The unifying concepts of the sick lobe hypothesis, field cancerisation and breast conservation treatment for multiple ipsilateral breast cancers: a narrative review

Abstract

Background and Objective: In the past, it was conventionally thought that multiple ipsilateral breast cancer (MIBC) was a contraindication to breast conservation surgery, especially if multicentric foci in different quadrants of the breast were present. However, over time, there has been a growing body of evidence in the literature demonstrating no survival detriment or poorer local control with breast conservation for MIBC. There is, however, a paucity of information integrating anatomy, pathology with surgical treatment of MIBC. Understanding mammary anatomy, pathology of the sick lobe hypothesis and molecular impact of field cancerisation contributes significantly to the understanding of the role of surgical treatment of MIBC. The purpose of this narrative overview is to review the paradigm shifts over time in the use of breast conservation treatment (BCT) for MIBC, and how the concepts of the sick lobe hypothesis and field cancerisation interact with this therapeutic strategy. A secondary objective is to explore the feasibility of surgical de-escalation for BCT in the presence of MIBC.Methods: A PubMed Search was performed for articles relating to BCT, multifocal, multicentric and MIBC. A separate literature search was performed for sick lobe hypothesis and field cancerisation and their interaction for surgical treatment for breast cancer. The available data was then analysed and synergised into a coherent summary of how the molecular and histologic aspects of MIBC interact with surgical therapy.