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Māori men are more likely to get testicular cancer and no one really knows why

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A pilot study is looking to find the reasons behind the high incidence of testicular cancer among Māori men.

When Jo Stafford was diagnosed with testicular cancer in 2005, six months after first going to the doctor with an enlarged and extremely painful testicle, he put the delay in getting a diagnosis down to bad luck. These days, Stafford sees the series of “Keystone Cop”-type mistakes – including being prescribed antibiotics despite an initial sonogram that showed a suspicious shadow in his testicle – as an example of unconscious bias towards Māori within the health system.

Stafford (Ngāti Rārua, Ngāti Maniapoto and Ngāti Tama) is chair of the Ministry of Health’s Cancer Consumer Advisory Group and he spends many volunteer hours working with clinicians and oncologists to ensure that cancer-care pathways are not just patient-centric, but also Māori-centric.

“It wasn’t until I became a patient advocate and started hearing other people’s stories that I began to see my own journey in that context. I’m now a lot more attuned to the impacts of unconscious bias and how that impacts on Māori.”

Macro alias: ModuleRenderer

Luckily for Stafford, the delay in getting a diagnosis did not affect his prognosis. In 2006, his affected testicle was removed, followed by a course of radiotherapy. He has been cancer-free since then.

That’s the normal scenario in most cases of testicular cancer, which has a survival rate of 90% to 100%, depending on whether the cancer has spread or not. However, as with other cancers, Māori men are twice as likely to die from it – largely because of delays in getting diagnosis and treatment.

More bafflingly, Māori men are also 80% more likely than Pākehā men to get testicular cancer in the first place. That huge disparity is the focus of a study being led by Jason Gurney, an epidemiologist and Māori health researcher at the University of Otago, Wellington.

He hopes the results of the study, which is now in the pilot stage, will not only explain why Māori men are so disproportionally affected by testicular cancer but also identify the factors that are driving a steady increase in the rate of the disease worldwide.

Lead researcher Jason Gurney.

“Internationally we actually have bugger all idea of what’s going on,” he says. “This study can make a meaningful contribution because it gives a prism to look through at why Māori men are more likely to get testicular cancer, at what exposures might be causing them to get it.”

Gurney says the discrepancy is particularly unusual because Pacific men are not similarly affected. In fact, they are less likely to get testicular cancer than any other ethnic group in New Zealand.

“It’s a rare example where disease incidence does not move in parallel between Māori and Pacific.”

Testicular cancer is relatively uncommon. About 180 new cases are diagnosed in New Zealand every year, about a quarter of them Māori. That compares with 3000 new cases of prostate cancer every year.

However, testicular cancer is the most commonly diagnosed cancer among men aged 15 to 39, and though it is rarely fatal, it can cause long-term problems such as infertility and erectile dysfunction.

Gurney’s is what is called a control study. It involves one group of men who have had testicular cancer and one group who haven’t. The study will use saliva samples to test for genetic factors and carry out interviews with the men to identify possible environmental factors such as exposure to pesticides.

The researchers will also interview the mothers of the men to get information about possible exposures during pregnancy and early life. One of these is smoking: Gurney says the high rates of smoking among Māori women is one thing that differentiates them from women in other ethnic groups.

The pilot study involves two groups of 60, half of whom are Māori. Providing he gets more funding, Gurney hopes to extend that to two groups of 410, each with 150 Māori men in them. He says the pilot is an opportunity to refine the questions and ensure that those involved don’t feel judged and blamed. “We’re asking about quite private and difficult exposures and we need to make sure we do that in a way that is not mana-reducing and makes clear to the women, and the men, that we don’t know if these things are important, but if we don’t ask about them we won’t know.”

This article was first published in the November 17, 2018 issue of the New Zealand Listener.