In a study, premenopausal women aged between 20 and 40 years who received adjuvant chemotherapy for breast cancer from January 2002 to April 2012 were classified into two groups: Women in one group were treated with GnRH agonists for ovarian protection during chemotherapy, and those in the other group were not administered GnRH. Here, GNRH1 is linked to breast carcinoma.