A contradiction in tumours

(Edmonton) Medical research at the University of Alberta suggests some breast cancer tumours may be resistant to a common chemotherapy treatment.

Principal investigator Ing Swie Goping and her team discovered some breast cancer tumours have low levels of certain genes, and that those tumours didn't respond well to taxane chemotherapy, a common treatment used in breast cancer.

"These tumours didn't shrink and were resistant to a common chemotherapy treatment. These results give us a strong incentive to continue our research," she said.

Goping and her team looked at tumour samples from 24 breast-cancer patients who had been treated with chemotherapy before surgery. The team found four genes in the "survival" system of tumour cells, which did not function well in some of the samples. According to Goping, this should indicate a weakened tumour survival system and thus the patient would be considered a good candidate for an effective chemotherapy treatment. Instead, Goping's team found that the stronger the tumours' survival system was, the better the chemotherapy worked.

"This discovery was a bit of a surprise," said Goping, a researcher in both the departments of biochemistry and oncology. "One would expect that tumour cells with strong survival systems would be more chemotherapy resistant, but that's not what we discovered."

Goping noted this research was purely curiosity-driven, and the finding underscores the importance of basic research. "It was a question we were asking at a very basic level and it turns out the discovery could be clinically relevant. At the moment there is no tool to determine which women would be good candidates for taxane chemotherapy. And chemotherapy resistance is a major clinical problem."

Goping says she hopes to continue this research by examining tumour samples from thousands of patients over a span of at least three years, in hopes of confirming what the team discovered is indeed a 'marker' that will predict which breast cancer patients will respond well to taxane chemotherapy. She noted it would be years before doctors would be able to actually start testing breast cancer patients for this marker.

The Canadian Breast Cancer Foundation - Prairies/NWT Region and Alberta Innovates - Health Solutions funded the research, which was published in the peer-reviewed journal Oncogene.