Cancer pathogenesis
is traceable back to DNA mutations that impact cell growth and
metastasis. Substances that cause DNA mutations are known as
mutagens, and mutagens that cause cancers are known as
carcinogens. Particular substances have been linked to specific
types of cancer. Tobacco smoking is associated with lung cancer
and bladder cancer. Prolonged exposure to asbestos fibers is
associated with mesothelioma.
Many mutagens are also carcinogens, but some carcinogens are not
mutagens. Alcohol is an example of a chemical carcinogen that is
not a mutagen. Such chemicals are thought to promote cancers
through their stimulating effect on the rate of cell mitosis.
Faster rates of mitosis leaves less time for repair enzymes to
repair damaged DNA during DNA replication, increasing the
likelihood of a genetic mistake. A mistake made during mitosis
can lead to the daughter cells receiving the wrong number of
chromosomes.
Decades of research have demonstrated the strong association
between tobacco use and cancers of many sites, making it perhaps
the most important human carcinogen. Hundreds of epidemiological
studies have confirmed this association. Further support comes
from the fact that lung cancer death rates in the United States
have mirrored smoking patterns, with increases in smoking
followed by dramatic increases in lung cancer death rates and,
more recently, decreases in smoking followed by decreases in
lung cancer death rates in men.
Causes Ionizing
radiation & Infectious diseases >>
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Cancer
Classification
1. Nomenclature
2. Adult cancers
3. Childhood cancers
Signs and symptoms
Diagnosis
1. Investigation
2. Biopsy
Treatment
1. Surgery
2. Radiation therapy
3. Chemotherapy
4. Targeted therapies
5. Immunotherapy
6. Hormonal therapy
7. Symptom control
8. Complementary and alternative
9. Treatment trials
Prognosis
1. Emotional impact
Causes
1. Chemical carcinogens
2. Ionizing radiation &
Infectious diseases
3. Hormonal imbalances & Immune system dysfunction
4. Heredity & Other causes
Pathophysiology
1. Epigenetics
2. Oncogenes
3. Tumor suppressor genes
4. Cancer cell biology
4.1 Clonal evolution
4.2 Biological properties of cancer cells
Prevention
1. Modifiable ("lifestyle") risk factors
2. Diet
3. Vitamins
4. Chemoprevention
5. Genetic testing
6. Vaccination
7. Screening
Epidemiology
History
Research |
