Monitoring the immune competence of cancer patients to predict outcome

Abstract

A new era of cancer immunotherapy has brought not only successful cancer vaccines but also immunomodulators, such as those that target checkpoint blockade in order to induce endogenous host immune responses. However, the immune system of cancer patients can be compromised through multiple means, including immune suppression by the tumor and by prior therapies such as chemotherapy and radiation. Therefore, a comprehensive means of assessing patient immunocompetence would seem helpful for determining whether patients are ready to benefit from immunotherapy, and perhaps even which immunotherapy might be most appropriate for them. Unfortunately, there are no standardized tests for immune competence, nor is there agreement on what to measure and what will be predictive of outcome. In this review, we will discuss the technologies and assays that might be most useful for this purpose. We argue for a comprehensive approach that should maximize the chances of developing predictive biomarkers for eventual clinical use.

Fig. 1

SPADE analysis of PMA + ionomycin-stimulated PBMCs from three healthy controls (top row) and six head and neck cancer patients (bottom row) prior to immunotherapy. Major cell lineages are annotated based on lineage marker expression. Cell clusters are colored for granzyme B (a), or for GM-CSF (b) median intensity (arbitrary units), and cluster size is proportional to cell number. Note the lack of granzyme B expression in NK cells and lack of GM-CSF expression in monocytes, in certain patients compared to controls (blue arrows)