Kongressbericht vom 32. Annual San Antonio Breast Cancer Symposium vom 10.–13.12.2009

Zusammenfassung

Das letztjährige San Antonio Breast Cancer Symposium wurde dominiert von den molekularen Grundlagen des Mammakarzinoms und den sich daraus ergebenden diagnostischen und v. a. therapeutischen Möglichkeiten. Während in der endokrinen Therapie keine wegweisend neuen Resultate vorgestellt wurden, dominierte die zielgerichtete Therapie in ihren vielseitigen Facetten deutlich das Kongressgeschehen. Wie auch in den vergangenen Jahren wurden zu gleichen Teilen Ergebnisse aus der Grundlagenforschung und Präklinik sowie von klinischen Studien vorgestellt und diskutiert. Im Bereich der antihormonellen Therapie der postmenopausalen Patientin zeigte sich in der 5-Jahres-Analyse der TEAM-Studie eine Äquieffektivität für die sequenzielle Therapie und die Upfront-Therapie mit Exemestan. Auch im Langzeit-Follow-up der IES-Studie bleibt die Überlegenheit des Switch auf Exemestan nach 2–3 Jahren Tamoxifen hinsichtlich der Prognose erhalten. Die erweiterte adjuvante Therapie ist für Frauen, die bei Erstdiagnose noch prämenopausal waren, von besonderer prognostischer Bedeutung. Dieser Effekt bleibt auch bei einem Beginn der erweiterten adjuvanten Therapie bis zu 6 Jahre nach Ende der Tamoxifeneinnahme erhalten. In der metastasierten Situation lässt sich durch die dauerhafte Einnahme von 500 mg Fulvestrant nur ein marginaler Benefit erreichen, die Kombination aus Fulvestrant und Anastrozol ist der Anastrozolmonotherapie nicht überlegen. Im Bereich der Knochengesundheit stand die Frage der prognostischen Bedeutung einer Bisphosphonattherapie im Vordergrund. Ein 2. Schwerpunkt war Denosumab, welches als monoklonaler Antikörper gegen RANK-Ligand eine höhere Wirksamkeit gegen Knochenmetastasen aufweist als die klassische Zoledronsäure. Im Bereich der zielgerichteten Therapien konnte der Wert einer Trastuzumabtherapie in der Adjuvanz unterstrichen werden. Dabei zeigte die gleichzeitige Verabreichung von Trastuzumab mit der taxanhaltigen Chemotherapie die besten Ergebnisse. Bei metastasierten Patienten unterstrichen neue Studienergebnisse den Wert einer Kombination aus Trastuzumab und Lapatinib und erhärteten die positiven Resultate der anfänglich bereits im vergangenen Jahr vorgestellten neuen Substanzen wie Neratinib und T‐DM1. Bei Her-2/neu-negativen Karzinomen etabliert sich Bevacizumab weiter als Kombinationspartner in vielfältigen Kombinationen. Neue Multityrosinkinasehemmer konnten im Falle von Motesanib und Sunitinib noch nicht überzeugen, während Sorafenib in Kombination mit Chemotherapie eine gute Effektivität besitzt. Alle diese neuen Tyrosinkinasehemmer haben gemein, dass sie ein frühes, gezieltes und konsequentes Nebenwirkungsmanagement unerlässlich machen.

Abstract

The molecular basics of breast cancer and the resulting diagnostic and therapeutic opportunities dominated last year's annual San Antonio Breast Cancer meeting. Even though no breakthroughs in endocrine therapy were presented, the many facets of targeted therapies took center stage in the conference program. As in previous years, basic research, preclinical and clinical studies were presented. In the field of endocrine therapy the 5-year follow-up analysis of the TEAM trial demonstrated equal efficacy of exemestane upfront or as a sequential therapy after 2 years of tamoxifen. Moreover, a switch to exemestane was confirmed to be superior according to the DFS and for overall survival in the long-term follow-up of the IES study compared to 5 years of tamoxifen. The results of the MA 27 trial demonstrated the high prognostic impact of extended adjuvant therapy, especially in premenopausal woman (at the time of primary diagnosis). This effect remains constant even if therapy is initiated up to 6 years after primary adjuvant therapy. In metastatic breast cancer 500 mg fulvestrant was found to provide a marginal prognostic benefit to women. A combination of fulvestrant and anastrozole just missed showing a higher efficacy than anastrozole monotherapy. With regard to bone health, priority was given to the prognostic impact of bisphosphonates and denosumab. The latter is a monoclonal antibody against RANK ligand and shows a superior efficacy to zoledronate in terms of pain relief and treatment of bone metastases. The value of adjuvant trastuzumab treatment was underlined by means of targeted therapies and concurrent treatment with taxane chemotherapy demonstrated the highest efficacy. In metastatic breast cancer a combination of trastuzumab and lapatinib was superior to monotherapy. Recent promising results of new EGF-receptor targeting drugs such as neratinib and T-DM1 confirmed the interesting data presented at an earlier meeting last year. In Her 2neu negative breast cancer, bevacizumab was demonstrated to be a good combination partner not only for taxanes but for capecitabine and gemcitabine as well. While some of the new multityrosine kinase inhibitors did not provide convincing results, others like sorafenib did demonstrate a good efficacy in combination with paclitaxel and capecitabine. All these tyrosine kinase inhibitors demand early and consequent prevention or treatment of associated side effects.

Schlüsselwörter

Brustkrebs - endokrine Therapie - Chemotherapie - zielgerichtete Therapie

Key words

breast cancer - endocrine therapy - chemotherapy - targeted therapy

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