INTEGRATING OUR KNOWLEDGE
Knowledge is our greatest strength in driving progress
against cancer. Knowing “why” a cancer develops, will help
us determine “how” to treat it. For example, comprehensive
analyses of human cancer genomes over the past decade
revealed several genetic changes associated with a variety
of cancers. These discoveries led to the development of a
series of therapeutics targeted to rectifying the cellular
changes that arise due to the mutations.
Cancer cells can stimulate the growth of blood and lymphatic
vessel networks, which supply the cancer cells with the nutrients and
oxygen required for rapid growth and survival, and provide a route
for cancer cell escape to distant sites (metastasis).
The matrix of proteins that surrounds the cancer cells can
influence cancer formation, metastasis, and other processes.
Systemic factors in the circulation, such as hormones and nutrients,
influence the development and growth of cancer.
The immune system can identify and eliminate cancer cells,
although in many cases this system is suppressed,
permitting the formation and progression of a tumor.
However, in some situations of chronic inflammation,
the immune system can promote cancer development and progression.
Other tissue-specific tumor-associated cells, such as pericytes, fibroblasts,
and astrocytes, can support tumor growth through various mechanisms
including stimulating tumor growth, triggering formation of
new blood vessels, and enhancing survival of cancer cells.
Cancer Growth: Local and Global Influences
Solid tumors are much more complex than an isolated mass of proliferating cancer cells because cancer
initiation, development, and progression are strongly influenced by interactions among cancer cells
and numerous factors in their environment. Among the components of the tumor microenvironment
are normal parts of the tissue in which the cancer is growing, systemic factors that transiently percolate
through the tissue, and cells that are actively recruited to the tissue.
Adapted from ( 30)