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Less Chemotherapy for Some Breast Cancers

By Stephen Luntz

A new combination of chemotherapy and radiotherapy has had 100% success in stopping the spread of a particularly aggressive form of breast cancer in mice.

Breast cancers that do not express genes for oestrogen, progesterone or human epidermal growth factor receptors are known as “triple-negative” and account for around 20% of all breast cancers. Although quite diverse, they are generally hard to treat as they lack surface receptors to target and have higher rates of relapse in the first 3–5 years.

Dr Fares Al-Ejeh of the Queensland Institute of Medical Research used lower than usual doses of chemotherapy to clear out the cancer cells most sensitive to this treatment. Then radiotherapy is targeted at the cancer cells via radioactive isotopes carried aboard antibodies to proteins on the surface of the cells. He believes this approach has potential against 60% of triple-negative cancers.

“Similar approaches may work against other cancers. It is a matter of finding the right protein to target,” Al-Ejeh says. “The idea has been around for a while, but did not work well on its own.”

Al-Ejeh says that the right antibody for cancers needs to be found, and for those cancer cells susceptible to chemotherapy to be cleared out first. Then an agent is applied that inhibits cancer cells from repairing themselves before the radiotherapy takes place.

“Cells resistant to treatment are not the entire population, but they hide among the bulk of the tumour. To get at them we need to get rid of the rest to expose them,” Al-Ejeh says.

The research was reported in the Journal of Nuclear Medicine. Al-Ejeh says the work is ready for clinical trials, and “we are hoping that within 10 years we will be able to provide a good therapy for women affected with this aggressive cancer”.