Colorectal Cancer

Colorectal cancer screening in South Africa

October 1, 2021 Word for Word Media 0Comment

Dr Leanne Prodehl expands on the various colorectal cancer screening tests available in South Africa.

Who gets colorectal cancer?

Colorectal cancer (CRC) is the third most common cancer and the second highest cause of cancer deaths globally.¹ The mortality remains high with 20-25% of patients having metastatic disease at presentation.² CRC incidence is associated with countries with higher socio-economic status, linked to changes in diet, lifestyle, and obesity.3 The majority of people diagnosed with CRC are > 50 years4 but patients are presenting at younger ages.⁵

Colorectal cancer in South Africa

In South Africa, CRC is the fourth most common cancer for women, the sixth for men and the sixth highest cause of deaths.⁶ The CRC in South Africa study showed an average age at diagnosis of 56 years with 27% of cancers in patients under 50 years old.  

What is screening?

Screening tests try to find a cancer in asymptomatic people, aiming to reduce the number of people who develop cancer and who die from cancer.⁷ In CRC, another aim is to detect precancerous lesions (polyps), as removal can prevent cancer developing.⁸ 

Screening is opportunistic or programmatic; opportunistic is where patients are noted to meet the criteria for screening which is then offered. Programmatic screening occurs in the UK and Europe where there is national screening for CRC.  

How do you screen?

There are a number of ways of screening varying in invasiveness and accuracy. 

Colonoscopy is a camera passed from the anus through the colon to the small bowel under sedation, usually as a day procedure. Colonoscopy detects and removes pre-cancerous lesions in the colon. It requires bowel preparation, time off work and is reserved for people at high-risk of colorectal cancer.

The faecal immunochemical test (FIT) stool test looks for markers of blood. This is non-invasive and relatively inexpensive but needs to be repeated regularly. It’s mainly used in low prevalence populations and programmatic screening.

Other tests include:

  • CT colonography – a CT scan looking at the inside of the bowel.
  • FIT Faecal DNA test – another stool test that detects markers of abnormal DNA.
  • Flexible sigmoidoscopy – a camera test looking at the rectum and the left side of the colon. It requires less bowel preparation but can’t examine the right colon.
  • Capsule colonoscopy and Septin⁹ biomarker assay are expensive with limited evidence.⁹

Colonoscopy and FIT are the two most commonly used screening tests. Only colonoscopy can sample or remove polyps.

Who should be screened?

There are a number of screening recommendations around the world. The American guidelines recommend that people at average risk be screened from age 50. If a colonoscopy is done and is normal, the next is done in 10 years’ time. The recommendation for African-Americans is to screen from age 45 as they tend to present at a younger age.⁹ In the UK, the FIT stool test is recommended yearly for people from the age of 56 to 75.10 Most programmes stop screening at age 75-80.

People at high risk are those with a family history and should be screened 10 years before the age at which the youngest family member was diagnosed, or from age 40. This is anyone with a first-degree relative with CRC below the age of 60 or more than two relatives with CRC.

Impact of COVID

Most healthcare systems delayed all non-urgent procedures at the start of the pandemic. Since then screening and management of cancers and chronic diseases are being re-evaluated as they are still responsible for most deaths.

Healthcare workers are concerned about the drop in numbers of people screened11 and are looking at alternatives to colonoscopy, such as the FIT test, which can be done at home.12 

It’s important to remember that a normal screening colonoscopy can decrease a person’s chances of getting CRC by 46% and of dying from CRC by 88%.


  1. Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68(6):394–424.
  2. Brand M, Gaylard P, Ramos J. Colorectal cancer in South Africa: An assessment of disease presentation, treatment pathways and 5-year survival. S Afr Med J. 2018 Feb 1;108(2):118–22.
  3. Goodarzi E, Beiranvand R, Naemi H, Momenabadi V, Khazaei Z. Worldwide incidence and mortality of colorectal cancer and Human Development Index (HDI): an ecological study. :8.
  4. Siegel RL, Miller KD, Sauer AG, Fedewa SA, Butterly LF, Anderson JC, et al. Colorectal cancer statistics, 2020. CA Cancer J Clin. 2020;70(3):145–64.
  5. Vuik FE, Nieuwenburg SA, Bardou M, Lansdorp-Vogelaar I, Dinis-Ribeiro M, Bento MJ, et al. Increasing incidence of colorectal cancer in young adults in Europe over the last 25 years. Gut. 2019 Oct 1;68(10):1820–6.
  6. 2014-NCR-tables-1.pdf [Internet]. [cited 2021 Aug 27]. Available from:
  7. Cancer Screening [Internet]. Cancer.Net. 2012 [cited 2021 Aug 30]. Available from:
  8. Zauber AG, Winawer SJ, O’Brien MJ, Lansdorp-Vogelaar I, van Ballegooijen M, Hankey BF, et al. Colonoscopic Polypectomy and Long-Term Prevention of Colorectal-Cancer Deaths. N Engl J Med. 2012 Feb 23;366(8):687–96.
  9. Rex DK, Boland CR, Dominitz JA, Giardiello FM, Johnson DA, Kaltenbach T, et al. Colorectal cancer screening: Recommendations for physicians and patients from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2017 Jul;86(1):18–33.
  10. Bowel cancer screening [Internet]. 2017 [cited 2021 Aug 30]. Available from:
  11. Laghi L, Cameletti M, Ferrari C, Ricciardiello L. Impairment of colorectal cancer screening during the COVID-19 pandemic. Lancet Gastroenterol Hepatol. 2021 Jun;6(6):425–6.
  12. Issaka RB, Somsouk M. Colorectal Cancer Screening and Prevention in the COVID-19 Era. JAMA Health Forum. 2020 May 13;1(5):e200588–e200588.
Dr Leanne Prodehl

MEET THE EXPERT – Dr Leanne Prodehl

Dr Leanne Prodehl is a surgical gastroenterologist with an interest in hepatopancreaticobiliary and upper gastrointestinal surgery and oncology. She was the site coordinator at Charlotte Maxeke Johannesburg Academic Hospital for the Colorectal Cancer in SA study, funded by the South African MRC. Enrolment in the new Wits/MRC study into oesophageal and colorectal cancer is about to start and is hoped to improve the understanding of cancer in SA.

This article is brought to you in the interests of medical education. The views expressed in this article or newsletter may not necessarily reflect those of Amgen. Readers are advised to consult with their healthcare practitioners for clinical advice regarding the management of personal health matters.

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