Bowel Cancer Treatments

Dr Gaya typically does not see patients with very early cancer (where a person’s bowel cancer is confined to the inner lining of the bowel) due to the effectiveness of surgical treatments.

For patients with stage 2 (where tumour grows through the muscular layer into the fatty tissue around it, but all lymph nodes clear) or Stage 3 (where tumour involves the bowel wall and local lymph nodes), surgery is considered the best option. Surgery allows for the complete removal of the tumour and affected lymph nodes, which significantly reduces the risk of cancer spreading and increases the chances of long-term survival.

Surgery

The type of surgery a person will have depends on whereabouts in the bowel their cancer is. These are the different bowel cancer surgeries:

1. Right Hemicolectomy: for right-sided bowel cancer, which affects the caecum and ascending colon. The surgery involves removal of the right side of the colon, including the caecum and ascending colon.
2. Left Hemicolectomy: for left-sided bowel cancer, which affects the transverse and descending colon. During the procedure the left side of the colon is removed, including the transverse and descending colon.
3. Sigmoid Colectomy or Anterior Resection: is for cancer in the sigmoid colon. The surgeon removes the sigmoid colon, the last part of the large intestine before the rectum.
4. Sub-total Colectomy: in rare cases the majority of or entire colon is removed, often for patients with inflammatory bowel disease (IBD) or a high risk of developing cancer again due to genetic factors.

Will I need a colostomy bag?

Not always. The decision to use a colostomy bag is made based on the specific circumstances of each patient and the surgical approach taken by the medical team. Both colostomy and ileostomy bags serve the purpose of collecting waste from the body when the normal route through the rectum and anus is not possible. The choice between a colostomy and an ileostomy depends on the location and extent of the disease or injury in the bowel. These may be temporary (to allow the bowel to heal after surgery) or permanent (if the cancer is located in a way that makes reconnection of the bowel impossible or unsafe).

Chemotherapy

• Neoadjuvant Chemotherapy – Sometimes chemotherapy is the first treatment and is used to shrink the tumour before surgery. The specific chemotherapy regimen may vary based on the patient’s overall health and the type of bowel cancer (adenocarcinoma or other subtypes). If the surgeon is worried about being able to remove the entire cancer and resect effectively then they may wish for the patient to undergo chemotherapy  first for the best chance of removing all cancerous tissues completely (there is more about bowel cancer chemotherapy regimens is in the next section).
• Adjuvant Chemotherapy – Adjuvant chemotherapy is commonly recommended for high-risk Stage 2 and most Stage 3 bowel cancer patients. It helps to eliminate any remaining cancer cells that may not have been removed during surgery.

Radiotherapy is rarely used for people with bowel cancer. It is usually reserved just for those patients who are not suitable for surgery. It may be used in combination with chemotherapy (known as chemoradiotherapy)

These treatments, alongside surgery, are tailored to the individual patient’s risk factors and overall health to provide the best possible chance of long-term survival and to prevent the cancer from coming back.

Advanced bowel cancer (Stage 4) means that the cancer has spread to distant organs such as the liver, lungs, or other parts of the body. Treatment for advanced bowel cancer usually involves a combination of therapies to manage the disease and improve quality of life.

• Surgery: While not always an option for stage 4, surgery may be used to remove primary tumours and metastatic lesions, especially if they cause symptoms e.g. bowel obstruction
• Chemotherapy: The standard treatment for advanced bowel cancer, aimed at shrinking or slowing tumour growth and relieving symptoms. Common chemotherapy regimens include:
  • FOLFOX: A combination of Fluorouracil (5-FU), Leucovorin, and Oxaliplatin.
  • FOLFIRI: A combination of Fluorouracil (5-FU), Leucovorin, and Irinotecan.
  • CAPOX: A combination of Capecitabine and Oxaliplatin.
• Most patients with stage 4 bowel cancer will undergo chemotherapy first, with the exception of patients with a tumour that is blocking the bowel and hindering its normal function; these patients need surgery first.

The chemotherapies above are the “backbone” and often other drugs can be added to make a triplet combination. These drugs are based upon the “genetic fingerprint” of the tumour and can include bevacizumab, cetuximab and panitumumab.

• Radiotherapy for stage 4 bowel cancer is predominantly SABR for ‘metastatic deposits’ where the cancer has spread to other parts of the body. Doctors might use a type of advanced radiation therapy called SABR (Stereotactic Ablative Radiotherapy). SABR is a highly precise treatment that delivers strong doses of radiation directly to the cancer spots, while minimising damage to the surrounding healthy tissues. It’s particularly useful for targeting small, specific areas where the cancer has spread.