Colon Cancer Treatment Side Effects
Treatment of Colon Cancer, by Stage
Treatment for colon cancer is based largely on the stage (extent) of the cancer, but other factors can also be important.
People with colon cancers that have not spread to distant sites usually have surgery as the main or first treatment. Adjuvant (additional) chemotherapy may also be used. Most adjuvant treatment is given for about 6 months.
Treating stage 0 colon cancer
Since stage 0 colon cancers have not grown beyond the inner lining of the colon, surgery to take out the cancer is typically all that is needed. This can be done in most cases by removing the polyp (polypectomy) or local excision through a colonoscope. Removing part of the colon (partial colectomy) may occasionally be needed if a tumor is too big to be removed by local excision.
Treating stage I colon cancer
Stage I colon cancers have grown into the layers of the colon wall, but they have not spread outside the colon wall itself (or into the nearby lymph nodes).
Stage I includes cancers that were part of a polyp. If the polyp is removed completely during colonoscopy, with no cancer cells at the edges (margins) of the removed sample, no other treatment may be needed.
If the cancer in the polyp is high grade (see Colorectal Cancer Stages) or there are cancer cells at the edges of the polyp, more surgery may be recommended. You may also be advised to have more surgery if the polyp couldn’t be removed completely or if it had to be removed in many pieces, making it hard to see if cancer cells were at the edges.
For cancers not in a polyp, partial colectomy ─ surgery to remove the section of colon that has cancer and nearby lymph nodes ─ is the standard treatment. You typically will not need any additional treatment.
Treating stage II colon cancer
Many stage II colon cancers have grown through the wall of the colon, and possibly into nearby tissue, but they have not yet spread to the lymph nodes.
Surgery to remove the section of the colon containing the cancer along with nearby lymph nodes (partial colectomy) may be the only treatment needed. But your doctor may recommend adjuvant chemotherapy (chemo after surgery) if your cancer has a higher risk of coming back (recurring) because of certain factors, such as:
The cancer looks very abnormal (is high grade) when viewed under a microscope.
The cancer has grown into nearby blood or lymph vessels.
The surgeon did not remove at least 12 lymph nodes.
Cancer was found in or near the margin (edge) of the surgical specimen, meaning that some cancer may have been left behind.
The cancer had blocked off (obstructed) the colon.
The cancer caused a perforation (hole) in the wall of the colon.
Not all doctors agree on when chemo should be used for stage II colon cancers. It’s important for you to discuss the pros and cons of chemo with your doctor, including how much it might reduce your risk of recurrence and what the likely side effects will be.
If chemo is used, the main options include 5-FU and leucovorin, oxaliplatin, or capecitabine, but other combinations may also be used.
Treating stage III colon cancer
Stage III colon cancers have spread to nearby lymph nodes, but they have not yet spread to other parts of the body.
Surgery to remove the section of the colon with the cancer along with nearby lymph nodes (partial colectomy) followed by adjuvant chemo is the standard treatment for this stage.
For chemo, either the FOLFOX (5-FU, leucovorin, and oxaliplatin) or CapeOx (capecitabine and oxaliplatin) regimens are used most often, but some patients may get 5-FU with leucovorin or capecitabine alone based on their age and health needs.
Radiation therapy and/or chemo may be options for people who aren’t healthy enough for surgery.
Treating stage IV colon cancer
Stage IV colon cancers have spread from the colon to distant organs and tissues. Colon cancer most often spreads to the liver, but it can also spread to other places such as the lungs, brain, peritoneum (the lining of the abdominal cavity), or to distant lymph nodes.
In most cases surgery is unlikely to cure these cancers. However, if there are only a few small areas of cancer spread (metastases) in the liver or lungs and they can be removed along with the colon cancer, surgery may help you live longer and may even cure you. This would mean having surgery to remove the section of the colon containing the cancer along with nearby lymph nodes, plus surgery to remove the areas of cancer spread. Chemo is typically given as well, before and/or after surgery. In some cases, hepatic artery infusion may be used if the cancer has spread to the liver.
If the metastases can not be removed because they are too large or there are too many of them, chemo may be given before any surgery (neoadjuvant chemo). Then, if the tumors shrink, surgery to remove them may be tried. Chemo would then be given again after surgery. For tumors in the liver, another option may be to destroy them with ablation or embolization.
If the cancer has spread too much to try to cure it with surgery, chemo is the main treatment. Surgery might still be needed if the cancer is blocking the colon (or is likely to do so). Sometimes, such surgery can be avoided by inserting a stent (a hollow metal or plastic tube) into the colon during a colonoscopy to keep it open. Otherwise, operations such as a colectomy or diverting colostomy (cutting the colon above the level of the cancer and attaching the end to an opening in the skin on the abdomen to allow waste out) may be used.
If you have stage IV cancer and your doctor recommends surgery, it’s very important to understand the goal of the surgery ─ whether it is to try to cure the cancer or to prevent or relieve symptoms of the disease.
Most patients with stage IV cancer will get chemo and/or targeted therapies to control the cancer. Some of the most commonly used regimens include:
FOLFOX: leucovorin, 5-FU, and oxaliplatin (Eloxatin).
FOLFIRI: leucovorin, 5-FU, and irinotecan (Camptosar).
CapeOX: capecitabine (Xeloda) and oxaliplatin.
FOLFOXIRI: leucovorin, 5-FU, oxaliplatin, and irinotecan.
One of the above combinations plus either a drug that targets VEGF (bevacizumab [Avastin], ziv-aflibercept [Zaltrap], or ramucirumab [Cyramza], or a drug that targets EGFR (cetuximab [Erbitux] or panitumumab [Vectibix].
5-FU and leucovorin, with or without a targeted drug.
Capecitabine, with or without a targeted drug.
Irinotecan, with or without a targeted drug.
Regorafenib (Stivarga) alone.
Trifluridine and tipiracil (Lonsurf).
The choice of regimens depends on several factors, including any previous treatments you’ve had and your overall health.
If one of these regimens is no longer effective, another may be tried. For people with certain gene changes in their cancer cells, another option after initial chemotherapy might be treatment with an immunotherapy drug such as pembrolizumab (Keytruda).
For advanced cancers, radiation therapy can also be used to help prevent or relieve symptoms such as pain. It may shrink tumors for a time, but it is very unlikely to result in a cure. If your doctor recommends radiation therapy, it’s important that you understand the goal of treatment.