Environmental Factors

Question 1

what causes cancer?

Answer 1

Mutations in genes resulting in a cell which grows and proliferates at an uncontrolled rate, is unable to repair DNA damage within itself, or refuses to die (apoptosis).

Question 2

what are 3 ways genetic errors can occur?

Answer 2

• viruses
• inherited
• exposure to chemicals/ radiation

Question 3

what are the areas of oral cancer?

Answer 3

tongue
buccal tissues
lips
salivary glands
gums

Question 4

what type of oral cancer accounts for 90% of cases?

Answer 4

squamous cell carcinoma

Question 5

what are the risk factors for oral cancer?

Answer 5

• Tobacco
• Alcohol
• Poor diet/ obesity
• Immunological defect
• Sunlight
• Previous cancer
• Genetic conditions e.g., phancomious anaemia (bone marrow suppression) and dyskeratosis congenita.
• Potentially malignant conditions

Question 6

what risk factors have a synergistic relationship?

Answer 6

alcohol and tobacco

Question 7

how much is risk increased with alcohol and tobacco?

Answer 7

24 times

Question 8

what does alcohol and tobacco do to mucosa in the mouth?

Answer 8

thinning and atrophy - more susceptible to carcinogens entering the epithelial barrier

Question 9

what are some cancer causing chemical compounds found in tobacco smoke?

Answer 9

tar
arsenic
polycyclic aromatic hydrocarbons - benzopyrene
nitrosamines
acrolein
hydrogen cyanide
CO
ammonia

Question 10

how many years after quitting smoking would you be classed as a non smoker?

Answer 10

20

Question 11

where has oral cancer got its biggest prevalence?

Answer 11

asia

Question 12

what cancer causing chemical is present in betel nut?

Answer 12

arecoline has an alkaloid in the nut

Question 13

what are the effects of betel nut on the oral cavity?

Answer 13

stimulate collagen synthesis by 170%
increase resistance of collagen degradation
DNA damage

Question 14

what are the effects of pan on the oral cavity?

Answer 14

increased scarring
trismus
submucosa fibrosis

Question 15

what makes alcohol carcinogenic?

Answer 15

metabolised to acetaldehyde

Question 16

where is alcohol metabolised?

Answer 16

salivary glands
mucosa
oral bacteria

Question 17

what are the stages in ethanol oxidation?

Answer 17

ethanol -> acetaldehyde (by ADH)
Acetaldehyde -> acetate (by ALDH)
CO2+ H20

Question 18

what are the alcohol recommendations daily and weekly?

Answer 18

daily - 2 units
weekly - 14 units
at least 2 days alcohol free

Question 19

what is classed as a binge of alcohol?

Answer 19

female - more than 6 units
male - more than 8 units

Question 20

why is the alcohol limit lower for females?

Answer 20

higher proportion of body fat and less water = higher concentration of alcohol in the body water

higher blood alcohol levels due to lower gastric ADH activity

Question 21

how much higher is a womans blood alcohol level compared to a male?

Answer 21

1/3rd

Question 22

what does a poor diet lack?

Answer 22

vit C
vit E
antioxidants
Zinc
beta-carotene
folate

Question 23

why is folate essential in a healthy diet?

Answer 23

if lacking (iron deficiency) the mucosa is thin and readily accessible for carcinogens

Question 24

where would you find lip cancer?

Answer 24

lower lip in tissue that forms lining of the lip up until the vermillion border

Question 25

what is lip cancer associated with?

Answer 25

immunosuppression