If cancer is found after treatment, and after a period of time when the cancer couldn’t be detected, it’s called a cancer recurrence.
The recurrent cancer might come back in the same place it first started, or it might come back somewhere else in the body. When cancer spreads to a new part of the body, it’s still named after the part of the body where it started. For instance, prostate cancer might come back in the area of the prostate gland (even if the gland was removed), or it might come back in the bones. In either case it’s a prostate cancer recurrence.
If cancer is found after you have been treated for one type of cancer, tests will be done to see if the cancer is the same type you had before or a new type.
It’s not possible to predict how likely a cancer is to recur, but cancer is harder to treat and more likely to come back if it’s:
- Fast growing
- More advanced or widespread
Most types of cancer recur in a typical pattern – your cancer care team can tell you more about this if it’s something you’d like to know.
What are the types of recurrence?
There are different types of cancer recurrence:
Local recurrence means that the cancer has come back in the same place it first started.
Regional recurrence means that the cancer has come back in the lymph nodes near the place it first started.
Distant recurrence means the cancer has come back in another part of the body, some distance from where it started (often the lungs, liver, bone, or brain).
If you have a cancer recurrence, your cancer care team can give you the best information about what type of recurrence you have and what it means to have that type. They can also talk to you about your options for treatment and outlook (prognosis).
What’s the difference between recurrence and progression?
When cancer spreads or gets worse, it’s called progression. Sometimes it’s hard to tell the difference between recurrence and progression. For instance, if cancer has been gone for only 3 months before it comes back, was it ever really gone? Is this a recurrence or progression? Chances are this is not really a recurrence. In this case, it’s likely 1 of 2 things happened:
- The surgery done to take out the cancer didn’t get all of it.Tiny clusters of cancer cells that couldn’t be seen or found on scans or other tests were left behind. Over time they grow large enough to show up on scans or cause symptoms. These cancers tend to be very aggressive (fast-growing and quick to spread).
- The cancer has become resistant to treatment.Cancer cells can become resistant to treatment just like germs can become resistant to antibiotics. This means chemotherapy or radiation may have killed most of the cancer cells, but some of them were either not affected or changed enough to survive the treatment. These cancer cells can then grow and show up again.
The less time between when the cancer was thought to be gone and the time it came back, the more serious the situation. There’s no standard length of time to decide if it’s recurrence or progression. But most doctors consider recurrence to be cancer that comes back after you’ve had no signs of it for at least a year.
Response and remission
Complete remission
When a treatment completely gets rid of all tumors that were seen on a test or were measured in some way, it’s called a complete response or complete remission. A complete response or complete remission does not mean the cancer has been cured, only that it can no longer be seen on tests.
Partial remission
In general, a partial response (or partial remission) means the cancer responded to treatment, but still has not gone away. A partial response is most often defined as at least a 50% reduction in measurable tumor. (If you’re in a clinical trial, response is usually defined very precisely.) The reduction in tumor size must last for at least a month to qualify as a response. Again, you can ask for more details about the kind of response to treatment the doctor sees, and how long it lasts.
What is a second cancer?
Getting a second cancer is different from having a cancer recurrence. If tests show a new area of cancer is a different type of cancer from the first type, you would have 2 types of cancer, or 2 primary cancers. These 2 types of cancer will have started in different kinds of cells and will look different under the microscope. This is much rarer than cancer recurrence, but it does happen. Having cancer once does not mean you cannot get another type of cancer in the future.
Let’s say, for instance, you were treated for colon cancer, and there are no signs of it at your check-up. Then the doctor finds a tumor in your liver. If this tumor turns out to be a type of cancer that starts in the liver cells – it’s not colon cancer that has spread to the liver. You would have colon cancer (in remission) and liver cancer – 2 different kinds of cancer. Your treatment for the liver cancer would be different from the treatment you would get if it had been recurrent colon cancer.
