Why does visiting a doctor, especially your surgeon who oversees your diagnosis and treatment feel so overwhelming?

Colorectal Cancer poses a significant health risk today, affecting millions of people worldwide. It is understandable that going through a life-threatening disease, facing its diagnosis, and discussing treatment options can become very overwhelming for patients and their families. Medical terminologies can be complicated and confusing, and it is easy to feel lost in a sea of information. In this article, I aim to share my knowledge on various treatment options available for colorectal cancer in a clear and accessible way.

As the third most common cancer worldwide, colorectal cancer or colon cancer is a type of cancer affecting the colon (large intestine) or rectum. It is a leading cause of cancer-related deaths, second only to lung cancer. The most common risk factors include age, family history of the disease and a poor lifestyle. The common symptoms include blood in the stool, diarrhoea, constipation, abdomen pain, low iron levels and unexplained weight loss. Unfortunately, most cases with colon cancer do not show symptoms in the early stage of the disease.¹

Like other cancers, colorectal cancer is diagnosed in four stages: stage 0, stage I, stage II, stage III, and stage IV. With each stage, the cancer spreads in the body through blood, nearby tissue, or lymph system.² While late diagnosis can limit treatment options, advancements in cancer treatment offers hope for improved outcomes even in advanced stages of the cancer. 

Colorectal cancer treatment approaches

Radical surgery 

The most common and the effective treatment option for Colon Cancer is surgery. The main motive is to remove the tumour, a section of healthy tissue around it, and lymph nodes from the body, preventing the cancer from coming back or spreading any further. Surgeons need to remove a significant amount of healthy tissues around the tumour to set clear margins. Approximately, 5 cm on both sides of the tumour of the healthy colon is removed, depending on the location of the tumour. Lymphatic mapping is a technique of examining the most likely lymph nodes containing cancerous cells, which helps to determine the stage of cancer.

In some cases, obstructions (blockages) and perforations (holes in colon) due to the cancer pose higher risks and a need for emergency surgery which is performed in stages or using alternative techniques. Since in later stages of cancer, there is a high risk of the cancer spreading and affecting other organs, especially the liver. In such cases, surgeons need to remove tumours along with the organs to improve the chances of cure. With advancements in medical science, a newer alternative surgical approach with fewer incisions and faster recovery, called laparoscopic surgery is in practice.³

Radiation therapy

This is a type of therapeutic approach that is performed either before surgery (neoadjuvant) to shrink tumour, or after surgery (adjuvant) killing any remaining cancer cells. In this treatment, high energy-rays are used to destroy the tumour cells. Often combined with Chemotherapy, it is the most common type of treatment for rectal cancer treatment. There are two types of radiation therapies: Short-course and Long-course. Short-course therapy involves fewer sessions, while long-course therapy is spread out for longer sessions.

A newer type of radiation therapy, called intensity-modulated radiation therapy (IMRT) is gaining popularity due to its precision targeting of the tumour cells. With less damage to the healthy surrounding cells, IMRT has led to fewer side effects and better outcomes.

Chemotherapy 

Similar to radiation therapy, Chemotherapy can be administered as a neoadjuvant or adjuvant therapy. In this treatment, strong drugs are used to destroy tumours. Often these drugs are used in combination to increase effectiveness (efficacy). Some of the common chemotherapy drugs for colorectal cancer include 5-FU, capecitabine, oxaliplatin and irinotecan. Each drug works in different ways in targeting cancer cells. While being very effective, these drugs also cause side effects like nausea, hair loss, and fatigue. 

Chemotherapy is the most important part of colorectal cancer treatment. It can improve survival rates and reduce the risk of cancer recurrence. If you are diagnosed with colorectal cancer, your doctor will discuss it for you.

Targeted therapy

Targeted therapies are newer type of therapeutics that target a specific molecule in the tumour. These are like ‘smart bombs’ that specifically attack the cancer cells, leaving the healthy cells unharmed. These techniques are being largely explored today as they result in fewer, if not, no side effects compared to the traditional chemotherapy and radiation therapy. 

Some of the commonly used targeted therapies are listed below:

• Non-coding RNA-mediated therapy: This treatment targets the tiny molecules, called non-coding RNA (ncRNA), which plays an important role in cancer development. Ongoing research in producing synthetic ncRNAs to block the cancer growth has demonstrated that it may increase the sensitivity of cancer cells towards chemotherapy
• Oncolytic viral therapy: This innovative approach uses genetically modified viruses to infect and kill the cancer cells in a targeted manner. These synthetic viruses can also stimulate the immune system to fight the cancer
• Biomarker-driven therapy: This is a type of precision medicine, in which the specific genetic mutations of the patient’s tumour are identified and drugs are used to target these mutations. For example, if BRAF gene is mutated, specific drugs targeting this gene would be produced to block the activity of BRAF gene

Although targeted therapies are in its early stage, they hold a strong promise in revolutionising the colorectal cancer treatment.

Immunotherapy

Immunotherapy is a type of cancer treatment that uses drugs to boost the immune system to fight against the cancer cells.

Different types of immunotherapies include:

• Anti-EGFR/EGF antibodies: These are drugs that block a protein called EGFR responsible for cancer growth
• Anti-VEGF/VEGFR antibodies: These drugs block a protein called VEGF which starves the tumour and slows its growth as VEGF is responsible for tumours forming blood vessels
• ICIs as immune boosters: These are the immunomodulatory antibodies that helps in reinforcing the immune system to fight against the tumour cells more effectively
• T-cell boosting therapies: In this type of therapy, T-cells (a type of immune cell) are taken out from the patient, genetically modified in the lab to make them stronger and given back to the patient. As a result, these modified T-cells with enhanced strengths effectively kill the cancer cells
• Vaccines: Cancer vaccines are being developed that can help the immune system to recognise the cancer cells and destroy them

Summary 

Immunotherapy is a rapidly evolving field in cancer treatment. As research moves forward, we can expect more therapies with better precision and fewer side effects.⁴

Despite the availability of such advanced treatments for colorectal cancer, it is also important to do regular follow-ups and monitoring with your respective doctor to avoid any recurrence. Irrespective of the type of cancer, navigating life during and after the treatment plays a crucial role in increasing the chances of better recovery. A healthy lifestyle which includes a healthy diet, daily exercise, regular health check-ups and positive thinking improves the quality of life, keeping you away from any kind of disease. Early detection is the key, so talk to your doctor about the appropriate treatment options. Even though advanced treatment options will always be there, you can only win this battle against cancer with optimism and strength.