Cancer

Neoplasia (abnormal growth)

Abnormal, uncontrolled growth and reproduction of cells, forming a neoplasm (tumor)

Reproduction of cells

Cancer - Disease of abnormal cell growth where cells divide uncontrollably, invade nearby tissue, and can spread (metastasize)

Hyperplasia

Increase in the number of cells in a tissue; cells look normal (can be normal or a response to stimulus)

Dysplasia

Abnormal change in cell size, shape, and organization; often precancerous

Carcinoma

Malignant tumor from epithelial tissue (ex: skin, lung, breast) Sarcoma | Malignant tumor from connective tissue (ex: bone, muscle, fat)

metastatis

Spread of cancer cells from the original site to distant sites through blood or lymph

Oncogene

Mutated gene that promotes uncontrolled cell growth ("gas pedal stuck on")

Tumor suppresor gene

Gene that normally stops cell growth or triggers apoptosis (ex: p53); when mutated, the "brakes" fail

differntiation

How much cells resemble the normal, mature cells of their tissue of origin

Well-differentiated cancer

Cells look close to normal; usually slower growing and less aggressive

Poorly differentiated cancer

Cells look very abnormal; usually faster growing and more aggressive

Apoptosis

Programmed, normal cell death; removes old or damaged cells. Cancer cells escape apoptosis

Neoplasia

New, uncontrolled cell growth that forms a tumor (benign or malignant)

Anaplasia

Loss of cell differentiation; cells become primitive and unrecognizable. Hallmark of malignancy

Metaplasia

One mature cell type is replaced by another mature cell type, usually from chronic irritation; reversible (ex: smoker's airway cells)

benign tumor

Well-differentiated, slow growing, encapsulated, does not invade or metastasize. Usually named with "-oma" (ex: lipoma)

Malignant Tumor

Poorly differentiated, fast growing, not encapsulated, invades tissue, can metastasize. Named carcinoma or sarcoma

Carcinogenesis

Process by which normal cells become cancer cells, through DNA mutations

Stage 1 of carcinogenesis

Initiation | A carcinogen (chemical, radiation, virus) causes a permanent DNA mutation

stage 2 of carcinogenesis

Promotion | Mutated cells are stimulated to multiply by promoters (hormones, diet, smoking); can be reversible

stage 3 of carcinogenesis

Progression | Cells become malignant, grow faster, invade tissue, and metastasize; irreversible

TNM System

T = tumor size, N = lymph node involvement, M = metastasis

Staging vs grading

Staging = how far the cancer has spread (TNM). Grading = how abnormal the cells look

how cachexia occurs

Severe wasting of muscle and fat, weight loss, and weakness in cancer: How cachexia occurs | Tumor and immune cells release cytokines (TNF-α, IL-1, IL-6) that raise metabolism, cause anorexia, and break down muscle and fat. Tumor also competes for nutrients

Chemotherapy

Cytotoxic drugs that destroy cells

Chemo collateral effect

Also affects healthy, rapidly multiplying cells: skin, hair, gastric, and bone marrow cells

chemo side effects

Dry mouth, anorexia, nausea and vomiting, alopecia, bone marrow suppression

Immunotherapy (biological cancer therapy)

Enhances the body's immune response to cancer cells

How immunotherapy works

Uses cytokines to attack cancer, inhibits T-cell deactivation, uses antibodies to target cancer cell antigens

Biomarkers

Unique genes, proteins, enzymes, or growth factors of a patient's cancer; used to assign treatment, monitor progress, and evaluate prognosis. Serial measurements are most important

Biomarkers and therapy

Biological, targeted, and immunotherapies work on cancers with specific biomarkers

Common metastasis sites

Liver, bone, and lungs

adenoma

Benign tumor of glandular tissue or organ

Lipoma

Tumor derived from fat cells

Hemangioma

Collection of blood vessels in skin or an internal organ

desmoid tumors

Can be highly invasive but does not metastasize

Nevi

Noncancerous moles on the skin

Myoma

muscle tumor

Adenocarcinoma

Cancer of glandular or ductal tissue

sarcoma

Cancer of mesenchymal origin (connective tissue, cartilage, bone)

Osteoma vs. osteosarcoma

steoma = benign bone tumor. Osteosarcoma = malignant Chondroma vs. chondrosarcoma | Chondroma = benign cartilage tumor. Chondrosarcoma = malignant

Proto-oncogenes

Regulate cell growth

Immunocompetence

Immune system should destroy abnormal cells; declines with aging

paraneloptic syndrome

Unexpected pathology provoked by cancer, not due to its space-occupying or metastatic effects (ex: secreted hormone-like substances). Often the 1st sign of cancer