This survey was designed to examine the effect on QOL improvement and convenience of switching to leuprorelin acetate 3 month depot 11.25 mg injection kit (Leuplin SR 11.25 mg injection kit) from a 4-week adjuvant therapy with a LH-RHa 1 month depot over 48 weeks in premenopausal breast cancer participants in daily medical practice, as well as to evaluate the influence of condition of estrogen receptor expression on the efficacy and safety of leuprorelin acetate SR 11.25 mg injection kit .