Hormone treatment for cancer of unknown primary

Some types of cancer grow in response to sex hormones in the body. For instance, most breast cancers have proteins called estrogen receptors on the surface of their cells. These cancers grow faster when exposed to the hormone estrogen. Likewise, most prostate cancers grow in response to male hormones called androgens (like testosterone).

In cases where a cancer of unknown primary (CUP) is likely to be a breast or prostate cancer, hormone treatment may slow the growth of the cancer, or even shrink it and may help you live longer. To learn more about how these hormones are used and the side effects they might have, see our documents, Breast Cancer and Prostate Cancer.