3 Cancer Study Guide.pdf

Malignant tumors: Characteristics Pathophysiology, including that promoting cancer cell survival Mesenchyme refers to a type of embryonic connective tissue that serves as the precursor to various tissues and orga...

Malignant tumors: Characteristics Pathophysiology, including that promoting cancer cell survival Mesenchyme refers to a type of embryonic connective tissue that serves as the precursor to various tissues and organs in vertebrate embryos. Cancer: diseases in which abnormal cells divide without control and are able to invade other tissues Tumor: describes a new growth, or neoplasm can be benign or malignant (cancerous) Carcinoma in situ (CIS) - Pathophysiology and characteristics CIS is an early stage cancer localized to the epithelium Cancer Prevention - mechanisms of healthy behaviors, especially physical activity Cancer Development Pathophysiology, including advanced malignancies and heritable cancers Example of overexpression: increased activity of telomerase enzyme, adds telomeric repeats to the ends of the chromosomes, maintaining telomere length Genetic lesions - type (e.g. point mutation, chromosome translocation, gene amplification, etc.) and pathophysiology driver mutations: drive the progression of cancer passenger mutations: random events along for the ride  i 6 7 7 8 5  Oncogenes and Proto-oncogenes - characteristics and functions Foremost hallmark of cancer: uncontrolled cellular proliferation Normal cells proliferate in response to growth factors Proto-oncogenes (Genes that direct normal cellular proliferation) Cancer cells express mutated proto-oncogenes → oncogenes Uncontrolled sustained proliferation EX: RAS (oncogene) stimulates more cellular growth. Mutates to never turn off. Autocrine stimulation Ability of cancer to secrete growth factors that stimulate their own growth Tumor-suppressor genes - functions and pathophysiology, especially related to heritable cancer Genetics and Cancer-Prone Families Mutagen exposure & mutation ◦ If in somatic cells, not transferred to offspring ◦ If in germ cells (germline mutant allele) may be transferred to future generations ‣ Usually in tumor suppressor gene ‣ Retinoblastoma (RB gene) ‣ Neurofibromatosis (NF1 gene) ‣ Breast cancer (BRCA1 gene) ‣ Polyposis / colon cancer (APC gene) Consequences of LOH in Cancer Unmasking Recessive Mutations: leads to the inactivation of a tumor suppressor gene → uncontrolled cell growth Increased Predisposition to Cancer: promote development of cancer by affecting genes involved in DNA repair and cell cycle control Heterogeneity: contributes to genetic diversity within tumor → impacts treatment response Diagnostic and Prognostic Marker: used as diagnostic and prognostic tool in cancer research and clinical practice Microsatellite Instability (MSI): characterized by errors in repetitive DNA sequences → further contributes to cancer development Telomeres and telomerase - function and role in cancer Avoid Immune Destruction Tumor: The Great Manipulator Tumor manipulation of inflammatory/immune responses ◦ Wound healing phenotype ◦ Cellular proliferation, neovascularization, local immune suppression Tumor-associated macrophages (TAMs) ◦ TAMs promote tumor survival ◦ TAMs release cytokines → monocytes migrate into tumor → become macrophages at tumor site ◦ Anti-inflammatory (healing) macrophage phenotype ‣ ↓ cytotoxic response ‣ Block Tc and NKC factors ◦ TAMs secrete cellular growth factors → increased tumor growth and invasion Epigenetic processes - mechanisms and interpretation/meaning loss of function mutation Inflammation, immunity, and cancer - pathophysiology Chronic inflammation Viral infections, especially human papillomavirus - immune response, pathophysiology Helicobacter pylori disrupts pH balance and homeostasis of the stomach environment, leading to inflammation G = Greater pH, D = Decreased pH Tumor staging - interpretation  Chemotherapy -- side effects Side effects: GI, bone marrow/hematologic, hair & skin, reproductive N/V, cachexia, myelosuppression, anemia, alopecia, infertility