Exam 5 L3-4 Flashcards
Neoplasia
Abnormal growth of cells or tissues, characterized by dysregulated cell proliferation
Difference between malignant and benign
Cancers are less differentiated, invasive, and metastatic
Grading
Estimate of aggressiveness level or malignancy, based on differentiation state and greater clinical value like pap smear
Three fundamental principles of carcinogenesis
Genetic changes (mutations) lie at the heart of carcinogenesis
Oncogenes and Tumor suppressor genes are targets of this damage
Carcinogenesis is often a multistep process with multiple genes involved
Oncogenes
genes that encode proteins that promote cancer
results from mutation, gene duplication, normal version is proto oncogene
Tumor suppressor gene
Genes that encode proteins that inhibit cancer
Two-hit hypothesis
Need a mutation in both genes to lose activity of tumor suppressor to develop cancer
Cancer risk increases with
age
Pediatric cancers
Tend to have single genetic events that are important at a specific developmental time
Adult cancers
Rarely have just a single mutation
Accumulations of somatic mutations
Decline in immune function
How telomerase overexpression leads to cell immortalization
Telomeres at the end of chromosomes shortened with every division can lead to abnormalities, TTAGGG repeats, Limitless replicative potential
How tumors induce angiogenesis
Tumor cells produce vascular endothelial growth factor to promote angiogenesis
How inflammation increases cancer risk
Inflammation results in persistent regenerative cell proliferation or hyperplasia and dna damage as a result of reactive oxygen and nitrogen species produced by immune cells
Staging
aggressiveness based on size and spread
Retinoblastoma
Childhood retinal cancer