Tailored surgery for early breast cancer: Biological aspects

Abstract

For most breast surgeons, the resection of any breast malignancy in the operating theatre appears a galaxy away from the molecular biological aspects of the cancer. The surgical adagium is simple: the breast cancer should be removed with clear margins with the best possible cosmetic result [1]. So why bother with biological markers, immunohistochemistry, gene profiling, and other sophisticated techniques to improve outcome of the surgical act in itself? The reality tells a more complex story: Half of the patients with stage I breast cancer still do have a mastectomy [2]. Over 30% of patients who have breast conserving therapy (BCT), have a poor cosmetic result, either by large excisions, higher doses of radiotherapy or the combination [3]. A breast relapse is experienced by 12-20% of patients after BCT (including radiotherapy) in the first 10 years [4, 5]. If after wide local excision the breast is not irradiated, about 70% of patients will remain free of disease at 7 years [6]. After locoregional relapse, patients do experience a worse prognosis, irrespective of whether they have had BCT or a mastectomy [7, 8]. The majority of patients undergo unnecessary axillary treatment. After a complete axillary lymph node (ALN) dissection for stage I-II breast cancer, on average 60% of the patients do not have axillary involvement [9]. After a positive sentinel lymph node (SLN), only 35% have further nonsentinel ALN involvement [10, 11]. Apparently, there is room for improvement for the indication to surgery and the extent of the surgery in individual patients. Molecular biology may help the surgeon. What do the surgeons want to know? A better determination of the in-breast behavior of the cancer and a better understanding of the risk of minimal residual disease and its viability after local resection, or even mastectomy. A better prediction of the chances of lymphatic dissemination. To better predict minimal residual disease after SLN biopsy in the remaining regional lymph nodes. Evidently, the surgical oncologist also wants to know the risk of distant disease and subsequent survival, the optimal prediction of the effect of adjuvant systemic treatments, and the indications and effectiveness of adjuvant radiotherapy. These aspects will be dealt with elsewhere in this book. This chapter will describe how molecular biology can help the surgeon to tailor the surgical locoregional treatment. © Springer-Verlag Berlin Heidelberg 2006.