Understanding Metastatic Colon Cancer
- Olympic runner Ciara Mageean, 34, refuses to let her stage 4 bowel cancer diagnosis stop her from marrying her fiancé Thomas Moran this October, even as she continues chemotherapy after subtle symptoms led to her diagnosis.
- Metastatic or Stage 4 colon cancer means that the cancer has spread from the colon to other organs. The most common sites for colon cancer to metastasize are the liver, lungs, and peritoneum (the lining in your abdomen).
- Colon cancers start out as a polyp, or small growth, in the colon that causes no symptoms. Although polyps can’t be felt, they can be picked up by screening tests before they cause a problem. It takes up to 10 years for a colon polyp to become a full-blown cancer, which gives doctors time to remove the polyp before it causes a problem.
- The U.S. Preventive Services Task Force recommends state colon cancer screenings should begin at 45-years-old. This is in response to a rise in colon cancer diagnoses in younger adults. In the past, the disease had predominantly been found in adults 50-years or older, but for those predisposed to get it at a younger age, these new guidelines could potentially help catch it at an earlier stage.
- The best and most complete way of screening is a colonoscopy every 10 years. In general, you should get your first colonoscopy at age 45 but the guidelines differ depending on your risk category.
- Clinical trials can be an option for people with cancer at many points during the treatment process. If you’re looking for a clinical trial, check out our SurvivorNet Clinical Trial Finder.
- Check out SurvivorNet’s My Health Questions, which allows patients and caregivers to get personalized, doctor-backed answers to their cancer care questions in real time by typing them in or using voice command technology.
“Myself and Thomas are getting married in October. I’m not going to let this cancer get in the way of that,” Magaeen, now 34, said on a recent episode of the BBC’s GAA Social podcast, according to Belfast Live. [BBC, which stands for British Broadcasting Corporation, is the U.K.’s primary national public service broadcaster]
Read Moreto celebrate me and Tommy. We are together a good few years.”
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Recounting what led to her diagnosis, Mageean said her symptoms weren’t very noticeable.
It wasn’t until after she withdrew from the 2024 Paris Olympics with an Achilles injury, that she began noticing changes in her bowel habits. [Hopkins Medicine explains the Achilles tendon to be a “fibrous band of tissue that links the muscles in your calf to your heel.”]
While recovering from her injury, she noticed she was having more frequent bowel movements, occasional cramping, and mucus and blood in her stool.
However, she dismissed the symptoms as she considered herself in top physical shape and healthy.
Expert Resources On Colon Cancer
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“I never would have suspected I would be diagnosed with stage four bowel cancer. The incidences of bowel cancer in younger population is increasing,” she said.
As for how she’s doing this summer, she admitted that her latest rounds of chemotherapy have been less successful than her earlier treatments, acknowledging there are “good days and bad days.”
However, she constantly reminds herself that “there is always hope,” Mageean, who announced she had cancer last summer on social media.
Mageean took to her Instagram in June 2025, to share, “To everyone who’s been part of my journey so far, I have some difficult news to share: I’ve been diagnosed with cancer. It’s been a lot to take in, but I’ve already started treatment and I’m incredibly grateful to be surrounded by the love and support of my family and close friends.
“Right now, my focus is on healing and taking things one day at a time. I kindly ask that you respect my privacy and that of my loved ones as we move through this together. Your understanding means more than I can say. Thank you for the love and strength. I’m ready to face this with the same fight I’ve always brought to the track.”
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Understanding Colon Cancer
Colorectal cancer happens when polyps are not removed and become cancerous. It can take up to 10 years for a colon polyp to become cancerous, according to SurvivorNet experts.
“We know that colon cancers can be prevented when polyps are found early,” Dr. Heather Yeo, a surgical oncologist who specializes in colorectal cancers at Weill Cornell Medicine, told SurvivorNet.
“Lowering the screening age helps somewhat with this, but access to care is a real problem,” Dr. Yeo added.
Dr. Zuri Murrell, a colorectal cancer surgeon and Director of the Cedars-Sinai Colorectal Cancer Center, previously explained the colonoscopy procedure to SurvivorNet.
“When we see a polyp, we actually physically take the polyp out through the colonoscope,” he explained.
“What does that mean? That means we basically put a wire through with a little bit of a flange at the end, and we pull the polyp out. Now, note there is no pain with that. Inside the colon, there are no pain fibers. So, there’s no pain,” Dr. Murrell added.
The advantage of a colonoscopy is that your doctor can remove any polyps found during the test. Many colon cancers can be caught on colonoscopy before they develop or when the polyps are small enough to be removed without surgery.
Looking for Polyps During Colonoscopy
The American Gastrointestinal Association lowered the recommended initial age for a colorectal screening from 50 to 45.
The U.S. Preventive Services Task Force recommends guidelines that state colon cancer screenings should begin at 45 years old. This is in response to the increase we see in colon cancer diagnoses in younger adults.
However, many insurance companies still do not cover the cost of screenings for those under 50. In the past, the disease had predominantly been found in adults 50 years or older, but for those predisposed to getting it at a younger age, these new guidelines could help catch it earlier.
Meanwhile, Dr. Heather Yeo, a colorectal surgeon and surgical oncologist at Weill Cornell Medicine and New York-Presbyterian, previously told SurvivorNet, “Colon cancer is considered a silent and deadly killer.
“What happens is people often don’t know that they have colon cancer. They don’t have any symptoms. That’s why we screen for colon cancer in the United States.”
The Rate of Colon Cancer is Increasing in Those Under 50
“You should be screened for colon cancer, even if you have no family history. Once you have your initial screening colonoscopy, if there are no polyps and you have no high-risk factors, usually once every 10 years is fine,” she advises.
“Colon cancer is a slowly progressing cancer. If you have any family history of colon cancer, you should be screened about 10 years before your family member had colon cancer. So if you have a family member that was 53, you should be screened at 43.”
Coping With an Advanced Diagnosis
Colon cancer is very treatable and curable if caught early. However, treatment may become more intense when the cancer is detected in later stages.
Chemotherapy is known to improve survival in patients with metastatic or stage 4 colon cancer.
“Colon cancer most commonly spreads to the lung and to the liver,” Dr. Heather Yeo, a board-certified in general surgery, colon and rectal surgery, and complex general surgical oncology, explains to SurvivorNet.
“We try not to do surgery right away. If you think about it, we can’t cut out all of the disease, and any time you do surgery, you’re actually compromising a patient’s immune system,” Dr. Yeo explains.
WATCH: Not all stage 4 colon cancer patients are the same.
The most common therapy is called FOLFOX, and your doctor may add medications like irinotecan (FOLFIRI) or cetuximab, depending on how well your tumor shrinks with treatment and other specifics about your particular tumor.
“If you respond really well, then we keep you on that until you stop responding really well. But if after a few cycles, your disease has progressed, that’s when we think about adding other additional chemotherapies,” Dr. Yeo said.
Colon cancer screenings can involve at-home tests such as Cologuard, but a colonoscopy is more effective, according to SurvivorNet experts. A colonoscopy involves examining the colon and rectum with a long, thin tube attached to a camera.
WATCH: Colon cancer symptoms.
The most poignant signature of colon cancer includes a change in bowel habits. This may include constipation or diarrhea due to changes in the size or shape of bowel movements. A change in stool color, particularly black or tarry stools, can indicate bleeding from a tumor that lies deep in the colon.
Other symptoms can be harder to pinpoint, such as abdominal pain and unintentional weight loss. Finally, some tumors bleed a small amount over a long period of time, resulting in anemia (low red blood cell count) that is picked up on blood work.
Colon Cancer Appearing More in Younger People
Although the average age people are diagnosed with colon cancer is 68 for men and 72 for women, according to the American Cancer Society, the National Cancer Institute reports that since the 1990s, colorectal cancer cases have been rising among adults younger than 50.
Research published in CA: A Cancer Journal for Clinicians found the proportion of cases in people younger than 55 years old increased from 11% in 1995 to 20% in 2019.
“We know rates are increasing in young people, but it’s alarming to see how rapidly the whole patient population is shifting younger, despite shrinking numbers in the overall population,” cancer epidemiologist and lead study author Rebecca Siegel said.
Researchers are still trying to determine why younger people are being diagnosed in greater numbers. Some experts point to risk factors, which include obesity, physical inactivity, and smoking, as a possible explanation for the increase.
“We don’t know for sure why we are seeing earlier onset and (cancer mortality) from colon cancer,” Dr. Yeo told SurvivorNet. It is likely a combination of factors, including diet and genetics as well as access to care and some environmental factors.”
Dr. Paul Oberstein Explains Common Colon Cancer Symptoms
What Increases Your Risk for Developing Colon Cancer?
For some people, certain risk factors can influence their risk of getting colon cancer. They include the following:
- Are older. About 90% of cases are in people aged 50 or older, according to the U.S. Centers for Disease Control & Prevention (CDC). Yet it is possible to get this cancer earlier in life.
- Have inflammatory bowel disease. Crohn’s disease or ulcerative colitis can, over time, cause cells in your intestines to turn cancerous.
- Have a family history of this cancer. Just under one-third of people who get colon cancer have family members with the disease.
- Have a gene mutation. About 5% of colorectal cancers are caused by an inherited genetic mutation that causes syndromes such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colorectal cancer (Lynch syndrome).
- Don’t exercise very often. Staying active can lower your risk.
- Eat a diet that’s high in meat. Regularly eating red meats like burgers and steaks, and processed meats such as hot dogs and bacon might put you at higher risk. Eating more fruits, vegetables, and whole grains instead might lower your risk.
- You are overweight or obese. Having too much weight increases your risk of both getting colon cancer and dying from it.
- Drink a lot of alcohol. Limiting alcohol to one drink daily for women and two drinks daily for men could help lower your risk.
- Use tobacco. Long-term smokers are more likely to get this cancer than nonsmokers.
Which Treatments are Best for You?
It’s important to understand that your doctor has many ways to treat colon cancer, depending on what stage the cancer is, including:
- Surgery
- Radiation therapy
- Chemotherapy
- Targeted therapy
- Immunotherapy
Surgery
Surgery is the main treatment for most early-stage colon cancers, according to the doctors SurvivorNet spoke with. The surgeon will remove the part of the colon or rectum where there is cancer, along with a small area of healthy tissue around it. Taking out as much of the cancer as possible is important for improving your outcome.
The surgery may be performed through small incisions (laparoscopy), or through a larger incision. Some people may need to wear a special bag (ostomy) to collect wastes after surgery.
Choosing the Right Surgery for Your Colon Cancer While Avoiding Marketing Gimmicks
Radiation Therapy
This treatment aims high-energy x-rays at the cancer to destroy the abnormal cells. The radiation can come from a machine outside your body, or be placed directly inside your body. Sometimes people get radiation before surgery, to shrink the tumor and make it easier for the surgeon to remove. This is called neoadjuvant radiation.
Chemotherapy
This treatment uses strong medicine to stop cancer cells from dividing, no matter where they are in your body. You may get a combination of chemotherapy drugs as your first treatment. Chemotherapy has been very well studied for colorectal cancer, and it is known to improve survival.
The most common therapy is a combination of chemo drugs called FOLFOX:
- FOL = leucovorin calcium (folinic acid)
- F = fluorouracil
- OX = oxaliplatin
Your doctor may add medications like irinotecan (FOLFIRI) or cetuximab, depending on how well your tumor shrinks with treatment and other specifics about your particular cancer. For FOLFOX, the medications are given through the vein and require regular doctor visits.
To determine exactly which chemotherapy regimen you get, your doctor will consider your age and how well you might tolerate the side effects of chemotherapy. Gene mutations (for example, BRAF and KRAS) and the location of the primary colon tumor also factor into the decision.
You can also get chemotherapy before colon cancer surgery, which is called neoadjuvant chemotherapy. Getting chemo first helps to shrink the tumor, which can make both the surgery and recovery easier, according to SurvivorNet’s experts. Chemo is also a treatment for cancer that returns after therapy.
Targeted Therapy
This treatment targets substances like proteins or genes that the cancer needs to grow. This makes targeted therapy more precise than chemotherapy, and less likely to damage healthy cells. One example of targeted therapy is bevacizumab (Avastin), which stops the growth of new blood vessels that feed tumors. Another group of targeted therapies are called epidermal growth factor receptor (EGFR) inhibitors, which block the cancer from growing.
Immunotherapy
This treatment makes your own immune system a more efficient cancer fighter. A group of drugs called checkpoint inhibitors, which includes pembrolizumab (Keytruda) and nivolumab (Opdivo), work by preventing cancer cells from hiding from your immune system. Checkpoint inhibitors may extend the amount of time before the cancer spreads.
Dr. Paul Oberstein, on which treatments doctors use to turn stage 4 colon cancer into a chronic but manageable disease
Contributing: SurvivorNet Staff
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