Understanding Colorectal Cancer with Dr Ntomboxolo Mboyi.

Understanding Colorectal Cancer with Dr Ntomboxolo Mboyi.

Colorectal cancer starts in the colon or the rectum. These cancers can also be called colon cancer or rectal cancer, depending on where they start. Colon cancer and rectal cancer are often grouped because they have many features in common.

There are multiple cancers affecting the colon which are mostly carcinomas specifically adenocarcinoma accounting for 96%, the other rare ones are neuroendocrine, lymphomas, mesenchymal and signet ring cells.

Colorectal cancer is the third most common cancer in men and second in women and according to the Globocan database in 2020 there were 1 931 590 cases (10% incidence) with 935 173 deaths (9,4%) globally. The overall survival rate for colorectal cancer is 65% but it is also dependent on stage. For the early stage, it is 91%, regional i.e nodal spread is 72% and metastatic is 15%.

Main factors that put the colon at risk of developing cancer?

• Age > 40 years
• Male
• Black
• History of colon polyps
• Family history
• Acromegaly
• Having a renal transplant
• Obesity
• Diabetes
• Ingestion of red and processed meat
• Tobacco
• Alcohol
• Use of androgen deprivation therapy
• Previous cholecystectomy
• Endometrial cancer
• Hereditary colon syndromes
• Inflammatory bowel disease and previous radiation to the abdomen.

Generally, there are no symptoms in the early stages, but some subtle symptoms like pallor, diarrhoea, weight loss, weakness or fatigue. If you come across something suspicious, consult your doctor and get referred to a gastroenterologist.

Symptoms to look out for:

Local or early-stage symptoms:

• Change in bowel habits
• Melaena stools or rectal bleeding
• Iron deficiency
• Anemia
• Abdominal or rectal pain
• Tenesmus
• Abdominal distension and nausea

Advanced stage or metastatic symptoms:

• Lymph nodes regionally and metastatic mostly in the supraclavicular area
• Umbilical lesions and spreading to the liver, lungs, bone and brain

Preventative measures:

• Regular physical activity
• Have a diet high in fruits and vegetables and also a high fibre intake of folic acid, vitamin B6, calcium, and vitamin D
• Eating fish and garlic, avoiding aspirin and non-steroidal anti-inflammatory drugs
• Bisphosphonates
• Hormone therapy in females

Treatment plan:

• Surgery for localised disease and metastatic disease is limited
• Radiation therapy mostly for rectal cancers as neoadjuvant, adjuvant treatment and lower colon cancers can also be given as palliative therapy
• Chemotherapy as neoadjuvant and adjuvant in early disease is the definitive treatment in metastatic disease

Advanced treatment:

• Endoscopic resection
• Surgical local excision
• Targeted therapy
• Ablative therapy for liver and lung lesions
• Immunotherapy

Dr Ntomboxolo Mboyi has a BSc (UKZN), MBCHB (Medunsa), Fc Rad Onc (SA), and is a Postgraduate in Cancer Biology and Therapeutics: High Impact Cancer Research Program (Harvard Medical School). She is likewise an individual from the South African Oncology Consortium (SAOC), South African Society of Clinical and Radiation oncology (SASCRO), American Society of Clinical Oncology (ASCO), and American Brachytherapy Society (ABS) and a Chairperson of the leading body of CanSurvive (non-benefit association offering support to patients).