Biomedical Laboratory Science

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Showing posts with label Response. Show all posts
Showing posts with label Response. Show all posts

Tuesday, February 13, 2018

Some Breast Cancers Fail to Respond to Treatments, Why?


Most breast cancers are estrogen receptor-positive, meaning that signals received from estrogen, a hormone, promote the growth of the tumors. To stop these cancers from spreading, estrogen inhibitors are usually prescribed. But what happens when tumors develop treatment resistance?


Studies suggest that "approximately 70 percent" of all the breast cancers are estrogen receptor-positive (ER-positive).

These types of cancer are typically treated with drugs — such as tamoxifen and fulvestrant — that either lower the levels of the hormone or inhibit the estrogen receptors to prevent the tumors from spreading. This is known as endocrine therapy.

However, around a third of the people treated with these drugs develop resistance to them, which negatively impacts their chances of survival. The mechanisms that underlie the tumors' resistance to therapy is not well understood and currently poses a major challenge.



Saturday, October 29, 2016

Breast Cancer: The Body of Knowledge Grows

Scientists’ understanding of the genetics/genomics of breast cancer continues to grow; a revolution is underway both in terms of categorizing breast cancers and targeting treatment that will be effective in individual cases. New perspectives are being offered on the interpretation of biopsies, too. Here is a round-up of some very recent studies.

Genetic variants alter cells’ response to estrogen
An international study of almost 120,000 women has newly identified five genetic variants affecting risk of breast cancer, all of which are believed to influence how breast cells respond to the female sex hormone estrogen.

Estrogen acts as a trigger, binding to a molecule known as an estrogen receptor in most breast cells and triggering a cascade of signals that cause the cell to behave normally. However, the estrogen receptor is switched off in some cells and these do not respond to the hormone.



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