Colorectal Cancer: Prevention, Screening, Diagnosis, Conventional Treatment and Integrated Therapeutic Modalities

 

In Malaysia there were 48,639 cases of cancers recorded in 2020 of which breast cancer is leading with 8,418 (17.3 %), colon and rectum (CRC) at 6,597 cases (13.6 %), lung cancer with 5,139 cases (10. 6 %), nasopharyngeal cancer, 2,222 cases (4.6 %) liver cancer, 2,149 cases (4.4 %) and other cancers with 24,114 cases (49.6 %). We can clearly see colorectal cancer or CRC for short, is the second most common cancer after breast cancer in this country as shown in this 2020 epidemiological statistics. 

 Most colorectal cancers begin as a noncancerous polyp, which can be detected during a routine screening by colonoscopy. From the time the first abnormal cells start to grow into polyps, it takes about 10 - 15 years for them to develop into colorectal cancer (CRC). Adenomatous polyps have a higher chance of turning into cancer, while hyperplastic and inflammatory polyps are not precancerous ². Dysplasia is a type of precancerous condition that is usually seen in people with long-standing ulcerative colitis or Crohn's disease as these conditions cause chronic inflammation of the colon. If cancer forms in the polyp or dysplastic area, it can invade the wall of the colon or rectum locally and progress via lymphatic or hematogenous spread. Patients with oligometastatic disease, where only one or two lesions are present in an organ such as the lungs (already written on this in this blog of mine), or liver (shall write on this later), can still experience long-term disease-free survival after treatment. 

 

Incidence and Prevalence:

 

The lifetime risk for developing CRC is about 1 in 20 (5 %), and it is 60 % more common in developed countries especially among meat-eaters. For instance, the incidence of colorectal cancer is 5 times higher among the Scots than among the South Indians in India whose diet is predominantly curry where salicylates (aspirin) are present and are plant-based, especially among vegetarians and vegans. In the UK, the same observations were seen among the Pakistanis living there compared to the local British whose diet is almost absent in curries and mainly meat based.  

 

In Malaysia, the incidence of CRC is highest among the  Chinese who eat a lot of the more expensive  meat, virtually no curry, followed by the Malays with a significant amount of curries in the diet, and lowest among and Southern Indians in the  country but higher than those in south India, the reason probably is because the Indians in Malaysia especially the richer Indian families in the cities often go to Chinese restaurants to eat Chinese food? However, this needs to be investigated further. Elsewhere outside Malaysia, for example, in the United States it is the leading cause of cancer-related cause of death. The risk of CRC is lower in women than in men. Survival rates have been improving possibly due to public awareness for higher rates of screening, improvement in therapeutic regimens, and the adoption of healthier dietary lifestyles and nutritional habits.

 

Screening: 

Regular screening can detect CRC early which gives it the best chance of curable and survival. In most people, screening can prevent CRC altogether because polyps can be seen and surgically removed before they become cancerous. CRC screening includes the presence of occult blood in the stool, especially the more sensitive guaiac-based faecal occult blood test (gFOBT) and the faecal immunochemical test (FIT), both of which are used to detect blood in the stool; together with a stool DNA test to check for polyps and cancer; together with sigmoidoscopy, colonoscopy, and computed tomography (CT) colonography, which directly visualize the polyp or cancer. The frequencies of screening are as follows: gFOBT / FIT annually, stool DNA test every 3 years, sigmoidoscopy every 5 years with gFOBT / FIT every 3 years, or colonoscopy every 10 years. One in three adults aged 50 - 75 has not been screened for CRC as recommended in the United States Preventive Services Task Force, and possibly none of these are done in Malaysia or in less developed countries.

Symptoms of CRC are vague and non-specific, to include blood in the stool during defecation which is often mistaken as internal piles. Sometimes it is presented as persistent abdominal pains, unexplained weight loss which are already late into the disease. It is imperative that clinicians should encourage their patients to go for routine screening for CRC. The number needed to screen (NNS) to detect one case of colon cancer is 154 for colonoscopy, 166 for stool DNA panel, and 208 for faecal immunochemical testing. ³

 

Risk Factors:

 

Regular screening and removal of polyps with colonoscopy reduces the risk of developing CRC by at least as high as 90 -95 % People with a first degree relative who has CRC have a two to three chance of developing the disease compared with those with no family history. Approximately 20 % of all CRC patients have a close relative who was diagnosed with the disease. About 5 % of individuals with CRC have a genetic syndrome that triggers this disease. These individuals should have more screening frequencies based on their risk.⁴

 

Primary and Secondary Prevention:

 

The modifiable risk factors such as nutrition and dietary lifestyles greatly reduces the chance of individuals developing CRC even though changes of dietary lifestyle from a constant meat-eater into a vegetarian or a vegan diet is not easy to follow for most people. Clinicians and nutritionists can use motivational interviewing methods to guide people on how to achieve sustainable health practices It has been shown that up to 70 % of CRC has been prevented by nutritional and lifestyle changes. ⁵

Integrative Therapeutic Modalities:

We shall go into integrative therapy and dietary intervention later. We shall stop here for the moment as I have at least 80 % more to write here to include conventional treatment, nutritional intevention, exercise, mind-body therapy supplements with calcium citrate, retinol, vitamins D3, B6, curcumin folic acid, the use of aspirin or salicylates, accupuncture support, and other therapeutic inteventions, such as the use  of ginger root, L-glutamine 10 g three times a day during the first 7 days of chemotherapy, and acetyl-L-catnitine 1 gram tds to reduce fatgiue and neuropathy.  

As this article has still another about 80 % more to go for the above integrative therapeutic modalities in the above last paragrah, it would be very time and effort consuming to continue, unless readers request personally, and I shall write the remaining part personally only for him or for her.