Pancreatic Cancer
Growth Mechanism
The human body is made up of myriads of living cells, the building blocks that make up tissues. Normal
body cells grow, divide, and die in an orderly fashion. During the early years of a
person's life, normal cells divide faster, giving the person opportunity to grow, while for adult person,
most cells divide only per demand
- to replace worn-out or dying cells or to repair
injuries.
Pancreatic cancer begins when cells associated
with pancreas start to grow out of control. Cancer cell
growth is different from normal cell growth. Instead of dying, cancer cells continue
to grow and form new, abnormal cells. Cancer cells can also invade (grow into) other
tissues, something that normal cells cannot do. Growing out of control and
invading other tissues converts a normal cell into a cancer cell.
Cells become cancer cells because of damage to
DNA, which controls each cell
functions. In a normal cell, when DNA gets damaged the cell
either manages to repair the damage or it dies. In cancer cells, the damaged DNA cannot be repaired, but the cell doesn't die like as it supposes to.
Instead, this cell goes on making new cells that the body does not need. These
new cells will all have the same damaged DNA as the first cell does. The
buildup of extra cells often forms a mass of tissue called a growth or tumor.
Cancer cells may travel to other parts of the body, where they
begin to grow and form new tumors that replace normal tissue. This process is
called metastasis. It happens when the cancer cells get into the bloodstream or
lymph vessels of our body.
Two Types of Cell Changes
A recent 2010 study
from Karolinska Institutet shows how two types of cell change interact in the
development of cancer. The results can improve the chances of early discovery
of pancreatic cancer, where the early detection is especially challenging. Cancer
of the pancreas is a form of cancer that has few treatment options and a poor
prognosis. It is linked to two particularly common cellular changes: mutations
in a family of cancer genes called RAS and increased activity in the 'Hedgehog'
signalling pathway, a molecular signal transmission mechanism that is normally
only activated during embryonic growth.
Study has shown how
RAS and the Hedgehog pathway interact in the development of pancreatic cancer
in mice. Activation of cancer genes in the RAS family causes the tumor cells to
secrete the factor (SHH) that activates Hedgehog signaling, and shuts off the tumor
cell's own ability to respond to this type of stimulation.
The blocking of the
Hedgehog response helps, in this phase, to secure the survival of the tumor
cells while the surrounding cells are stimulated to grow. In a later phase,
when the tumor has become more aggressive, the block is lifted so that tumor
cell growth is also precipitated though Hedgehog signaling. The scientists have
also identified the proteins that govern the tumor cells' sensitivity to SHH.
The Length of Cell Mutation
A significant breakthrough
in the pancreatic cancer development mechanism has been achieved with the
recent research performed at Johns Hopkins University School of
Medicine and the Howard Hughes Medical Institute. The scientists found that pancreatic cancer may take up to 20 years to grow to
the point where it is diagnosed by conventional medical doctors. This was
determined by sequencing the DNA of cancer tumor cells from deceased patients.
Because cancer mutations occur in growing tumors at a known rate, scientists
were able to map the timing of the development of full-blown pancreatic cancer
tumors.
Here are the details of their findings:
• It takes 11.7 years for one mutation in a pancreas cell to grow into a "mature" pancreatic tumor (which might show up on a medical scan).
• It takes another 6.8 years for the pancreatic tumor to spread and cause tumors to appear in other organs of the body.
So, it takes about 20 years for a person to grow a cancer tumor and see it spread to the point where their doctor may diagnose them with pancreatic cancer. In other words, by the time doctors diagnose you with cancer, you've already been growing it for two decades.
Here are the details of their findings:
• It takes 11.7 years for one mutation in a pancreas cell to grow into a "mature" pancreatic tumor (which might show up on a medical scan).
• It takes another 6.8 years for the pancreatic tumor to spread and cause tumors to appear in other organs of the body.
So, it takes about 20 years for a person to grow a cancer tumor and see it spread to the point where their doctor may diagnose them with pancreatic cancer. In other words, by the time doctors diagnose you with cancer, you've already been growing it for two decades.
This fact highlights
the importance of changing your lifestyle in order to impede the possible
cancer development, if you have a genetic predisposition, and the importance of
the ongoing medical screening to catch the disease on early stages.
Sources and Additional Information:
