Metastatic colorectal cancer — or stage IV colorectal cancer — is cancer of the colon or rectum that has spread to other parts of the body, such as the liver or lungs. There are a range of treatments, but sometimes your plan may have to change.
"I often tell my patients that treating metastatic colorectal cancer is a marathon, not a sprint," says gastrointestinal oncologist Christopher Lieu, MD, medical scientific adviser for the Colorectal Cancer Alliance. "We can expect to change treatments a few times over the course of a cancer treatment journey."
When Might a Treatment Change Be Needed?
Your treatment might be working well, and then it may stumble.
"We use the most effective treatments upfront," says Amy An, MD, a gastrointestinal oncologist at The University of Texas MD Anderson Cancer Center. "Change in treatment plan may be needed if you are not tolerating the treatment well, or when the cancer has become resistant to the treatment."
There are a few different reasons that your doctor may suggest a switch.
Disease progression. Sometimes the cancer figures out how to fight your current treatment. "Cancer cells can change in a way that makes it resistant to the current chemotherapy," says Lieu, who's also associate director for clinical research at the University of Colorado Cancer Center in Aurora. "If scans show tumors growing or new spots appearing, it's time to make a change."
Side effects. Often, the treatment can be working and the cancer can be getting smaller, but the side effects – like nerve damage, severe diarrhea, or allergic reactions – are too hard to handle. Your doctor may suggest changing drugs or doses to something your body can tolerate.
A new target. Sometimes your health team will do a biopsy to check the state of your cancer. They might find a specific mutation that they can treat with a new drug.
How Will Your Care Team Determine It's Time for a Change?
With metastatic colorectal cancer, you likely get CT scans of your chest, abdomen (belly area), and pelvis every two to three months. Your doctor is looking for signs that tumors are growing or cancer is spreading.
Your care team also keeps watch on a blood protein called carcinoembryonic antigen (CEA). One high result isn't usually worrisome. If readings increase consistently over several months, that usually suggests that your treatment plan may no longer be working.
It's also important to have biomarker testing done. Biomarkers are specific traits found in tissue or blood that can help doctors learn more about your specific cancer. Some biomarkers affect how certain treatments work, so knowing your biomarkers can help develop successful treatment plans.
"Regardless of the scans and lab results, you and your goals are still the most important priority when it comes to treatment decision-making," says Lieu. "If you have worsening pain, your energy drops significantly, or you're losing weight unintentionally, we will likely order imaging tests earlier."
What Does Success Look Like After Making a Treatment Change?
"If you are new to treatment and have a lot of cancer-related symptoms, you may notice an improvement after just one or two cycles," says An. "If you are further along in your cancer journey (for example, if this is your third-line treatment or beyond), you may not notice improvement."
Once you've made a treatment switch, your doctor will order imaging tests – like CT scans or MRIs – to see if your tumors are responding. They'll check to see if they are getting smaller, are staying the same, or even going away completely.
"However, many times our patients will tell us whether a treatment is working or not because their symptoms improve," says Lieu. "If our patients are feeling better, that is practically better than the results of any imaging test!"
Treatment Options
Oncologists used to treat everyone with metastatic colorectal cancer the same way. But now there's a shift toward personalizing treatment, tailored to the type of cancer you have.
Treatment can include:
Chemotherapy. As a first-line, or initial, treatment, most patients will receive a type of chemotherapy, which are drugs that work to kill cancer cells or slow their growth. It's typically a 5-fluorouracil (5-FU) chemotherapy with the drugs oxaliplatin (Eloxatin) and/or irinotecan (Camptosar). If the chemotherapy stops working, your doctor may switch to another type.
Immunotherapy. Chemotherapy is often combined with a biologic, a drug that helps your immune cells look for and destroy cancer cells. If one is no longer successful, a different biologic drug may be used.
Surgery. Treatment may also include surgery to remove the initial cancer or the places where it has spread, like the liver or lungs.
Radiation. Radiation uses high-energy rays to kill cancer cells. It can sometimes be given along with other treatments to help ease side effects.
Targeted therapies. These look for changes seen in cancer cells and target those changes. They block the specific genes or proteins that cause the cancer to grow or spread. Some are given as an IV and others are pills.
Side effects to watch for after a change in treatment
With any treatment, you're likely to have side effects. They might include fatigue, nausea, rashes, or nerve pain. When you switch treatments, your doctor will be looking for certain ones.
"We look for side effects that are specific to the regimen we are giving," says Lieu. "For instance, if we give a targeted therapy like cetuximab (Erbitux) or panitumumab (Vectibix), we will watch closely for an acne-like rash on the face and chest." In this case, it means the drug is working the way it's supposed to.
Always keep track of any side effects or changes when you move to a new treatment, and keep your health care team informed.
Changing treatment can be a trade-off, says Lieu. The aim is to better fight the cancer while handling any new side effects. One treatment might do away with tingling in your hands or feet, but it might increase the odds of having diarrhea.
"Sometimes, a change means doing less," says Lieu. "If the cancer is stable, we might drop the harshest chemo drug and keep you on a lighter maintenance therapy. This allows your body to recover while keeping the cancer in check."
Takeaways
- You may consider a change in treatment for metastatic colorectal cancer because of disease progression, side effects, or a new cancer target.
- To keep track of treatment success, your team will schedule regular CT scans, keep an eye on blood protein, and have biomarker testing done. Report any side effects like fatigue, pain, or weight loss.
- Common treatments include chemotherapy, surgery, biologics, and targeted therapy. You may change treatments and dosages several times.
- Changing treatment can be a trade-off. The goal is to fight the cancer cells while balancing side effects.
FAQs
If we switch now, does that mean I can never go back to the same treatment?
Not necessarily. Sometimes your doctor will try a drug you've used before to see if your cancer responds again.
Will I eventually run out of treatment options?
Rarely, says Lieu. "There are standard lines of therapy, clinical trials, and localized treatments like radiation or embolization to consider."
Can I take a break from treatment?
Yes. "We treat the patient, not the scan," says Lieu. "If you have a wedding or a vacation, we can often pause therapy safely for a period of time."
Are clinical trials a good option?
The answer is always yes, says Lieu. "We want every patient to ask this question to their doctor, and sometimes, answering this question may require a second opinion, which is always OK to get!"
Show Sources
Photo Credit: E+/Getty Images
SOURCES:
Christopher Lieu, MD, medical scientific adviser, Colorectal Cancer Alliance; associate director for clinical research, University of Colorado Cancer Center, Aurora.
Amy An, MD, gastrointestinal oncologist, University of Texas MD Anderson Cancer Center.
University of Chicago Medicine: "Metastatic Colorectal Cancer Treatment."
Colorectal Cancer Alliance: "What is stage IV colorectal cancer?" "Side effects of colorectal cancer treatment."
European Society for Medical Oncology: "Metastatic Colorectal Cancer."
National Cancer Institute: "Biomarker Testing for Cancer Treatment."
Fight Colorectal Cancer: "What Is Biomarker Testing?"
American Cancer Society: "Targeted Therapy Drugs for Colorectal Cancer," "Treatment of Colon Cancer, by Stage," "Radiation Therapy for Colorectal Cancer."
Cleveland Clinic: "Biologics (Biologic Medicine)."
Mayo Clinic: "Stage 4 (metastatic) colon cancer."
MD Anderson Cancer Center: "Colon Cancer Treatment," 5-fluorouracil/5-FU: 5 things to know about this common chemotherapy drug."
Journal of Clinical Oncology: "Treatment of Metastatic Colorectal Cancer: ASCO Guideline."
BMC Cancer: "Comparison of irinotecan and oxaliplatin as the first-line therapies for metastatic colorectal cancer: a meta-analysis."
Surgical Oncology Clinics of North America: "Surgical Treatment of Metastatic Colorectal Cancer."
