Nutritional and environmental impact on carcinogenesis
Tumor:
A mass of cells which growth is atypical when referenced to the normal surrounding tissue structure.
Neoplasm:
Literally means “new growth” and is a term commonly used the same way that the term tumor is used.
An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli that evoked the change
Causes:
1. genetic
2. environmental
Nutritional and environmental impact on carcinogenesis
Genetic evidence
1. induction of genes (activated oncogenes)
loss of contact inhibition + uncontrolled division
2. transgenic mice (knock-out mice) higher incidence of cancer
3. BRCA-1 and BRCA-2 mutation familial breast and ovarian cancer
4. familial polyposis coli mutations in the
Adenoma-Polyposis coli gene
Nutritional and environmental impact on carcinogenesis
Genetic and environmental factors in tumor development
Death rates from gastric, liver, colon and prostate cancers in
Japanese
compared to
California whites
Nutritional and environmental impact on carcinogenesis
Agent
Occupation
Cancer site
Ionizing radiations, radon
Certain underground miners
bronchus
X-rays, radium
Radiologists, radiographers
skin
Radium
luminous dial painters
bone
Ultraviolet radiation
Farmers, sailors....
skin
Polycyclic hydrocarbons in soot chimney sweepers,oil workers
scrotum, skin, bronchus
2-Naphthylamine; 1naphthylamine
Rubber workers
bladder
Benzidine;
4-aminobiphenyl
Chemical workers
bladder
Asbestos
shipyard and insulation workers
mesothelioma lung
Arsenic
sheep dip manufacturers, gold miners skin and bronchus
Benzene
workers with glues, varnishes, etc.
Bone marrow (leukemia)
Vinyl chloride