Tumour Microenvironment in Therapy of Metastatic Cancer

GLOBOCAN 2020 has reported that the global cancer burden is 19.3 million cases, with 10 million deaths¹. The overall survival (OS) after treatment with innovative cancer therapies has not changed for most metastatic cancer patients, and more in-depth study is needed. Several studies have suggested that understanding the cellular and molecular mechanisms underlying metastatic processes can be used as a novel strategy to disrupt cancer cell pathways and contribute to the development of effective and safe therapies against metastatic cancer. Recent studies have shown that the tumour microenvironment (TME) is responsible for reprogramming tumour initiation, progression, invasion, and metastasis. Thus, TME probably hinders positive responses to innovative therapies. Therefore, clinicians must consider targeting major cell components associated with TME instead of only using presently available genomic profiles of tumours for effective treatment of metastatic cancer patients. Various investigators have already identified specific cell types from TME that are involved in the progression and resistance of cancer cells². These include circulating tumour cells (CTCs), cancer-associated fibroblasts (CAFs), cancer stem cells (CSCs), immune cells, endothelial cells, etc., from highly metastatic cancer patients. The development of this support niche is critical for persistent uncontrolled growth of cancer at the metastatic stage. This special issue on “Tumour Microenvironment in Therapy of Metastatic Cancer” describes various cell types and components involved in tumour growth, invasion and metastasis, and also addresses various strategies that can be implemented to target these resistant cancer cells for effective cure of metastatic cancer in the near future.