Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 237

Breast cancer cells are compared to normal cells for grading. Breast cancers are graded on a 1 to 3 scale, with grade 3 cancers being the most different looking and considered the most aggressive. Some breast cancers are sensitive to the body’s naturally occurring female hormones—estrogen and progesterone. The breast cancer cells have receptors on the outside of their walls that can catch specific hormones that circulate through the body. Knowing breast cancer is sensitive to hormones gives physicians a better idea of how best to treat the cancer or prevent cancer from recurring. Breast cancer can be divided into types on the basis of hormonal expression.

 Estrogen receptor (ER) positive. This type of breast cancer is sensitive to estrogen.

 Progesterone receptor (PR) positive. This type of breast cancer is sensitive to progesterone.

 Hormone receptor (HR) negative. This type of cancer does not have hormone receptors, so it will not be affected by treatments aimed at blocking hormones in the body.

Figure 2 Histopathology of invasive ductal carcinoma of breast

Source: Medscape.

With ER positive or PR positive breast cancer, hormone-blocking medications, such as tamoxifen, may be an option to slow the cancer’s growth. HR negative cancers do not respond to hormone-based therapy.