The Cancer Society fears the nationwide Covid-19 lockdown has delayed some cancer diagnoses and treatment, and is calling on district health boards to act immediately.

Fearing further delays "will cost lives", the society wants cancer care to be prioritised, citing overseas evidence that lockdowns led to half as many cancer diagnoses being made.

CHRISTEL YARDLEY/STUFF Cancer Society calls for DHBs to 'prioritise cancer diagnosis and treatment' to avoid preventable deaths.

Medical director Dr Chris Jackson said a three-month diagnosis delay could result in 400 additional cancer deaths.

Director-general of health, Dr Ashley Bloomfield, admitted on Monday "there was no doubt some people's care has been delayed".

READ MORE:

* Coronavirus: Cancer patients out of pocket and questioned during travel

* Coronavirus: For those with cancer, lockdown brings about questions of life and death

* National Portrait: For Chris Jackson, patients are his passion

* Coronavirus: Why diabetes, cancer, old age makes people vulnerable to Covid-19

POOL VISION Prime Minister Jacinda Ardern and director-general of health Dr Ashley Bloomfield give their final press conference under alert level 4.

Jackson said that heavy restrictions imposed by the weeks' long nationwide lockdown meant fewer GP visits, fewer scans and fewer diagnostic tests being carried out.

With the country now sitting at alert level 3, Jackson believed swift action from DHBs was required.

SUPPLIED Cancer Society medical director Dr Chris Jackson says cancer diagnosis and surgery must 'proceed with urgency' to prevent non-Covid-19 cancer deaths.

"Fewer people are seeing their GPs so that means symptoms are going ignored. These delays will cost lives," Jackson said.

Among those impacted was Aucklander Elisa Wijohn who had a CT scan – needed to see how far her advanced breast cancer had spread – abruptly cancelled this month due to the lockdown.

The Cancer Control Agency has issued advice about scans, surgeries, chemotherapy and radiation treatments that can be safely delivered during levels 3 and 4.

However, the society said it was aware some DHBs had sent patients back to their GPs because they were unable to carry out certain operations and procedures.

DAVID WHITE/STUFF Aucklander Elisa Wijohn, living with advanced breast cancer, had a CT scan cancelled this month due to coronavirus.

"As the health system ramps up after level 4 lockdown, we must prioritise cancer diagnosis and treatment in order to avoid preventable deaths. DHBs must make sure this happens.

"We support the lockdown which has kept people with cancer safe from Covid-19, but cancer diagnosis and surgery must now proceed with urgency in order to prevent non-Covid-19 cancer casualties," Jackson added.

TVNZ Director-general of health Dr Ashley Bloomfield says "there is no doubt" some cancer treatments have been delayed during the Covid-19 lockdown which ended last night.

Bloomfield conceded cancer patients had experienced delays in both diagnostic procedures and treatment during the lockdown, but work had been carried out to prevent negative repercussions.

"There's been some excellent work done between Diana Sarfati, the acting chief executive of the Cancer Control Agency, and clinicians across the sector about how to reduce the likelihood of any harm resulting from that.

"And in particular, how to make sure, as we go into alert level 3, that we can prioritise the investigations and treatment of people with cancer to make sure that they are getting what they need," Bloomfield said.

DHBs had received "clear guidance" from the Ministry of Health over the services they should be providing at level 3, he added.

"The key principle for DHBs and their hospitals over coming days will be starting to move back to providing more elective and planned services, both outpatient appointments and also potentially surgery and other procedures.

"And then easing into that within the context of wanting to keep everyone safe, so making sure their infection prevention control procedures are all A1, while still maintaining that ability, if necessary, to scale up a response to Covid-19."