Understanding Colorectal Cancer

How is Colorectal Cancer Treated?

This is the eighth page in the Understanding Colorectal Cancer Guide. This guide was developed by the HealthTree Education Team and was last updated and reviewed on April 6th, 2026.

The treatment for colorectal cancer depends on several factors, including the stage of the cancer, where in the colon or rectum the tumor is located, the genetic features of the tumor, your overall health, and whether this is a new diagnosis or a recurrence.

Treatment often involves a combination of therapies. It is important to discuss all of your treatment options with your care team to make the best decision for your unique situation. Getting a second opinion from another oncologist is normal and encouraged.

After your diagnosis, it is normal to get a second opinion. During a second opinion, another oncologist will look at your biopsy results and other tests you had during your diagnosis. They will offer their opinion for your treatment.

Surgery for colorectal cancer

Surgery is the main treatment for most colorectal cancers and the primary way to cure early-stage disease. The type of surgery depends on the location and size of the tumor:

• Polypectomy or local excision. For very early cancers found during a colonoscopy, the surgeon removes the polyp or tumor through the colonoscope without cutting into the abdomen.
• Colectomy (colon resection). During a colectomy, the surgeon removes the section of the colon containing the cancer, along with nearby lymph nodes, and reconnects the remaining colon.
• Proctectomy. During a proctectomy, the surgeon removes all or part of the rectum.
• Abdominoperineal resection (APR). An APR is used for some rectal cancers close to the anal sphincter; removes the rectum and anus.
• Colostomy. In some cases, a temporary or permanent opening (stoma) is created in the abdomen to allow waste to exit the body into a pouch. Many temporary colostomies are reversed after healing.

Radiation therapy for colorectal cancer

Radiation therapy uses high-energy X-rays to destroy cancer cells. It is used more often for rectal cancer than colon cancer. Radiation may be given:

• Before surgery to shrink the tumor and make it easier to remove. Treatment given before surgery is called neoadjuvant. 
• After surgery to destroy any remaining cancer cells. Treatment given after surgery is called adjuvant. 
• To relieve symptoms in advanced disease. This is called palliative radiation.

Radiation is often given together with chemotherapy, which makes cancer cells more sensitive to radiation. This combination is called chemoradiation.

Chemotherapy for colorectal cancer

Chemotherapy uses drugs to kill cancer cells throughout the body. Common chemotherapy drugs used in colorectal cancer include 5-fluorouracil (5-FU), capecitabine (Xeloda), oxaliplatin (Eloxatin), and irinotecan (Camptosar). They are often given together in combinations called regimens. 

Common regimens include:

• FOLFOX, a combination of 5-FU, leucovorin, and oxaliplatin
• FOLFIRI, a combination of 5-FU, leucovorin, and irinotecan
• CAPOX (or XELOX), a combination of: capecitabine and oxaliplatin
• FOLFOXIRI, a combination of all three chemotherapy drugs

Chemotherapy may be given after surgery (adjuvant) to lower the risk of recurrence. It may also be given as the main treatment for metastatic disease, often combined with targeted therapy.

Targeted therapy for colorectal cancer

Targeted therapies are drugs that attack specific proteins on cancer cells. These are often used for advanced or metastatic colorectal cancer:

Anti-VEGF therapies block the blood vessel growth that feeds tumors. Examples include:

• Bevacizumab (Avastin)
• Ramucirumab (Cyramza)
• Ziv-alfibercept (Zaltrap)

Anti-EGFR therapies block a protein that helps cancer cells grow. These only work in tumors without KRAS or NRAS mutations. Examples include:

• Cetuximab (Erbitux)
• Panitumumab (Vectibix)

BRAF inhibitors treat tumors with a BRAF V600E mutation, in combination with anti-EGFR therapy. Encorafenib (Braftovi) is a BRAF inhibitor. 

HER2-targeted therapy can be used to treat HER2-positive metastatic colorectal cancer. Examples include the combination of trastuzumab (Herceptin) with either pertuzumab (Keytruda) or lapatinib (Tykerb), or with chemotherapy.

NTRK inhibitors, specifically larotrectinib (Vitrakvi) and entrectinib (Rozlytrek), are used for the rare group of tumors with NTRK gene fusions.

Immunotherapy for colorectal cancer

Immunotherapy helps your immune system find and destroy cancer cells. 

Checkpoint inhibitors are the main type of immunotherapy used in colorectal cancer. They are most effective in tumors that are MSI-H (microsatellite instability-high) or dMMR (mismatch repair deficient).

• Pembrolizumab (Keytruda) is approved as a first-line treatment for MSI-H/dMMR metastatic colorectal cancer.
• Nivolumab (Opdivo) with or without ipilimumab (Yervoy) is another option for MSI-H/dMMR disease

Only about 4% to 5% of metastatic colorectal cancers are MSI-H, but these patients often respond very well to immunotherapy.

Treating metastatic colorectal cancer

For colorectal cancer that has spread to other organs, treatment is typically focused on controlling the cancer and extending life. However, for some patients with limited spread to the liver or lungs, surgery to remove metastases may offer the chance of cure. Ablation techniques (using heat, cold, or other energy to destroy tumors) and radiation may also be used.

Supportive and palliative care for colorectal cancer

Treating the symptoms of cancer and side effects of treatment is called supportive and palliative care. This is an important part of cancer treatment at every stage, not just at the end of life. Palliative care can include:

• Pain management
• Ostomy support and education
• Nutritional support from a registered dietitian
• Physical and occupational therapy
• Mental health support and counseling

There is a common misconception that palliative care is only given at the end of life. Palliative and supportive care can be given at any time during cancer treatment.  

It is important to talk to your care team about the symptoms and side effects you are feeling. Tell them how much they are affecting your day-to-day life. They may be able to adjust your treatment schedule, change medications, or treat the symptom or side effect directly to help you feel better. 

Follow-up care for colorectal cancer

After colorectal cancer treatment ends, regular follow-up appointments are essential to watch for signs of recurrence and monitor your long-term health. This typically includes colonoscopies, CT scans, CEA blood tests, and physical exams on a regular schedule.