The purpose of the present invention is to provide: a photochromic compound having an excellent color fading rate and excellent durability; a naphthol derivative that can become an intermediate for the photochromic compound; and a curable composition, an optical article, a lens and eyeglasses each containing the photochromic compound. According to embodiments, a photochromic compound having a backbone represented by formula (1) is provided. In formula (1), M represents C, Si or Ge; R.sup.1 represents a haloalkyl group having 1 to 20 carbon atoms inclusive; R.sup.2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms inclusive or a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms inclusive.

Disclosed herein are methods of treating subjects suffering from estrogen receptor positive cancer of the brain by administering a selective estrogen receptor degrader (SERM). Also disclosed are methods of treating a cancer that is resistant to an estrogen receptor modulator by administering a SERM.

Disclosed herein are methods of treating subjects suffering from estrogen receptor positive cancer of the brain by administering a selective estrogen receptor degrader (SERM). Also disclosed are methods of treating a cancer that is resistant to an estrogen receptor modulator by administering a SERM.

Disclosed herein are methods of treating subjects suffering from estrogen receptor positive cancer of the brain by administering a selective estrogen receptor degrader (SERM). Also disclosed are methods of treating a cancer that is resistant to an estrogen receptor modulator by administering a SERM.

Disclosed herein are methods of treating subjects suffering from estrogen receptor positive cancer of the brain by administering a selective estrogen receptor degrader (SERM). Also disclosed are methods of treating a cancer that is resistant to an estrogen receptor modulator by administering a SERM.

The purpose of the present invention is to provide: a photochromic compound having an excellent color fading rate and excellent durability; a naphthol derivative that can become an intermediate for the photochromic compound; and a curable composition, an optical article, a lens and eyeglasses each containing the photochromic compound. According to embodiments, a photochromic compound having a backbone represented by formula (1) is provided. In formula (1), M represents C, Si or Ge; R.sup.1 represents a haloalkyl group having 1 to 20 carbon atoms inclusive; R.sup.2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms inclusive or a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms inclusive.

The purpose of the present invention is to provide: a photochromic compound having an excellent color fading rate and excellent durability; a naphthol derivative that can become an intermediate for the photochromic compound; and a curable composition, an optical article, a lens and eyeglasses each containing the photochromic compound. According to embodiments, a photochromic compound having a backbone represented by formula (1) is provided. In formula (1), M represents C, Si or Ge; R.sup.1 represents a haloalkyl group having 1 to 20 carbon atoms inclusive; R.sup.2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms inclusive or a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms inclusive.