Cancer Flashcards
what is cancer?
- the causes of cancer are known to be __________ –> explain
a group of diseases with processes associated with uncontrolled and abnormal cell growth and proliferation
- cancer can be caused by various things in different people = IDIOPATHIC! –> cause of cancer in a given person may never be known
at least how many types of cancers are there?
- we can separate them into 4 groups: name + describe
at least 30 different types!
CARCINOMA:
- cancer in skin or tissues that line the internal organs (epithelial tissues)
- ie skin, breast, prostate
SARCOMA:
- cancer in muscle, connective tissue, fat and bone
LYMPHOMA:
- cancer in lymphatic system
LEUKEMIA:
- cancer in blood-forming tissue (bone marrow)
- cancer is which position on chart of causes of death in Canada in 2021? vs in US in 2017
- US 2017: how many men and women have cancer in their lifetime?
- globally how many deaths are due to cancer in 2018? rate is expected to increase/decrease due to what?
- only ___-____% of cancers are linked to heredity –> most are due to what?
- cancer = leading cause of death in Canada in 2021, followed by heart disease
- second leading cause in US in 2017 –> 40% men + 38% women over lifetime
- approx. 9.6M deaths –> rate is expected to RISE due to growth and ageing of world population
- 10-15% –> most are due to external factors such as lifestyle or environmental factors
- do all cancer types have the same economic cost? –> why? (3 ish)
- 2015: estimated cost of cancer due to direct medical case = ?
- this number doesnt account for what?
CONCLUSION?
- no! direct and indirect costs of cancer differ by cancer type –> different cancers have different outcomes –> long-term treatment vs quick fatality vs curable if diagnosed early –> lots of variation!
- 80.2B USD!
- doesn’t account for lost productivity of ppl living with cancer + lost productivity
*Cancer is important to address as a public health problem! –> very big economic burden
- cancer is caused by both _________ (3) and _________ (4) factors
- these factors can act __________ or ___________ over time
INTERNAL
- heredity
- immune dysfunction
- abnormal metabolism
EXTERNAL:
- smoking
- sedentary lifestyle
- pollution
- radiation exposure
can act alone OR in synergy over time
explain the multistage model of carcinogenesis
- same for all types of cancer?
same for all types of cancers!
STAGE 1 = INITIATION
- irreversible genetic mutation, spontaneous change or an external cause (ie carcinogen or UV)
- genetic material altered (becomes converted cells) and cells grow more quickly
STAGE 2 = PROMOTION
- some converted cells become precancerous by more genetic alterations (caused by tumor promoter or UV)
- characterized by rapid proliferation of converted cells
STAGE 3 = PROGRESSION
- Proliferating precancerous cells become full, invasive tumors –> leads to metastasis
- these cells can now be identified as cancer cells
what are the 2 types of tumors? describe
BENIGN
- non-cancerous
- do not spread and are usually non life-threatening
MALIGNANT
- cancerous
- invade neighbouring tissue and spread to other parts of the body –> metastasis
why is it important to understand the multi-stage model of carcinogenesis?
bc it allows us to study the possible mechanisms by which PA and other factors can interrupt this process and prevent cancer from progresing
what are the 3 traditional cancer treatments? + describe
CHEMOTHERAPY
- systemic radiation therapy uses radioactive substances that travel in blood and kill cancer cells
RADIATION THERAPY
- high energy radiation to shrink tumors and kill cancer cells
- no substances
HORMONE THERAPY
- offered if tumor is hormone receptor positive
- removes hormones from body and blocks their actions to limit growth of cancer cells
____% of annual cancer deaths from cancer in US were related to lifestyle risk factors in 2014
- what are the 4 general lifestyle risk factors that lead to cancers?
45%!
- obesity
- Physical inactivity
- unhealthy eating
- smoking
what are 3 nonmodifiable risk factors of cancer? describe
AGE
- greater risk if older –> bc most cancers develop over time from damaged genes
- >70% of cancers occur in adults over age of 55
HEREDITY (GENETICS)
- cancer depends somewhat on genetics
BUT engaging in healthy lifestyle can lessen overall risk by improving circulation, ventilation, bowel transit time, E balance, immune function and DNA repair
SEX
- some cancers are sex-specific (ie prostate for males vs reproductive (ovarian/endometrial) for females)
what are 6 modifiable risk factors for cancer?
- physical inactivity
- tobacco use
- poor nutrient intake
- obesity
- sun exposure
- toxic environmental exposure
explain how
- physical inactivity
- tobacco use
- obesity
can increase risk of cancer
PHYSICAL INACTIVITY
- emerging as an important risk factor for many cancers
- being physically active may lower risk of developing cancer
TOBACCO USE
- associated with 169 000 cancer deaths in 2009
- main risk factor for lung and bronchial cancers
- associated with lower levels of aerobic capacity and functional health
OBESITY
- having BMI >25 or 30 significantly increases risk of most cancers
explain how
POOR NUTRIENT INTAKE
SUN EXPOSURE
TOXIC ENVIRONMENTAL EXPOSURE
can increase risk of cancer
POOR NUTRIENT INTAKE
- diet low in essential nutrients (those found in f&v) + consumption of excessive alcohol can increase risk of cancers
SUN EXPOSURE
- excessive sun exposure and indoor tanning are 1° risk factors for skin cancers
TOXIC ENVIRONMENTAL EXPOSURE
- long-term exposure to chemical, ionizing radiation and infectious diseases increase risk of most cancers
relationship btw PA and reduced cancer risk have been found consistently in which 2 cancers? explain
+ both found what type of relationship?
a dose response relationship!
BREAT CANCER
- avg risk of breast cancer is 10-15% lower among most physically active women VS inactive women
COLON CANCER:
- ppl who are most physically active have 19% lower risk of developing colon cancer VS least active
