Why do rats die from cancer? - briefly
Rats succumb to cancer because tumors rapidly invade essential organs, impairing physiological functions and leading to systemic failure. Many laboratory strains possess a high predisposition to neoplastic disease, which accelerates progression and results in death.
Why do rats die from cancer? - in detail
Rats develop malignant tumors that compromise vital organ function, disrupt metabolic balance, and trigger systemic failure. Genetic predisposition in laboratory strains often includes mutations in tumor‑suppressor genes such as p53, which accelerate uncontrolled cell proliferation. Environmental carcinogens—polycyclic aromatic hydrocarbons, nitrosamines, and radiation—induce DNA adducts that escape repair mechanisms, leading to oncogenic transformation.
Key mechanisms of lethality include:
- Rapid tumor growth that obstructs blood flow, causing ischemia in surrounding tissue.
- Invasion of surrounding structures, resulting in loss of organ integrity (e.g., lung carcinoma impairing respiration).
- Metastatic spread through lymphatic and vascular routes, establishing secondary lesions in liver, brain, and bone marrow.
- Paraneoplastic syndromes, where tumor‑derived factors alter hormone levels and immune responses, producing cachexia and anemia.
- Suppression of immune surveillance; malignant cells down‑regulate major histocompatibility complex expression, evading detection by cytotoxic lymphocytes.
Physiological stress from tumor burden elevates cytokine production (TNF‑α, IL‑6), leading to chronic inflammation and multi‑organ dysfunction. As tumor mass expands, nutrient depletion and hypoxia intensify, further impairing cellular viability. End‑stage disease culminates in organ failure, typically respiratory or cardiovascular collapse, which accounts for the observed mortality in rodent cancer models.