A combination of breast cancer drugs without chemotherapy could soon be used to treat patients with a rare form of liver cancer.
Tucatinib and trastuzumab, when used together, have been shown to shrink tumors in patients with bile duct cancer.
The cancer affects the tubes in the liver that carry bile, which helps the body digest food by breaking down fat, and there are few effective treatments.
For those whose cancer has not spread beyond the bile ducts, the five-year survival rate is around 20 percent, but once it spreads, this rate drops to just two percent.
Researchers in the pioneering trial in Japan used the two drugs to treat patients with a variety of tumors linked to a protein in the body called human epidermal growth factor receptor 2, or HER2.
Tucatinib and trastuzumab, when used together, were shown to shrink tumors in patients with bile duct cancer (file image)
Tumors with high levels of HER2 are more likely to spread quickly through the body. Tucatinib and trastuzumab are already used to treat patients with HER2-positive breast cancer.
The tablets are more effective than traditional chemotherapy and have fewer side effects.
The trial concluded that bile duct cancer had the strongest response to the drugs, with almost half seeing their tumors shrink.
Every year in Britain around 2,700 people are diagnosed with bile duct cancer, also known as cholangiocarcinoma. Cases have doubled in the last two decades, but the reason is unknown.
Experts say tucatinib and trastuzumab should now be offered to patients with bile duct cancer who have not responded to existing treatments.
“This combination without chemotherapy has been shown to be safe and well tolerated,” said Dr. Yoshiaki Nakamura, an oncologist at the National Cancer Center Hospital East in Kashiwa.