Research involving almost 200,000 people from NSW found that those who were screened for bowel or colorectal cancer were 44 per cent less likely to develop the disease in the following four years compared to those who had not been tested.

And the reduced risk could have gone on for even longer, the report's co-author Professor Emily Banks from the National Centre for Epidemiology and Population Health at the Australian National University said.

"We already know from international evidence that colorectal screening saves lives, we know it's effective in reducing death rates and we also know that people who have colorectal cancer diagnosed at screening are likely to have an earlier stage disease," she said.

"This is really another piece in the puzzle that says not only will we be saving lives by detecting colorectal cancer early there's also potential to pick up pre-cancerous lesions… and you'll also have reassurance that on average there's around a halving in the risk of colorectal cancer after being given the all clear at screening."

Professor Banks said Australia had one of the highest rates of bowel cancer in the world, with the disease killing around 80 people each week.

She said the research reinforced the federal government's plan to accelerate the National Bowel Cancer Screening Program, offering free screening every two years to Australians aged between 50 and 74 by 2020.

"If we were to be able to implement full scale population screening for bowel cancer we could save up to 500 lives a year," she said.

"If you receive a kit in the mail and you're invited to join the program it's really worth seriously considering because of the benefits."

Professor Banks said in the past people found it embarrassing or difficult to talk about bowel cancer and testing, but people were getting used to the idea.

"Nearly half of the people in the study had been screened … it is something that is now commonplace," she said.

"A while ago people would have thought something like a pap smear was something they'd rather not have, but over time people have understood it's actually really important and the discomfort and embarrassment is outweighed by the long term benefits."

The research, published in the Medical Journal of Australia on Monday, was based on data from the Sax Institute's 45 and Up study accounting for about 10 per cent of the NSW population aged 45 and over.

Professor Banks said the researchers were unable to get funding to include Canberrans in the study.

"We're really only able to do this type of research because people have filled in the questionnaires and given us permission to follow their health over time," she said.

"It's a really important service these people are doing for the community."