The number of people diagnosed with cancer in Queensland has more than tripled in 30 years, but the number of people surviving has risen, statistics show.

Data from the Queensland Cancer Registry showed 25,614 cases of cancer were diagnosed in 2012, compared with 8,250 cases in 1982.

Cancer Council Queensland spokeswoman Katie Clift said the figure was the result of an ageing and increasing population but also better screening options and changing risk factors, like obesity.

"People may not draw the link as naturally but if you eat an unhealthy diet, you don't move enough, it increases your risk of being overweight or obese and that increases your risk of a range of chronic diseases," Ms Clift said.

"We know across the board about a third of all cancer cases are preventable ... that's down to things like eating, a healthy lifestyle, getting enough exercise, making sure you're the right weight.

"Really simple things we can keep under control."

Prostate cancer 'most commonly diagnosed'

The figures, released by the Cancer Council's research centre, showed prostate cancer was the most commonly diagnosed cancer in 2012, accounting for 16 per cent of all cases.

But 92 per cent of all men diagnosed survived for more than five years.

Melanoma was the second-most commonly diagnosed cancer, followed by breast cancer, colorectal and lung cancer.

In men, prostate cancer was the leading cancer diagnosed, while for women it was breast cancer.

In Queenslanders aged under 35, melanoma was the main disease.

Lung cancer was the leading cause of cancer death, followed by colorectal.

The figures showed 85,140 Queenslanders who had been diagnosed with cancer in the previous five years were still alive in 2012.

Ms Clift said more people were surviving cancer but that created new challenges in helping to get survivors' lives back to normal and meeting their physical and emotional needs.

"We know one of the greatest distress or fears that people have after being diagnosed with cancer is the fear of that cancer recurring," she said.

"That's one of the top emotional concerns that people have and for a lot of people that won't go away.

"Some people are very resilient, very positive but definitely for a lot of people it will stay with them for the rest of their lives."

Support for people with toddlers who have cancer

Ami Reynolds, 28, was diagnosed with bowel cancer two-and-a-half-years ago, six months after the birth of her son Rupert.

Ms Reynolds said she had had stomach cramps but dismissed them until she, her husband and son suffered a bad bout of gastro.

They recovered but she did not, with testing showing she had cancer.

Ami Reynolds, 28, has started a support group for people diagnosed with cancer who have toddlers. ( ABC News )

"I remember at the time it was quite a numb feeling, I didn't really know what to think," she said.

"It was very, very hard at the beginning as when I first had surgery I wasn't able to lift [Rupert], so it was very, very difficult.

"He couldn't even crawl and my husband had taken all his leave from work, so he had to go to work.

"Luckily we did manage to get some help that was funded from the government to come in and help care for my little boy through the day."

Ms Reynolds, who is from the UK, started a support group for people diagnosed with cancer who have toddlers.

"I often ask myself what defines who survives and who doesn't and whose case is worse than whose, and yes, [I] feel very lucky," she said.