Lung cancer remains the leading cause of cancer-related deaths, with an estimated 1.76 million deaths reported in 2018. Numerous studies have focused on the prevention and treatment of lung cancer using rodent models. Various chemicals, including tobacco-derived agents induce lung cancer and pre-cancerous lesions in rodents. In recent years, transgenic engineered rodents, in particular, those generated with a focus on the well-known gene mutations in human lung cancer (KRAS, EGFR, and p53 mutations) have been widely studied. Animal studies have revealed that chronic inflammation significantly enhances lung carcinogenesis, and inhibition of inflammation suppresses cancer progression. Moreover, the reduction in tumor size by suppression of inflammation in animal experiments suggests that chronic inflammation influences the promotion of tumorigenesis. Here, we review rodent lung tumor models induced by various chemical carcinogens, including tobacco-related carcinogens, and transgenics, and discuss the roles of chronic inflammation in lung carcinogenesis.
Despite advances in diagnostics and therapeutics, the prognosis of pancreatic cancer remains dismal. Because of a lack of early diagnostic methods, aggressive local progression, and high incidence of distant metastasis, most pancreatic cancers are inoperable; therefore, the characteristics of early pancreatic cancer have not been well understood. Autopsy studies revealed the characteristics of prediagnostic pancreatic malignancies, including precancerous lesions, early stage pancreatic cancer, and pancreatic cancer without clinical symptoms (occult cancers). Animal models using hamsters and genetically engineered mice have focused on mechanisms of carcinogenesis, thereby providing insights into risk factors and prevention and serving as a preclinical test for the development of novel diagnostic and treatment modalities. In this review, we have summarized pathological changes in the pancreas of humans and experimental animals during carcinogenesis.