Tang M, et al. - Researchers conducted the PARAGON study with the primary aim to prospectively examine the clinical benefit rates (CBR) of anastrozole, an aromatase inhibitor, in patients with estrogen receptor (ER) and/or progesterone receptor (PR) positive low-grade ovarian cancers (LGOCs) and serous borderline ovarian tumors (SBOTs). Treatment with anastrozole 1 mg daily until progression or unacceptable toxicity was provided to 36 post-menopausal women with ER-positive and/or PR-positive recurrent/metastatic LGOCs and SBOTs and evaluable disease by RECIST v1.1 or GCIG CA125 criteria. Outcomes revealed CBR of 61% in correlation to anastrozole treatment among patients with recurrent ER-positive and/or PR-positive LGOC or SBOT for at least 6 months with tolerable toxicity.