When treating cancer, there are two primary treatment types: local treatments and systemic treatments. Local treatments are those that directly treat the tumor without affecting the rest of the body. This type of treatment is typically used for smaller tumors that are usually seen in earlier-stage cancers. Common types of local treatments are surgery, ablation, and radiation therapy. Systemic treatments are those that reach the entire body to target circulating and metastasized cancer cells wherever they are present. Common types of systemic treatments are chemotherapy, hormone therapy, and immunotherapy. [1]

For early-stage colon cancers, surgery is the go-to treatment. However, the type of surgery used for treatment depends on factors such as the cancer stage and location. Most polyps and very early stage colon cancers can be removed during a colonoscopy. This method of surgical tumor removal is minimally invasive, with a goal of removing the tumor or pre-cancerous growth completely. However, sometimes when the cancer has spread further, a colectomy is required. This is when part or all of the colon is removed as well as nearby lymph nodes so that they may be checked for cancer. [2]

Ablation is a treatment option that can be used on small tumors. It is commonly used when colorectal cancer has spread to create small masses in organs such as the liver and lungs. It is also helpful for patients that may not be ideal candidates for more invasive surgical techniques. [3] Ablation is a minimally invasive method where specialized probes are guided to the tumor using imaging techniques such as an ultrasound or CT scan, at which point the probe is used to “burn” or “freeze” the tumor, thereby killing the cancer cells. [4] Radiation therapy, another type of localized therapy, is not commonly used for treating colon cancer, but can be used in some instances such as prior to surgery to shrink a tumor and make it easier to remove or ease symptoms of advanced colon cancer. [5]

A common type of systemic therapy used to treat colon cancer is chemotherapy, which is a treatment where anti-cancer drugs are administered. These drugs travel through the bloodstream to eliminate cancer cells throughout the body. Chemotherapy may be given after surgery to kill remaining cancer cells (adjuvant chemotherapy), before surgery to try to shrink the tumor to make it easier to remove (neoadjuvant chemotherapy), and for hindering the progression of advanced cancers. [6] Targeted therapies, like chemotherapies, are drugs that travel through the bloodstream to target cellular changes, such as growth factor changes, that are responsible for cancer growth. [7] Immunotherapy, a form of therapy that aims to help a person’s own immune system fight cancer, can be used to treat specific gene mutations that have made the cancer resistant to the patient’s immune system. [8]

References:

1.     Colorectal cancer treatment: How to treat colorectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating.html (accessed Jan 31, 2022).

2.     Colon cancer surgery: Types of colon cancer surgery. https://www.cancer.org/cancer/colon-rectal-cancer/treating/colon-surgery.html (accessed Jan 31, 2022).

3.     Ablation and embolization for colorectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating/ablation-embolization.html (accessed Jan 31, 2022).

4.     Molnar, H. Tumor ablation. https://www.hopkinsmedicine.org/interventional-radiology/procedures/tumor/#:~:text=What%20is%20Cancer%20Ablation%3F,needle% 0probe%20into%20the%20tumor. (accessed Jan 31, 2022).

5.     Radiation therapy for colorectal cancer: Radiation for colorectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating/radiation-therapy.html (accessed Jan 31, 2022).

6.     Colorectal cancer chemotherapy: Chemo for colon & rectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating/chemotherapy.html (accessed Jan 31, 2022).

7.     Colorectal cancer targeted therapy: Targeted drugs for colorectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating/targeted-therapy.html (accessed Jan 31, 2022).

8.     Immunotherapy for colorectal cancer: Immunotherapy for rectal cancer. https://www.cancer.org/cancer/colon-rectal-cancer/treating/immunotherapy.html (accessed Jan 31, 2022).