Abstract The following manuscript summarises the con- tent of the Breast Symposium that was held in May 2008 in Barcelona in which four controversies regarding the management of breast cancer were discussed. The design of the symposium included two speakers per controversy, one in favour and one diverging, and the audience had to vote before and after the presentations to assess changes in the participants’ views. The four controversies included: (1) the role of non-conventional predictive factors in se- lecting treatment for breast cancer; (2) the role of surgery in disseminated disease; (3) are taxanes indicated in the adjuvant treatment of patients with lymph-node-negative disease?; (4) is treatment with tamoxifen (TAM) always required after surgery in patients with ductal carcinoma in situ (DCIS)? The symposium concluded with the presenta- tion titled: ‘Features of a well designed clinical trial in the adjuvant treatment of breast cancer’. Keywords Breast cancer · Non-conventional predictive factors · Surgery · Taxanes · Adjuvant treatment · Negative lymph node · Tamoxifen · DCIS · Clinical trial design First controversy: Role of non-conventional predictive factors in selecting treatment for breast cancer A predictive factor in medicine is defined as a clinical, his- tological, biological or, more frequently, molecular variable that predicts the response to certain treatments. For a predic- tive marker to be clinically useful, it needs to have certain characteristics including reproducibility and precision. In addition, the correlation with outcome must have been well established in properly designed prospective randomised clinical trials. The information provided needs to be differ- ent from what can be obtained by examining clinical param- eters and must be obtained at a reasonable cost and pace. In breast cancer, the classic criteria used to select treat- ment include size of the tumour and lymph node involve- ment. These factors define the extension of the disease and have well defined prognostic values. However, they do not provide information about the biological characteristics of the tumours and do not influence the benefit of systemic treatments. In addition to these factors, breast cancer treat- ment is also based on certain histological and molecular features such as histological grade and the expression of oestrogen receptor (ER) and ErbB2. These last two groups of markers are not only prognostics but also provide infor- mation with regards to the efficacy of specific treatments. However, their positive predictive values are rather low. Thus, the response rate to hormone inhibition is 30–60% in ER-expressing tumours while for Her2-positive tumours treated with trastuzumab the response rate ranges from 20% to 50%. These facts suggest a need for the develop- ment of new markers. Over the last few years, however, there have been ma- jor changes in breast cancer understanding, diagnosis and treatment. From a mere pathological classification, the disease is now classified into groups that are based on mo- lecular characteristics [1, 2]. In this regard, breast cancer tumours have been recently classified into four subgroups The affiliations are listed at the end of the article I. Tusquets () Servicio de Oncología Médica Unidad Funcional de Patología Mamaria Hospital del Mar. IMAS Passeig Maritim, 25-29 ES-08003 Barcelona, Spain e-mail: itusquets@imas.imim.es Clin Transl Oncol (2010) 12:278-286 DOI 10.1007/s12094-010-0504-x SPECIAL ARTICLE Current controversies in the management of breast cancer Ignasi Tusquets · Laura García-Estévez · Encarna Adrover · Lourdes Calvo · Isabel Álvarez · Jesús García Mata · Yolanda Fernández · Mireia Margueli · Miquel Ángel Seguí · César Rodríguez · Álvaro Rodríguez Lescure · Ramon Colomer · Pere Gascón · Miguel Martín · Emilio Alba · Agusti Barnadas · Antonio Llombart · Joan Albanell · Ana Lluch Received: 27 October 2009 / Accepted: 8 November 2009