A case report has been published on long-term control of metastatic endometrioid carcinoma using megestrol acetate and letrozole for over 9 years. However, it is unclear if this treatment approach is being explored for other types of cancer, as separate studies are investigating the use of megestrol and letrozole in early-stage estrogen-receptor-positive breast cancer and the effects of aromatase inhibitors like letrozole on bone loss. The relationship between these different research efforts is not immediately clear.