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
• Stage I Rectal Cancer
• Stage II Colon Cancer
• Stage II Rectal Cancer
• Stage III Colon Cancer
• Stage III Rectal Cancer
• Stage IV (Metastatic or Recurrent) Colorectal Cancer

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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.

STAGE 0 (IN SITU) COLON CANCER

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

STAGE I COLON CANCER

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

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.

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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:

Chemotherapy

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.

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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)

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.

Radiation

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.

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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.

Surgery

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)

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Stage IV (Metastatic or Recurrent) Colorectal Cancer

Treatment for stage IV, recurrent, colorectal cancer is complex, and generally requires consultation with medical, surgical, and radiation oncology specialists. For a list of questions to ask if you have stage IV or recurrent colorectal cancer, and for examples of treatment options combined to treat metastatic disease over time, download Your Guide in the Fight.

Your treatment will be specialized depending on your specific circumstances, which include the organs your cancer has spread to, which biomarkers your cancer possesses, and what therapies you have already tried.

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.

Looking for a second opinion?

Biomarker testing

All stage IV colorectal cancers should undergo biomarker testing. Biomarkers are targetable features of a cancer, often mutations or changes in specific genes that can be targeted by specific drugs or therapies. Biomarker testing can give your treatment team a better idea of which therapies might work, and which therapies they should avoid.

It is possible to test for many biomarkers at one time using a process called next generation sequencing (NGS). NGS can find some rare biomarkers that may have specific treatments available, such as:

• POLE/POLD1 mutations
• RET fusions
• NTRK fusions

Surgery

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.

Interventional radiology procedures

Ablation and chemoembolization are advanced interventional radiology techniques used to target and treat tumors.

Radiation therapy

Two advanced radiation therapy techniques used to treat colorectal cancer are:

Chemotherapy combinations

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

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 capecitabine (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. Lonsurf may also be administered with the targeted therapy bevacizumab.

Targeted therapies

Targeted therapies are not chemotherapy, and work in different ways. They may work when chemotherapy doesn’t and may present different side effects. Targeted therapies may be used alone, with chemotherapy, or in combination with other targeted therapies. There are approved targeted therapies for colorectal cancer, including:

Immunotherapies

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, MSI, or dMMR.

Immunotherapy is only recommended if you haven’t already had treatment with a checkpoint inhibitor, such as pembrolizumab or nivolumab. All colorectal cancer patients of all stages should know their MSI/MMR status!

Colorectal cancer treatment by stage can be straightforward in the early stages, but it can become incredibly complicated once the cancer progresses. Your Guide in the Fight includes more detailed colorectal cancer treatment by stage for stages III and IV (recurrent) cancers.