Cancer Flashcards
how many people will get cancer
1 in 2
lists the main factor that causes cancer
smoking weight fruit and veg alcohol sun red meat fibre PA salt
how many mutated genes are needed to cause cancer
at least 5/6
how many bases are lost from telomeres after each divide
30 - 200 base pairs
how many cancerous cells are needed for it to be detected
10 billions
what is remission
when the cancer can no longer be detected, below 10 billion cancerous cells
how do PA and energy intake effect colon cancer
low PA and High EI are assocatied with colon cancer
exercise and cancer prevention - oestrogen
active women
- have lower oestrogen
- achieve menarche later; active women achieve menopause earlier
- have lower body fat - Adipose tissue produces oestrogen
- have increased sex hormone binding globulins (SHBG)
- SHBG known to decrease breast cancer risk
- SHBG lowers concentration of circulating oestrogens
- SHBG reduces breast cancer cell growth and proliferation - have greater insulin sensitivity and reduced IGF
- Lower circulating [insulin] = greater [SHBG]
- IGF promotes breast tissue proliferation
effect of oestrogen on breast cancer
increased exposure to oestrogens increase risk of breast cancer
exercise and cancer prevention
- PA increases immune function
- PA increases activity of - Killer T lymphocytes - Macrophages
- Promotes clearance of cancer cells
- PA promotes antioxidant status
- PA decreases transit time
• PA aids smoking cessation
evidence for PA as cancer intervention
prelimianry evidence that exercsie interventions for cancer patients can lead to moderate increase in physical function and are not assocaited with increased symptons of fatigue
but impossible to determine whether exercsie has long term beneficial effects on survival or quality of life
physiological benefits of exercise for people with cancer
- Enhanced physical function & aerobic capacity
- Improved body composition
- Decreased nausea
- Reduced fatigue
- Improved flexibility
psychological beneifts of exercise for people with cancer
- Greater quality of life
- Better psychological adjustment
- Reduced depression and anxiety
- Maintenance of body image
- Limited effect on self-esteem
why should we be cautious about benefits of exercise
Should advocate exercise for cancer patients to improve QoL, not as a means to fight cancer or improve survival
things to consider when prescribing exercise
- Effects of surgery – Range of motion, pain, scar tissue
- Deconditioning – Cardiopulmonary function
- Muscular weakness – Lean body tissue, sarcopenia, scar tissue
- Treatment side-effects – Fatigue, nausea, weight change
- Medications – May influence HR response
- Psychological well-being – Depression, anxiety, stress, self-esteem, body image
- Other chronic conditions – CVD/CHD, osteoporosis, diabetes, age
contraindications to exercise
- Haemoglobin level < 10.0 g/dL – Avoid high-intensity (i.e. significant O2 transport burden)
- Absolute neutrophil count < 0.5 x 109/µL – Avoid activities which increase risk of bacterial infection (e.g. swimming)
- Platelet count < 50 x 109/µL – Avoid activities with increased risk of bleeding/bruising (e.g. contact)
- Fever > 38°C (100.4°F) – May indicate systemic infection, so avoid high-intensity exercise
- Ataxia, dizziness, peripheral sensory neuropathy – Avoid activities which require significant balance & coordination
- Severe loss of > 35% of pre-morbid weight – Loss of muscle mass usually limits exercise to moderate intensity
- Dyspnoea – Investigate cause; exercise to tolerance
- Pain/nausea/fatigue/muscle weakness – Investigate cause; exercise to tolerance
cancer and proto-oncogens
growth and development
become activated due to risk factors
increase cell divison
- rapid and uncontrolled
cancer and tumor supressor gene
becomes deactiavted
cannot signal for cell death
protein has changed so no longer recognised
what is a teleomere
end of a chromosone
base pairs which dont code for anything
act as a buffer - each replication, teleomere gets shorter as we never fully replicate
prevents good sequence getting affected
what is an imortal cell
cancerous cells have teleomere which continally adds to the teleomere
so never get to senecent stage
process of metastasis
cell becomes cancerous - divides becoming a neoplasim
once 1 billion + cells can no longer rely on diffusion for supply
angiogensis - own blood suppply = now melignant
breaks into blood and lymph
travels round the body
proliferates into other cells
why do many cancers spread to the lungs
all blood travels through the lungs
