Colorectal Cancer Treatment by Stage

Learn more about what treatment may be recommended by your healthcare team after a colorectal cancer diagnosis.

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Fight Colorectal Cancer, along with our Medical Advisory Board, has taken the time to break down colorectal cancer treatment by stage, which includes both colon cancer treatment by stage and rectal cancer treatment by stage. For detailed information about stage III and stage IV colon and rectal cancer treatment, check out Your Guide in the Fight.

Stage 0 and Stage I Colon Cancer

Patients diagnosed with stage 0 and stage I colon cancer are highly likely to be cured (>90% cure rate) by a procedure (polypectomy) or surgery (colon resection) that removes the cancerous polyps or tumor.


Surgery or polypectomy is usually the only recommended treatment for stage 0 colon cancer.

  • Polypectomy — snaring and removing polyps containing cancer during a colonoscopy
  • Local excision — removal of flat colon growths “piecemeal” during colonoscopy
  • Open abdominal surgery — remove cancer, part of colon, and nearby lymph nodes in high-risk situations


For stage I colon cancer, surgery is often the only recommended initial treatment. It will typically be either:

  • Colectomy (resection) — removal of all or part of your colon through an incision or incisions (laparoscopic surgeries often require several small incisions while open surgery is usually done using a single, larger incision).
  • Laparoscopic colectomy — when a surgeon makes a few small incisions in your abdomen through which they pass a tiny camera and tools to access your colon

Stage I Rectal Cancer

There are a variety of different surgeries used to treat stage I rectal cancer:

  • Local excision through the anus
  • Low anterior resection (LAR) for tumors that are high enough in the rectum to permit reconnecting the colon or rectum to the anus (anastomosis)
  • Abdominoperineal resection with permanent colostomy when the distance between tumor and anus is too short to allow safe anastomosis (reconnection).

Tumor Imaging

Endorectal ultrasound (a procedure where an ultrasound probe is inserted into the rectum), MRI scans, or CT scans are commonly used to make images of rectal tumors to assess the depth of tumor invasion and whether there are signs of lymph node invasion by the tumor. If the tumor has invaded through the rectal wall or has spread to lymph nodes it is not a Stage I tumor and its treatment is covered elsewhere.

Possible Chemotherapy

If the tumor has gone through the outer layer of the rectum (T3) or there are cancer cells in lymph nodes (N1 or N2), then preoperative chemotherapy and chemoradiation may be recommended to reduce the size of the tumor and increase the likelihood of avoiding a permanent colostomy. In some cases, chemotherapy and/or chemoradiotherapy (if no radiation was administered before surgery) may be recommended after surgery as well. This is generally done when the tumor is felt to have progressed beyond Stage I based on examination and tumor imaging.

Possible Watch and Wait

For some stage I rectal cancers, there may be the option to watch and wait after removal of the tumor via a polypectomy or after a surgical procedure where the tumor is removed through the anus when that is possible. In all cases surveillance for local or distant tumor recurrence is critical so that any recurrence can be addressed quickly and examinations and/or imaging is often done every 3-6 months for several years.

Stage II Colon Cancer

Initial treatment for stage II colon cancer is surgery to remove the section of colon that contains the tumor and surrounding tissue with its blood vessels and lymph nodes. It could be either:

  • Open colectomy — when a surgeon makes a long incision in your abdomen so that they can access and remove a portion of your colon
  • Laparoscopic colectomy — when a surgeon makes a few small incisions in your abdomen through which they pass a tiny camera and tools to access and remove a portion of your colon


The potential benefits of treatment of node-negative stage II colon cancer with chemotherapy after surgery is controversial. While surgery to remove the tumor in the colon is universally accepted as an initial treatment, the value of chemotherapy after that surgery (adjuvant chemotherapy) to keep cancer from recurring (coming back) has been tested in many trials and the outcome has shown that it does not improve outcomes except in some cases which are judged to carry a higher risk of recurrence. New techniques such as blood tests looking for circulating tumor DNA (ctDNA) are being tested to help determine the risk for recurrence and to help doctors to determine if chemotherapy after surgery may be warranted.

Clinical Trials

There are often clinical trials available for stage II colon cancer patients.

Stage II Rectal Cancer

For patients who are medically fit and able to undergo combined methods of therapy, treatment for stage II and III rectal cancer may consist of:

  • Chemotherapy and/or Chemoradiation before surgery
  • Abdominal surgery
  • Adjuvant chemotherapy

Patients with medical issues that make chemoradiation difficult may go directly to surgery, followed by:

  • No further treatment if their tumor hasn’t spread through the rectal wall or to lymph nodes
  • A reconsideration of adjuvant chemotherapy and chemoradiation if there is spread through the wall (T3) or into lymph nodes (N1 or N2)

Your Guide in the Fight

Download this FREE resource for stage III and stage IV colorectal cancer patients and their loved ones.

Stage III Colon Cancer

Most stage III colon cancer patients will receive a recommendation of surgery, followed by chemotherapy.

Combination Chemotherapy

Patients who are able to tolerate combination chemotherapy that includes Oxaliplatin (Eloxatin®) are often prescribed:

  • Folfox — combination treatment with infusional 5-FU (fluorouracil), leucovorin, and oxaliplatin
  • CapeOx — combination treatment with capecitabine (a chemotherapy pill similar to 5-FU) and oxaliplatin.

Alternative Chemotherapy

Patients who have medical reasons not to use combination chemotherapy may be prescribed chemotherapy with a single drug:

  • Xeloda® (capecitabine) — an oral “prodrug” which is converted to 5-FU in the tissues
  • 5-FU and leucovorin — an intravenous chemotherapy drug given with a vitamin (leucovorin) that enhances the effect of 5-FU.

Your doctor can discuss the advantages and disadvantages of the different chemotherapy regimens for your individual needs.


If surgery reveals the tumor has spread outside the colon so that the tumor extends into other tissues such as the lining of the abdomen (the peritoneum), follow-up radiation may be recommended. Radiation is not a routine treatment for stage III colon cancer.

Clinical Trials

There are often clinical trials available for stage III colon cancer.

Stage III Rectal Cancer

Most stage III rectal cancer patients will receive a recommendation that their tumor be treated with a combination of chemotherapy, chemoradiation, and surgery.

Chemotherapy Combinations

For stage III rectal cancer patients who are medically fit and can tolerate combined methods of therapy, treatment can consist of chemoradiation (chemotherapy and radiation) before surgery (adjuvant therapy), abdominal surgery, and/or adjuvant chemotherapy after surgery. When chemotherapy and/or radiation are administered before surgery this approach is known as neoadjuvant therapy. In some cases, doctors will recommend total neoadjuvant therapy where a full course of chemotherapy and radiation are administered prior to surgery. In other cases, chemotherapy may be recommended without radiation and radiation may be reserved for after surgery in cases with high-risk features in their tumors noted when the pathologist examines the surgical specimen.

Patients who cannot tolerate chemoradiation at first, may go directly to surgery with no additional treatment, and then onto adjuvant chemotherapy and/or chemoradiation after surgery.

For a list of chemoradiation options, adjuvant chemotherapy options, and adjuvant chemotherapy options (a “sandwich” of chemo-chemoradiation-chemo), download Your Guide in the Fight.


For rectal cancer, abdominal surgery is often required to remove tumors. You may be treated with radiation and/or chemotherapy before surgery.

  • Low Anterior Resection (LAR)
  • Abdominoperineal Resection (APR)

Medically reviewed by Dr. Richard Goldberg, Director Emeritus, West Virginia University Cancer Institute, 3/24/2024 

Stage IV (Metastatic or Recurrent) CRC

Treatment for stage IV or recurrent colorectal cancer is complex, and generally requires consultation with medical, surgical and radiological doctors.

Take time to get the best information and advice possible from a multidisciplinary team. This process is vitally important. Make sure to get a second opinion, even if it takes extra time.


If the liver, lungs, or the lining of the abdomen (peritoneum) are affected, you may undergo multiple surgeries to remove metastatic disease. Often, chemotherapy and radiation are combined with surgery to shrink tumors.

  • Partial Hepatectomy — also known as a liver resection, this surgery is intended to remove tumors from the liver
  • Pulmonary Metastasectomy — a surgery where tumors which have metastasized to the lung are removed
  • Chemoembolization Surgery — sometimes called transarterial chemoembolization (TACE), it is a combination of an embolization procedure (a procedure that reduces blood flow to the liver) and chemotherapy
  • Hyperthermic Intraperitoneal Chemotherapy — also called HIPEC, this surgery involves filling the abdominal cavity with heated chemotherapy drugs

Chemotherapy Combinations

There are a variety of chemotherapy combinations that may be prescribed.

  • Capox or Xelox — Capecitabine (Xeloda®) plus oxaliplatin (Eloxatin®). Capecitabine is an oral drug that works the same way as 5-FU inside the cancer cell.
  • Folfox — 5-FU, Oxaliplatin (Eloxatin®), and Leucovorin
  • Folfiri — 5-FU, Irinotecan (Camptosar®), and Leucovorin

These regimens may be combined with targeted therapies such as bevacizumab (Avastin®), cetuximab (Erbitux®), or panitumumab (Vectibix®).

Patients who are not able to tolerate intensive therapy have other options. Doctors may recommend:

  • 5-FU plus leucovorin with or without bevacizumab (Avastin®)
  • Capecitabine (Xeloda®) with or without bevacizumab (Avastin®)

Treatment with capectiabine (Xeloda®) alone should only be considered a reasonable option for selected patients who are not candidates for more aggressive combination regimens with oxaliplatin (Eloxatin®) or irinotecan (Camptosar®).

Other Options

Patients who have stopped responding to other treatments or who cannot receive certain chemotherapy medicines have other options, like trifluridine and tipiracil (Lonsurf®), a nucleoside-analogue drug.

Targeted Therapies

There are approved targeted therapies for colorectal cancer, including:


Immunotherapy uses certain parts of a person’s immune system to fight disease. Immunotherapy for colorectal cancer has been shown to be effective in a small subset of patients with a certain biomarker, microsatellite-instability (MSI) or mismatch repair deficiency (MMR). All colorectal patients should know their MSI/MMR status!

Pembrolizumab (Keytruda ®)

This is an option for patients who have the microsatellite instable-high (MSI-H) or deficient mismatch repair (d-MMR) biomarkers. This treatment is indicated for adult and pediatric patients with unresectable or metastatic solid tumors that have been identified as having a MSI-H or dMMR biomarker, including patients with solid tumors that have progressed following prior treatment and who have no alternative treatment options.

Nivolumab (Opdivo ®)

This therapy is for use in microsatellite instability high (MSI-H) or mismatch repair deficient (dMMR) metastatic colorectal cancer (mCRC). Nivolumab has been approved for mCRC patients whose cancer either progressed after being treated with a fluoropyrimidine, oxaliplatin, and irinotecan, or did not respond to those treatments.

Ipilimumab (Yervoy®)

This drug may be used in combination with nivolumab as a treatment option for metastatic colorectal cancer (mCRC) with microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) cancer following the progression on a fluoropyrimidine, oxaliplatin, and irinotecan.

Colorectal cancer treatment by stage can be straightforward in the early stages, but it can become incredibly complicated once the cancer progresses.

NCCN Patient’s Guide

The National Comprehensive Cancer Network is a “not-for-profit alliance of centers that develops practice guidelines to help in making informed treatment decisions.” NCCN Guidelines for Patients® are easy-to-understand resources and may help you with treatment decision making.