This monitoring report describes the performance of the National Bowel Cancer Screening Program (NBCSP) for people invited to participate in the program in the period 1 January 2008 to 31 December 2008. Individual progression of participants through the screening pathway is analysed up to 31 January 2009. Data were provided by the NBCSP Register maintained by Medicare Australia, and are presented as measures of program activity, performance and outcome.
Phase 1 of the NBCSP was implemented in August 2006 by the Australian Government, in partnership with state and territory governments. Phase 2, which was introduced mid-2008, continued the phase 1 target ages of 55 and 65 years, and added people aged 50. Therefore, this report on participants invited in 2008 includes data from both phases of the NBCSP.
Of the participants screened by the NBCSP in this period, less than 1% were found to have bowel cancer; however, this represents a partial picture of outcomes due to incomplete reporting.
Of the 685,915 people invited into the NBCSP in 2008, an estimated 39.3% agreed to participate. This proportion was lower than previous years, mainly due to the later inclusion of invitees aged 50 years—many of whom may not have had time to complete and return the kit. Participation of those aged 55 (39.3%) and 65 years (48.1%) was similar to previous years.
Faecal occult blood test outcomes
The proportion of positive screening test results for the 248,475 participants who correctly completed a faecal occult blood test (FOBT) was 6.6%. This was statistically significantly lower than in 2007, mainly due to the inclusion of invitees aged 50 years from 1 July 2008 who generally had lower positivity rates than the older target ages.
Male (7.7%) participants had a higher FOBT positivity rate than females (5.7%), which correlated with known bowel cancer incidence patterns between the sexes. FOBT positivity rates increased with increasing disadvantage, from 5.5% for participants with the highest socioeconomic status to 7.8% for those with the lowest socioeconomic status.
Follow-up of positive faecal occult blood test results
Of the 16,436 people who returned a positive FOBT, 42.9% had a primary health care practitioner visit recorded, and 64.5% had been recorded as undergoing a colonoscopy to investigate the positive FOBT result.
Of the participants who visited the primary health care practitioner after their positive FOBT result, 83.7% reported having experienced no symptoms beforehand.
Of the 7,042 people who returned a positive FOBT and had valid follow-up data, 63 confirmed and 239 suspected cancers were found. Pre-cancerous adenomas were found in a further 979 participants. The 239 suspected cancers, plus 2,467 polyp specimens, were awaiting a final histopathology diagnosis. Outcomes for a further 9,394 participants with a positive FOBT result were unknown as follow-up data was not available.