Progress towards advanced breast cancer treatments

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Breast cancer is still considered as the most commonly occurring cancer in women globally, with over two million new cases tallied by the World Cancer Research Fund in 2018. In response to this alarming health issue, scientists have conducted researches that gradually determine how this cancer can be mitigated. Recent studies have discovered novel treatments to breast cancer its various types: the hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER2) positive, and triple-negative (TNBC).

In the United Kingdom, several new drugs for HR-positive breast cancer are being developed and assessed by its National Institute for Health and Care Excellence and the Scottish Medicines Consortium to decide whether they can be used by the National Health Service.

British research and care charity Breast Cancer Now listed down these newer drugs on its Web site. First in the list are palbociclib, ribociclib, and abemaciclib, which are known as CDK4/6 inhibitors. These drugs are “already being used in combination with aromatase inhibitors, as a first treatment for women with ER-positive secondary breast cancer”.

The ribociclib, in particular, has gained the attention of The Guardian. It reported last June the findings by a study led by Dr. Sara Hurvitz of the University of California in Los Angeles that the combination of ribociclib with hormone therapy is “found to cut risk of death by up to a third.”

“The use of ribociclib as a frontline therapy significantly prolonged overall survival, which is good news for women with this terrible disease,” Dr. Hurvitz was quoted as saying.

With this, ribociclib is now considered as “one of the greatest advances in breast cancer research in recent decades”.

In the United States, palbociclib, ribociclib, and everolimus are approved by the country’s Food and Drugs Administration for use with hormonal therapy for treatment of advanced breast cancer, according to US’ National Cancer Institute. Abemaciclib, meanwhile, “can be given with hormonal therapy or alone after treatment with hormonal therapy to women with advanced [estrogen receptor] positive, HER2-negative breast cancer”.

Other drugs that have been tested for treating HR-positive cancer, Breast Cancer Now adds, are taselisib, alpelisib, crizotibib, and chidamide (in combination with exemestane).

For HER2-positive breast cancer, palbociclib and trastuzumab are being tested in the UK with women “with secondary HER2-positive breast cancer, who had already been treated with at least two types of anti-HER2 therapy”.

In the US, meanwhile, trastuzumab and pertuzumab are approved to be used in combination with chemotherapy for both early and advanced breast cancers.

Since TNBC does not respond to therapies directed at HR or HER2, treating it is the hardest and can only be dealt with by chemotherapy. Nonetheless, studies continue to test new treatments for TNBC. 

In the UK, drugs such as atezolizumab and nab-paclitaxel combined and sacituzumab govitecan are being tested.

Also, Breast Cancer Now has conducted the Triple Negative Trial. The test compared which among carboplatin and docetaxel is the most effective chemotherapy treatment for women with advanced TNBC. Its results favored carboplatin for delaying cancer’s progression longer and for being a cheaper alternative. — Adrian Paul B. Conoza