Rectal Cancer: Symptoms, Treatment and Surgery

What is rectum and rectal Cancer?

The last part of the digestive system is the rectum. Because of the similarities between rectal and colon cancer, the two are referred to as colorectal cancer. But there are differences. The rectum rests against the side wall and adjacent organs in a small cavity called the pelvis. The tumour could also be near the anal sphincter (the muscle ring responsible for holding the stools).

Four layers of tissue comprise the rectal wall. The innermost layer of cells that produce mucus is where rectal cancer initially appears. Most begin as polyps, which are little lumps of flesh. Some of these polyps eventually transform into cancer, which spreads and grows.

What are the signs and symptoms of rectal cancer?

• Change in bowel habits; persistent diarrhoea or constipation
• Feeling of incomplete evacuation
• Patches of dark blood in stool
• Narrow stools or mucus in stool
• Painful bowel movements
• Unexplained fatigue and loss of appetite
• Unintentional weight loss
• Fall in haemoglobin (anemia)
• Pain or discomfort in abdomen

What are risk factors of rectal cancer?

• Genetic
  • Hereditary nonpolyposis colorectal cancer (HNPCC), also called Lynch syndrome
  • Familial adenomatous polyposis (FAP)
• Western diet (high fat and low fibre diet)
• Older age
• History of colorectal polyps
• Family history of colorectal cancer
• Inflammatory conditions such as ulcerative colitis and Crohn's disease
• Diabetes and obesity
• Smoking and alcoholism

How is rectal cancer diagnosed and staged?

Colonoscopy diagnoses rectal cancer. A thin, flexible camera is used to view the rectum from the inside. Biopsy and microscopic examination confirms the diagnosis.

Blood is also tested for CEA (carcinoembryonic antigen), which is produced by most rectal cancers.

Positron emission tomography (PET) or computed tomography (CT) scans are used for staging. For precise local staging, an MRI scan of pelvis is done.

What is TNM staging for rectal cancer

TNM (tumour, node and metastasis) classification developed by the American Joint Committee on Cancer (AJCC) is used for exact classification of stage and it spans from I to IV.

• The extent (size) of the tumour (T): How far has the cancer grown into the layers of the rectal wall? Has the cancer reached nearby structures or organs?
• The spread to nearby lymph nodes (N): Has cancer spread to nearby lymph nodes? And to how many?
• The spread (metastasis) to distant sites (M): Has cancer spread to distant lymph nodes or distant organs such as the peritoneum or lungs?

How is rectal cancer treated?

An appropriate treatment is determined by the stage and location of the tumour in the rectum. The mainstay of treatment for people with localised cancer is surgery. Surgical resection of early tumours is done upfront.

Radiotherapy is the use of powerful X-ray beams to destroy cancer cells, and chemotherapy is the use of specific medications to do the same.

For advanced tumours, radiation and chemotherapy are used prior to surgery to provide the best results.

For metastatic rectal cancers chemotherapy and targeted therapy is used.

Rectal cancer surgery

• Transanal excision, transanal endoscopic microscopic surgery (TEM) and transanal minimally invasive surgery (TAMIS)
• Anterior resection and low anterior resection
• Ultra-low anterior resection, proctectomy with colo-anal anastomosis, intersphincteric resection
• Abdominoperineal resection (APR)
• Pelvic exenteration
• Total colectomy (proctocolectomy)

Laparoscopic Surgery - What is it?

In laparoscopic surgery, we make a few small holes over the abdomen. The surgeon operates using long and thin instruments and a slender high-resolution camera that projects a magnified view of the inside of the abdomen onto a high definition monitor.

Minimally invasive surgery is beneficial for the patient in several ways. Post-operative stress and pain are markedly reduced, leading to a faster recovery and shortened hospital/ICU stay. The amount of blood loss in the process of surgery has decreased. There is a quicker return of intestinal movement. The overall complication rate is decreased. All this results in an earlier return to home and work.

Who should be screened for Rectal Cancer?

• If your age is over 45 years.
• If you have a family history of colorectal cancer or polyps
• If you have a personal history of colorectal cancer or polyps
• If you are suffering from long-standing inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
• If you have a family history of a hereditary colorectal cancer syndrome such as familial adenomatous polyposis (FAP) or Lynch syndrome (also known as hereditary non-polyposis colon cancer or HNPCC)
• If you have a history of radiation to the abdomen (belly) or pelvic area to treat a prior cancer

Wish you a speedy recovery!