Cancer disparities in low- and middle-income countries (LMICs) arise from multifaceted interactions between environmental exposures, infectious agents, and systemic inequities, such as limited access to care. The exposome, a framework encompassing the totality of non-genetic exposures throughout life, offers a powerful lens for understanding these disparities. In LMICs, populations are disproportionately affected by air and water pollution, occupational hazards, and oncogenic infections, including human papillomavirus (HPV), hepatitis B virus (HBV), Helicobacter pylori (H. pylori), human immunodeficiency virus (HIV), and neglected tropical diseases, such as schistosomiasis. These infectious agents contribute to increased cancer susceptibility and poor outcomes, particularly in immunocompromised individuals. Moreover, climate change, food insecurity, and barriers to healthcare access exacerbate these risks. This review adopts a population-level exposome approach to explore how environmental and infectious exposures intersect with genetic, epigenetic, and immune mechanisms to influence cancer incidence and progression in LMICs. We highlight the critical pathways linking chronic exposure and inflammation to tumor development and evaluate strategies such as HPV and HBV vaccination, antiretroviral therapy, and environmental regulation. Special attention is given to tools such as exposome-wide association studies (ExWASs), which offer promise for exposure surveillance, early detection, and public health policy. By integrating exposomic insights into national health systems, especially in regions such as sub-Saharan Africa (SSA) and South Asia, LMICs can advance equitable cancer prevention and control strategies. A holistic, exposome-informed strategy is essential for reducing global cancer disparities and improving outcomes in vulnerable populations.

Thyroid cancer (TC) is a significant global health issue that exhibits notable heterogeneity in incidence and outcomes. In low-resource settings such as Africa, delayed diagnosis and limited healthcare access exacerbate mortality rates. Among follicular cell-derived thyroid cancers—including papillary (PTC), follicular (FTC), anaplastic (ATC), and poorly differentiated (PDTC) subtypes—the role of CD44 variants has emerged as a critical factor influencing tumor progression and multidrug resistance (MDR). CD44, a transmembrane glycoprotein, and its splice variants (CD44v) mediate cell adhesion, migration, and survival, contributing to cancer stem cell (CSC) maintenance and therapy resistance. Differential expression patterns of CD44 isoforms across TC subtypes have shown diagnostic, prognostic, and therapeutic implications. Specifically, CD44v6 expression in PTC has been correlated with metastasis and aggressive tumor behavior, while in FTC, its expression aids in distinguishing malignant from benign lesions. Furthermore, CD44 contributes to MDR through enhanced drug efflux via ABC transporters, apoptosis evasion, and CSC maintenance via the Wnt/β-catenin and PI3K/Akt pathways. Targeted therapies against CD44 such as monoclonal antibodies, hyaluronic acid-based nanocarriers, and gene-editing technologies hold promise in overcoming MDR. However, despite the mounting evidence supporting CD44-targeted strategies in various cancers, research on this therapeutic potential in TC remains limited. This review synthesizes existing knowledge on CD44 variant expression in follicular cell-derived thyroid cancers and highlights potential therapeutic strategies to mitigate MDR, particularly in high-burden regions, thereby improving patient outcomes and survival.

Anaplastic thyroid carcinoma (ATC) is an aggressive and lethal malignancy that carries a poor prognosis. Moreover, there are limited therapeutic options for managing ATC. There is increasing evidence that implicates the role of cancer stem cells (CSCs) in the processes of dedifferentiation in the progression, therapeutic resistance, and metastatic potential of ATC. In this review, we integrate the molecular and cellular insights into the CSCs paradigm in ATC to highlight the role of stemness-associated markers that include CD44, CD133, and ALDH1. We put special emphasis on the role of CD44 and its variant isoforms (CD44v), which play a role in the interface of cancer stemness, tumour microenvironment crosstalk, modulation of epithelial–mesenchymal transition (EMT), chemoresistance, and metastasis. The contribution of signalling pathways (PI3K/AKT/mTOR, MAPK, Notch, Wnt/β-catenin, and Hedgehog) to hypoxia, cancer-associated fibroblasts (CAFs), and tumour-associated macrophages (TAMs) in sustaining CSC niches will be discussed. The review explores advances in molecular diagnostics, imaging technologies, and targeted therapeutic strategies with the potential to disrupt CSC-driven tumour maintenance. Through integration of multigenic, epigenetic, and microenvironmental perspectives, this review highlights the potential necessity of CSC-targeted and combination therapies to improve disease outcomes in ATC.