New research led by the University of South Australia shows just how effective bowel cancer screening is in helping to reduce the number of bowel cancer deaths by up to 45 percent.

Bowel (or colorectal) cancer kills almost 6000 people in Australia each year and 700,000 worldwide but this number would be much higher without pre-diagnostic colonoscopies, a study published in the journal BMC Cancer has found.

Data from 12,906 bowel cancer patients indicate that faecal occult blood testing (FOBT) with a follow-up colonoscopy plays a key role in catching the disease early, before symptoms appear.

Researchers from UniSA's Cancer Epidemiology and Population Health found that having one pre-diagnostic colonoscopy was associated with a 17 percent reduction in cancer deaths; a 27 percent reduction with two pre-diagnostic colonoscopy procedures and 45 percent for three or more.

Of the 12,906 records analysed, 37 percent of the patients had pre-diagnostic colonoscopies and were more likely to live longer than those who were diagnosed after experiencing cancer symptoms.

Dr Ming Li, one of the study leaders, says that in South Australia, where the study was undertaken, those patients who had pre-diagnostic colonoscopies showed a "significant increase" in survival.

"The risk of colorectal cancer death reduces step-wise with increasing numbers of colonoscopy examinations before symptoms appear, cutting the mortality rate from 17 percent to 45 percent," Dr Li said. "Our findings show the value of the National Bowel Screening Program which is now being rolled out to everyone in Australia over the age of 50 on a two-yearly basis. It involves doing a simple, non-invasive faecal occult blood test (FOBT) which, if positive, is followed up with a colonoscopy."

Bowel cancer causes the second highest number of cancer deaths in Australia after lung cancer, and is the third most common cancer worldwide, but 90 percent can be cured if detected early, according to the Cancer Council.

Currently, just 39 percent of the eligible population in Australia undertake a FOBT if invited, which is predicted to prevent 92,000 cancer cases in the next 20 years.

If the participation rate were to increase to 60 percent, an additional 24,300 bowel cancer deaths would be prevented, the Cancer Council estimates.

Source: University of South Australia