Tumor characteristics and causes of cancer

Cancer

Unrestrained and excessive growth of cells

Neoplasm

New growth; may be benign or malignant

Malignant tumor

Cancerous growth that invades surrounding tissues and can spread to distant sites

Benign tumor

Noncancerous growth that generally grows slowly and does not spread

Metastasis

Spread of a malignant tumor to a secondary site

Carcinogenesis

Transformation of a normal cell into a cancerous cell

Anaplasia

Loss of cell differentiation; reversion to a more primitive cell type

Differentiation

Specialization of cells

Dedifferentiation

Loss of cell differentiation; reversion to a more primitive cell type

Encapsulated

Surrounded by a capsule; characteristic of benign tumors

Invasive

Able to enter and destroy surrounding tissue

Infiltrative

Extending beyond normal tissue boundaries into adjacent tissues

Mutation

Change in a cell's genetic material (DNA)

Apoptosis

Programmed cell death

Mitosis

Cell division that produces two daughter cells

DNA

Genetic material that controls cell division and protein synthesis

RNA

Cellular substance copied from DNA that directs protein formation

Gene

Segment of DNA containing instructions for making a protein

Nucleotide

DNA component consisting of a sugar, phosphate, and base

Carcinogen

Agent that can cause cancer

Oncogene

Gene that can promote cancerous transformation when activated

Suppressor gene

Gene that helps regulate cell growth and suppress cancer development

Translocation

Movement of genetic material between chromosomes

Philadelphia chromosome

Chromosome formed by a translocation involving the bcr and abl genes, associated with chronic myeloid leukemia

Genetic screening

Testing to determine whether a person has inherited a cancer-associated gene

Carcinogenesis environmental agents

Chemicals, radiation, and viruses that can damage DNA and cause cancer

Chemical carcinogens

Cancer-causing substances such as asbestos, dyes, industrial chemicals, hydrocarbons, and insecticides

Radiation as a carcinogen

Energy from sunlight, x-rays, or radioactive substances that can damage DNA

Viral carcinogens

Viruses associated with cancers, including HPV and hepatitis B and C viruses

ras

Oncogene associated with colon cancer in the chapter

myc

Oncogene associated with lymphoma in the chapter

bcr-abl

Abnormal gene combination associated with chronic myeloid leukemia

Heredity and cancer

Inherited DNA mutations can increase susceptibility to certain cancers

Retinoblastoma

Tumor of the retina associated with an inherited cancer syndrome