From the article:
The researchers found that breast cancer incidence was higher in estrogen plus progestin users than incidence in nonusers. Women who started hormone therapy closer to menopause had a higher breast cancer risk with a weakening influence as the time from menopause increased.
“Because survival after breast cancer diagnosis did not differ between estrogen plus progestin users and nonusers, the higher breast cancer incidence of those using estrogen plus progestin may lead to increased breast cancer mortality on a population basis,” the authors write.
[…]
“In general, tumors in estrogen plus progestin users in the WHI Observational Study were not significantly different from those in non-hormone users with regard to number of positive lymph nodes or tumor size, but were more likely to be well differentiated and positive for hormone receptors, findings which are similar to other observational studies.” This, however, did not translate into a survival benefit.