Just one district health board (DHB) is meeting the government's faster cancer treatment target.
Under the target, DHBs should give 85 percent of patients who have a high suspicion of cancer their first treatment within 62 days.
Latest quarterly findings show Waitematā is exceeding the target, offering this care to 86 percent of patients.
But it's the only DHB doing so, with Wellington's Capital and Coast second on 84 percent, and West Coast at the other end of the spectrum on 63 percent.
Cancer Society medical director Chris Jackson said the result would worry many patients.
"Any kind of delay is agonizing for them, and when they have their operations cancelled because of inadequate resourcing or when they're waiting for a scan result, that delay is just so distressing for patients. And they need and they deserve to have access to timely and speedy investigations and treatment."
Nationally, 78 percent of patients began cancer treatment within the target timeframe, up by 4 percent since the last quarter.
Dr Jackson said it was a start, but it only covered the most urgent cancer patients.
While it varied between different cancers, Dr Jackson said there were hold-ups within the system.
"Patients are missing the target because they can't get access to their CT scans in time - the wait lists for CT are way too long.
"Every week patients are having their surgery cancelled because surgeons can't get access to theatre, and from time to time operations are cancelled because they can't get the support they need from the intensive care department because of pressure on the resources."
The data shows considerable variation between DHBs, from those near the top, like Wellington's Capital and Coast and the Waikato DHBs to Hawke's Bay, Hutt Valley and West Coast - the latter trailing with 63 percent of patients treated within 62 days.
Dr Jackson said the variability posed a challenge.
"There's variability in the level of care that people are receiving around the country and it shows that a lot of DHBs have got a long way to go."
The Ministry of Health's acting chief medical officer and cancer programme leader, Andrew Simpson, said DHBs were doing well.
"We've got five DHBs above 80 percent. We've got one that has achieved the target. This target's only been going just over two years so it's tight. The DHBs are doing well and we've got full confidence that they'll achieve 85 percent."
He said the ministry had put in both time and money to improving what's known as the patient "pathway" to treatment.
"We've had the cancer nurse co-ordinator initiative, which is putting cancer nurse co-ordinators to help patients get through these pathways in a more timely manner and provide the support they need.
"We've had the regional cancer networks working with the DHBs, we've had a national forum to provide learnings from what one DHB has done to help influence another DHB."
But Labour's health spokesperson, Annette King, said it was clear not enough is being done.
"I suspect that you've got some DHBs that are struggling to recruit and retain some of their workforce, they don't have capacity. In my view we ought to be sharing as much as possible all our capacity, particularly in an area as crucial as cancer."
Meanwhile, the target will become even tougher next year, with 90 percent of these patients expected to be seen within 62 days.