Data from thousands of New Zealanders could help reshape treatments and identify specific factors

Women diagnosed with breast cancer could get a clearer prognosis and different treatment options with a new model built from the data of thousands of New Zealand patients.

The model, now being developed by a team of Auckland researchers, could also reveal fresh insights into Kiwi breast cancer factors missing from international data that clinicians use to identify specific risk factors in patients.

One of the scientists leading the project, University of Auckland cancer epidemiologist Professor Mark Elwood, said comprehensive statistical tools had already been built from patient data in the US and Europe.

"Doctors and surgeons do use these in New Zealand and Australia, but we are using them on the assumption that may apply to our own population and we've never done this sort of work here."

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A New Zealand system could potentially pinpoint how breast cancer outcomes might be different in Kiwi women with certain genes or from specific ethnic backgrounds.

"Factors around weight and obesity could also be important, but we are going to be limited on that because we don't have so much information on it."

In the year-long study, Elwood and his team will analyse data from the combined Auckland-Waikato breast cancer registries, provided by more than 7000 women with at least five years' follow up information from the point they were diagnosed.

"In New Zealand, there has been a lot of analysis looking at the various factors related to the outcome of breast cancer, but this has got a different emphasis," he said.

"What we are trying to do is see how we could put all of the data together in a way where a doctor could use all of the information they have about a patient at the point of diagnosis and give the best prediction of their outcome.

"We can already do this informally because we already know the major risk factors, but this is about developing a statistical method to do it in an optimum fashion."

Elwood said he hoped it could improve the way doctors set treatment plans for patients, potentially sparing some patients aggressive treatment, or isolating other groups of women who could require more care than otherwise might be ordered for them.

Palmerston North breast cancer survivor Vicki Carter said knowledge is power for women when it comes to their diagnoses. She said she thought the data project would help women be more prepared for what is to come.

Carter, 46, was diagnosed a year ago with lobular cancer when she had her first mammogram. Her cancer was aggressive and was made up of lots of tiny tumours clustered in her right breast which later spread to her left breast.

Carter was treated with a double mastectomy, chemotherapy and radiation

"I never would have felt a lump. My biggest tumour was only 7mm.

"If I hadn't gone for a mammogram I could have easily been having secondary cancers. It would have travelled through my body."

Carter had her right breast removed first. When her surgeon told her that her left breast was "going to be a constant threat to your life" she said the decision to remove that too, was easy.

"I'm cool with that [losing my breasts], that's fine. They're gone, but I'm still me. It hasn't affected me. You grieve as you go through it."

It was chemotherapy that was the worst treatment, Carter said. She urged other women to avoid this by observing the "prevention is better than cure" maxim. She said 10 minutes of discomfort while getting a mammogram was well worth not going through some of the horrendous treatments needed for advanced breast cancer.

"Chemotherapy is just terrible. Your hair falls out, you're vomiting.

"It really pays to just be vigilant. Not paranoid. Check your breasts for any unusual pain, appearance or lumps."

While the medical professionals believe there is little cancer left in Carter they will keep a close eye on her. She has a yearly appointment with her surgeon for the next 20 years and goes for checkups every three months with her oncologist for the next five years.

"It's been a lot of soul searching. It's a time when you don't know what the outcome's going to be. It's a journey."

Meanwhile, another new study just funded by the Auckland Medical Research Foundation could help children suffering from an aggressive form of blood cancer.

Only 60 per cent of children diagnosed with acute myeloid leukaemia (AML) survive the cancer in the long-term and often not without lasting side-effects from treatment.

Scientists know that leukaemia involving mutations in a gene called ETV6 has much worse outcomes, yet the reasons why remain poorly understood.

A team led by paediatric haematologist-oncologist Dr Andrew Wood will create models of ETV6 mutant leukaemias in cells and tropical zebra fish, which could reveal new information that may lead to better treatments, improving cure rates and easing the suffering of patients.

Wood, a former Fulbright scholar and a clinician at Starship Children's Hospital, has already been investigating AML and cell mutations in zebra fish, which have proven valuable to scientists because they develop blood in a similar way to humans.

Breast cancer in New Zealand

• Breast cancer is the most common cancer for women, and the third-most common cancer overall. On average, seven New Zealand women per day hear the news that they have breast cancer, and it affects 1 in 9 New Zealand women over their lifetime.

• Most will survive five years or longer if the cancer is detected early enough but tragically, more than 600 women die of the disease every year.

• Some women are at greater risk of breast cancer because there is a history of close family members having the disease, but most women who develop it have no close relatives with the disease.