Exploring the Tumour Microenvironment (TME) in AIDS-Defining Cancers (ADC) and Non-AIDS Defining Cancers (NADC) in the HIV Population: Implications on Remission, Relapse and Resistance

cell signalling-mediated host responses.Predominantly, the TME comprises cellular, noncellular, supporting physical and chemical milieu characteristics signalling pathways and crosstalk mechanisms that modulate multi-dimensionally coordinated evolutionary interactions among the various subunits of the ecosystem.The cellular component includes cancer cells, T-lymphocytes, B-lymphocytes, natural killer (NK) cells, macrophages, dendritic cells, cancer-associated fibroblasts (CAFs), endothelial cells, neutrophils, adipocytes and immune cells [2].The acellular components consist of extracellular matrix (fibronectin, laminins, collagens, proteoglycan, hyaluronan and thrombospondin), extracellular vesicles, apoptotic bodies, exosomes, tumour necrosis factor, interferon-gamma (IFN-), growth factors (plateletderived growth factor (PDGF), epidermal growth factor (EGF), nerve growth factor (NGF), transforming growth factor and (TGF- and TGF-)), chemokines, interleukins and stroma [3].The supporting physical and chemical milieu of TME includes hypoxia (low oxygen levels), low pH (acidic), insufficient blood, and elevated interstitial fluid pressure (interstitial hypertension) [2, 3].The TME not only plays a significant role in tumour initiation, proliferation and progression but also in host immunosuppression, immune evasion, metastasis, treatment failure and multidrug resistance and prognosis.Human immunodeficiency virus (HIV) has been around since the early 1980 s when the complications were discovered in five homosexuals.HIV-associated cancers are often the term used to denote acquired immunodeficiency syndrome (AIDs)-defining cancers (ADC) or "AIDS-defining malignancies (ADM) that people living with HIV manifest as a result of HIV/AIDS infection.Non-acquired immunodeficiency syndrome (AIDs)-defining cancers (NADC) are neoplasms developed by people living with HIV/AIDS that are not necessarily HIV/AIDS-related.Patients living with HIV might have double jeopardy of cancers, that is, ADCs