Why are so few Kiwi cancer patients in clinical trials?

Survival rates for some forms of what is New Zealand's biggest-killing disease have risen sharply over recent decades, as a result of new therapies and patients joining trials. Photo / 123RF

Most Kiwi cancer patients are keen to take part in clinical trials, a survey shows, despite a tiny proportion actually being involved in them.

Cancer now affects one in two Kiwis - either directly, or through a friend or family member being diagnosed - and survival rates for some forms of what is New Zealand's biggest-killing disease have risen sharply over recent decades, as a result of new therapies and patients joining trials.

Despite that, participation rates in New Zealand have been traditionally low - the number in enrolled in trials was estimated to be only between 1 and 2 per cent, far below international targets.

Previous studies have put that down to a mix of factors like the personal cost involved, age, confidence in the study and a lack of trials on offer.

In a new paper just published in the New Zealand Medical Journal, Auckland University and Auckland District Health Board researchers surveyed nearly 700 patients to find out what could be done to address the issue.

Three quarters of the patients were over 50, nearly two thirds were women, around 80 per cent were pakeha, and around 40 per cent had annual household incomes lower than $55,000.

While the vast majority had heard of clinical trials, just 23 per cent of the patients had a trial mentioned to them, and 18 per cent had prior experience with them.

Around 60 per cent wanted to be told about a trial at any time there was one open to them, and just 10 per cent thought the option should be a last resort.

Respondents also didn't mind travelling to take part - a third were willing to travel up to two hours, and tenth were even happy to relocate.

Of those who had already been involved in one, 94 per cent said they'd consider joining further ones - and only one patient among 2.5 per cent who said they definitely wouldn't again gave toxicity related to the treatment as their reason.

When asked what factors influenced them to consider trials, 92 per cent said they might benefit fellow patients, 85 per cent said it could help doctors' research, and 82 per cent said it could offer them better access to treatment.

Factors that might discourage them from trials were the fear of randomisation (78 per cent), treatment toxicities (71 per cent), the time and cost involved with visits (40 per cent) and uncertainty about how tissue might be used in the future (32 per cent).

Up to a quarter of Maori, Pacific Island and Asian patients raised cultural issues - something that wasn't much of an issue with pakeha patients.

The study authors said their work confirmed most patients were interested in joining clinical trials - and that there was a responsibility at a national level to improve access to them.

"It is important for all our patients as there is clear evidence that patients treated at cancer institutions with high research involvement have better outcomes," they said.

"It is also important to note (in our study) that of those who had been involved in a clinical trial, 94 per cent would like to be involved in future trials, implying that their involvement had been a positive experience.

"We plan to look into patient experience on trials in more detail in the future."

In the meantime, they said some barriers could be tackled through ongoing education, more equal access to trials and "improved patient awareness of research opportunities".