Could a Four-Times-a-Year shot replace daily breast cancer pills?

This study tests whether a new quarterly injection of letrozole delivers the same amount of drug into the bloodstream as the standard daily letrozole pill in postmenopausal women with hormone receptor-positive early breast cancer. About 120 women who have already completed at least 4-5 years of hormone therapy will receive both treatments in sequence. The goal is to see if the injection can offer a more convenient dosing option without changing effectiveness.