Relationship between cytokines and symptoms in people with incurable cancer: A systematic review

Background: Development and spread of cancer is linked to the inflammatory response, in which cytokines serve a key role. The inflammatory response may also form the basis for symptoms of cancer. This systematic review examines the relationship between cytokines and symptoms in incurable cancer.

Methods: MEDLINE, EMBASE, Cochrane Library, CINAHL, Web of Science and PsycINFO databases were searched for studies from January 2004 to January 2020.

Results: Twenty studies were selected (n = 1806 patients, 119 controls). Symptoms studied included depression, fatigue, pain, and loss of appetite. Nine studies examined patients with a specified tumour type, the remainder included patients with a mix of tumour types. Thirty-one cytokines were examined; multiple associations between cytokines and symptoms were described, supporting the hypothesis that cytokines may have a key role in symptom generation.

Conclusion: Symptoms of incurable cancer are associated with circulating cytokines. Further study is required to characterise these relationships, and to explore their therapeutic potential.