Christou et al. BMC Public Health 2010, 10:373 http://www.biomedcentral.com/1471-2458/10/373 reduced access to and low quality primary care, diagnos- tic and specialist services, and a disinclination to seek advice for symptoms because of certain beliefs regarding cancer and the chance of successful treatment [4,32]. Late presentation and poor survival is also influenced by communication and cultural barriers which may impact the effectiveness and choice of treatment, as well as the decision to engage in preventive and diagnostic activities including cancer screening [19,20,33]. The presence of other chronic diseases or environmental conditions also limits provision of treatment due to the risk of compli- cations [4,21,26,34]. National cancer screening programs can partly address the survival discrepancy in Indigenous Australians by facilitating early diagnosis. If implemented in a culturally sensitive manner, cancer screening can aid in reducing mortality from the disease [26]. This has been demon- strated in the NT and WA where cervical cancer mor- tality declined substantially following the provision of a culturally appropriate holistic cancer screening services [35-37]. However, Australia’s national bowel cancer screening program in its current form has not taken such an approach, reflected in the very low uptake by the Indigenous population. 1.2 Bowel cancer screening and Australia’s National Bowel Cancer Screening Program Bowel cancer screening is an effective means of reducing the mortality and burden of CRC in the community through the early detection of abnormal changes in the bowel [38,39]. It is an ideal malignancy to target for population screening and fits the World Health Organi- sation’s criteria for suitability for population based screening [38]. Importantly, it has an identifiable early precursor lesion, usually in the form of an adenomatous polyp which in most cases is asymptomatic; it has a long latency period (for a polyp to become cancerous), thus providing an opportunity for early diagnosis; and there is a high cure rate if found with available effective treatment. Five year survival rates can be almost 90% if a tumour is detected in the earliest stages (Stage A) while still asymptomatic and localized. Once cancer has proceeded through the bowel wall, to the lymph nodes and beyond, five year survival is reduced to only 7% [38,40]. In South Australia (SA), a monitoring system showed that only 15% of bowel cancers were detected at Stage A indicating that substantial potential improve- ments in survival could be achieved with earlier diagno- sis [41]. Australia is one of a few countries implementing a formal, government funded, population-based CRC screening program - others include the UK, Canada, France, Italy and Finland [42-44]. Following a bowel cancer screening pilot program in 2002-2004 which examined the feasibility, acceptability and Page 4 of 21 cost-effectiveness of the program in the Australian community, the first phase of the National program was rolled out in 2006 and was offered to people turn- ing 55 and 65 years of age. The second phase began in July 2008 and expanded eligibility to all men and women turning 50, 55 or 65. The program targets only specific ages due to limited funding and to ensure that health services can cope with the increased service demands [9]. The target population age range was cho- sen based on the National Health and Medical Research Council guidelines which indicated the risk of developing bowel cancer increases significantly over the age of 50 years, with over 90% of those diagnosed with CRC in Australia aged over 50 [25]. Funding for the NBCSP has been secured only until 2011, allowing for once-off testing of the population - despite the fact that the mortality benefit associated with screening depends on regular participation [45]. The program is freely available to people aged 50, 55 and 65 years only and no plans have been announced for second yearly screening. If fully implemented to a broader age range and with ongoing screening rounds, the program could potentially save up to 2,000 lives per year in Australia [46]. Furthermore, sequential screening can also provide an estimation of incidence (new dis- ease) since last screen, as opposed to the initial screen- ing round which cannot differentiate between new and old cases. The Bowel Cancer Screening Implementation Com- mittee chose the faecal occult blood test (FOBT), a sim- ple non-invasive test that detects small amounts of blood in the bowel motion, as the test of choice for population screening in Australia. The presence of blood in faeces is a sign that abnormalities such as a precancerous lesion or cancer may be present in the bowel. Landmark trials have shown that regular popula- tion screening using FOBT can reduce the risk of death from CRC by up to 33% in those who (regularly) partici- pate [39,45,47]. FOBT is the only screening test for CRC where evidence from RCTs demonstrated a reduction in mortality [48], although the trials used the guaiac FOBT (gFOBT) as opposed to immunochemical FOBTs (iFOBT), the test used in Australia. One recently com- pleted RCT using the iFOBT demonstrated increased detection and compliance, although long-term mortality benefits have yet to be demonstrated [49]. The screening pathway is shown in Figure 1. Screen- ing test kits are mailed to individuals following identifi- cation of eligible program participants from enrolment in the national healthcare insurance scheme (Medicare). Kits are completed at home by taking samples of two consecutive bowel motions and mailed back to a pathol- ogy laboratory for testing without cost to the patient. Results are sent back to participants and their