Pseudo-Progression and Immuno-Oncology

Pseudo-progression may reflect development of antitumor immunity

The nature of the antitumor immune response can create the appearance of disease progression, either as tumor growth or appearance of new lesions.¹ This is known as pseudo-progression. Pseudo-progression does not reflect tumor cell growth, but may be misclassified as disease progression.^1,2

Tumors may appear to grow or new lesions may appear when immune cells infiltrate the tumor site.¹ Due to the time required to mount an adaptive immune response, pseudo-progression may also reflect continued tumor growth until a sufficient response develops.^1,3

Pseudo-progression should be considered until disease progression can be confirmed

It can be difficult to differentiate pseudo-progression from disease progression.¹ Histologic confirmation is not always possible, but close monitoring of the following factors may help identify pseudo-progression^1,4:

While uncommon, pseudo-progression is an important consideration when evaluating response to Immuno-Oncology therapies.³ Research is ongoing to identify measures differentiating between pseudo-progression and disease progression.

View the nature of antitumor responses and how they may resemble disease progression.