Colon cancer is a major health problem, worldwide. Studies have linked increased risk of colorectal cancer with a diet high in red meat and animal fat, low in fibre and lacking in overall intake of fruits and vegetables. Lifestyle choices such as alcohol and tobacco consumption, obesity, and lack of exercise also seem to contribute to increased risk.
Due to increased emphasis on screening, colon cancer is now often detected during screening procedures. Other common clinical presentations include iron-deficiency anaemia, rectal bleeding, change in bowel habits [particularly to loose stools] and abdominal pain. Colon cancer may present as an emergency with intestinal obstruction or perforation.
Staging is the term that doctors use to describe the extent of colon cancer and consists of two broad areas; the extent of the local [or primary] tumour and whether or not the cancer has spread to other organs.
Dukes’ stage is a helpful staging system in widespread use.
• Dukes A means the cancer is confined to the bowel wall without any spread
• Dukes B means the cancer has grown through the muscle layer of the colon but has not spread
beyond the bowel
• Dukes C means the cancer has spread to at least one lymph node in the area
• Dukes D means the cancer has spread to somewhere else in the body, like the liver or lung.
Treatment of colon cancer depends on the location and stage of the disease; very early [often screen detetected] cancer can be cured colonoscopically, otherwise the only answer is surgery.
The general principle for surgical treatment is to resect the primary tumour with the surrounding areas of lymphatic drainage.
For cancer in the right colon, a right hemicolectomy is indicated, which can be extended for tumours of the transverse colon or high left colonic tumours. For left and sigmoid colon tumours, a left hemicolectomy is appropriate. Total abdominal colectomy with ileorectal anastomosis may be required for selected patients. Laparoscopic colectomy has transformed the surgery for colonic cancer. Early results seem to favour laparoscopic surgery, which offers a reduction in size of incision, and the potential for reduced pain and earlier return to normal activity.
Chemotherapy for colon cancer can help to improve survival in some patients with the disease. It is most commonly used after surgery [adjuvant chemotherapy]. 5-Fluorouracil [5-FU] remains the main drug of choice for chemotherapy regimens for colon cancer. It is used in selected patients with higher risk tumours and is usually prescribed in combination with a vitamin called folinic acid [also called leucovorin].
Side effects of bowel cancer chemotherapy can include
• A sore mouth
• Feeling sick (nausea) and being sick
• Thinning hair
• Redness/soreness of palms and soles of the feet
• Numbness/tingling of hands and feet
• Drop in blood counts
Chemotherapy is a highly specialised area and you will be extensively counselled by your oncologist prior to starting any treatment.