Patterns of Early and Late Recurrence Across Breast Cancer Subtypes in the Canadian Cancer Trials Group MA.32 Trial
Ana Elisa Lohmann, Bingshu E. Chen, Wendy R. Parulekar, Katarzyna J. Jerzak, Pamela J. GoodwinPurpose
We describe patterns of early and late recurrence across breast cancer (BC) subtypes (luminal: estrogen and/or progesterone receptor [ER and/or PgR] positive, human epidermal growth factor receptor 2 [HER2] negative); triple negative (TN); HER2+, any ER, PgR in the Canadian Cancer Trials Group MA.32 adjuvant BC trial involving 3,649 patients with high-risk BC.
Methods
Post-random assignment annual rates of local and distant recurrences as well as new breast and nonbreast primaries were calculated for each BC subtype and averaged for early (years 0-5) and late (>5 years) events.
Results
Patterns of events varied across subtypes and early versus late events. The early versus late annual invasive cancer rates were 3.04 versus 2.31% (late/early 0.76) in luminal, 4.60% and 1.21% (late/early 0.35) in TN and 2.93 versus 1.47% (late/early 0.50) in HER2+. Annual early versus late rates of distant recurrence were 2.33 versus 1.72% (late/early 0.74) in luminal, 3.09 versus 0.2% (late/early 0.28) in TN, and 2.25 versus 0.71% (late/early 0.32) in HER2+. Second primaries were the most frequent late event in patients with TN and HER2+ BC.
Conclusion
Risk of late cancer events differed across BC subtypes; distant recurrences were most common in luminal while second primaries were most common in TN and HER2+ BC.