Bowel cancer is a term used for cancer that begins in the large bowel or intestine depending
on its site, it may be termed either colon or rectal cancer. It’s a very common cancer.
It affects 41, 000 new patients annually. It affects both men and women equally and
the majority of sufferers are aged over 60. The underlying cause of bowel cancer itself
is unknown. However, we know that it develops from a disordered growth of cells within the
lining of the large intestine named polyps. Ten percent of these polyps will go on to
become a bowel cancer. However, polyps, if found, can also regress back to normal, healthy
bowel lining. Polyps themselves in the majority of cases
asymptomatic and are found on routine colonoscopic examination of the large intestine. During
this examination, they can also be removed and if found, patients would undergo a surveillance
program which may be a further colonoscopy after one or five years depending on the number
or size of polyps found. The symptoms of bowel cancer are often very
subtle. It is unlikely to make you feel ill. And it is also unlikely to make you lose excessive
weight which is a common occurrence in a number of cancers. Ninety percent of people will
suffer from the following symptoms. Either a change in bowel habit which may be a change
to passage of more looser stools or an erratic bowel habit. This may also be associated with
tummy pain or bloating. The second symptom is rectal bleeding. This may be either bright
red blood or darker blood. Often bright red blood is associated with a commonest form
of rectal bleeding which is either as a result of haemorrhoids or piles and is termed anorectal
bleeding. Symptoms such as constipation particularly the passage of harder stool less frequently
are unlikely to be caused by a developing bowel cancer.
Following diagnosis of a bowel cancer which is usually after colonoscopy and biopsy and
a CT scan to ensure there is no spread to other organs particularly the liver and the
lungs. The mainstay of treatment of a bowel cancer is surgical. This can be either an
open operation which is the traditional method. This is where the tumour is removed with its
lymph glands through a long incision to the middle of the abdomen.
More recently, innovations have been the keyhole laparoscopic surgery. This can be performed
for roughly 70% of tumours by a specialist surgeon. The tumour is removed in the similar
way, however, it is a minimally invasive technique through four to five 1-2cm incisions, the
tumour and lymph glands immobilised and through a small 5cm incision, the specimen is extracted.
The cosmetic result is better and the length of stay is significantly reduced as few as
four days following surgery. Once the specimen is removed, it’s analysed
and if the lymph glands are deemed to be involved, the patient may be offered chemotherapy. Chemotherapy
is a medical way to kill cancer cells and can last up to six months.
In a small proportion of patients who have rectal cancer, radiotherapy may be used. This
is a technique where radiation is used to kill cancer cells and the hope is that rectal
tumours can be reduced in size to that they can be safely removed at surgery which is
still the mainstay of treatment for rectal cancers.