Toronto Workshop on Late Recurrence in Estrogen Receptor-Positive Breast Cancer: Part 1: Late Recurrence: Current Understanding, Clinical Considerations

Abstract

Disease recurrence (locoregional, distant) exerts a significant clinical impact on the survival of estrogen receptor-positive breast cancer patients. Many of these recurrences occur late, more than 5 years after original diagnosis, and represent a major obstacle to the effective treatment of this disease. Indeed, methods to identify patients at risk of late recurrence and therapeutic strategies designed to avert or treat these recurrences are lacking. Therefore, an international workshop was convened in Toronto, Canada, in February 2018 to review the current understanding of late recurrence and to identify critical issues that require future study. In this article, the major issues surrounding late recurrence are defined and current approaches that may be applicable to this challenge are discussed. Specifically, diagnostic tests with potential utility in late-recurrence prediction are described as well as a variety of patient-related factors that may influence recurrence risk. Clinical and therapeutic approaches are also reviewed, with a focus on patient surveillance and the implementation of extended endocrine therapy in the context of late-recurrence prevention. Understanding and treating late recurrence in estrogen receptor-positive breast cancer is a major unmet clinical need. A concerted effort of basic and clinical research is required to confront late recurrence and improve disease management and patient survival.

Figure 1.

Association between pathological nodal status and the risk of distant recurrence or death from breast cancer (BC) during the 20-year study period. Shown are data regarding the risk of distant recurrence (A) and death from BC (B) among 74 194 women with estrogen receptor–positive T1 or T2 disease who were enrolled in 78 trials at year 0 and were scheduled to receive 5 years of endocrine therapy. (Data for another 10 200 women who enrolled in 10 trials after year 0 are not shown here.) The risk was calculated according to the patients’ pathological nodal status at the time of diagnosis: N0, N1–3, or N4–9. The number of events and annual rate are shown for the preceding period (eg, data for years 0–4 are shown at 5 years). The I bars indicate 95% confidence intervals. The dashed lines indicate that the event rate is for the whole 5-year period rather than for individual years, as is otherwise shown. The annual rate of death from BC was estimated by subtracting the death rate in women without recurrence from the rate in all women. From (1). Copyright © (2017) Massachusetts Medical Society. Reprinted with permission from the Massachusetts Medical Society and the Early Breast Cancer Trialists’ Collaborative Group.