Lung cancer rates in women are on the increase, except in the highest socio-economic areas.

The gap in lung cancer rates among the poorest and richest women has not changed in nearly 30 years and is actually widening despite the many tobacco control interventions implemented in Australia.

New research by Cancer Council NSW has found that overall lung cancer incidence among women aged 25-69 living in the state increased between 1985 and 2009 except for those living in the highest socio-economic areas.

Over this period, 9840 women were diagnosed with primary lung cancer in NSW, with the overall rates increasing from 19.8 cases per 100,000 women in 1985 to 25.7 om 100,000 in 2009.

However, the trend was not the same across all socio-economic areas.

After 1995, the rate of women diagnosed with the number one cancer killer started to decrease in more advantaged areas.

Honorary Professor Dianne O'Connell, Senior Researcher at the Cancer Council says this concerning trend is likely to be mirrored nationally.

"We know because NSW has a third of the population of Australia that the patterns and the rates of cancer that we observe in NSW very much mirror those that we see nationally," she said.

Professor O'Connell says there are a number of factors to blame for the the increasing gap in lung cancer incidence among women but is largely due to differences in the smoking rates.

"We think that people in the higher socio-economic areas may have been more responsive to the anti-smoking public health messages, they're more likely to have access to effective resources for quitting smoking.

"Also, they may be much more restricted particularly in their work environments where smoking is banned in offices compared to people in the lower socio-economic areas who may be doing more outdoor work and are able to continue smoking," Prof O'Connell told AAP.

Tobacco smoking kills around 15,000 Australians every year.

Smoking just 10 cigarettes per day doubles your risk of dying and smoking more than 25 cigarettes a day increases your risk of dying four-fold compared to those who have never smoked.

Since the 1970s, there has been a significant decline in smoking rates as a result of interventions, including taxation, smoking bans and plain packaging of cigarettes.

But their true impact on lung cancer won't be known for many years and it's critical that complacency doesn't set in, warns Prof O'Connell.

"The lung cancer rates now are still reflecting the smoking pattern of 20 to 30 years ago, so we can't become complacent we just need to keep moving those smoking rates down," she said.

"It really is important that we identify those groups where the interventions haven't been as successful and really start to target them and give them methods that they can actually use to reduce their smoking."