Bowel cancer screening update GP education event 28 Nov 2017 Dr. Hooi Ee Gastroenterologist Sir Charles Gairdner Hospital 1

Most common cancers - Australia AIHW, Cancer in Australia: an overview, 2014

Bowel cancer - Australia Most common cancer affecting both men and women Risk: M = 1:10 F = 1:15 Second biggest cancer killer in Australia In 2016: 17,520 estimated cases 4,094 estimated deaths Incidence may increase with increased risk factors Increased obesity, unhealthy diet, low exercise Incidence set to increase Why? Living longer Ageing population Poor lifestyle choices Males have higher incidence and mortality from bowel cancer. Why? Worse diet; more alcohol; less physical activity.

Age is a major risk factor AIHW, Bowel cancer , 2016

Slow rate of development Polyps are quite common in the colon, especially as you age. There are different types of polyps – one is type is the adenoma. Adenomas can potentially change and become cancerous but as it is hard to tell the difference between these and other polyps it is important that polyps are removed Less than 5% of all adenomas turn into bowel cancer. 5 – 15 year sequence

Signs & Symptoms Early bowel cancer has no symptoms If present, can include: Rectal bleeding Symptoms of anaemia Change in bowel habit (diarrhoea more important) Abdominal pain Rectal bleeding is a common symptom in the general population and affects up to 15% of all adults Prevalence of rectal bleeding in a 6 month period ranges from 4.4% and 16% Although most cases of rectal bleeding are due to self limiting local anorectal conditions, it may also be the only sign of colorectal neoplasia

Earlier diagnosis = better prognosis

Bowel cancer screening Why screen? Early detection of bowel cancer greatly improves prognosis Better use of limited resources Repeat screening at regular intervals is necessary Screening ≠ diagnosis Assists in determining who might best benefit from the definitive (and more invasive and expensive) diagnostic procedure Short term expense for long term gain 8

What is cancer screening? Population screening is: Systematic application of a Suitable screening test to identify Individuals at risk of a condition to warrant Intervention Participants have no symptoms

Bowel cancer is ideal for screening Common serious disease No symptoms during early phases Removing precursors can prevent cancer Earlier detection improves survival Widespread screening saves lives

Updated NHMRC Guidelines 2017 (i) Consensus-based recommendations: Resources should be invested in increasing participation in the existing NBCSP target age group of 50–74 In 45–49 y.o. who request screening, GPs could offer an iFOBT every 2 years until NBCSP invitation at age 50 https://wiki.cancer.org.au/australia/Guidelines:Colorectal_cancer/Population_screening _for_colorectal_cancer https://wiki.cancer.org.au/australia/Guidelines:Colorectal_cancer/Population_screening _recommendations

Updated NHMRC Guidelines 2017 (ii) Practice points Encouragement by GPs and practice staff substantially boosts participation in screening GPs have a critical role in managing the interface between screening and personalised care: Advising on appropriateness of NBCSP participation, balancing life expectancy, comorbidities GPs should advise those at average or slightly above average risk that iFOBT is the preferred screening. GPs should discourage inappropriate use of colonoscopy

National Bowel Cancer Screening Program iFOBT kits in 2017: 50, 54, 55, 58, 60, 64, 68, 70, 72, 74 2-yearly screening for everyone aged 50-74 by 2019 Names and addresses are automatically obtained from the Medicare Registry and Department of Veterans Affairs Registry

iFOBT kit The FOBT is performed at home, placed into a reply-paid envelope and sent to a pathology laboratory for analysis Participants with a positive result will need to undergo further diagnostic tests, usually a colonoscopy

Faecal Occult Blood Test (iFOBT) Sensitivity (with disease and positive test): 83% for cancer regular testing increases sensitivity Positive predictive value 5% for cancer, 20% for advanced adenoma, 25% for precancerous growth called a non-advanced adenoma iFOBT(+) is 12 - 40 X more likely to have bowel cancer than iFOBT (-) The test itself cannot confirm cancer and further investigations must be undertaken. The iFOBT is the best performing screening tool available for population screening for bowel cancer with numerous RCT studies confirming this. The test effectively identifies those for whom colonoscopy is necessary and prevents an unnecessary invasive procedure for those with a negative result. ~52% of people with a positive FOBT will have some type of neoplastic lesion (adenoma or cancer).(2)  The remainder usually have a noncancerous condition such as haemorrhoids. So a lot of positive cases will NOT be a diagnosis of bowel cancer or adenoma. A negative result does not mean that you will not develop bowel cancer in the future. Hence the need for 2 yearly testing because your risk continues to increase with age. Appleyard, 2011

Summary of NBCSP Pathway Invitation and kit sent Participant performs test -ve result +ve result GP submits form Repeat test in 2 years Assessment colonoscopy (if needed) Participant treated (if needed) Pre-invitation letter Those who have a clear colonoscopy will return to 2-yearly FOBT screening Colonoscopy clear – test repeated in 4 yrs

NBCSP GP Assessment form

Good Economic Sense ACPS Stage Cost to treat1 1 $30,890 2 $47,354 3 $74,225 4 $61,423 Pignone et al 2011 Ananda et al 2010

Summary of NBCSP performance Cancers being detected earlier Participation rate – all Participation rate – male Participation rate – female 39% 37% 41% Positive FOBT 7% Presence of cancer 3-4% Cancers being detected earlier http://www.aihw.gov.au/cancer-data/cancer-screening/

Summary Bowel cancer is a very common cancer Mainly a disease of middle and older age Early diagnosis improves outcome Screening should be encouraged, especially NBCSP Inappropriate (low yield) colonoscopy should be avoided