This can lead some individuals to stop their cancer treatment early.
This article offers an overview of pseudoprogression related to immunotherapy.
It also covers how this condition is diagnosed and managed and how to cope.
Verywell / Laura Porter
Pseudoprogression vs. With true progression, treatment results in tumors continuing to grow as expected as if no treatment was given.
Definitions of Pseudoprogression
There is not a universally accepted definition of pseudoprogression.
On biopsy samples taken during pseudoprogression, the actual size of the tumor may have actually decreased significantly.
Delayed Response
Checkpoint inhibitors work by essentially taking the brakes off the body’s own immune system.
During this time, a tumor may continue to grow (delayed response) before responding to the drug.
Since then, the phenomenon has also been seen with other drugs in this category.
There are three subcategories of checkpoint inhibitors that are currently FDA approved for the treatment of cancer.
PD-1 Inhibitors:
PD-L1 Inhibitors:
CTLA-4 Inhibitor:
What Is Pseudoprogression in Brain Cancer?
This leads to destroying the bad cells in a more directed way.
The incidence of pseudoprogression is somewhat difficult to define as there is no universally accepted definition.
The incidence also appears to vary between different types of cancer.
In the study, 20% of people responded to the drug, and 53% experienced progression.
A different 2018 study published inJAMA Oncologyfound the incidence to be 4.7%.
Other Cancers
Pseudoprogression has also been noted uncommonly in kidney cancer and bladder cancer.
How Long Does Pseudoprogression Last?
Diagnosis
Before starting immunotherapy, it’s difficult to know whether pseudoprogression may occur.
At that time, it’s important to venture to distinguish pseudoprogression from true progression of the tumor.
However, this process is still challenging despite the development of specific criteria.
This means that PET scan results can mimic the true progression of a tumor.
In some cases, changes on imaging tests may indicate a true progression is more likely.
New metastases in organs where metastases were not previously present increases the chance that it is true progression.
Some physicians recommend a scan in four or eight weeks.
Measuring ctDNA was only applicable for those who had tumor mutations that could be identified.
There isn’t a set protocol, but many physicians will check scans in four to eight weeks.
Prognosis
Pseudoprogression can be seen as a good thing.
People who have pseudoprogression tend to do better than those who have true progression.
Overall, people who have pseudoprogression tend to have similar outcomes to those who don’t have pseudoprogression.
However, it indicated a high likelihood that people would survive more than one year.
Often times, initial testing for these cancers may not return results for two to four weeks.
This waiting time, though long, is important for properly treat the disease.
Already familiar with the anxiety related to waiting for scan results (scanxiety), this can be challenging.
Summary
Pseudoprogression describes when cancer appears to worsen, despite actually improving.
Looking at an individual’s symptoms, as well as scans can help a healthcare provider diagnose pseudoprogression.
However, waiting for scans can lead to anxiety.
If you or loved one may be experiencing pseudoprogression, there are many ways to cope.
