Toxicology 08 – Chemical carcinogenesis
Short introduction to cancer
Cancer; collective name for diseases
Characterized; unlimited cell division (proliferation)
• Concentrated; tumor, mass
• Diffuse; leukemia, no mass
Tumor;
• Benign (goedaardige tumor). Risk is that it can block
vessels and surrounding tissues, and risk that is will grow
out to malign tumor.
o Encapsulated, differentiated cells (cells that have
normal features), slow growth
• Malign (kwaadaardige tumor)
o Dedifferentiated cells, invasive (penetrate
(binnendringen) the surrounding tissues), metastasis
(uitzwaaingen)
Risk factors for cancer;
• Genetic factors
• Environmental factors;
o Food; fat (-), alcohol (-), anti-oxidants (+), vitamins (+)
o Radiation
o Compounds other than food; smoking
o Fibers
o Viruses
• Hormonal and reproduction factors;
o Pregnancy at later age
o Contraceptives? (voorbehoudsmiddelen)
o Number of sexual contacts
Multistage process
• Initiation; change in DNA (mutation) → pre-neoplasmic cells
• Promotion; dedifferentiation of cells, increased in proliferation → tumor cells
• Progression; invasion (binnendringen omliggende weefsels) and metastasis
(uitzaaingen) → malignant tumor
Each phase can be influence by;
• Compounds (chemical carcinogenesis)
o Initiation; mutagens
o Promotion; tumor promotors
o Progression; tumor progressors
• Other factors
o Initiation; viruses, radiation
o Promotion; endogenous hormones
o Progression; spontaneous mutations
Short introduction to cancer
Cancer; collective name for diseases
Characterized; unlimited cell division (proliferation)
• Concentrated; tumor, mass
• Diffuse; leukemia, no mass
Tumor;
• Benign (goedaardige tumor). Risk is that it can block
vessels and surrounding tissues, and risk that is will grow
out to malign tumor.
o Encapsulated, differentiated cells (cells that have
normal features), slow growth
• Malign (kwaadaardige tumor)
o Dedifferentiated cells, invasive (penetrate
(binnendringen) the surrounding tissues), metastasis
(uitzwaaingen)
Risk factors for cancer;
• Genetic factors
• Environmental factors;
o Food; fat (-), alcohol (-), anti-oxidants (+), vitamins (+)
o Radiation
o Compounds other than food; smoking
o Fibers
o Viruses
• Hormonal and reproduction factors;
o Pregnancy at later age
o Contraceptives? (voorbehoudsmiddelen)
o Number of sexual contacts
Multistage process
• Initiation; change in DNA (mutation) → pre-neoplasmic cells
• Promotion; dedifferentiation of cells, increased in proliferation → tumor cells
• Progression; invasion (binnendringen omliggende weefsels) and metastasis
(uitzaaingen) → malignant tumor
Each phase can be influence by;
• Compounds (chemical carcinogenesis)
o Initiation; mutagens
o Promotion; tumor promotors
o Progression; tumor progressors
• Other factors
o Initiation; viruses, radiation
o Promotion; endogenous hormones
o Progression; spontaneous mutations
