July 15, 2019 - 12:11 AMT
PanARMENIAN.Net - Chemotherapy treatment for people who have advanced bowel cancer and a particular genetic mutation is commonly ineffective. A combination of three different drugs could be the key to improved treatment, Medical News Today says.
The outlook for people with standard bowel cancer — also known as colorectal cancer — and those with an advanced form of the disease can differ greatly.
While more than half of the former tend to survive bowel cancer for 10 or more years, the outlook for the latter can be just a few months if the cancer involves a specific gene mutation.
The BRAF gene is responsible for producing a protein that transmits signals and supports cell growth. But a particular change to this gene — the BRAF V600E mutation — can speed up the spread and growth of certain cancer cells.
Up to 15% of metastatic colorectal cancer (mCRC) patients have the BRAF V600E mutation. Treating this form of cancer is difficult as it can be aggressive and tends not to respond to combination treatments involving chemotherapy.
Now a new study has tested a combination of targeted therapies without the chemotherapy. Researchers call this the BEACON CRC Phase III trial.
Their study appears in the Annals of Oncology and featured at the ESMO World Congress on Gastrointestinal Cancer 2019.
A mixture of three drugs — two targeting the cancer cells and one inhibiting the BRAF gene — was analyzed on a number of individuals who had not responded to one or two previous treatment regimes.
There were 665 participants in total. Researchers gave some all three drugs: encorafenib, cetuximab, and binimetinib. Others had a double therapy of BRAF inhibitor encorafenib and cancer-treating cetuximab.
A third group received a choice of the chemotherapy drug irinotecan or folinic acid, fluorouracil, and irinotecan (FOLFIRI) and cetuximab.
"Colorectal cancer does not respond to BRAF therapy alone because tumor cells adapt through other mechanisms after initial treatment," explains Dr. Scott Kopetz, study author from the University of Texas MD Anderson Cancer Center in Houston.
"With this triple targeted therapy, we are using a very scientifically logical combination to inhibit BRAF and these other mechanisms."
The focus was on triple therapy, and this proved to be the most successful option. While standard therapy gave a general survival rate of 5.4 months, the three-drug combination provided a median survival rate of 9 months.