Patho Chapter 10: Biology of Cancer – Flashcards

Benign: grows slowly, well-defined capsule, not invasive, well differentiated, low mitotic index (not undergoing mitosis as often), do not metastasize (localized) Malignant: grows rapidly, not encapsulated, invasive, poorly differentiated (anaplasia), high mitotic index (don't pay attention to the body's growth control), can spread distantly (metastasis), express tissue antigens, produce substances that they don't normally do

Carcinoma: epithelial tissue (skin cancers) Adenocarcinoma: from ductal or glandular tissue Sarcoma: mesenchymal tissue (ex: CIS) Lymphoma: lymphatic tissue Leukemia: blood-forming cells (WBC) Carcinoma in situ (CIS): pre invasive (has the ability to become invasive) epithelial malignant tumors of glandular or epithelial origin that have not broken through the basement membrane or invaded the surrounding stroma (not benign or malignant)

- abnormal substances produced by cancer cells that are found on or in tumor cells, in the blood, CSF, or urine Used to: screen and identify individuals at high risk for cancer, diagnose specific types of tumors, observe clinical course of cancer *problems occur with false positives and negatives* Examples: hormones, enzymes, genes, antigens, & antibodies - prostate specific antigen

mutation of tumor-suppressor genes (allows unregulated cellular growth) - allows apoptosis to stop oncogene - proto-oncogene can convert to oncogenes (going from to controlled to uncontrolled)normal to mutation

loss of differentiation - occurs in malignant tumors

the cells become more slippery and do not stick together (nonadhesive), shed easily

Proto-oncogene: normal genes that direct protein synthesis and cellular growth Oncogene: mutant genes Viral Oncogene: responsible for oncogenesis resulting from persistent viral infection Tumor-supressor gene: encode proteins that in their normal state negatively regulate proliferation - apoptosis (referred to as anti-oncogenes)

Cytokine release that increases vulnerability of cancer • Helicobacter pylori leads to chronic inflammation associated with . . . - peptic ulcer disease - stomach carcinoma - mucosa-associated lymphoid tissue lymphomas • Tumor-associated macrophage (TAM) . . . - key cells that promote tumor survival - presence of frequently correlates with a worse prognosis - have diminished cytotoxic response - develop the capacity to block T-cytotoxic cell and NK cell functions and produce cytokines that are advantageous for tumor growth and spread - produces cytokines

Viral : change cells DNA - mutations keep occurring due to uncontrolled cell division not resulting in apoptosis - Hepatitis B and C viruses - Epstein-Barr virus (EBV) - Kaposi sarcoma herpesvirus (KSHV) - Human Papillomavirus (HPV) - Human T-cell leukemia-lymphoma virus (HTLV) Bacterial: inflammatory response and how it causes cancer - stomach carcinoma - peptic ulcer disease

Growth Rate: cancer cells can activate telomerase (unlimited division and proliferation) Angiogenesis: creation of new blood vessels - advanced cancers can secrete angiogenic factors (VEGF) Lack of Cellular Adhesion: cells no longer adhere together and they become slippery moving throughout the body Absence of cellular barriers:

Favor: - right types of tissues - strong cells Inhibit: - weak cells - wrong types of tissues

Pain: • little or no pain is associated with early stages of malignancy • influenced by fear, anxiety, sleep loss, fatigue, & overall physical determination • mechanisms . . . - pressure - obstruction - ischemia - invasion of sensitive structures - stretching of visceral surfaces - tissue destruction - inflammation/infection Fatigue: • most frequently reported symptom • subjective clinical manifestation • tiredness, weakness, lack of energy, exhaustion, lethargy, inability to concentrate, depression, sleepiness, boredom, and lack of motivation • suggested causes . . . - sleep disturbance - biochemical changes secondary to disease & treatment - psychological factors - level of activity - nutritional status - environmental factors - anemia Cachexia: • most severe form of malnutrition (looks skeletal) • includes anorexia, early satiety, weight loss, anemia, asthenia, taste alterations, & altered protein, lipid, & carbohydrate metabolism Anemia: • a decrease of hemoglobin in the blood (not getting enough oxygen) • mechanisms . . . - chronic bleeding resulting in iron deficiency - severe malnutrition - medical therapies - malignancy in blood-forming organs Leukopenia/Thrombocytopenia: - decreased WBC count and platelets • direct tumor invasion to the bone marrow causes leukopenia and thrombocytopenia • chemotherapy drugs are toxic to the bone marrow Infection: • risk increases when the absolute neutrophil and lymphocyte counts fall Gastrointestinal: *occurs with treatment* • oral ulcers causes by decreased cell turnover from chemotherapy and radiation • malabsorption • diarrhea • therapy-induced nausea Hair and Skin: *occurs with treatment* • alopecia (hair loss) from chemotherapy (usually temporary) • skin breakdown and dryness

Surgery: - to prevent cancer (colon polyps) - biopsy for diagnosis and staging - lymph node sampling - palliative surgery Chemotherapy: - takes advantage of specific vulnerabilities in target cancer cells - usually given in combinations designed to attack a cancer from many different weaknesses at the same time • inductive - for shrinkage or disappearance of tumors • adjuvant - eliminate micro metastasis after surgery • neoadjunvant - given before localized treatment to shrink tumor Radiation: -eradicate cancer without excessive toxicity - avoid damage to normal structures - ionizing radiation damages the cancer cell's DNA (causes it to die) Immunotherapy: - vaccines against oncogenic viruses provide protection and prevent the onset of viral-induced tumors - numerous potential therapeutic vaccines have been tested with little success