A group of German breast cancer experts (medical oncologists and gynaecologists) reviewed and commented on the results of the first international ‘Advanced Breast Cancer First Consensus Conference’ (ABC1) for the diagnosis and treatment of advanced breast cancer. The ABC1 Conference is an initiative of the European School of Oncology (ESO) Metastatic Breast Cancer Task Force in cooperation with the EBCC (European Breast Cancer Conference), ESMO (European Society of Medical Oncology) and the American JNCI (Journal of the National Cancer Institute). The main focus of the ABC1 Conference was metastatic breast cancer (stage IV). The ABC1 consensus is based on the vote of 33 breast cancer experts from different countries and has been specified as a guideline for therapeutic practice by the German expert group. It is the objective of the ABC1 consensus as well as of the German comments to provide an internationally standardized and evidence-based foundation for qualified decision-making in the treatment of metastatic breast cancer.

Summary

About 10-25% of breast cancer patients achieve a pathologically confirmed complete response after neoadjuvant chemotherapy. Tissue samples of pretreatment core biopsies are a valuable resource for translational research aiming towards predictive biomarkers for selecting patients who are likely to benefit from neoadjuvant therapy. The German Breast Group (GBG) and the AGO-B Group (AGO = Working Group Gynecological Oncology) have extensive experience in conducting neoadjuvant clinical trials. Technologies as immunohistochemistry on tissue microarrays and standardized reverse transcription-polymerase chain reaction (RT-PCR) approaches on formalin-fixed paraffin-embedded samples allow high-throughput investigation of protein and mRNA biomarkers. With these approaches, we could demonstrate that molecular tumor subtypes and immunological infiltrates are valuable and independent predictors of therapy response. New biomarkers such as poly(ADPribose) polymerase (PARP) might be useful for the prediction of response to conventional and new targeted therapies. This review summarizes current research projects focusing on biomarker discovery in the neoadjuvant setting.

Summary

Background: Docetaxel and paclitaxel are among the most active substances for the treatment of breast cancer. As both drugs are used today in adjuvant regimens, efficacy data from pivotal trials in the metastatic setting in taxane-naive populations cannot reliably be used as references. Patients and Methods: The Taxane Re-Challenge Cohort Study identified participants from 6 prospective (neo-)adjuvant taxane-based studies with recurrent disease and collected data on their subsequent treatment. Out of 381 recurrent patients, 106 (27.8%) were re-challenged with a taxane-based treatment as first- or later-line therapy for recurrent disease. Results: Taxanes were used as first-line therapy in 74 patients and showed a response rate of 48.6% (including complete responses in 27.0%). The response rate was dependent on the disease-free interval (<1 year: 34.8%; 1-2 years: 42.9%; >2 years: 63.3%; p = 0.04) and visceral metastasis (present: 62.5%; not present 32.4%; p = 0.01). Patients without visceral metastasis and with a disease-free interval of >2 years achieved the longest overall survival. Hormone and HER2 receptor status were not predictive; however, triple-negative tumors responded in 50.0%. The overall response rate of later-line taxane-based treatment was 28.2%. Conclusion: Re-challenging taxanes appears to be effective and therefore represents a reasonable option in this population.

Summary

The treatment of patients with breast cancer continues to evolve, with cytotoxic chemotherapy, endocrine therapy, and molecular targeted therapies representing the backbones of modern systemic breast cancer treatment. As we learn better to understand the biology of breast cancer cells, therapies to target specific pathways continue to be developed with the goal of expanding available effective therapy in specific populations. Several targeted drugs with different molecular pathways have achieved approval for metastatic breast cancer, but for early breast cancer trastuzumab is the only one that is currently approved in combination with chemotherapy for adjuvant or neoadjuvant treatment in women with HER2-positive breast cancer. Lapatinib and bevacizumab are both approved for the treatment of metastatic breast cancer and are now investigated in phase III clinical trials testing their effectiveness in the treatment of early breast cancer. In this publication, we review the current status in the treatment of early and locally advanced breast cancer with molecular targeted therapies that are currently approved or in advanced clinical development.

Summary

Women with advanced or metastatic ErbB2 (HER2)-positive breast cancer have limited therapeutic options once their disease has progressed on trastuzumab-based standard initial chemotherapy regimens. Therefore, there has been a clear need for alternative treatments in this advanced setting. The small molecule lapatinib is a dual receptor tyrosine kinase inhibitor of both ErbBl and ErbB2. In the pivotal phase III trial, lapatinib combined with capecitabine has demonstrated superior efficacy over capecitabine alone in this group of patients, with a median time to tumor progression of 8.4 months in the combination therapy group versus 4.4 months in the monotherapy arm. This improvement was achieved without an increase in serious toxic effects or symptomatic cardiac events. In addition, with the advent of Lapatinib, the empirically adopted practice of continuing trastuzumab beyond progression has to be seen in a different light. This is especially true since an exploratory analysis has suggested that the earlier use of the combination lapatinib plus capecitabine is associated with a benefit in time to progression and overall survival.

Summary

In recent years, new classes of molecules have been established as opportunities for the treatment of breast cancer. The approval of trastuzumab, the antibody against Her2/neu, in the late 1990s was followed by the approval of the antiangiogenic antibody bevacizumab in 2007. Progress in the understanding of the molecular mechanisms of carcinogenesis and tumour growth led to the development of new molecules, mostly kinase inhibitors. A few of these new molecues gained approval in several countries; clinical trials aiming at further approvals are ongoing. This short review covers the actual state-of-the-art and possible future developments in the targeted therapy of breast cancer.

Neoadjuvant therapy, also known as primary, induction, or preoperative therapy, is defined as the first systemic treatment a patient receives after cancer is diagnosed and indicates that subsequent therapies are intended. It was first used in the early 1970s for the treatment of inoperable locally advanced or inflammatory breast cancer. Based on a large body of clinical evidence and on the fact that primary breast cancer is today considered a systemic disease with a locoregional component, primary systemic therapy is now increasingly considered for women with operable disease for reducing mortality with lower toxicity, improving surgical options, and acquiring early information on response and biology of the disease.

The adjuvant treatment of women with endocrine-sensitive early breast cancer has been dominated for the last 40 years by tamoxifen. However, the side-effects associated with this therapy have prompted a search for safer and biochemically more selective endocrine agents and led to the development of the third-generation aromatase inhibitors (AIs) anastrozole, letrozole and exemestane. Promising results in advanced disease have paved the way for treating early breast cancer, and AIs are increasingly replacing tamoxifen in the adjuvant setting. Several large, randomized trials with AIs have been completed or are ongoing in women with early-stage breast cancer, documenting the significant impact that these drugs are making on the risk for recurrence of breast cancer. As a result, there is increasing and widespread use of AI therapy for the treatment of early-stage endocrine-responsive breast cancer. This review summarizes the data for exemestane in the adjuvant setting, showing that a switch to exemestane after 2 to 3 years of tamoxifen therapy is associated with a statistically significant survival benefit and is regarded as being sensitive by international and national experts.

Summary

Background

The Organgruppe Mamma of the Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) performed a nationwide 3-phase analysis of the structure of care and standard of therapy given to patients with breast cancer from 2002 (4th quarter) to 2004 (4th quarter). The extent to which national and international treatment recommendations are implemented in routine clinical practice had so far not been evaluated in an interdisciplinary approach. No reliable data on the pattern of care of these patients have been published in Germany before.

Patients and Methods

The project included early breast cancer in the adjuvant and neoadjuvant setting as well as metastatic disease. We present the results of phase III of the AGO analysis, which are based on a survey conducted by the Organkommission Mamma in the 4th quarter of 2004.

Results

Evaluation of the data reveals that treatment based on the guidelines is now being implemented very reliably in certain sectors. This is of particular relevance to the pattern of adjuvant treatment in early breast cancer. In contrast, in metastatic breast cancer (MBC), the complexity of the interdisciplinary treatment approach is complicating this kind of straightforward analysis.

Conclusion

The present analysis conducted by the AGO was the first attempt to analyse the treatment provided in patients presenting with MBC in a systematic fashion. The fundamental problem remains, irrespective of the stage of the tumour, that too few patients are treated in randomised clinical trials. The mission set by the AGO-Organkommission Mamma is the longitudinal observation of the therapy practices for breast cancer on the basis of the observations discussed here, which should ultimately benefit the optimisation of therapy quality in Germany.