Otago researchers optimistic about treatment for especially aggressive form of disease

Researchers are encouraged by the early findings of a major New Zealand study to find a better way to treat an aggressive form of breast cancer.

Triple negative breast cancer, or TNBC, accounts for around 15 to 20 per cent of breast cancer diagnoses in New Zealand and particularly affects younger women.

Drugs used in chemotherapy to treat the cancer kill rapidly dividing cells where the cancer cells are found.

But these also kill the cells that line the gastrointestinal tract, as well as hair cells, leaving patients suffering from sickness and hair loss.


Avoiding these side-effects could be just one benefit of a new, high-tech approach using nano-medicine that zeroes in on the cancer cells.

The treatment, being investigated by Otago University researchers and funded by the New Zealand Breast Cancer Foundation could also prove safer, cheaper and ultimately more effective.

Study leader and toxicologist Associate Professor Rhonda Rosengren and her team are targeting hormone-resistant cancers such as TNBC, named for its tumours' lack of the three hormone receptors that fuel most breast cancers - estrogen, progesterone and HER2.

The researchers hope to create a low-cost nano-medicine based on RL-71, a powerful new chemotherapeutic agent developed by Associate Professor Rosengren's team.

This would be applied directly to the cancer cells through a new delivery platform, co-patented by study collaborator Dr Khaled Greish.

Associate Professor Rosengren hoped the research would eventuate in a drug costing less than $100 a dose.

An early tumour suppression test carried out on mice had promising results, but more animal tests are needed to measure the drug against metastasis - the spread of cancer.

"People who die from cancer die from the spread of the disease, so we still need to test this in a spread model," the professor said.


While the research was still in pre-clinical stages, it was hoped clinical trials in women could be held within two to three years.

Associate Professor Rosengren described the project as the most exciting she had worked on.

"I think we are on the uphill slope, but I think this stuff has the potential to turn into something worthwhile."

New Zealand Breast Cancer Foundation spokeswoman Adele Gautier said that while TNBC was a focus for many researchers internationally, her organisation was still looking for a breakthrough that would make a widespread difference.

"The study caught our attention with its novel delivery mechanism and low toxicity," Ms Gautier said.

"The focus on affordable treatment is a real plus when public health systems like ours are juggling increasing demand for new drugs within finite budgets."

Triple negative breast cancer (TNBC)

• The three most common types of receptors known to fuel most breast cancer growth - estrogen, progesterone, and the HER-2/neu gene - are not present in the cancer tumour.

• Therefore common treatments such as hormone therapy and drugs that target those receptors are ineffective, but chemotherapy is still considered an effective response.

• TNBC makes up between 15 and 20 per cent of breast cancers diagnosed in New Zealand.

The study

• Otago University researchers have developed a drug, RL-71, which is a synthetic derivative of curcumin.

• The medicine would be applied to the cancer cells through a new delivery platform, called styrene maleic acid (SMA) micelles.

• The SMAs encapsulate the drug and selectively deliver it to the tumour.