ASO Author Reflections: Breast Cancer Local Recurrence Versus New Primary—Clinical Predictors and Prognostic Implications

Excerpt

It has long been observed that controlling a locally recurrent tumor that persisted despite definitive therapy is more challenging than the management of a de novo unselected primary cancer. Indeed, 10-year overall survival rates can approximate 40% following local recurrence, whereas overall breast cancer outcomes are significantly more favorable.1,2 An in-breast tumor recurrence (IBTR) may represent a true recurrence (TR) arising from the original tumor, or a new primary (NP). However, there is no standard approach for differentiating TRs from NPs. Some have used in-quadrant recurrence as an indicator of a TR, whereas others have used concordance of histology and subtype, all with variable reliability.3 Our study sought to establish the presence of an in situ component within an IBTR as a marker of a NP that, thereby, portends favorable disease-free survival (DFS). To date, the majority of breast cancer studies have focused on overall IBTR, likely overestimating treatment failures given the occasional presence of de novo carcinogenesis. …