Colon Cancer Treatments and Medications

Like any cancer diagnosis, colon cancer can be a scary prospect. It’s a tough illness to beat in all but its early stages. It turns out, though, that colon cancer can be caught early and avoided entirely. The reason for this is that it typically takes 10 to 15 years for the earliest manifestations, called polyps, to advance to full-blown tumors. Early screening saves tens of thousands of people from ever having to hear that they’ve been diagnosed with colon cancer.

What is colon cancer?

Colon cancer (Cca) is a cancer of the large intestine, the organ that is responsible for gathering and passing waste products as the last step in the digestive system. Because the colon and rectum are closely joined, colon cancer is often grouped with rectal cancer as colorectal cancer (CRC). Colon cancer and rectal cancer tend to be similar in symptoms and treatment methods.

Colon cancer develops slowly, starting as benign, noncancerous polyps, looking like bumps or swollen blisters on the colon’s inner surface. Colon polyps result from changes to cellular DNA, the molecule that encodes all the “instructions” for making a cell and running its chemical processes. The DNA changes cause colon cells to grow more actively than usual, resulting in small polyp growths. Over time, as polyps grow, the DNA can change even more. Eventually, the cells can grow out of control and turn cancerous. Not all polyps develop into colon cancer, but, when they do, polyps usually take about 10 to 15 years after they first appear to become cancerous. Colorectal cancer screening and early detection can help prevent colon cancer by identifying polyps before they become cancerous.

Around 100,000 Americans are diagnosed with colon cancer each year. Colorectal cancer is the third leading cause of cancer death in the United States, claiming around 50,000 lives each year. However, as the percentage of at-risk Americans being screened for colon cancer increases, the number of annual colon cancer diagnoses in that group has been decreasing (about a 3% decrease per year in people 55 and older). Clearly, screening is hands-down the best treatment for colon cancer.

How is colon cancer diagnosed?

Colon cancer is diagnosed through a colonoscopy, a diagnostic procedure in which a flexible tube with a camera is inserted through the rectum to view the inner lining of the colon. Colon cancer symptoms are the most common trigger for diagnostic colonoscopies, but one in ten colon cancer diagnoses result from routine colonoscopy screening.

A gastroenterologist, or digestive system doctor, performs diagnostic colonoscopies, and pathologists will perform biopsies on the samples taken during a colonoscopy. Once polyps or colon cancer are detected, the treatment plan could involve a gastroenterologist, oncologist (cancer doctor), radiation oncologist, or medical oncologist.

Routine screening is the key to diagnosing colon cancer early enough to increase survival odds. Early screening can detect precancerous polyps or early-stage tumors that can then be removed and treated.

Everyone at risk for colon cancer should be routinely screened. Age is the primary risk factor for colon cancer. Most cases involve patients 50 or older. Other risk factors calling for regular colon cancer screening include inherited conditions such as familial adenomatous polyposis (FAP) or Lynch syndrome, a family history of colon cancer, inflammatory bowel disease (ulcerative colitis or Crohn’s disease), or previous radiation treatment for cancer. Other risk factors include excess weight, sedentary lifestyle, diabetes, smoking, alcohol use, and a low-fiber, red meat diet.

The gold standard for colon cancer screening is a diagnostic colonoscopy performed every ten years. In place of a colonoscopy, a doctor may use other screening tests such as a yearly stool test detecting either blood or cancer DNA in stool samples.

Colon cancer symptoms that trigger a diagnostic colonoscopy are rectal bleeding, blood in the stool, fatigue, a change in bowel habits, and abdominal pain.

Identifying a tumor through colonoscopy and verifying it as cancer through biopsy is sufficient for a colon cancer diagnosis. A CT scan with contrast dye of the abdomen, chest, and pelvis will help determine the stage of the cancer as well as provide a comprehensive picture to guide surgery.

A key part of diagnosis is determining the stage of the cancer. Colon cancer stages represent how far the cancer has grown and determine the most appropriate treatment. Here are the stages:

• Stage 0—Colon cancer has just started growing and has not penetrated the inner layer of the colon.

• Stage I—Colon cancer has grown into inner layers of the colon and has not spread to any nearby lymph nodes.

• Stage II—colon cancer has grown into the outer layers of the colon or beyond but has not spread to lymph nodes or other parts of the body.

• Stage III—Colon cancer has spread out of the colon to nearby lymph nodes.

• Stage IV—Metastatic colon cancer has spread to other parts of the body.

Colon cancer treatment options

Colon cancer treatment will depend on the cancer’s stage. Surgery, chemotherapy, targeted therapy, immunotherapy, and radiation are the standard treatments.

Surgery

Surgical removal of the tumor is the only treatment necessary for early-stage (stage 0 or stage I) colon cancer. Later stages will involve surgery and a few months of chemotherapy, called adjuvant chemotherapy, to guarantee any remaining cancer is killed. When colon cancer spreads to other parts of the body (stage IV colon cancer), surgery is rarely possible.

Depending on the cancer’s stage, a surgeon might perform:

• Polypectomy

  If precancerous polyps are detected during a diagnostic colonoscopy, they are removed with surgical tools inserted into the colonoscope.

• Local excision

  An early-stage tumor can also be removed during a colonoscopy.

• Colectomy

  The tumor and a part or all of the colon is removed either in open surgery or using a laparoscope. In laparoscopic surgery, a small, flexible tube with a camera is inserted through the abdominal wall into the colon. The surgeon performs the surgery using a video monitor and tools inserted through other incisions. The surgeon will also remove at least 12 lymph nodes around the tumor site. The surgeon will then rejoin the remaining colon segments.

• Colostomy

  If after a colectomy the two colon segments cannot be rejoined, the surgeon will perform a temporary colostomy. The surgeon cuts an opening in the abdomen, called a stoma, and connects the colon to that opening. Waste products will pass through that opening into an attached bag.

Radiation treatment

Radiation therapy kills cancer cells by exposing tissues to high-energy X-rays, gamma rays, or charged particles. Though it is a standard rectal cancer treatment, radiation therapy is rarely used for colon cancer. For colon cancer, radiation may be used to shrink a tumor before surgery or to kill any remaining cancer cells following surgery.

Medications

Surgery for stage II or stage III colon cancer is followed by a chemotherapy regimen. Called adjuvant therapy, chemotherapy is intended to eliminate any cancer remaining after surgery. For metastatic (stage IV) cancer, cancer drugs are usually the first-line therapy.

Enormous advances have been made in the medical management of late-stage colon cancer, substantially increasing the survival rate. Medical oncologists may use a combination of chemotherapy, targeted therapy, and immunotherapy medications.

Colon cancer medications

Colon cancer medications are used as a follow-up therapy to surgery. However, for early-stage colon cancer, surgery alone is enough to cure cancer, but the doctor may offer drug therapy as an additional option. For later-stage cancers, medications are often the only treatment that can help.

Chemotherapy

Doctors follow established regimens for drug therapy depending on the stage of the cancer. For colon cancer, the most common drug therapy following colon surgery is a combination of oxaliplatin, a platinum-based drug, with fluorouracil and leucovorin, a therapy known as FOLFOX. Oxaliplatin interferes with the ability of cancer cells to grow, fluorouracil kills cancer cells by blocking their ability to make copies of their DNA, and leucovorin is a substance similar to folate (vitamin B9) that amplifies the effects of fluorouracil.

Other first-line therapies for colon cancer include irinotecan, fluorouracil, and leucovorin (FOLFIRI) or oxaliplatin with capecitabine (CAPOX). Irinotecan is an alkaloid that causes cancer cell DNA to break down, both killing the cell and preventing its growth. Capecitabine is a drug that the body converts into fluorouracil.

Targeted therapy

Targeted therapy drugs attach to proteins on the outside of cancer cells and prevent them from growing. Braftovi (encorafenib) blocks the growth of colon cancer cells that have a particular mutation, called the BRAF mutation. Stivarga (regorafenib) “turns off” proteins, called tyrosine kinases, that signal tumor cells to grow.

Monoclonal antibodies

Monoclonal antibodies are a type of targeted therapy that uses synthetic antibodies similar to those produced naturally by the body. Avastin (bevacizumab) and Cyramza (ramucirumab) are used to block a protein called VEGF that tumors need to grow new blood vessels to the tumor. Without new blood vessels, the cancer cells die from lack of oxygen. Erbitux (cetuximab) and Vectibix (panitumumab) attach to and shut down a protein, called EGFR, which activates the growth of cancer cells.

Examples of first-line drug therapies for late-stage colon cancer are a combination of Avastin (bevacizumab) with two chemotherapy drugs, oxaliplatin and capecitabine, a therapy known as BCapOx, or a combination of Avastin and FOLFOX. After an initial course of drugs, maintenance therapy commonly consists of Avastin and capecitabine.

Immunotherapy

For later-stage, inoperable colon cancer, patients may be given drugs that ramp up the immune system’s attacks on the tumors, including Keytruda (pembrolizumab), Libtayo (cemiplimab-rwlc), and Opdivo (nivolumab). These drugs are synthetic antibodies that attach to the “off” switch, called a checkpoint, on immune system cells. With the “off” switch blocked, immune cells go into overdrive attacking cancer cells.

What is the best medication for colon cancer?

The types of colon cancer medications used are determined by the cancer stage, response to treatment, and tolerance of side effects. Physicians follow well-researched regimens, so there is no “best” medication for colon cancer, just the most appropriate combination of drugs for the medical situation.

Save big on your prescriptions

with the free SingleCare app.

4.8 average rating

Text a link to get the app

Send

What is the best medication for colon cancer?