- Singapore Cancer Registry Annual Report 2019.
- Bretthauer et al. NordICC Study Group. Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death. N Engl J Med. 2022 Oct 9. doi: 10.1056/NEJMoa2208375.
- https://www.straitstimes.com/world/united-states/screening-procedure-fails-to-prevent-colon-cancer-deaths-in-large-us-study. Accessed 11/2/2023.
- Dominitz JA, Robertson DJ. Understanding the results of a randomized trial of screening colonoscopy. N Engl J Med. 2022 Oct 9. doi: 10.1056/NEJMe2211595
In Singapore, our healthcare systems are recognised to be some of the best in the world. We have some of the most highly trained doctors, nurses and allied health staff. We have top notch state of the art facilities with new hospitals and polyclinics being developed at a rapid pace with majority of the population having easy geographical access, and a robust academic research culture in clinical, translational and basic science to ensure we are up to date with the latest developments. Our policy makers also review trends and identify gaps in care, and shore up areas that potentially create strain in the future in both manpower and healthcare budget of the country.
Our statistics with regards to Colorectal Cancer (CRC) however remain dismal. Singapore Cancer Registry's latest report of 2019 statistics show that the majority of CRCs are still diagnosed at advanced stage III and IV (male 57.8%, female 57.3%). It is stated in the report that since its collection of Stage information in 2003, males with other cancers such as prostate, liver and pancreatic have registered the largest shift towards an early-stage diagnosis. Females with lung and stomach cancers have also noted an earlier stage of diagnosis, but there just has been no improvement in CRC although there was some improvement in better overall survival at 61%.
This is in sharp contrast to data from South Korea, where three in four CRCs (78.4%) are picked up in earlier stages (stage I and II). The population also enjoys one of the best 5-year survival rates in the world and have seen tremendous improvements from 56.2% (1993-1995) to 74.3% (2015-2019). Robust cancer screening programmes in South Korea have allowed early detection of polyps with CRC now falling from the second most common cancer in 2003-2007, to fourth in 2008. CRC in Singapore however continues to be the top ranked cancer.
The relevance of colorectal cancer (CRC) screening was called into question last year when a large study questioned the relevance of colonoscopy screening as it failed to prevent colon cancer deaths in a 10-year study. This study sparked off vigorous debate and many medical professionals including those in Singapore quickly debunked the conclusions of the study. Unfortunately, as the replies were not covered in the mainstream media, many in the public remained confused as to the rationale to continue screening.
This is a quick summary of the study:
The Nord-European Initiative on Colorectal Cancer (NordICC) trial findings was released in the New England Journal of Medicine on October 10th 2022. This is a landmark randomised control trial involving almost 85000 participants from Poland, Sweden, Netherlands and Norway. Study participants were randomised to undergo screening colonoscopy or not. The study looked at outcomes after 10 years and noted of those who were invited for screening, only 42% proceeded with the colonoscopy. The overall risk of death from any cause was similar in both groups after a 10 year follow up.
Large media networks reported these outcomes. These include "New study questions effectiveness of colonoscopy" by CNN, and "Screening procedure fails to prevent colon cancer death in study" by Bloomberg. Locally, the Straits times also reported this on October 10th 2022 'Screening procedure fails to prevent colon cancer deaths in large US study'.
These news headlines created an uproar with many pointing out that the headlines were misleading as it was not appropriate to focus on the comparisons on overall death rates due to the flaws in the study. When the study was looked at in detail, for those who underwent screening colonoscopy, there was in fact significant CRC risk reduction of 31%. The risk of death from CRC was in fact reduced by about 50%. The conclusions that made by the media unfortunately did not state many of these important facts and the rebuttals made by doctors around the world were also not reported.
Colonoscopy screening must continue to be encouraged
Colonoscopy still and will remain as the gold standard for early polyp detection and colorectal cancer prevention. It is necessary, although the process may be tedious. Bowel preparation which happens the day before, often requires the patient to go to the toilet many times to empty their bowels. This is crucial however as a clean colon is essential for the endoscopist to pick up small polyps and remove them safely.
The procedure is usually completed quickly in less than 20-30 minutes on average, under monitored sedation. Post procedure the patient is monitored for a few hours to ensure the sedation has worn off and the patient can be safely discharged. A hospitalisation medical certificate is issued, and the patient is encouraged to rest for the day. Post procedure advice usually entails to eat light for a day as one may feel mildly bloated due to the air insufflation used during the colonoscopy. The procedure is very safe and risks are minimal with the incidence of bleeding (<0.1%) or bowel injury/perforation (<0.1) in Singapore is very, very low. All patients will have had a thorough discussion with their doctor prior to the procedure in clinic and a risk evaluation is done with the patient and their caregiver to ensure the best outcomes. A colonoscopy is considered a hospitalisation procedure so insurance claims are allowed. The colonoscopy fees are also within Ministry of Health (MOH) fee benchmark guidelines and all endoscopists follow these strictly.
There has been continued progression and development in many areas. Firstly, colonoscopy has embraced the use of Artificial Intelligence (AI) and many hospitals have embarked on the utility with higher polyp detection rate. Scopes also utilise narrow band imaging and these technology advancements help procedurists spot difficult to view polyps better.
A strong national effort in structuring training in all public hospitals over the last decade has ensured uniform standards in both surgeons and gastroenterologists. The public has access to skilled endoscopists both in public and private sector island wide.
Insurers also may provide free colonoscopy screening in certain packages and this is laudable as they recognise that there are tremendous cost savings in colorectal cancer prevention.
Public forums and talks led by doctors, societies, insurers and grassroots also continue to provide constant reminders to go for cancer screening early and these will continue to be an important facet of the fight against cancer. As our nation moves to a "Healthier SG" campaign with an emphasis on prevention, we look forward to a more coordinated effort in encouraging the nation in this important area.
CRC screening is still relevant and highly necessary and there remains an urgent and coordinated need to reduce colorectal cancer incidence and mortality. In Singapore, there remains a high prevalence of advanced cancers diagnosed and patients should continue to be encouraged to undergo colonoscopy routinely.
This article was contributed by Dr Chew Min Hoe, AIA Preferred Provider, and Director of The Surgeons Pte Ltd. To request an appointment with Dr Chew Min Hoe, please click here.