Cancer as a Complex Chronic Condition Flashcards
What are the three stages of cancer?
- Non - metastatic primary tumor
- Metastatic sub clones
- Metastases
What is the progression of cancer in term of stages?
- tumour initiation (>10 years)
- Parental clone (~ 5 - 6 years)
- Metastatic seeds (~3 years)
- Patient’s death
What is the process and goal of the clinical evolution of cancer?
- Risk assessment = cancer prevention
- Screening = early detection
- Classification, stage, grade, biomarker expression = guidance of local therapy or selection of systemic therapy and prediction of response
- Monitoring for recurrence = early intervention
What are stages are included when cancer progresses?
- Initiation
- Promotion
- Late phase of promotion
- progression
What happens during initiation?
- epidermal cell undergoes rapid, irreversible alteration or mutation of DNA
- Cells undergoes proliferation producing altered progeny or initiated cells
What happens during promotion/ late phase of promotion
- Initiated cells undergo interrupted exposure to promoter; early reversible precancerous lesions
- Initiated cells undergo continuous exposure to promoter, causing malignant cell changes
What happens during progression?
- Primary epidermal tumor - Invasion
- Metastasis
What is the goals in cancer prevention approaches?
- Modify carcinogen activation by inhibiting enzymes
- Promotes scavenging of DNA - reactive electrophiles and (electron - donating) free radicals
- Scavenging of reactive oxygen species
- Alter the expression of genes involved in cell signaling, especially those in regulating cell proliferation, apoptosis and differentation
- Decrease inflammation
What is the first and second hit of carcinogenesis?
- Carcinogen (1st hit) and promoter (2nd hit)
What is a carcinogen?
Any substance that induces cancer in animals
What is the process of carcinogen?
- Exposure to carcinogens
- Carcinogen attacks DNA
- Reaction with cellular targets, DNA damage, mutagenesis
What is IARC classification of group 1?
The agent is carcinogenic to humans (Asbesto, solar radiation, tobacco)
What is IARC classification of group 2A?
The agent is probably carcinogenic to humans (chemotherapy drugs, diesel engine exhaust, PCBs)
What is IARC classification of group 2B?
The agent is possibly carcinogenic to humans (lead, mercury, gasoline engine exhaust)
What is IARC classification of group 3?
The agent is not classifiable as to its carcinogenicity to humans
What is IARC classification of group 4?
The agent is probably not carcinogenic to humans
What are some agent examples of carcinogens?
- Aflatoxin
- Arsenic
- Asbestos
- Benzene
- Chlorambucil
- Epstein - Barr virus
- Hepatitis B virus
- Gamma radiation
- Solar radiation
What are some mixture examples of carcinogens?
- Coal tar
- Soots
- Tobacco products
What’s included in the stages of cancer
- Initiation (normal cell + First mutation)
- Promotion ( second mutation + third mutation)
- Progression (fourth mutation + cancer cells)
What are some well established environmental factors ?
- Environmental tobacco smoke
- UV radiation
- Asbestos
- Rubber industry
What are some controversial environmental factors?
- Electromagnetic fields
- Cell phones
- Air pollution
What are some environmental carcinogens components?
- Physical
- Chemical
- Biological
What are the two environmental cancer promoters?
- Chemical
- Biological
What agents are environment and cancer issues of concern to community at large?
- Chemical (passive smoking, pesticides, plastic)
- physical (EMFs, cellular phones, UV)
