More people are discovering their lung cancer diagnosis in emergency rooms, not through their GP

An article published in the New Zealand Medical Journal has found 40 percent of lung cancer patients attend ED in the two weeks before their diagnosis.

Report author and Population Health Professor Ross Lawrenson says by the time it's being identified there it tends to more advanced and have a higher mortality rate.

He says there needs to be greater funding and access to GPs.

Lawrenson says there are a quarter of a million people who aren't registered to a GP because of shortages.