Ten‐year recurrence rates for breast cancer subtypes in the Netherlands: A large population‐based study

Here we report for the first time the relation between breast cancer subtypes and 10‐year recurrence rates and mortality in the Netherlands. All operated women diagnosed with invasive non‐metastatic breast cancer in 2005 in the Netherlands were included. Patients were classified into breast cancer subtypes according to ER, PR, HER2 status and grade: luminal A, luminal B, HER2 positive and triple negative. Percentages and hazards of recurrence were compared among subtypes. Adjusted 10‐year overall (OS) and recurrence‐free survival (RFS) were calculated using multivariable Cox regression. Of 8,062 patients, 4,482 (56%) were luminal A, 2,090 (26%) luminal B, 504 (6%) HER2 positive and 986 (12%) triple negative. Local recurrences (7.5%) and distant metastases (25.6%) occurred most often in HER2 positive disease and the least often in luminal A (3.7% and 9.5%, respectively). Regional recurrences were most often diagnosed in triple negative disease (5.2%), and the least often in luminal A (1.7%). HER2 positive and triple negative subtypes had the highest recurrence rates in the second year, while luminal A and B showed a more continuous pattern over time, with lobular tumours recurring more often. After adjustment for differences in baseline characteristics, triple negative disease showed worse 10‐year OS and triple negative and HER2 positive disease had the lowest 10‐year RFS. In the Netherlands, breast cancer subtypes are important predictors for 10‐year recurrence rates. Knowledge on recurrence and survival rates according to these different subtypes, in combination with other prognostic factors, can support patient‐tailored treatment and individualised follow‐up. What's new? While breast cancer subtypes are known independent predictors of survival and recurrence risk, data on long‐term recurrences in daily practice remain scarce. In this population‐based study reporting on 10‐year recurrences, HER2 positive and triple negative subtypes showed the highest recurrence rates, which occurred most often in the second year, while luminal A and B recurred later on during the follow‐up. Lobular tumours recurred more often than ductal tumours. In the Netherlands, breast cancer subtypes are thus important predictors for 10‐year recurrence rates. Knowledge on recurrence and survival rates according to these different subtypes can help support patient‐tailored treatment and individualised follow‐up.