Analysis during the post-intervention period following the estrogen-plus-progestin trial continues to reveal the strong association between estrogen- plus-progestin usage and breast cancer risk. Following the halt of the estrogen-plus-progestin trial, there was a sharp decrease in breast cancer risk in the early post-intervention period, though the hazard ratio remained greater than 1, followed by a sustained risk during the late post-intervention period that was significantly greater than 1. It is hypothesized that the initial decrease was due to the resulting change in the hormone environment, while the subsequent persistent increase in breast cancer incidence may be attributed to the persistence of oncogenic mutations and subsequent expansion of these mutation-harboring cell lineages. The most recent update, published July 28, 2020 in JAMA, reported that increased breast cancer risk has persisted among women randomized to estrogen plus progestin compared with placebo