HYPE or HOPE: the prognostic value of infiltrating immune cells in cancer

Abstract

Interactions between immune and malignant cells have been known to have clinical relevance for decades. The potential for immune control is now being therapeutically enhanced with checkpoint inhibitors and other novel agents to improve outcomes in cancer. The importance of the immune infiltrate as a prognostic marker is increasingly relevant. In this minireview, we present an overview of the immune infiltrate and its spatial organisation, and summarise the prognostic value of immune cells in different cancer types. International collaborative efforts are standardising histopathologic reporting of the immune infiltrate, to allow application of these parameters in the clinical and research settings. In general terms, a ‘pro-inflammatory’ tumour microenvironment and infiltrating CD8-expressing T lymphocytes are associated with improved clinical outcomes in a broad range of tumour types. The inhibitory function of other immune cells, for example, myeloid-derived suppressor cells and regulatory T cells, appear to have a major role in disrupting the capacity for the immune control of cancers.

Development and validation of a seven‐immune‐feature‐based prognostic score for oral squamous cell carcinoma after curative resection

“…To achieve optimal outcomes of immunotherapy against cancer, comprehensive knowledge regarding location, density and functional status of TIIs might be a prerequisite . Indeed, the importance of in situ immune infiltrates as key prognostic biomarkers has increasingly been recognized and validated in a broad spectrum of human cancers . Here, we characterized the locations and densities of seven TIIs subsets in OSCC and developed a novel and powerful prognostic classifier for OSCC based on selected seven immune features.…”

“…Immune deficiency and evasion have been recognized as emerging hallmarks of cancer which are critically involved in tumor initiation and progression . Quantification of tumor‐infiltrating immune cells (TIIs) and functional interrogation of these tumor‐associated immune cells have been demonstrated with great clinical importance and translational significance . Mounting evidence has demonstrated that various TIIs including cytotoxic, memory and regulatory T, neutrophil, NK, dendritic cell, macrophage as well as B cell are intricately involved in cancer initiation and progression and regarded as key biomarkers and therapeutic targets with tremendous translational potentials .…”

Density and location of CD3+ and CD8+ tumor‐infiltrating lymphocytes correlate with prognosis of oral squamous cell carcinoma

“…Marginally improved long‐term survival in OSCC necessitates identification and validation of novel and optimized biomarkers with diagnostic and prognostic relevance . Notably, TILs have been regarded as not only immune reactions of the host to cancer cells, prominent pathological features of solid cancers, but also prognostic biomarkers as well as promising immunotherapeutic targets against cancer . Here, we evaluated the locations and densities of CD3 + and CD8 + TILs in OSCC from 2 independent well‐annotated cohorts, identified optimized cutoff values for their abundance to stratify patients, and determined their prognostic significance.…”

“…Mounting evidence has established that various numbers and types of TILs have been identified in different locations, for example within tumor or surrounding the tumor. Indeed, they are not randomly distributed but are located in specific areas . Several previous studies have suggested that high densities of CD3 + and/or CD8 + TILs associate with favorable outcomes in patients with HNSCC .…”

Toll‐like receptors: The role in bladder cancer development, progression and immunotherapy

“…Thus, cancer immunotherapy has progressed significantly via identification of prognostic biomarkers . Several studies have demonstrated the positive prognostic significance of CD3, CD4 and CD8 T cells and negative correlation of FOXP3‐positive T cells regarding overall survival of bladder cancer patients …”