Sixteen of New Zealand's 20 District Health Boards are falling below expected cancer treatment times.

The Ministry of Health said the sickest 15 percent of cancer patients should be treated within 62 days of being diagnosed.

But only four are meeting this Waitemata, Waikato, Canterbury and Nelson Marlborough.

The worst performing health board was West Coast where 44 per cent of patients waited longer than 62 days to be seen, while in Whanganui 36 per cent of patients waited longer than two months.

Latest ministry health target results showed only 81.4 per cent of cancer patients between April and June received their first treatment within 62 days of being referred to a specialist with a high suspicion of cancer.

Cancer Society medical director, Chris Jackson, said Government funding for doctors, nurses and treatment facilities hasn't kept up with increasing rates of cancer.

"When you've heard the words 'I've got cancer' every single day that you wait for your treatment is agonising and any unnecessary delays need to be eliminated."

He said they only tell us about the sickest sufferers and not all the others, who are also waiting for treatment.

"So we think that the real situation is a whole lot worse than is seen by these targets. We think all cancer patients need to have their time to treatment measured."

The most recent figures published by the Ministry of Health showed the number of people diagnosed with cancer each year increased by 4247 between 2005 and 2014 to a total of 23,023.

The targets:

• 85 per cent of patients receive their first cancer treatment within 62 days of being referred with a high suspicion of cancer and a need to be seen within two weeks.
• The target has increased to 90 per cent by June 2017.
• Health boards were also expected to provide a first treatment to patients confirmed to have cancer within 31 days of a decision being made to treat them. 
• First cancer treatments can include surgery, radiation treatment, chemotherapy, targeted therapy, non-intervention management such as active surveillance or palliative care.

- with content from NZ Herald