What Is Cancer Recurrence?

Posted on January 17, 2022 in Cancer

Written by Cromer, Amanda

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A cancer diagnosis can be devastating. But when the disease returns after months or even years of living cancer-free, many patients feel disappointed, helpless, and angry. They may wonder “Why me?” or “What did I do wrong?”

Recurrent cancer, or cancer that comes back after remission, happens when cancer cells go undetected by blood tests and scans. These cells then divide and grow into cancerous lesions that, in many cases, are harder to treat than primary tumors. With this in mind, SERO’s radiation oncologists offer the most advanced radiotherapy techniques for treating recurrent cancers.

What Is Remission?

cancer ribbon with physician

Remission is a milestone in your cancer journey. However, it does not mean that your cancer is cured. 

Rather, remission means “a decrease in or disappearance of signs and symptoms of cancer.” Remission represents a major step in cancer care and long-term health. Blood tests may indicate a reduction in cancer cells or scans like X-rays may show a reduction in the size of your tumor or complete disappearance. This reduction has to last for at least a month for your cancer to be considered in remission.

When patients reach this stage, symptoms like pain and weakness often lessen. A patient’s cancer care team may decide to continue chemotherapy or radiation to prevent existing cancer cells from growing, though the dosage is often less. Some patients stop treatment altogether. Whether or not your oncologist adjusts your treatment plan depends on what type of remission you are in. 

There are two types of remission:


Complete Remission

Complete remission is defined by an absence of disease. No evidence of cancer can be detected using blood tests or radiological tests such as CT scans, MRIs, or PET scans. Oncologists often refer to complete remission as “NED,” which stands for “no evidence of disease.”


Partial Remission

In partial remission, the cancer is still detectable. However, the primary tumor has shrunk to at least half of its original size or has stopped growing. In the case of blood cancers like leukemia, there are fewer cancer cells in the bloodstream.

How Is Remission Different Than Cured?

Though patients often use the terms “remission” and “cured” interchangeably, the two are significantly different

Complete remission means no evidence of cancer can currently be detected. However, cancerous lesions that are too small to visualize using a CT scan or X-ray may still exist. A tumor as small as one-millimeter, for example, does not show up on scans but can still contain as many as 100,000 cancer cells1.

Because the probability that the cancer will return is still high, complete remission does not mean a patient is cured. 

Rather, the term “cured” is only used when the patient is in complete remission for five years or longer. Since certain cancers can return even after this five-year mark, some patients are never truly cured.

What Is Cancer Recurrence?

Even when a cancer patient enters remission, there is still a chance that the cancer will come back. This is called a cancer recurrence and happens when a small number of cancer cells survive treatment but are not detected during blood tests or imaging scans. Over time, these cells grow and multiply. 

Recurrent cancer is different from second cancer, which is a cancer unrelated to any previous diagnosis. 

There are three types of recurrent cancer:


Local Recurrence

Local recurrence means the cancer has returned to the same area as the original tumor. 


Regional Recurrence

Regional recurrence means the cancerous lesion has spread to lymph nodes or tissues near the original tumor. 


Distant Recurrence

Distant recurrence means the cancer has spread throughout the body. This is also referred to as metastatic cancer. 

Symptoms of Cancer Recurrence

It is easy to let the fear of cancer recurrence dominate your life. Many cancer survivors obsess over their health, worrying about random headaches or digestive issues. It is important to remember that we all experience unexplained aches and pains. However, if certain symptoms persist, notify your doctor immediately. 

Let your cancer care team know if you experience any of the following symptoms:

  • Return of the cancer symptoms you experienced before (for example, a new growth where your cancer started)
  • New or unusual pain
  • Easy bleeding or bruising
  • Unexplained weight loss
  • Chills or fevers
  • Frequent headaches 
  • Nausea, vomiting, or loss of appetite
  • A persistent cough 

After a physical exam, your doctor may order blood tests or an imaging test. If these diagnostic tools suggest cancer, your oncologist will order a biopsy to confirm the type and stage of your cancer and to determine an appropriate cancer treatment plan.  

Treatment Options for Recurrent Cancer

How your care team treats your cancer depends on a number of factors, including:

  • Type of cancer
  • When and where it recurs
  • If it has metastasized 
  • Your health
  • Your goals and values 

Sometimes, your oncologist may suggest the same treatment you received previously. For instance, a patient who previously had surgery to remove a cancerous polyp in their colon may have a second surgery. This procedure may be followed by radiotherapy, a localized treatment used to kill any remaining cancer cells.  

But if a patient previously received a more aggressive treatment such as chemotherapy, the oncologist may suggest a different approach. Cancer cells can become resistant to chemotherapy drugs. These drugs are also very hard on the body and can cause serious issues like heart and vascular problems. 

As your doctor explains different care options, remember that you ultimately choose your cancer treatment. Only you can decide if you want to move forward with treatment or if you would rather seek palliative care to improve your quality of life

Risk of Cancer Recurrence

What is the probability that your cancer will return? That depends on many different factors, including:


Type of Cancer

Certain types of cancers have high rates of recurrence even with modern therapies, while other cancers have low recurrence rates. This difference is largely dependent upon the molecular features of each individual cancer type and their susceptibility to available treatment options. 


Stage of Cancer

The stage of the original cancer also affects recurrence. Typically, the later the cancer is diagnosed, the higher the risk of recurrence. For example, a study of Swedish colon cancer patients found that within five years after initial treatment, the recurrence rates were five percent for patients with stage I and 33 percent for patients with stage III4.


Previous Treatment

Cancer cells can evade even the most advanced treatment modalities. For example, if a patient undergoes surgery to remove a cancerous lesion, pathology reports may indicate clear margins. That means no cancer cells have been detected on the outer edge of the tissue that was removed. However, outside of imaging techniques, it is not always possible to determine if cancer cells already spread to nearby tissues, lymph nodes, or the bloodstream. 

The same may be true for radiotherapy. Since radiation therapy is another type of localized cancer treatment, it only treats cancer cells in targeted area. If a patient has uterine cancer, for instance, radiation would be targeted at the pelvic region. Since radiation therapy does not treat cells that have spread to other parts of the body, it is often coupled with a systemic therapy like chemotherapy. 

However, in some cases, chemotherapy is not completely effective either. Chemotherapy drugs are either cell-cycle specific or cell-cycle nonspecific. Cell-cycle specific drugs kill cancer cells only when they are dividing, or creating new cells. Cell-cycle nonspecific drugs kill cancer cells only when they are at rest. Since not all cancer cells are simultaneously dividing or simultaneously at rest, some may survive treatment. 

A cancer survivor’s overall health can also impact cancer recurrence. Individuals who eat a diet low in processed foods, avoid smoking and alcohol, and exercise regularly are less likely to develop recurrent cancer. Researchers analyzing the dietary trends of cancer survivors, for instance, found higher rates of mortality among individuals who followed a Western diet (i.e. red meat, high-fat dairy, high-sugar foods) than those who followed a diet that consisted mostly of fish and vegetables7

How Do I Prevent Cancer Recurrence?

There is always a possibility that your cancer will return. No amount of clean eating or aerobic exercise can truly prevent cancer recurrence. However, there are some steps you can take to be as healthy as possible. 

More specifically, SERO’s radiation oncologists suggest that cancer survivors:

  • Eat a plant-based diet that incorporates a variety of fruits, vegetables, and whole grains. Limit or avoid red meats (beef, pork, lamb) and avoid sugary beverages. 
  • Achieve a healthy weight. Studies show that being overweight or obese puts you at risk for developing 13 types of cancer8
  • Talk to your cancer care team about beneficial vitamins and supplements. Certain supplements may actually increase the risk of cancer, so consult your doctor first. 
  • Get at least two hours and 30 minutes of moderate-intensity aerobic activity each week. This could be hiking, biking, and even raking leaves. The key is to find an activity that you enjoy doing.

It can be hard to accept that, despite positive lifestyle changes, your cancer has returned. But these changes are still worthwhile. By adopting a healthy diet and regular exercise routine, you can prevent comorbidities like diabetes and heart disease that make successful cancer treatment more difficult. Download our free Guide to Diet & Nutrition During Radiation Therapy for additional insights.

Radiotherapy for Recurrent Cancer

At SERO, our radiation oncologists improve patient outcomes by providing the most effective and advanced radiotherapy techniques for treating recurrent cancer. To learn more about your cancer treatment options, contact us to schedule an appointment at one of our cancer treatment centers. We offer convenient oncological services across the Charlotte area.