US Breast Cancer Mortality—Reply

In Reply Dr Jatoi suggests that a reduction in the incidence of ER-negative breast cancer over the past decades could have contributed to the decline in breast cancer mortality observed in SEER between 1975 and 2019. Indeed, a decline in cancer incidence can have a primary role in decline of cancer-specific mortality, as in the case of lung cancer. Similarly, a change in the composition of molecular subtypes among people diagnosed with incident breast cancer could affect mortality rates and even decrease mortality if the subtype with the higher mortality rate became less prevalent.