| dc.description.abstract | BACKGROUND: Cancer is one of the leading causes of mortality in the world, and lung cancer is the leading cause of cancer mortality worldwide. The emergence of immunotherapy has demonstrated the need to further understand the tumor immune microenviroment. This review article aims to evaluate the prognostic value of tumor-infiltrating regulatory T cells (Tregs) and helper T cells (Th1, Th2 and Th17 cells) in non-small cell lung cancer (NSCLC).
METHODS: MEDLINE, Embase, Scopus, Web of Science and Cochrane Library were searched on the 18th of January 2020. Titles, abstracts and full text of retrieved articles were screened for eligibility and assessed for validity and quality.
RESULTS: The searches retrieved a combined amount of 3,361 results. In the end, 33 of the articles were eligible for critical appraisal. All articles studied the prognostic potential of Tregs. 16 studies found that Tregs had no significant association with survival, while 14 found Tregs to have a negative association with survival. 2 studies had conflicting results. Only 1 article studied Th1 cells, observiing that intraepithelial Th1 cells had a positive effect on survival
outcomes. Only 1 article studied Th2, showing no association with survival, while no articles of Th17 were discovered.
CONCLUSION: Several studies found suggest that Tregs were associated with worse survival outcomes. However, an almost equal number of studies showed Tregs were not associated with
survival. Although FOXP3 is a well-known marker for Tregs, alone it seems to be an unreliable prognostic marker. Further research characterizing the tumor microenvironment will enable the identification of new prognostic and predictive biomarkers, new targets for immunomodulatory treatment, and the development of first-line treatment algorithms. | en_US |