St. Gallen Consensus 2009: A Radically Different Approach To Treating Early Breast Cancer

Main Category: Breast Cancer
Article Date: 19 Jun 2009 - 1:00 PDT

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A radically different approach to choosing the best treatment options for early breast cancer has been proposed by an international panel of experts in a report from the 11th St Gallen conference.

The report was published online in the cancer journal, Annals of Oncology [1] on Thursday 18 June, and represents the consensus on early breast cancer treatment that emerged from the conference of more than 4,800 participants from 101 countries, which took place in March 2009.

The authors expect the consensus report to change clinical practice. While it continues to recognise that early breast cancer is a heterogeneous disease and that patients should receive personalised care targeted at their particular type of disease, the report proposes a different way of assessing the disease, its risk and the appropriate treatment.

The authors write: "In distilling patient and tumour features to reach patient treatment decisions, the panel has adopted a fundamentally different approach from that used in previous consensus reports. Clinical decisions in systemic adjuvant therapy of early breast cancer must address three distinct questions: (i) what justifies the use of endocrine therapy, (ii) what justifies the use of anti-HER2 therapy, and (iii) what justifies the use of chemotherapy. Because these decisions are based on quite separate criteria, the previous attempt to produce a single-risk categorization and a separate therapy recommendation are no longer considered appropriate." The authors then give a new algorithm for clinicians to use when deciding on the best treatment approach for each patient.

One of the authors, Professor Richard Gelber (Professor in Biostatistics at Harvard University and Dana-Farber Cancer Institute, Boston, MA, USA and Director of the Statistical Center, International Breast Cancer Study Group), said: "This consensus is important because it provides solutions to open questions in controversial areas concerning treatment of women with early breast cancer. While the 2009 consensus maintains an emphasis on targeting adjuvant systemic therapies according to subgroups defined by predictive markers, it further refines the treatment algorithm by identifying 'thresholds for indication' of each type of systemic treatment modality (endocrine therapy, anti-HER2 therapy, chemotherapy) based on criteria specific to each modality. We expect the refined algorithm to change clinical practice because it clarifies the indications for each treatment modality available today."

Early breast cancer is defined as breast cancer that is confined to the breast, with or without axillary lymph node involvement, and which is easily removable by surgery. However, there are many different types, some of which carry a much higher risk of recurrence and metastases than others.

Therefore, the report emphasises the importance of identifying which type of breast cancer a patient has and which treatment, or combination of treatments, are most likely to be successful.

For instance, the panel recommends the inclusion of adjuvant endocrine therapy for most patients whose tumours show evidence of any detectable oestrogen receptor. Anti-HER2 therapy such as trastuzumab (Herceptin) is recommended for almost all patients with HER2-positive disease. The indication for use of adjuvant chemotherapy is more complex. Chemotherapy should be the mainstay of treatment for patients with triple-negative disease and conventionally is used before or concurrently with trastuzumab for patients with HER2 positive disease, while its use is less clear-cut for patients with ER-positive, HER2-negative disease.

The increasing use of genetic profiling using microarrays (gene chip technology) is expected to help in such cases where treatment decisions are more difficult. Another of the authors, Professor Aron Goldhirsch (Professor of Medical Oncology, Director of the Department of Medicine, European Institute of Oncology, Milan, Italy, and Co-Chair of the Scientific Committee, International Breast Cancer Study Group), said: "High quality pathological work up has been recognized as essential to define the biological characteristics of the disease, especially in terms of markers of responsiveness to various treatments. Modern multi-gene arrays, if readily available, might be increasingly useful in defining features of prognosis and responsiveness and require further validation."

The panel highlighted the importance of clinical trials. "Randomized clinical trials provide essential information on the safety and efficacy of treatments, but generally do not provide information about how best to care for individual patients. Therefore, a paramount role for the consensus panel was to identify areas of controversy, providing solutions for questions which have not yet been answered by randomized clinical trials," said Prof Gelber.

A third author, Professor Alan Coates (Clinical Professor at the School of Public Health, University of Sydney, Sydney, New South Wales, Australia and Co-Chair of the Scientific Committee, International Breast Cancer Study Group) said: "The panel recognized and endorsed the refinement of surgery so that it is aimed at treating the tumour only, while preserving normal tissue as much as possible."

The authors believe that the patient should be at the centre of all treatment decisions. "We recognize the importance of quality of life, supportive care and patient preference in the treatment decision-making process," said Prof Coates.

[1] Threshold for therapies: highlights of the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2009. Annals of Oncology. doi:10.1093/annonc/mdp322

Source:
Emma Mason
European Society for Medical Oncology