@callalloo the conclusions of this study were more complicated, mainly because of missing date that affected results. All in all the article you linked favors the use of both drugs, Femara and Ibrance (brand names). I urge people to read the entire article and not just the headline, which is misleading. I am posting excerpts and hope people will read them.

"To demonstrate the impact of missing data, Dr. Finn showed a post hoc analysis excluding patients for whom survival data were not available. In that analysis, the median overall survival was 51.6 months with palbociclib/letrozole vs 44.6 months with letrozole alone (HR = 0.869; 95% CI = 0.706–1.069)."

"The time to chemotherapy was 38.1 months with palbociclib/letrozole vs 29.8 months with letrozole alone (HR = 0.730; 95% CI = 0.607–0.879)."

"Regarding other outcomes that affected quality of life, Dr. Finn reported the median duration of treatment and the time to chemotherapy were prolonged with palbociclib plus letrozole. The median treatment duration was 22.0 months vs 13.8 months, and at each benchmark, more of the palbociclib arm were still on treatment. “At 6 years or longer, this was three times as many (16% vs 5%),” he noted."

" For the largest subgroup of patients—those with a disease-free interval of more than 12 months—overall survival increased from 44.6 months in the control arm to 64.0 months with palbociclib/letrozole"