carcinogenesis Flashcards
define carcinogenesis
- the transformation of normal cells to neoplasmic cells through permenet genetic alterations or mutations
outline the difference between carcinogenesis and oncogenesis.
- Oncogenesis: Refers to the process of tumor formation, which includes both benign and malignant tumors.
- Carcinogenesis: Refers specifically to the process of cancer formation, describing the transformation of normal cells into malignant cancer cells with the potential to invade and spread.
outline the different classes of carcinogens.
- Chemical
- Viral
- Ionising and non-ionising (UV) radiation
- Hormones, parasites and mycotoxins
- Miscellaneous (doesn’t fit into a category)
define the term mutagenic and how does it relate to carcinogenesis and oncogenesis?
- process which alters DNA
- is baso what happens in both these
name some ways we have begun to identify carcinogens and what they are.
- lab tests including animal testing, cell and tissue cultures and testing on bacteria
- epidemiological studies - strong associations between specific events and the development of cancers eg Chernobyl and thyroid cancer
- epidemialogical evidence - eg in japan they have more oesophageal cancer bc they drink scolding hot drinks
- assessment of occupational risks - eg in rubber and dye workers
- behavioural risks eg smoking
outline a few examples of chemical carcinogens
polycyclic aromatic hydrocarbons - found in smoking and mineral oils - lung and skin cancer
aromatic amines - bladder cancer - rubber/dye workers
nitrosamines - gut cancer - proven in animals
alkylating agents (cancer meds) - leukaemia - small risk
outline some examples of viral carcinogens
- hepB and hepC - hepatocellular carcinoma
- human papillomavirus - common wart (benign) and cervical carcinoma
- epstein-Barr virus - Burkitts lymphoma and nasopharyngeal cancer - needs a cofactor thought to be malaria
outline some examples of some ionising and non-ionising carcinogens and give an example of what types of cancer they cause.
non ionising - UVA and UVB - sunlight
- UVB more so than UVA
- malignant melanoma and basal cell carcinoma
ionising - xrays, uranium mining - increased risk of leukemia
outline some biological carcinogens.
- increase in oestrogen - mammary / endometrial carcinomas
- anabolic steroids - hepatocellular cancer
- mycotoxins which come from fungi - hepatocellular carcinoma
- bacteria, H. pylori - gastric adenocarcinoma
- parasites - bladder cancer
outline a few miscellaneous carcinogens
- asbestos
- metals - lead
name some host factors which are cancer causing
- race - dec in skin cancer bc more melanin
- Diet / Lifestyle - fatty foods, red and processed meats meats, smoking and alcohol
- Constitutional factors - age (more cell divisions), gender, (eg women w breast bc of oestrogen) etc.
- Premalignant lesions - polyp
- Transplacental exposure - things exposed to in placenta before birth
outline some premalignant condition host factors
Identifiable local abnormality associated with increased risk of malignancy at that site:
Colonic polyps
Cervical dysplasia (CIN)
Ulcerative colitis
Undescended testis
outline a transplacental host factor carcinogen
Diethylstilboestrol (drug) was administered to pregnant women to prevent them miscaraging → ↑ vaginal cancer - increased daughters chance of getting cancer
jared has been smoking the lit end of a cigarette for the majority of his adult life, what type of cancer does this increase his changes of getting?
oral
define a co-factor in the context of carcinogenesis
- something which does not directly cause carcinogenesis but when paired with a primary carcinogen, increases the risk of carcinogenesis
