Preoperative Systemic Therapy Versus Upfront Surgery in HER2-Positive Breast Cancer in the Real World

Purpose

To compare survival in different strategies, preoperative systemic treatment versus upfront surgery, in HER2-positive early breast cancer patients in the real world.

Methods

According to the actual upfront treatment, eligible patients from 2012 to 2015 were classified as preoperative systemic treatment or upfront surgery group prospectively. The primary endpoint is disease-free survival; the second endpoint is overall survival. All the outcomes were examined in the propensity score matching model and inverse probability of treatment weighting model.

Results

Included in the analysis were 1,067 patients (215 in the preoperative systemic treatment group, 852 in the upfront surgery group). In the propensity score matching model (matching at 1:1 ratio), the disease-free survival of the preoperative systemic treatment group was significantly higher than that of the upfront surgery group (hazard ratio, 0.572, 95%CI, 0.371–0.881, P, 0.012). In the inverse probability of treatment weighting model, there was no significant difference in disease-free survival between the two groups (hazard ratio, 0.946, 95%CI, 0.763–1.172, P, 0.609). For overall survival, there was no significant difference between the two groups.

Conclusion

The HER2-positive patients who accepted preoperative systemic treatment had better disease-free survival than those who underwent upfront surgery by real-world statistic methods.

Clinical Trial Registration

Clinicaltrials.gov, identifier NCT04249440.

A clinical perspective on escalating or de-escalating adjuvant therapy in HER2+ breast cancer

Introduction: Patients with early HER2-positive breast cancer (BC) benefit from HER2-targeted systemic therapy. The endorsed standard adjuvant treatment for patients with early HER2-positive breast cancer is chemotherapy plus trastuzumab administered for 1 year. Areas covered: Several trials have investigated modifications of the standard treatment in terms of de-escalation by either shortening the duration or giving less resource-demanding regimens and in terms of escalation by either adding a second anti-HER2 agent or extending the duration of HER2-targeted treatment for more than 12 months. In this perspective, we would offer a comprehensive view of these trials and discuss their findings. Expert commentary: At the current state of knowledge, there are still open questions regarding the management of HER2+ BC patients, such as the most adequate duration of trastuzumab therapy, the optimal chemotherapy regimen that should be combined with trastuzumab, and the addition of a second anti-HER2 agent. Growing evidences suggest that some HER2+ BC patients may not need chemotherapy. If these patients could be recognized upfront, optimal response could potentially be reached with HER2-targeted therapy alone.

HER-targeted tyrosine kinase inhibitors enhance response to trastuzumab and pertuzumab in HER2-positive breast cancer

Despite trastuzumab and pertuzumab improving outcome for patients with HER2-positive metastatic breast cancer, the disease remains fatal for the majority of patients. This study evaluated the anti-proliferative effects of adding anti-HER2 tyrosine kinase inhibitors (TKIs) to trastuzumab and pertuzumab in HER2-positive breast cancer cells. Afatinib was tested alone and in combination with trastuzumab in HER2-positive breast cancer cell lines. TKIs (lapatinib, neratinib, afatinib) combined with trastuzumab and/or pertuzumab were tested in 3 cell lines, with/without amphiregulin and heregulin-1β. Seven of 11 HER2-positive cell lines tested were sensitive to afatinib (IC₅₀ < 80 nM). Afatinib plus trastuzumab produced synergistic growth inhibition in eight cell lines. In trastuzumab-sensitive SKBR3 cells, the TKIs enhanced response to trastuzumab. Pertuzumab alone did not inhibit growth and did not enhance trastuzumab-induced growth inhibition or antibody-dependent cellular cytotoxicity. Pertuzumab enhanced response to trastuzumab when combined with lapatinib but not neratinib or afatinib. In two trastuzumab-resistant cell lines, the TKIs inhibited growth but adding trastuzumab and/or pertuzumab did not improve response compared to TKIs alone. Amphiregulin plus heregulin-1β stimulated proliferation of SKBR3 and MDA-MB-453 cells. In the presence of the growth factors, neither antibody inhibited growth and the TKIs showed significantly reduced activity. The triple combination of trastuzumab, pertuzumab and a TKI showed the strongest anti-proliferative activity in all three cell lines, in the presence of exogenous growth factors. In summary, addition of anti-HER2 TKIs to combined anti-HER2 monoclonal antibody therapy results in enhanced anticancer activity. These data contribute to the rationale for studying maximum HER2 blockade in the clinic.

The updated network meta-analysis of neoadjuvant therapy for HER2-positive breast cancer

BACKGROUND

We previously described a systematic assessment of the neoadjuvant therapies for human epidermal growth factor receptor-2 (HER2) positive breast cancer, using network meta-analysis. Accumulation of new clinical data has compelled us to update the analysis.

METHODS

Randomized trials comparing different anti-HER2 regimens in the neoadjuvant setting were included, and odds ratio for pathologic complete response (pCR) in seven treatment arms were assessed by pooling effect sizes. Direct and indirect comparisons using a Bayesian statistical model were performed. All statistical tests were two-sided.

RESULTS

A database search identified 993 articles with 13 studies meeting the eligibility criteria, including three new studies with lapatinib (lpnb). In an indirect comparison, dual anti-HER2 agents with CT achieved a better pCR rate than other arms. The credibility intervals of CT + tzmb + lpnb arm were largely reduced compared to our former report, which we added sufficient clinical evidence by this update. Values of surface under the cumulative ranking (SUCRA) suggested that CT + tzmb + pzmb had the highest probability of being the best treatment arm for pCR, widening the difference between the top two dual-HER2 blockade arms compared to our former report. The overall consistency with our first report enhanced the credibility of the results.

CONCLUSION

Network meta-analysis using new clinical data firmly establish that combining two anti-HER2 agents with CT is most effective against HER2-positive breast cancer in the neoadjuvant setting. New pzmb related trials are required to fully determine the best neoadjuvant dual-HER2 blockade regimen.

First-line therapy in HER2 positive metastatic breast cancer: is the mosaic fully completed or are we missing additional pieces?

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in the biology of breast cancer and the subsequent development of HER2-targeted therapies, have dramatically improved clinical outcomes for women with early-stage and advanced HER2-positive breast cancer (BC).

HER-2 targeted therapies represent a major step forward in achieving the goal of delivering individualized targeted therapy for BC, and trastuzumab was the first anti-HER-2 strategy to be approved for treatment of HER-2 positive BC.

This review discusses the treatment of metastatic HER2-positive BC and describes efficacy and safety of novel anti-HER2 target therapies in first-line metastatic settings and the future challenges include refining such treatments, reducing toxicity and simultaneously developing innovative therapies. Furthermore, combinations of trastuzumab and drugs targeting the downstream pathway are described.

In the next future will be possible to use an ample armamentarium of combination therapies directed against HER2 and key signaling components integrated in the HER network. This approach will allow clinicians to tailor the management of the individual patient on the basis of tumor- specific biomarker profiles.

There is an urgent need for prospective biomarker-driven trials to identify patients for whom targeting is cost-effective.

5-year analysis of neoadjuvant pertuzumab and trastuzumab in patients with locally advanced, inflammatory, or early-stage HER2-positive breast cancer (NeoSphere): a multicentre, open-label, phase 2 randomised trial

BACKGROUND

In the primary analysis of the NeoSphere trial, patients given neoadjuvant pertuzumab, trastuzumab, and docetaxel showed a significantly improved pathological complete response compared with those given trastuzumab and docetaxel after surgery. Here, we report 5-year progression-free survival, disease-free survival, and safety.

METHODS

In this multicentre, open-label, phase 2 randomised trial in hospitals and medical clinics, treatment-naive adults with locally advanced, inflammatory, or early-stage HER2-positive breast cancer were randomly assigned (1:1:1:1) to receive four neoadjuvant cycles of trastuzumab (8 mg/kg loading dose, followed by 6 mg/kg every 3 weeks) plus docetaxel (75 mg/m(2) every 3 weeks, increasing to 100 mg/m(2) from cycle 2 if tolerated; group A), pertuzumab (840 mg loading dose, followed by 420 mg every 3 weeks) and trastuzumab plus docetaxel (group B), pertuzumab and trastuzumab (group C), or pertuzumab and docetaxel (group D). After surgery, patients received three cycles of FEC (fluorouracil 600 mg/m(2), epirubicin 90 mg/m(2), and cyclophosphamide 600 mg/m(2)) every 3 weeks (patients in group C received four cycles of docetaxel prior to FEC), and trastuzumab 6 mg/kg every 3 weeks to complete 1 year's treatment (17 cycles in total). Randomisation was done by a central centre using dynamic allocation, stratified by operable, locally advanced, and inflammatory breast cancer, and by oestrogen and/or progesterone receptor positivity. Safety analyses were done according to treatment received. The primary endpoint (pathological complete response) was previously reported; secondary endpoints reported here are 5-year progression-free survival (analysed in the intention-to-treat population) and disease-free survival (analysed in patients who had surgery). Secondary and exploratory analyses were not powered for formal statistical hypothesis testing, and therefore results are for descriptive purposes only. The study ended on Sept 22, 2014 (last patient, last visit). This study is registered with ClinicalTrials.gov, number NCT00545688.

FINDINGS

Between Dec 17, 2007, and Dec 22, 2009, 417 eligible patients were randomly assigned to group A (107 patients), group B (107 patients), group C (107 patients), or group D (96 patients). One patient in group A withdrew before treatment. One patient assigned to group D received group A treatment, one patient assigned to group D received group B treatment, and one patient assigned to group B received group C treatment. At clinical cutoff, 87 patients had progressed or died. 5-year progression-free survival rates were 81% (95% CI 71-87) for group A, 86% (77-91) for group B, 73% (64-81) for group C, and 73% (63-81) for group D (hazard ratios 0·69 [95% CI 0·34-1·40] group B vs group A, 1·25 [0·68-2·30] group C vs group A, and 2·05 [1·07-3·93] group D vs group B). Disease-free survival results were consistent with progression-free survival results and were 81% (95% CI 72-88) for group A, 84% (72-91) for group B, 80% (70-86) for group C, and 75% (64-83) for group D. Patients who achieved total pathological complete response (all groups combined) had longer progression-free survival compared with patients who did not (85% [76-91] in patients who achieved total pathological response vs 76% [71-81] in patients who did not achieve total pathological response; hazard ratio 0·54 [95% CI 0·29-1·00]). There were no new or long-term safety concerns and tolerability was similar across groups (neoadjuvant and adjuvant treatment periods combined). The most common grade 3 or worse adverse events were neutropenia (group A: 71 [66%] of 107 patients; group B: 59 [55%] of 107; group C: 40 [37%] of 108; group D: 60 [64%] of 94), febrile neutropenia (group A: 10 [9%]; group B: 12 [11%]; group C: 5 [5%]; group D: 15 [16%]), and leucopenia (group A: 13 [12%]; group B: 6 [6%]; group C: 4 [4%]; group D: 8 [9%]). The number of patients with one or more serious adverse event was similar across groups (19-22 serious adverse events per group in 18-22% of patients).

INTERPRETATION

Progression-free survival and disease-free survival at 5-year follow-up show large and overlapping CIs, but support the primary endpoint (pathological complete response) and suggest that neoadjuvant pertuzumab is beneficial when combined with trastuzumab and docetaxel. Additionally, they suggest that total pathological complete response could be an early indicator of long-term outcome in early-stage HER2-positive breast cancer.

FUNDING

F Hoffmann-La Roche.

Resistance to Targeted Therapies in Breast Cancer

Seventy five percent of all breast cancer (BC) patients express estrogen receptor (ER) but a quarter to half of patients with ER positive BC relapse on ET (endocrine therapy), tamoxifen, aromatase inhibitors (AIs), surgical castration, amongst other treatment strategies. ER positive BC at relapse loses ER expression in 20 % of cases and reduces quantitative ER expression most of the time. ER is not the only survival pathway driving ER positive BC and escape pathways intrinsic or acquired are activated during ET. This overview gives an account of ligand-independent ER activation, namely by receptor networks cross talk, and by the various genomic factors and mechanisms leading to ET response failure. Also the mechanisms of Her1 and Her2 inhibition resistance are dealt within this overview, along with the therapeutic indications and limitations of tyrosine kinase inhibitors, PARP inhibitors, PI3K/AKT/mTOR inhibitors, RAS/RAF/MEK/ERK/MAPK inhibitors, and antiangiogenic drugs. In spite of the many advances in controlling the division of BC cells and the progression of BC tumors these still remain the main cause of death among women in age range of 20-50 years requiring even more efforts in new therapeutic approaches besides the drugs within the scope of the overview.

Pilot trial of paclitaxel-trastuzumab adjuvant therapy for early stage breast cancer: a trial of the ECOG-ACRIN cancer research group (E2198)

BACKGROUND

Blockade of human epidermal growth factor receptor type 2 (HER2) has dramatically improved outcome for patients with HER2-positive breast cancer. Trastuzumab, an anti-HER2 monoclonal antibody, has previously demonstrated improvement in overall survival (OS) in patients with metastatic and early stage HER2-positive breast cancer. However, trastuzumab can cause congestive heart failure (CHF) with an increased frequency for patients who have also received an anthracycline. The current trial was designed to evaluate the impact of the duration of trastuzumab on CHF.

METHODS

E2198 included 227 eligible women with histologically confirmed stage II or IIIA HER2-positive breast cancer. The patients were randomised to receive 12 weeks of paclitaxel and trastuzumab followed by four cycles of doxorubicin and cyclophosphamide (abbreviated Arm) or the aforementioned treatment with additional 1 year of trastuzumab (conventional Arm). The primary end point was to evaluate the safety of this variable duration of trastuzumab therapy, particularly cardiac toxicity defined as CHF or left ventricular ejection fraction decrease >10%. Secondary end points included disease-free survival (DFS) and OS.

RESULTS

Compared with 12-week treatment with trastuzumab, 1 year of trastuzumab-based therapy did not increase the frequency or severity of cardiac toxicity: three patients on the abbreviated Arm and four on the conventional Arm experienced CHF. The 5-year DFS was 76% and 73% for the abbreviated and conventional Arms, respectively, with a hazard ratio (HR) of 1.3 (95% CI: 0.8-2.1; P=0.3). There was also no statistically significance difference in OS (HR, 1.4; P=0.3).

CONCLUSIONS

Compared with 12 weeks of treatment, 1 year of treatment with trastuzumab did not significantly increase the risk of cardiac toxicity. Although not powered for efficacy comparisons, the longer duration of trastuzumab therapy did not demonstrate a signal for marked superiority.

Demographic, tumor and clinical features of clinical trials versus clinical practice patients with HER2-positive early breast cancer: results of a prospective study

BACKGROUND

Several randomized clinical trials (RCTs) have demonstrated the efficacy of trastuzumab-based adjuvant therapy in HER2-positive breast cancer (BC). However, RCT patients may not invariably be representative of patients routinely seen in clinical practice (CP). To address this issue, we compared the clinical and tumor features of RCT and CP patients with HER2-positive BC.

PATIENTS AND METHODS

From January to December 2012, 650 consecutive patients with HER2-positive early BC, treated in 36 different types of Italian healthcare facilities, were enrolled in this study. Age, treatment, tumor size (T), nodes (N), grade (G), estrogen receptor (ER) and progesterone receptor (PgR) status were prospectively collected in these CP patients. The same data were extracted from the main adjuvant trastuzumab RCTs and pooled using the random-effects model of DerSimonian and Laird. RCT and CP patients were compared by using the Cochran Q statistics.

RESULTS

Versus RCT patients, CP patients were more likely to be older than 50 years (65 vs. 49 %; p < 0.0001) and to have HR (ER and/or PgR)-positive (72 vs. 54 %; p < 0.0001) BC and less likely to have tumor >2 cm (T ≥ 2 cm 39 vs. 59 %; p < 0.0001), positive N (47 vs. 89 %; p < 0.0001) and a high G (61 vs. 67 %; p = 0.0241). CP patients more frequently received adjuvant endocrine therapy (70 vs. 57 %; p < 0.0003) and less frequently adjuvant chemotherapy (97 vs. 99.7 %; p < 0.0001).

CONCLUSIONS

Most tumor and clinical features differed significantly between CP and RCT patients. These data raise concerns about the applicability of RCT results to CP patients.

Pathological complete response in neoadjuvant treatment of breast cancer

BACKGROUND

There has been recent interest in using pathological complete response (pCR) as a potential surrogate endpoint for long-term outcomes in the neoadjuvant treatment of high-risk, early-stage breast cancer.

METHODS

We review the clinical trials that have contributed to our understanding of the association between pCR and long-term outcomes, describe the various definitions of pCR, describe patient populations in which pCR may predict long-term benefit, and discuss the implications of pCR on drug development and accelerated approval for neoadjuvant treatment of breast cancer.

RESULTS

Varying definitions of pCR across clinical trials conducted in heterogeneous patient populations make understanding the association of pCR with long-term outcomes challenging. The US Food and Drug Administration established the Collaborative Trials in Neoadjuvant Breast Cancer group to evaluate the potential use of pCR as a regulatory endpoint. The group demonstrated that pCR defined as no residual invasive cancer in the breast and axillary nodes with presence or absence of in situ cancer (ypT0/is ypN0 or ypT0 ypN0) provided a better association with improved outcomes compared to eradication of invasive tumor from the breast alone (ypT0/is).

CONCLUSION

Even though pCR was not validated as a surrogate endpoint for long-term outcomes, the promising data regarding the strong association of pCR with substantially improved outcomes in individual patients with more aggressive subtypes of breast cancer supported the opening of an accelerated approval pathway for patients with high-risk, early-stage breast cancer.

Management of locally advanced breast cancer-perspectives and future directions

Locally advanced breast cancer (LABC) constitutes a heterogeneous entity that includes advanced-stage primary tumours, cancers with extensive nodal involvement and inflammatory breast carcinomas. Although the definition of LABC can be broadened to include some large operable breast tumours, we use this term to strictly refer to inoperable cancers that are included in the above-mentioned categories. The prognosis of such tumours is often unfavourable; despite aggressive treatment, many patients eventually develop distant metastases and die from the disease. Advances in systemic therapy, including radiation treatment, surgical techniques and the development of new targeted agents have significantly improved clinical outcomes for patients with this disease. Notwithstanding these advances, LABC remains an important clinical problem, particularly in developing countries and those without widely adapted breast cancer awareness programmes. The optimal management of LABC requires a multidisciplinary approach, a well-coordinated treatment schedule and close cooperation between medical, surgical and radiation oncologists. In this Review, we discuss the current state of the art and possible future treatment strategies for patients with LABC.

The development of dose-dense adjuvant chemotherapy

Dose-dense chemotherapy has made a significant contribution to the adjuvant treatment of breast cancer. One way of achieving dose-density is through the use of sequential therapy with noncross resistant therapies to cause cell kill in tumors composed of heterogeneous cells. Another way to achieve this is to shorten the inter-treatment interval to minimize the re-growth of tumor cells, thus allowing for more effective cell killing. Several trials have tested this concept with the majority demonstrating improved efficacy with a dose-density when compared with the traditional schedule. One such notable trial was CALGB 9741 that showed that when dose size and cycle numbers were kept constant, shortening the interval between each chemotherapy dose, with granulocyte-colony stimulating factor support, significantly improved disease-free and overall survival. This important and practice-changing trial led to the wide adoption of dose-dense chemotherapy and formed the basis of many subsequent studies, including allowing for the addition of biologic and targeted agents with excellent safety profile.

Cardiovascular toxicities from systemic breast cancer therapy

Cardiovascular toxicity is unfortunately a potential short- or long-term sequela of breast cancer therapy. Both conventional chemotherapeutic agents such as anthracyclines and newer targeted agents such as trastuzumab can cause varying degrees of cardiac dysfunction. Type I cardiac toxicity is dose-dependent and irreversible, whereas Type II is not dose-dependent and is generally reversible with cessation of the drug. In this review, we discuss what is currently known about the cardiovascular effects of systemic breast cancer treatments, with a focus on the putative mechanisms of toxicity, the role of biomarkers, and potential methods of preventing and minimizing cardiovascular complications.