What is Colon and Rectal Cancer?
Colon and rectal cancer (colorectal cancer) is a malignant lesion of the rectum and colon that affects the lower part of the bowel. The majority of colorectal cancers (though not true in all cases) generally develop over time from adenomatous (precancerous) polyps.
It is one of the most common cancers in Western societies and is the third most common cause of cancer deaths worldwide, as well as in Cyprus. While in the UK, this type of cancer is the 2nd most common, for both men and women, with a population of around 30,000 people developing the condition each year, and with a quarter of these being diagnosed when it is too late, and therefore untreatable, due to the advanced stage the condition has reached.
Sadly, although there are now several alternative treatments for colorectal cancer, this condition still causes thousands of deaths every year. This is due to its untimely detection. Treatment is most effective in the early stages, which is why it is critical that colorectal cancer is detected as soon as possible after it occurs.
For this reason, the international medical community recommends that everyone over the age of 45, regardless of gender or family history, should have a colonoscopy to check their colorectal health, whether or not there are symptoms. (If there is a family history, your specialist will advise you on how often to repeat a colonoscopy.)
In most cases, colon cancer appears as a polyp. A polyp is a mass of tissue that takes years to grow inside the bowel. Some polyps, not all of them of course, will develop into cancer if not removed in time. If a polyp is detected and removed before it becomes malignant, the risk of developing bowel cancer is eliminated. Polyps are detected and removed during colonoscopy.
Is Colon and Rectal Cancer linked to age and family history?
95% of cases of colorectal cancer occur after the age of 40 years. The majority of cases occur after the age of 60 years. It is possible for someone to develop colon and rectal cancer before the age of 40, but only if there is a genetic predisposition in their family. Therefore, an important factor when asking about the above symptoms is the “Family History”.
Heredity due to family history plays a role in the risk of developing colorectal cancer when there is one or more First Degree Relatives who have developed this condition. By SPB, we mean parents or children, only.
The potential for genetic predisposition to colorectal cancer is higher if the SPBs have developed Rectal Cancer at a relatively young age. If there are one or more SPBs who have developed cancer at less than 40 years of age, then there may be a genetic predisposition in the family to Familial Adenomatous Polyposis (FAP) or Non Polyposis Non Polyposis Colorectal Cancer (HNPCC).
We note that when these conditions are suspected, full genetic testing by qualified geneticists is indicated. Screening tests of several family members may also be indicated. It should be emphasised that both FAP and HNPCC are rare diseases and account for less than 5% of cases of colorectal cancer.
What are the symptoms of Colorectal cancer?
The symptoms of colorectal cancer are unfortunately “insidious”, and can often be mistaken for symptoms of common conditions such as gastroenteritis, irritable bowel syndrome, hemorrhoids, etc.
An experienced doctor can easily distinguish, by asking questions, whether it is cancer or one of these benign conditions. The main symptoms, which are suspicious for cancer of the colon and rectum are the following:
- Rectal bleeding
- Change in bowel habits for more than 6 weeks
- Abdominal pain
It should be stressed that all of the above symptoms can be caused by benign conditions and the presence of one or more of them does not mean that the patient has cancer.
1. Rectal Bleeding
This is a very common symptom, and in 95% of cases, it is caused by haemorrhoids or fissures in the anus, especially if the patient is younger than 40 years old.
The bleeding may appear as a light red stain on the toilet paper, usually caused by haemorrhoids. It may also appear as drops of light-coloured blood, either at the beginning or after the end of bowel movements, also usually caused by haemorrhoids.
The suspicious type of blood is that which is darker and mixed with the stools, because it may mean that it is coming from an upper part of the bowel and therefore needs to be examined.
Sometimes, the bleeding is so minimal that it becomes ‘hard to detect‘, so that the patient is unaware of its presence. The suspicion of bleeding is strengthened when iron deficiency is detected in the patient without any other obvious cause. This can be confirmed with the help of the test “Faecal Occult Bleeding Microscopic Bleeding Test (FOBT)“. The presence of unexplained iron deficiency and a positive FOB is an indication to investigate the possibility of bleeding from the bowel and stomach.
Bleeding can be caused by other causes such as polyps, diverticulosis, hemangiomas, etc.
2. Change in Bowel Habits
Every individual has a slightly different way of intestinal motility or “intestinal habits”. Intestinal habits may depend on the biology of each organism, but they also depend on nutritional factors, a person’s lifestyle and even psychological factors.
There are wide variations, apart from extreme cases or pathological syndromes, and in most cases it is not easy to identify ‘normal’ and ‘abnormal’ intestinal habits. Moreover, intestinal habits tend to be long-lasting. Of course, anyone can experience a temporary change in bowel habits due to gastroenteritis, dietary change, travel, stress, etc., however, most changes of this kind tend to recover on their own within a few weeks.
Intestinal changes that persist for more than six weeks may be an indication of an intestinal condition.
There are three types of intestinal changes that may occur:
- Constipation or decreased frequency, with or without a gagging of bowel movements
- Diarrhea or increased frequency with patterned stools
- Constipation-diarrhea alternation
Of the above, constipation is the least suspicious symptom, and does not always require immediate examination if its occurrence is reasonably explained. Before interventional tests are done, the patient may try to follow a fiber-rich diet by taking some mild laxatives.
Diarrhea, or simply increased frequency with unformed stools, is more suspicious. This symptom can be diarrhea as we know it, i.e. watery stools, or simply increased frequency of bowel movements with unformed stools. Sometimes there may also be a symptom of incomplete emptying, which forces the patient to visit the toilet repeatedly, without any particular result.
In cases of persistent diarrhoea, a number of inflammatory bowel diseases are implicated, such as colitis, diverticulosis, Crohn’s disease, colon and rectal cancer, etc. Tests are almost always necessary in case of persistent diarrhea.
Constipation-diarrhea alternation is particularly suspicious when it occurs for a long time after the age of 50. On the contrary, it is often caused by Irritable Bowel Syndrome if the patient is younger than 40 years of age. Tests are usually required.
3. Abdominal Pain
Abdominal pain, i.e. pain in the abdomen, is something we have all felt at some point in our lives. There are many types of abdominal pain caused both by an organ within the abdomen and by organs outside the abdomen, such as the chest, spine, etc. Obviously, there are many cases of abdominal pain, most of which are benign, and in order to make a diagnosis, a careful session and several examinations are very often necessary.
Abdominal pain is suspected in Colorectal Cancer only when it is accompanied by any of the other symptoms mentioned above, or in case an abdominal mass is palpated.
Unexplained iron deficiency anemia, with low blood values, needs to be checked by bowel and stomach examination to detect any blood loss from bleeding, which may possibly have been caused by cancer.