[{"from": "human", "value": "What can you tell me about this molecule? [C][C][Branch1][C][C][Branch1][Ring1][C][#N][C][=C][C][=Branch1][S][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][C][N][C][=N][C][=N][Ring1][Branch1][C][Branch1][C][C][Branch1][C][C][C][#N]"}, {"from": "gpt", "value": "The molecule is a non-steroidal aromatase inhibitor (AI), similar to [letrozole], used to decrease circulating estrogen levels in the treatment of postmenopausal women with estrogen-responsive breast cancer. Anastrozole is also related to [exemestane], a steroidal AI, but its non-steroidal nature provides stark advantages including a lack of steroid-associated adverse effects such as weight gain and acne. Aromatase inhibitors, including anastrozole, have become endocrine drugs of choice in the treatment of postmenopausal breast cancer due to a more favourable efficacy and adverse effect profile as compared to earlier estrogen receptor modulators such as [tamoxifen].  Anastrozole was first approved for use in the United States in 1995."}]