Lives will be lost if the country does not urgently catch up on cancer tests put off during the Covid-19 lockdown, says the Cancer Society.
A report by the Cancer Control Agency shows there were 1031 fewer cancer cases registered in April, compared to the same month last year.
Nationally, there were 79 per cent fewer gastrointestinal endoscopies in April compared to the same month last year, and a 75 per cent decrease in bronchoscopies.
There was also a 33 per cent drop in curative cancer surgeries for prostate, lung and colorectal cancers.
"The decrease in curative surgery appears to be largely driven by the decrease in diagnostic services," the report said.
Cancer Society medical director Chris Jackson said while the country did well in maintaining cancer treatment during the lockdown, many people chose to have diagnostic procedures deferred.
"That means the catch-up has to happen and it has to happen fast. Data from the UK shows if you have a long delay in cancer diagnoses, it does cost lives," he said.
"Some cancers absolutely have to be diagnosed and extremely quickly.
"On average, if you delayed cancer diagnoses by several months, then absolutely you would lose hundreds of lives in New Zealand if we had a blow out and didn't catch up."
There needed to be a concerted and coordinated effort to catch up, rather than a slow processing of the deferred cases over the coming year, Jackson said.
The government has made money available for the Covid catch-up, but it was not clear how it would be spent, he said.
"You have to have the capacity created across the entire spectrum - so primary care as well as all your diagnostic and therapeutic areas," he said.
Use of the private sector services would be needed, as well as an increase in public services, Jackson said.
"We do have to look at using all the capacity which is around the regions.
"There are regions where capacity is not stretched and others where it is so we have to make sure... that people can cross DHB boundaries if need be."