Apoptosis, anoikis and anoikis resistance in cancer: A comprehensive review

Apoptosis is a highly regulated form of programmed cell death essential for normal development, tissue homeostasis, and elimination of damaged or unwanted cells. Anoikis represents a specialized form of apoptosis triggered when anchorage?dependent cells lose contact with neighboring cells or the extracellular matrix (ECM). While anoikis serves as a critical barrier against inappropriate cell survival and dissemination, cancer cells frequently acquire resistance to anoikis, enabling survival during detachment, circulation, and metastatic colonization. This review provides an integrated and detailed account of apoptosis and anoikis, focusing on their molecular mechanisms, signaling pathways, and morphological features. Special emphasis is placed on the mechanisms underlying anoikis resistance, including constitutive activation of anti?apoptotic signaling, epithelial-mesenchymal transition (EMT), oxidative stress, hypoxia, and their contribution to tumor metastasis. Understanding these processes offers valuable insights into cancer progression and identifies potential therapeutic targets to prevent metastasis.