Waitemata is the only District Health Board in the country currently achieving the Ministry of Health's cancer patient treatment goals.
The goal is for 85 percent of patients to receive treatment within 62 days of a GP's referral, but 19 of the country's 20 DHBs are failing.
Andrew Simpson, clinical director for the Ministry of Health's cancer programme, says the target is a focus for improvement - the old rate was 66 percent achievement and it's now at 78 percent.
"There's a lot of people working hard to improve the pathways, there's a lot of projects going on looking at what's actually happening to our patients at the moment, how we can improve that timeliness," he told Paul Henry on Wednesday.
West Coast DHB is one of those noticeably trailing behind the target, at a rate of 63 percent.
Dr Simpson says it can be complex as often the hospitals which receive the referrals aren't the ones diagnosing or treating the patient.
"They may start off the process but then they need to refer to another hospital," he said.
"So it's how do we streamline that process, and get that working in the best manner possible?"
Dr Simpson says the target was based on similar ones internationally, particularly in England and the UK.
"At the moment they're sitting at 82 percent, and they've been going longer than we have," he said.
All DHBs are working hard on meeting the target, Dr Simpson says.
"The DHBs are engaged, the clinicians are engaged, and people are working on this."
Dr Simpson says if anyone has any concerns about their care they should contact their hospital.