Advocates for lung cancer patients say the country's deadliest cancer is being ignored by health authorities.

They're pointing to a stark gap between treatment options in New Zealand and Australia.

Lung Foundation chief executive Philip Hope says figures show New Zealand hasn't been keeping up with new treatments and the approval process is moving too slowly.

He says despite the high mortality rate, lung cancer only receives about $2.7 million of Pharmac's nearly $1 billion dollar budget.

He told Mike Hosking this disparity is causing more harm to New Zealand patients.

"The underspend, the underinvestment in treatment, actually is causing inequity, and in actual fact it is causing mental health issues as well."

Although 900,000 New Zealanders have smoked in their lifetime, Hope says the Government is not doing enough.

"Our government and our health system does not educate patients about symptoms about lung disease and about lung cancer."

Hope says this lack of education means that many people are diagnosed late, and 80 percent of patients are diagnosed with stage 4 cancer.

However, the Government's drug-buying agency says more options don't necessarily mean better results.

Pharmac told the New Zealand Herald that: "a simple count of funded medicines won't show you how successful a health system is. It's not about how many you have, but having access to the ones that work.

"Some of the cancer medicines that Australia funds that we don't, do not provide meaningful gains in health," Pharmac director of operations Lisa Williams said.