Annual Report 2003 Aventis - Sanofi

Medical Background
Cancer develops when cells in a part of the body
begin to grow out of control. This can happen
when DNA is damaged and not repaired. People
can inherit damaged DNA or a person’s DNA can
become damaged by environmental factors, such as
smoking. Although there are many kinds of cancer,
they all start because of out-of-control growth of
abnormal cells.
Cancer cells can form a mass of tissue commonly
referred to as a tumor. Metastasis occurs when cancer
cells move via the bloodstream or lymph vessels
to other parts of the body and begin to grow and
replace normal tissue. Not all tumors are cancerous.
Benign tumors do not spread to other parts of the
body (metastasize) and are rarely life-threatening.
Different types of cancer can behave very differently.
For example, lung cancer and breast cancer
are very different diseases. They grow at different
rates and respond to different treatments.
Breast cancer is the second leading cause of
cancer deaths among women in the major pharmaceutical
markets. More than 80 % of patients
Aventis approaches to treat cancer
DNA
damage
Normal
cell cycle
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