-based chemotherapy. We aimed to provide evidence for this approach in a population-based cohort. All T1N0M0 HER2-positive breast cancer patients diagnosed between 2006 and 2012 were identified from the Netherlands Cancer Registry. Patient, tumor, and treatment characteristics were recorded. Kaplan-Meier statistics were used for overall survival (OS) and breast cancer-specific survival (BCSS) estimations overall and in T1a, T1b, and T1c tumors separately. Cox regression analyses were performed to account for imbalances in baseline characteristics between treated and untreated patients. A total of 3512 patients were identified: 385 with T1a, 800 with T1b, and 2327 with T1c tumors. Forty-five percent of patients received chemotherapy and/or trastuzumab: 92 % received both. Chemotherapy and/or trastuzumab significantly improved 8-year OS (95 vs. 84 %; hazard ratio [HR] 0.29; 95 % confidence interval [CI] 0.21-0.41, P < 0.001). The effect remained significant in multivariable analyses (HR 0.35; 95 % CI 0.23-0.52, P < 0.001). BCSS was also improved with systemic treatment in univariable (96 vs. 92 %; HR 0.41; 95 % CI 0.27-0.63, P < 0.001) and multivariable analyses (HR 0.31; 95 % CI 0.19-0.53, P < 0.001). Treatment effect on OS and BCSS was similar in T1a, T1b, and T1c tumors. Chemotherapy and/or trastuzumab improves OS and BCSS and can be considered in all patients with small node-negative HER2-positive breast cancer.

Contemporary Locoregional Recurrence Rates in Young Patients With Early-Stage Breast Cancer

Purpose

The aim of this study was to evaluate contemporary rates of local recurrence (LR) and regional recurrence (RR) in young patients with breast cancer in relation to tumor biology as expressed by biomarker subtypes.

Patients and Methods

Women < 35 years of age who underwent surgery for primary unilateral invasive breast cancer between 2003 and 2008 were selected from the Netherlands Cancer Registry. Patients were categorized according to biomarker subtypes on the basis of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. The 5-year risks of developing LR and regional lymph node recurrence were estimated by using Kaplan-Meier statistics.

Results

A total of 1,000 patients were identified, of whom 59% had a known subtype: 39% HR-positive/HER2-negative; 17% HR-positive/HER2-positive; 10% HR-negative/HER2-positive; and 34% HR-negative/HER2-negative (triple negative). Overall 5-year LR and RR rates were 3.5% and 3.7%, respectively. A decreasing trend for both rates was observed over time and was accompanied by a significant decrease in the risk of distant metastases (DM). LR occurred in 4.2%, RR in 6.1%, and DM in 17.8% of patients in 2003, and in 3.2%, 4.4%, and 10.0%, respectively, in 2008. LR and RR rates varied with biomarker subtype. These differences were borderline significant when analyzed for the entire study period (P = .056 and P = .014, respectively) and leveled off after the introduction of trastuzumab after 2005 (P = .24 and P = .42, respectively). Patients with lymph node metastases at the time of diagnosis had an increased risk of RR. The type of surgery performed—breast-conserving or mastectomy—did not influence rates of LR and RR.

Conclusion

Overall, the rates of LR and RR in young patients with early-stage breast cancer were relatively low and varied by biomarker subtype.

Cardiac Outcomes of Patients Receiving Adjuvant Weekly Paclitaxel and Trastuzumab for Node-Negative, ERBB2-Positive Breast Cancer

IMPORTANCE

Trastuzumab is a life-saving therapy but is associated with symptomatic and asymptomatic left ventricular ejection fraction (LVEF) decline. We report the cardiac toxic effects of a nonanthracycline and trastuzumab-based treatment for patients with early-stage human epidermal growth factor receptor 2 (ERBB2, formerly HER2 or HER2/neu)-positive breast cancer.

OBJECTIVE

To determine the cardiac safety of paclitaxel with trastuzumab and the utility of LVEF monitoring in patients with node-negative, ERBB2-positive breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

In this secondary analysis of an uncontrolled, single group study across 14 medical centers, enrollment of 406 patients with node-negative, ERBB2-positive breast cancer 3 cm, or smaller, and baseline LVEF of greater than or equal to 50% occurred from October 9, 2007, to September 3, 2010. Patients with a micrometastasis in a lymph node were later allowed with a study amendment. Median patient age was 55 years, 118 (29%) had hypertension, and 30 (7%) had diabetes. Patients received adjuvant paclitaxel for 12 weeks with trastuzumab, and trastuzumab was continued for 1 year. Median follow-up was 4 years.

INTERVENTIONS

Treatment consisted of weekly 80-mg/m2 doses of paclitaxel administered concurrently with trastuzumab intravenously for 12 weeks, followed by trastuzumab monotherapy for 39 weeks. During the monotherapy phase, trastuzumab could be administered weekly 2-mg/kg or every 3 weeks as 6-mg/kg. Radiation and hormone therapy were administered per standard guidelines after completion of the 12 weeks of chemotherapy. Patient LVEF was assessed at baseline, 12 weeks, 6 months, and 1 year.

MAIN OUTCOMES AND MEASURES

Cardiac safety data, including grade 3 to 4 left ventricular systolic dysfunction (LVSD) and significant asymptomatic LVEF decline, as defined by our study, were reported.

RESULTS

Overall, 2 patients (0.5%) (95% CI, 0.1%-1.8%) developed grade 3 LVSD and came off study, and 13 (3.2%) (95% CI, 1.9%-5.4%) had significant asymptomatic LVEF decline, 11 of whom completed study treatment. Median LVEF at baseline was 65%; 12 weeks, 64%; 6 months, 64%; and 1 year, 64%.

CONCLUSIONS AND RELEVANCE

Cardiac toxic effects from paclitaxel with trastuzumab, manifesting as grade 3 or 4 LVSD or asymptomatic LVEF decline, were low. Patient LVEF was assessed at baseline, 12 weeks, 6 months, and 1 year, and our findings suggest that LVEF monitoring during trastuzumab therapy without anthracyclines could be simplified for many individuals.

Appropriate margin for lumpectomy excision of invasive breast cancer

The management of patients with early-stage breast cancer has evolved over time, with the understanding that tumor biology, and not just disease burden, impact local control. Local control is greatly improved with systemic therapy, providing an opportunity to decrease the morbidity of local therapy in women with invasive breast cancer. In women undergoing breast-conserving therapy, which consists of lumpectomy and whole-breast irradiation, there has been a lack of consensus as to what constitutes a negative margin. Current evidence indicates that wider margins do not reduce local recurrence compared to "no tumor on ink". In this article, we will review the available data on the relationship between margin status and local control for invasive breast cancer, and discuss the impact of molecular subtypes and systemic therapy on local control.

Locoregional Control According to Breast Cancer Subtype and Response to Neoadjuvant Chemotherapy in Breast Cancer Patients Undergoing Breast-conserving Therapy

BACKGROUND

Our group previously published data showing that patients could be stratified by constructed molecular subtype with respect to locoregional recurrence (LRR)-free survival after neoadjuvant chemotherapy and breast-conserving therapy (BCT). That study predated use of trastuzumab for human epidermal growth factor receptor 2 (HER2)-positive patients. The current study was undertaken to determine the impact of subtype and response to therapy in a contemporary cohort.

METHODS

Clinicopathologic data from 751 breast cancer patients who received neoadjuvant chemotherapy (with trastuzumab if HER2(+)) and BCT from 2005 to 2012 were identified. Hormone receptor (HR) and HER2 status were used to construct molecular subtypes: HR(+)/HER2(-) (n = 369), HR(+)/HER2(+) (n = 105), HR(-)/HER2(+) (n = 58), and HR(-)/HER2(-) (n = 219). Actuarial rates of LRR were determined by the Kaplan-Meier method and compared by the log-rank test. Multivariate analysis was performed to determine factors associated with LRR.

RESULTS

The pathologic complete response (pCR) rates by subtype were as follows: 16.5% (HR(+)/HER2(-)), 45.7% (HR(+)/HER2(+)), 72.4% (HR(-)/HER2(+)), and 42.0% (HR(-)/HER2(-)) (P < 0.001). Median follow-up was 4.6 years. The 5-year LRR-free survival rate for all patients was 95.4%. Five-year LRR-free survival rates by subtype were 97.2 % (HR(+)/HER2(-)), 96.1% (HR(+)/HER2(+)), 94.4% (HR(-)/HER2(+)), and 93.4% (HR(-)/HER2(-)) (P = 0.44). For patients with HR(-)/HER2(+) disease, the LRR-free survival rates were 97.4 and 86.7% for those who did and those who did not experience pCR, respectively. For patients with HR(-)/HER2(-) disease, the LRR-free survival rates were 98.6% (pCR) versus 89.9% (no pCR). On multivariate analysis, the HR(-)/HER2(-) subtype, clinical stage III disease, and failure to experience a pCR were associated with LRR.

CONCLUSIONS

Patients undergoing BCT after neoadjuvant chemotherapy have excellent rates of 5-year LRR-free survival that are affected by molecular subtype and by response to neoadjuvant chemotherapy.

Prognostic Factors for Local, Loco-regional and Systemic Recurrence in Early-stage Breast Cancer

Aim: The risk of recurrence in breast cancer depends on factors such as treatment but also on the intrinsic subtype. We analyzed the risk factors for local, loco-regional and systemic recurrence, evaluated the differences and analyzed the risk of recurrence for different molecular subtypes. Material and Methods: A total of 3054 breast cancer patients who underwent surgery followed by adjuvant treatment at HSK hospital or Essen Mitte Hospital between 1998 and 2011 were analyzed. Based on immunohistochemical parameters, cancers were divided into the following subgroups: luminal A, luminal B (HER2-), luminal B (HER2+), HER2+ and TNBC (triple negative breast cancer). Results: 67 % of tumors were classified as luminal A, 13 % as luminal B (HER2-), 6 % as luminal B (HER2+), 3 % as HER2+ and 11 % as TNBC. After a median follow-up time of 6.6 years there were 100 local (3.3 %), 32 loco-regional (1 %) and 248 distant recurrences (8 %). Five-year recurrence-free survival for the overall patient collective was 92 %. On multivariate analysis, positive nodal status, TNBC subtype and absence of radiation therapy were found to be independent risk factors for all forms of recurrence. Age < 50 years, tumor size, luminal B (HER2-) subtype and breast-conserving therapy were additional risk factors for local recurrence. Compared to the luminal A subtype, the risk of systemic recurrence was higher for all other subtypes; additional risk factors for systemic recurrence were lymphatic invasion, absence of systemic therapy and mastectomy. Conclusion: Overall, the risk of local and loco-regional recurrence was low. In addition to nodal status, subgroup classification was found to be an important factor affecting the risk of recurrence.

Rethinking the Local Therapy of Breast Cancer: Integration of Biology and Anatomy

Local control has traditionally been considered a function of disease burden. Local control is now known to differ among biologic subtypes of breast cancer and is greatly improved with the use of systemic therapy. This offers opportunities for decreasing the morbidity of treatment and individualizing local therapy. The use of smaller margins in breast-conserving surgery and elimination of axillary dissection for some node-positive breast cancer patients are current examples of leveraging the benefits of systemic therapy to reduce surgery. Emerging evidence indicates that molecular profiling can identify patients at high and low risk for locoregional recurrence after surgery in a more accurate way than tumor burden, potentially allowing individualization of the use of postmastectomy and comprehensive node field irradiation. Future clinical trials should incorporate both disease burden and molecular profiling when examining treatment strategies.

Biological Subtype Predicts Risk of Locoregional Recurrence After Mastectomy and Impact of Postmastectomy Radiation in a Large National Database

PURPOSE

To evaluate locoregional recurrence (LRR) after mastectomy and impact of postmastectomy radiation (PMRT) by breast cancer subtype.

METHODS AND MATERIALS

Between 2000 and 2009, 5673 patients with stage I to III breast carcinoma underwent mastectomy and nodal evaluation; 30% received PMRT. Isolated LRR (iLRR) and LRR were compared across groups defined by biological subtype and receipt of trastuzumab: luminal A (estrogen [ER]/progesterone [PR]+, HER2-, low/intermediate grade), luminal B (ER/PR+, HER2-, high grade), HER2 with trastuzumab, HER2 without trastuzumab, and triple negative (TN; ER-, PR-, HER2-). LRR hazard ratios (HR) were estimated with multivariable Fine and Gray models. The effect of PMRT on LRR was evaluated with Fine and Gray models stratified by propensity for PMRT.

RESULTS

With a median follow-up time of 50.1 months, there were 19 iLRR and 109 LRR events. HER2 patients with trastuzumab had no iLRR and only a single LRR. Compared with luminal A patients, TN patients had significantly greater adjusted risk of iLRR (HR 14.10; 95% CI 2.97%-66.90%), with a similar trend among luminal B (HR 4.94; 95% CI 0.94%-25.82%) and HER2 patients without trastuzumab (HR 4.41; 95% CI 0.61%-32.11%). Although PMRT reduced LRR, the effect of PMRT varied by subgroup, with the greatest and smallest effects seen among luminal A (HR 0.17; 95% CI 0.05%-0.62%) and TN patients (HR 0.59; 95% CI 0.25%-1.35%), respectively.

CONCLUSIONS

TN patients had the highest risk of LRR and the least benefit from PMRT; these patients may benefit from alternative treatment strategies. In contrast, in the era of HER2-directed therapy, the role of local therapy may need to be reassessed among HER2 patients.