Lecture 16 - Neoplasia 3 And 4 Flashcards
What does carcinogenesis mean?
The causes of cancer
What are the 2 types of factors which are risks for the multi factorial nature of neoplasia?
Intrinsic factors
Extrinsic factors
What are 3 Intrinsic factors of carcinogenesis?
Heredity
Age
Sex (particularly hormones)
What are the 2 categories of Extrinsic factors of carcinogenesis?
Environment
Behaviour/lifestyle
What falls in the environment category for extrinsic factors of carcinogenesis?
Chemicals
Radiation
Infection
What is meant by a gene/allele being highly penetrant?
If present will very likely be apparent in the individual
What genes are mutated in breast cancer?
BRCA1
BRCA2
Why does the intrinsic factor of Age increase or make you more likely to develop a neoplasm?
Older you are the more exposer you will have to extrinsic carcinogens
What lifestyle factor makes developpping Endometrial carcinogenesis in post menopausal women more likely?
Obesity
Why does obesity increase risk of Endometrial cancer in post menopausal women?
Adipocytes produce oestrogen (peripheral conversion of androstenedione to oestrogen)
Oestrogen stimulates constant proliferation of endometrial cells
More likely to get endometrial cancer
What are lifestyle factors that can help prevent cancer from developing?
Smoking cessation
Maintains health weight
Balanced diet
Sun safety
Low alcohol consumption
Being Active
How can alcohol cause cancer?
Synergist with tobacco
Liver cirrhosis can lead to hepatocellular carcinoma
What type of cancers does TOBACCO (smoking) increase the risk of developing?
LUNGS
Mouth
Pharynx
Larynx
Oesophagus
Liver
Cervix
What types of cancer does excess alcohol consumption increase the risk of getting?
Pharynx
Larynx
Oesophagus
Liver
Why does smoking increase the risk of getting cervical cancer?
Smoking lowers the immune system
Means cervical cells more vulnerable to HPV (Human Papilloma virus)
What type of cancer is likely to develop with exposure to the chemical 2-napthylamine (in dyes)?
Bladder cancer
What does the risk of cancer depend on?
Total carcinogen dose
How long does it take for a neoplasm to develop following an exposure to a carcinogen?
Long delay
What are the 2 classes of Chemical Carcinogenesis??
Initiators
Promoters
What is special about the chemical carcinogen Tobacco?
Can act as both an Initiator and Promoter
What order do the 2 classes of chemical carcinogens need to be given in for a neoplasm to develop?
Initiator first
Promoter second
What is an Initiator? (Chemical carcinogen)
Chemical carcinogen that produces the initial mutation
What are promoters?
Chemical carcinogens that stimulate the proliferation of the mutated cells allowing for the monoclonal neoplastic population to develop/grow
Where is the chemical carcinogen Benzopyrene normally found?
From Cigarette smoke
Where is the chemical carcinogen 2-naphthylamine normally found?
Cigarette smoke
Dye industry
Where is the chemical carcinogen Aflatoxin B1 normally found?
Fertiliser
What type of cancer is the chemical carcinogen Asbestos likely to cause?
Mesothelioma
What organ does mesothelioma normally affect?
Lungs
What is Mesothelioma?
Cancer which affects the outer lining of organs
Most commonly affects the Pleura of the lungs
Pleura appears thick due to chronic inflammation
What enyzmes convert a Pro-carcinogen to a carcinogen?
Cytochrome P450
Where is cytochrome P450 found?
Liver
What are the 2 classes of chemical carcinogen?
What carcinogen can act as both?
Initiator
Promoter
Tobacco
What types of radiation are ionising/mutagenic?
Alpha particles
Beta particles
Gamma rays
X-rays
UV rays
What are the 2 general ways radiation can be mutagenic?
Directly damage DNA
Indirectly damage DNA
How can radiation Directly damage DNA?
Missense mutations
DNA breaks
How can radiation indirectly damage DNA?
Generating free radicals
E.g: interacting with water forming hydroxyl free radicals