Untitled Quiz

Study Notes

Carcinogens are substances that cause cancer.
Cancer is a disease caused by uncontrolled division of abnormal cells in a part of the body.
Cancer is a malignant growth of a tumor resulting from cellular division.

Neoplasm: An abnormal new growth of tissue that grows faster than normal cells, competing with them for nutrients. It's a general term, potentially including benign or malignant growths. Tumor is a synonym.
Tumor: A general term for a mass of tissue. This can be benign or malignant.
Benign tumor: A non-cancerous tumor that usually stays localized, rarely spreads, and responds to treatment. However, if untreated, it can become serious.
Malignant tumor: A cancerous tumor that resists treatment, can spread throughout the body, and often recurs after removal. Cancer refers to a malignant tumor.

Genetic:
- Oncogenes
- Tumor suppressor genes
Biological agents:
- Human viral pathogens (retroviruses, DNA viruses like Epstein-Barr, HPV, HBV)
- Bacteria
- Endoparasites (like Schistosoma)
Physical agents:
- Ionizing radiation (causing DNA damage through O2 free radicals).
- Non-ionizing radiation (like UV, specific wavelength range).
Chemical agents:
- Exposure to dyes, luminous paints, and asbestos are linked to lung and bone cancers.
- Arsenic, chrome, nickel salts, nitroso compounds, and some drugs also cause cancer.
Immunosuppressants/immunotoxins: Substances that suppress the immune system. Weakened immune response increases susceptibility to infectious diseases and cancer.

Caloric intake (high fat), protein deficiency
Deficiencies in certain vitamins and minerals: Carotenes, retinoids, tocopherols, selenium (glutathione peroxidase), zinc, flavanoids

Normal cells: Characterized by exact reproduction, stopping when appropriate, sticking together as a group, self-destruction when damaged, specialization, and normal functioning.
Cancer cells: Differ from normal cells; do not properly stop dividing, can migrate to other body parts, generally don't specialize and stick together, don't self-destruct, and may invade surrounding tissues; increased tendency to metastasize (travel outside the original site).

Viral theory: Viruses as a cause for carcinogenesis.
Two-stage mechanism: Cancer development through initiation, promotion, and progression.
Steps in Chemical Carcinogenesis: Biotransformation, initiation, fixation, gene expression/transformation, neoplastic growth/proliferation, progression, metastasis.