Lecture 6 Flashcards
Lecture 6:
What are the top 3 believed causes of Cancer?
Tobacco, overweight/obesity, & infection
Lecture 6:
What is the link between relative cancer risk & BMI?
Bodies with lower BMI’s have less cellular proliferation so decreased chances of mutations
- low weight however still associated with increase cancer risks as underweight people tend to have pre-existing implications (so not just the underweight part)
Lecture 6:
What are the 2 cancers that are the biggest risks for obese people?
1.) Endometrial adenocarcinoma
2.) Esophageal adenocarcinoma
Lecture 6:
How are Obesity & Endometrial Cancer related?
Has the strongest relationship between increasing BMI & endometrial cancer risks
- independent of menopausal status
- each 5kg/m^2 increase in BMI increases risk by 60%
Lecture 6:
How is obesity & esophageal cancer related?
Esophageal cancer increasing, possibly due to higher rate of acid-reflux in obese
- dose-effect relationship with mortality
Lecture 6:
How are obesity & Breast Cancer related?
Pre-menopausal = protective against cancer but post-menopausal = increased risk of breast cancer
- obesity & post-menopausal = most risky combo
- poorer 5-year survival for obese (56%) vs lean (80%)
Lecture 6:
How are Obesity & Colorectal Cancer related?
Linked to early stage tumorigenesis
- may be an interaction with PA (highest BMIs & lowest PA = greatest risk for collateral cancer)
Lecture 6:
How are Obesity & Renal-Cell cancer related?
Moderate relationship between the 2, & causes increased risk independent of hypertension & diabetes
- bigger the BMI = more likely to die of renal cell cancer
Lecture 6:
How are Obesity & Prostate cancer related?
Research currently limited
- body naturally has increased hormones when fat
Lecture 6:
What are some pathophysiological Mechanisms related to obesity & cancer?
- best understood in endocrine cancers (hormone related)
- hyperinsulinemia/IGF-1
- Endogenous sex steroids
- Inflammation & oxidative stress
Lecture 6:
What is Hyperinsulinemia/Insulin-like Growth Factor-1 & what does it do to pancreatic inculin?
Insulin-resistance caused by obesity leading to muscle & liver tissues having reduced response to insulin
- causes an overcompensation of pancreatic insulin to be released
- more of this insulin released due to reduced responses, causing increased risk for cancer
Lecture 6:
What cancers is chronic Hyperinsulinemia/Insulin-like Growth Factor-1 linked to?
- what does it promote
Chronic hyperinsulinemia & IGF-1 is linked to cancer in the colon, endometrium, pancreas, & breasts
- promotes tumour development & inhibits apoptosis
Lecture 6:
What do Endogenous Sex steroids stimulate/promote?
Stimulate cellular proliferation, inhibit apoptosis & increase risk of tumour development
Lecture 6:
How does IGF-1 & Insulin influence Endogenous Sex Steroids?
IGF-1 & insulin stimulate synthesis of sex steroids But inhibit synthesis of sex-hormone binding globulin (which gets “rid of” sex steroids)
Lecture 6:
What is the impact of body fat on Endogenous Sex Steroids?
Body fat = primary producer of estrogen in postmenopausal women
Lecture 6:
What influence does obesity have on Endogenous Sex Steroids?
Obesity increases production of androgens which cause less ovulation & lower progesterone levels
- This is called Polycystic Ovary Syndrome
- causes increased risk of endometrial cancer
lecture 6:
What impact does obesity have on inflammation & cancer risk?
Obesity is associated with chronic inflammation
- causes high production of certain cytokines which can increase tumour initiation & progression
*inflammation = helpful for tumour growth (not ideal)
Lecture 6:
What are 5 ways Physical Activity is Associated worth Increased Cancer Risk?
1.) Caloric Intake
2.) Free Radicals
3.) Trauma
4.) Pulmonary Function
5.) Immune Function
Lecture 6:
How does caloric intake influence cancer risk?
- does more or less calories increase risk?
- Athletes (active people) typically consume more food(exposing them to more toxins/carcinogens)
- Food restriction reduces cancer risk
- Normally not a problem for moderately active people
*less food means body in maintenance stage rather than cellular proliferation
Lecture 6:
What influence does high protein intake have on Cancer risk?
- high animal protein consumption associated with increased cancer risk (eat so much as wanting to increase muscle mass)
- Vegetarians = 60% less risk of cancer compared to meat eaters
Lecture 6:
What influence do free radicals intake have on Cancer risk?
Vigorous PA increases free radicals Which cause cellular damage
- not so problematic for moderately active people intensity activities
Lecture 6:
What influence does Trauma have on Cancer risk?
Can increase risk of some cancers
- vigorous PA causes increase risk of injury, more cell division, & increased risk of cancer
- Bike riding related to increased risk of prostate & testicular cancers
Lecture 6:
How does pulmonary function relate to cancer risk?
Endurance athletes with large lung space have increased cancer risk due to having more epithelial cells & altered air flow patterns
- easier fro particles & pollution to get into lungs
*not a problem for moderately active people exercisers
