cancer Flashcards
what is cancer
another name for malignant tumour
- disease in which abnormal cells divide without control and are able to invade other tissues
- Is an abnormal growth resulting from uncontrolled proliferation; it serves no physiologic function
- also referred to a neoplasm–> “new growth”
what is a benign tumour?
not cancer
- usually encapsulated w/ connective tissue and contain fairly well-differentiated cells and well-organized stroma
- they retain normal tissue structure
- they do not invade beyond their capsule, nor do they spread to lymph nodes or distant locations
when do benign tumors become harmful?
when they become extremely large and, depending on their location in the body, cause cause morbidity or be life-threatening by compressing normal tissues, preventing blood flow to the region (ischemia) or causing necrotic death of normal tissue
what is anaplasia?
loss of cellular differentiation
malignant cells are…?
- pleomorphic (variability of size/shape)
- often have large dark stained nuclei
- mitotic cells are common
- they have substantial amount of stroma but it is disorganized
- loss of normal tissue structure
- lack a capsule
- grow to invade nearby blood vessels, lymphatics, and surrounding structures
what is the most important/ deadliest characteristic of malignant tumors?
ability to spread far beyond the tissue or origin, process known as metastasis
what is the first hallmark of cancer?
uncontrolled cellular response to growth factors that bind to specific receptors on the cell surface
what impacts the development of cancer?
- genetics
- age
- epigenetics and tissue
- in utero (before birth) and early life conditions
- environment
- lifestyle (smoking, nutrition, obesity, alcohol, physical inactivity)
how does genetics, epigenetic and tissue affect cancer?
- cancer is driven by genetic alternation and changes in epigenetic regulation
- cancer development and progression involve tissue microenvironment or stroma
- Infiltrating immune cells cause chronic inflammation, creating a permissive tumour-progressing environment.
- epigenetic influxes cancer initiation, progression, and treatment
factors that influence cancer risk?
- detoxifying enzymes
- DNA repair genes
- immune/inflammatory system
- cell’s immediate environment
- metabolic/hormonal factors
why is age and cancer correlated?
bc the older u get the more your cells divide= causing cancer
what is the leading cause of death with cancer patients?
sepsis due to the treatment
what are the incident trends r/t cancer?
- cancer rates are higher for men than women
- highest cancer rates are found in Denmark
- decline in lung cancer correlates to decreased tabacco use
- cancer rates have increased for ages 0-19
what are the mortality trends r/t cancer?
- cancer deaths have decreased in men, women, children
- liver cancer is most predominant cancer
- mortality rates for men with liver cancer are more than double the rate for women
how does in utero affect cancer development?
- conditions that increase susceptibility to cancer include:
- prenatal and early life exposure
- parental exposures before conception
- nutrition and DES ( it an estrogen hormone) exposure
- gene and environment interactions
what is developmental plasticity?
Degree to which development is contingent on its environment
how to reduce the risk of cancer?
must start early in life
- avoiding sun exposure during peak hours
- covering your skin
- increasing physical activity
- avoiding high-risk sexual partners/practices
tabacoo and risk to cancer
- smoking is is carcinogenic and the most important risk factor for cancer
- Is linked to cancers of the lung, mouth, lips, nasal cavity and sinuses, larynx, pharynx, esophagus, pancreas, kidney, uterus, cervix, colon and rectum, liver, and acute leukemia
- second hand smoking + environmental tobacco smoke increases the risk for lung cancer
what is nutrigenomics?
Is the study of nutrition on the phenotypic variability of individuals, based on genomic differences.
what are the primary dietary donors of DNA methylation include?
- folate
- choline
- b vitamins
what kind of foods improve DNA repair and decreases the risk of cancer?
-eating kiwi fruits, cooked carrots, or supplemental coenzyme q10 improves DNA repair
dietary factors?
- Altered micro-ribonucleic acid (miRNA): Predisposes an individual to cancer
- Suppress cancer stem cell renewal: Decreases the risk of cancer.
what is Glutathione-S-transferases (GSTs)?
Enzyme housekeepers that metabolize environmental carcinogens and reactive oxygen species (ROS)
-If GSTs are lacking, then the risk for cancer is higher
diets high in red meats and processed meats, pt is at risk for?
colorectal cancer
humans are constantly exposure to a variety of compounds termed xenobiotics
xenobiotics include toxic, mutagenic, and carcinogenic chemicals
- many of these chemicals are found in the human diet
- most xenobiotics are transported in the blood by lipoproteins and penetrate lipid membranes
- these chemicals can react w/ cellular macromolecules like proteins and DNA or can react directly w/ cell structure to cause cell damage
the body has 2 main defense system for counteracting xenobiotics effects
- detoxification enzymes
2. antioxidant systems
phase 1
enzymes that activate xenobiotics are called phase 1 activation enzymes and are represented by the mutligene cytochrome p-450 family
phase II
phase II detoxification enzymes then protect against further against a large array of reactive intermediates and nonactivated semiotics
-enzymes are mainly in the liver and provide clearance of compounds through the portal circulation that prevents the carcinogenic agents from entering the body through the GI tract or portal circulation
obesity
- is associated w/ endometrial, colorectal, kidney, esophageal, breast (postmenopausal), pancreatic, and several other cancers.
- Energy expenditure involves resting metabolic rate, thermic food effects, and physical activity.
- causes poorer outcomes for some cancers
- increases insulin resistance-producing hyperinsulinemia/ hyperglycemia
- insulin promotes insulin-like growth factor 1
- adipose tissues secretes adiokine
- circadian disruptions may affect cancer growth
alcohol
is classified as a human carcinogen
- a combo of cigarette smoking and alcohol consumption increases a person’s risk for malignant tumors
- increases the risk for oral cavity, pharynx, larynx, esophageal, liver, colorectal, and breast cancers
physical activity
-decreases the risk for cancer
-decreases insulin and insulin-like growth factors
-decreases obesity
-decreases inflammatory mediators
-decreases circulating sex/metabolic hormones
and improves immune function
-Reduces the risk for breast, colon, and endometrial cancers, independent of weight changes
-After a cancer diagnosis, physical activity is associated with improved cancer-specific and overall survival with early-stage breast, prostate, and colorectal cancers
air pollution
-is linked to lung cancer
-outdoor pollution- smog and particle pollution
smog- increases daily mortality
-particle pollution- causes pulmonary inflammation, oxidative stress and oxidation of DNA, nonfatal heart attacks, irregular heartbeat, and decreases lung function
-indoor pollution- is worse than outdoor pollution –> cigarette smoking
radon: lung cancer
how does radiation impact the development of cancer?
- Enters cells and randomly deposits energy in tissues
- Oncogene activation
- tumour-suppressor genes deactivation
- Chromosomal aberrations and DNA damage
- Cell transformation
- Nontargeted/bystander effects