Health Minister Simeon Brown says more than 3300 bowel cancers have been detected through the National Bowel Screening Programme.
More than half of those newly eligible in the second group of districts had been invited since that rollout began on March 23.
So far, 1320 people have returned positive screening results under the expanded eligibility and 37 cancers have been detected.
“Every one of those 37 people would have had to wait another two years for a screening kit under the old age limit,” Brown said.
“Instead, their cancer has been found sooner, giving them the best possible chance of successful treatment.”
Budget 2026 included funding to lower the screening age again, from 58 to 56.
The Government estimates the change will make more than 200,000 additional New Zealanders eligible for free screening.
It is projected to prevent 638 cases of bowel cancer and save 522 lives over the next 25 years.
The Government ultimately intends to bring New Zealand’s eligibility in line with Australia.
In Australia, people aged 45 to 74 are eligible for screening every two years.
Those aged 45 to 49 can request their first free kit, while people aged 50 to 74 are automatically mailed one every two years.
A home test known as the FIT for symptomatic pathway rolled out nationwide in July for people experiencing possible bowel cancer symptoms.
Brown said the test was designed to help clinicians determine which patients most urgently needed colonoscopies, while freeing up specialist capacity as screening eligibility expanded.
“We are committed to lowering the bowel screening age to match Australia, and we will keep going as quickly and as safely as we can.”
New Zealand has comparatively high rates of bowel cancer internationally.
Ministry of Health advice last year described it as the country’s second-highest cause of cancer death, behind lung cancer.
Figures also show bowel cancer is now the leading cause of cancer-related death among New Zealanders under 50.