Certainly, all Jamaicans remember this very sad and distressing newspaper headline from late last year, ‘Jamaican songbird Karen Smith has died, ending her one-year battle with colon cancer’. Colorectal cancer respects nobody; it can affect any of us and it can be very devastating. Well-known international celebrities have been its victim. Celebrities like Sharon Osbourne and Katie Couric survived colon cancer. Couric encouraged others to get screened by televising her colonoscopy live on TV in 2001.

Globally, colorectal cancer is the third most diagnosed cancer and the second most deadly cancer. It is the third-leading cause of cancer-related deaths in Jamaica. In 2018, the Jamaica Cancer Society (JCS) revealed that 642 new cases were recorded, and 373 persons died from the disease. The important thing to remember is that colorectal cancer is usually preventable with proper screening.

The current recommendation is that we get colorectal screening from 45 to 75 years old, unless there are mitigating circumstances. Screening should begin 10 years earlier in people who have a first-degree relative afflicted with colorectal cancer at a relatively young age – like at 50 years old. Early and frequent screening should be done in people with a previous history of inflammatory bowel conditions (like Ulcerative Colitis and Crohn’s disease), and in people with a genetic predisposition to colorectal cancer. Frequent screening should be done in people with a previous colorectal polyp.

IDEAL SCREENING TEST

The ideal screening test should be safe, readily available, affordable, convenient, highly sensitive (able to find what you are looking for), highly specific (be accurate that what is found is precisely what it is and nothing else), and as non-invasive as possible. The screening method used depends on all of the above criteria, in addition to the patient’s existing physical condition and economic fortitude. Screening methods range from various kinds of stool testing to virtual (3D) multi-detector, low-dose computerised tomography, sigmoidoscopy and colonoscopy. The latter three are classified as ‘direct visualisation techniques’.

A relevant family history is important, and here is where problems tend to occur. This is sad on many levels because the absence of a father negatively impacts children socio-economically, psychologically and medically – since many people either do not know their father, know who their father is but know nothing about him, or have the wrong paternity assignment. Therefore, half of their essential family history is a mystery.

The simplest, easiest and cheapest screening method for people with limited funds, no (known) family history of colorectal cancer, and no genetic evidence of a propensity to having colorectal cancer is the guaiac faecal occult blood test (gFOBT, or simply FOBT). It checks for hidden blood in the stool. Dietary and medicinal restrictions apply. Three samples are collected over a period of days. The test is done annually and reduces 13-year mortality by 33 per cent. It detects (hidden) blood, so non-bleeding lesions will not be detected and blood from anywhere in the gastro-intestinal tract will be detected. There could be false positives. If positive, a colonoscopy needs to be done.

The faecal immunochemical test (FIT) specifically detects the antibody to human globin, and is therefore specific for colonic blood. No dietary or medicinal restrictions are needed and only one stool sample is necessary. It can detect advanced adenomas and cancer, and is 79 per cent sensitive in doing so. If positive, follow-up scoping is necessary. This is not readily available and costs a lot more than the FOBT.

The stool DNA test (cologuard) detects altered DNA from exfoliated cells in the stool. It is 92 per cent sensitive at detecting cancers and 42 per cent at detecting advanced adenomas. This test is expensive and not available in Jamaica.

DIRECT VISUALISATION TECHNIQUES

The direct visualisation techniques include the low-dose, 3D MDCT virtual colonoscopy. It requires good bowel prep (a ‘washout’), is non-invasive, needs no sedation, uses an intravenous contrast, gently inflates the bowel with air, can observe the outer surface of the colon, and is very efficient. However, any lesion seen will require a colonoscopy for excision biopsy or sampling. The price can be challenging for some.

Sigmoidoscopy screening – using a flexible sigmoidoscope that can look up the left side of the colon, where most colorectal cancers occur – is utilised in people with a previous partial colon resection, people with unusual angles that are difficult to negotiate with colonoscopy, people who did a virtual colonoscopy and a lesion was seen within reach of the sigmoidoscope or in combination with FOBT in certain instances. It requires minimal bowel prep, some bowel inflation, but no sedation.

Colonoscopy is the gold standard. It requires good bowel prep, sedation, inflation, and visualises the entire colon. Biopsies, excisions and sometimes curative treatment can be done via this route. This screening method reduces overall colorectal cancer mortality by 68 per cent, and colorectal cancer mortality from cancers near the beginning of the colon by 53 per cent. However, the cost can be challenging.

When I began colon screening, I was 50 years old. A small polyp was seen and removed – it was not malignant. However, because of this, I do repeat colonoscopies every five years (most require screening every seven–10 years). I felt prompted to pen this piece after reading, ‘Do not delay: Get screened for colorectal cancer’, published in The Gleaner on March 2, 2022, and after attending an online colon cancer symposium hosted by the JCS.

Garth A. Rattray is a medical doctor with a family practice. Email feedback to columns@gleanerjm.com and garthrattray@gmail.com.