CAUSES OF CANCER :
- include certain cancer causing agents
virus and genes.
(a) carcinogens :
are cancer causing agents. they may be the
following
following
- CHEMICALS used in cigarette smoke, benzopyrene, dyes, paint, etc
- biological oncogenes viruses, some parasites, etc.
- physical ionizing radiation, like X rays and gamma rays, non-ionising radiations like UV-rays.
(b) Cancer causing viruses are called oncogenic
viruses. They have genes called viral oncogenes at
the time of viral infection these are transferred and can lead to cancer.
(c) normal cells have genes called cellular
oncogenes or proto-oncogenes which are present
in inactive state, but under certain conditions like
mutations on transformation of the cells may
occur due to this cellular oncogenes are turned on and they can lead to cancer.
* CANCER DETECTION AND DIAGNOSIS :
- cancer can be detected by the following methods :-
(a) Blood and bone marrow tests for increased cell counts.
(b) BIOPSY and histopathological studies of the tissue.
(c) COMPUTED TOMOGRAPHY(CT) :-
using x-rays to generate a 3-D image of internal tissue.
(d) MAGNETIC RESONANCE IMAGING (MRI) :-
-involves the use of non-ionising
radiation and strong magnetic field to
detect pathological and physiological changes in living tissue.
(e) RADIOGRAPHY :-
- by x-rays, to detect cancer of the internal organs.
(f) MONOCLONAL ANTIBODIES :-
- against cancer-specific antigens are also used for cancer detection.
These antibodies bind to antigens
which are relaeased by cancerous cells in the body.
TREATMENT OF CANCER :
(1) SURGERY
Tumours are removed by surgery to check the further spread of cancer cells.
(2) RADIATION THERAPY :
Tumour cells are irradiated by lethal doses of
radiation, such as cobalt 60 while taking care to protect the surrounding normal cells.
(3) CHEMOTHERAPY :
Several chemotherapeutic drugs are used to kill
the cancer cells. But their side effects like hair
losses, anaemia, etc. Are also reported.
(4) IMMUNOTHERAPY :
Biological modifiers like alpha-interferons are
used to activate the immune system and help in destroying the Tumour.
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