I knw the word CANCER is not a new word to so many people but then again what is really cqncer about then we start to mumble and try to act like doctors so I did a little research these are my findings Unedited :Least I forget you will need a Dictionary beside you :)
What Is Cancer? What Causes Cancer?
Cancer is a class of diseases characterized by out-of-control cell growth.
There are over 100 different types of cancer, and each is classified by the
type of cell that is initially affected.
Cancer harms the body when damaged cells divide uncontrollably to form
lumps or masses of tissue called tumors (except in the case of leukemia
where cancer prohibits normal blood function by abnormal cell division in
the blood stream). Tumors can grow and interfere with the digestive,
nervous, and circulatory systems, and they can release hormones that alter
body function. Tumors that stay in one spot and demonstrate limited
growth are generally considered to be benign.
More dangerous, or malignant, tumors form when two things occur:
1. a cancerous cell manages to move throughout the body using
the blood or lymph systems, destroying healthy tissue in a
process called invasion
2. that cell manages to divide and grow, making new blood vessels
to feed itself in a process called angiogenesis.
When a tumor successfully spreads to other parts of the body and
grows, invading and destroying other healthy tissues, it is said to have
metastasized. This process itself is called metastasis, and the result is a
serious condition that is very difficult to treat.
How cancer spreads - scientists reported in Nature Communications
(October 2012 issue) that they have discovered an important clue as to why
cancer cells spread . It has something to do with their adhesion (stickiness)
properties. Certain molecular interactions between cells and the scaffolding
that holds them in place (extracellular matrix) cause them to become
unstuck at the original tumor site, they become dislodged, move on and
then reattach themselves at a new site.
The researchers say this discovery is important because cancer mortality is
mainly due to metastatic tumors, those that grow from cells that have
traveled from their original site to another part of the body. Only 10% of
cancer deaths are caused by the primary tumors.
The scientists, from the Massachusetts Institute of Technology, say that
finding a way to stop cancer cells from sticking to new sites could interfere
with metastatic disease, and halt the growth of secondary tumors.
In 2007, cancer claimed the lives of about 7.6 million people in the world.
Physicians and researchers who specialize in the study, diagnosis, treatment,
and prevention of cancer are called oncologists.
Causes
The causes of cancer are diverse, complex, and only partially understood.
Many things are known to increase the risk of cancer, including tobacco
use, dietary factors, certain infections , exposure to radiation , lack of
physical activity, obesity , and environmental pollutants.
Genes - the DNA type
Cells can experience uncontrolled growth if there are damages or mutations
to DNA, and therefore, damage to the genes involved in cell division. Four
key types of gene are responsible for the cell division process: oncogenes
tell cells when to divide, tumor suppressor genes tell cells when not to divide,
suicide genes control apoptosis and tell the cell to kill itself if something
goes wrong, and DNA-repair genes instruct a cell to repair damaged DNA.
Cancer occurs when a cell's gene mutations make the cell unable to correct
DNA damage and unable to commit suicide. Similarly, cancer is a result of
mutations that inhibit oncogene and tumor suppressor gene function,
leading to uncontrollable cell growth.
Carcinogens
Carcinogens are a class of substances that are directly responsible for
damaging DNA, promoting or aiding cancer. Tobacco, asbestos, arsenic,
radiation such as gamma and x-rays, the sun, and compounds in car
exhaust fumes are all examples of carcinogens. When our bodies are exposed
to carcinogens, free radicals are formed that try to steal electrons from
other molecules in the body. Theses free radicals damage cells and affect
their ability to function normally.
Genes - the family type
Cancer can be the result of a genetic predisposition that is inherited from
family members. It is possible to be born with certain genetic mutations or
a fault in a gene that makes one statistically more likely to develop cancer
later in life.
Other medical factors
As we age, there is an increase in the number of possible cancer-causing
mutations in our DNA. This makes age an important risk factor for cancer.
Several viruses have also been linked to cancer such as: human
papillomavirus (a cause of cervical cancer), hepatitis B and C (causes of
liver cancer), and Epstein-Barr virus (a cause of some childhood cancers).
Human immunodeficiency virus (HIV) - and anything else that suppresses or
weakens the immune system - inhibits the body's ability to fight infections
and increases the chance of developing cancer.
What are the symptoms of cancer?
Cancer symptoms are quite varied and depend on where the cancer is
located, where it has spread, and how big the tumor is. Some cancers can be
felt or seen through the skin - a lump on the breast or testicle can be an
indicator of cancer in those locations. Skin cancer (melanoma) is often
noted by a change in a wart or mole on the skin. Some oral cancers present
white patches inside the mouth or white spots on the tongue.
Other cancers have symptoms that are less physically apparent. Some brain
tumors tend to present symptoms early in the disease as they affect
important cognitive functions. Pancreas cancers are usually too small to
cause symptoms until they cause pain by pushing against nearby nerves or
interfere with liver function to cause a yellowing of the skin and eyes
called jaundice. Symptoms also can be created as a tumor grows and pushes
against organs and blood vessels. For example, colon cancers lead to
symptoms such as constipation, diarrhea, and changes in stool size. Bladder
or prostate cancers cause changes in bladder function such as more
frequent or infrequent urination.
As cancer cells use the body's energy and interfere with normal hormone
function, it is possible to present symptoms such as fever, fatigue, excessive
sweating, anemia, and unexplained weight loss. However, these symptoms are
common in several other maladies as well. For example, coughing and
hoarseness can point to lung or throat cancer as well as several other
conditions.
When cancer spreads, or metastasizes, additional symptoms can present
themselves in the newly affected area. Swollen or enlarged lymph nodes are
common and likely to be present early. If cancer spreads to the brain,
patients may experience vertigo, headaches, or seizures. Spreading to the
lungs may cause coughing and shortness of breath. In addition, the liver
may become enlarged and cause jaundice and bones can become painful,
brittle, and break easily. Symptoms of metastasis ultimately depend on the
location to which the cancer has spread.
How is cancer classified?
There are five broad groups that are used to classify cancer.
1. Carcinomas are characterized by cells that cover internal and external
parts of the body such as lung, breast, and colon cancer.
2. Sarcomas are characterized by cells that are located in bone, cartilage,
fat, connective tissue, muscle, and other supportive tissues.
3. Lymphomas are cancers that begin in the lymph nodes and immune system
tissues.
4. Leukemias are cancers that begin in the bone marrow and often accumulate
in the bloodstream.
5. Adenomas are cancers that arise in the thyroid, the pituitary gland, the
adrenal gland, and other glandular tissues.
Cancers are often referred to by terms that contain a prefix related to
the cell type in which the cancer originated and a suffix such as -sarcoma,
-carcinoma, or just -oma. Common prefixes include:
Adeno- = gland
Chondro- = cartilage
Erythro- = red blood cell
Hemangio- = blood vessels
Hepato- = liver
Lipo- = fat
Lympho- = white blood cell
Melano- = pigment cell
Myelo- = bone marrow
Myo- = muscle
Osteo- = bone
Uro- = bladder
Retino- = eye
Neuro- = brain
How is cancer treated?
Cancer treatment depends on the type of cancer, the stage of the cancer
(how much it has spread), age, health status, and additional personal
characteristics. There is no single treatment for cancer, and patients often
receive a combination of therapies and palliative care. Treatments usually
fall into one of the following categories: surgery, radiation, chemotherapy,
immunotherapy, hormone therapy, or gene therapy.
Surgery
Surgery is the oldest known treatment for cancer. If a cancer has not
metastasized, it is possible to completely cure a patient by surgically
removing the cancer from the body. This is often seen in the removal of
the prostate or a breast or testicle. After the disease has spread, however,
it is nearly impossible to remove all of the cancer cells. Surgery may also
be instrumental in helping to control symptoms such as bowel obstruction or
spinal cord compression.
Innovations continue to be developed to aid the surgical process, such as the
iKnife that "sniffs" out cancer. Currently, when a tumor is removed
surgeons also take out a “margin” of healthy tissue to make sure no
malignant cells are left behind. This usually means keeping the patients
under general anesthetic for an extra 30 minutes while tissue samples are
tested in the lab for “clear margins”. If there are no clear margins, the
surgeon has to go back in and remove more tissue (if possible). Scientists
from Imperial College London say the iKnife may remove the need for
sending samples to the lab.
Radiation
Radiation treatment, also known as radiotherapy, destroys cancer by
focusing high-energy rays on the cancer cells. This causes damage to the
molecules that make up the cancer cells and leads them to commit suicide.
Radiotherapy utilizes high-energy gamma-rays that are emitted from
metals such as radium or high-energy x-rays that are created in a special
machine. Early radiation treatments caused severe side-effects because
the energy beams would damage normal, healthy tissue, but technologies
have improved so that beams can be more accurately targeted.
Radiotherapy is used as a standalone treatment to shrink a tumor or
destroy cancer cells (including those associated with leukemia and
lymphoma), and it is also used in combination with other cancer treatments.
Chemotherapy
Chemotherapy utilizes chemicals that interfere with the cell division process
- damaging proteins or DNA - so that cancer cells will commit suicide.
These treatments target any rapidly dividing cells (not necessarily just
cancer cells), but normal cells usually can recover from any chemical-
induced damage while cancer cells cannot. Chemotherapy is generally used
to treat cancer that has spread or metastasized because the medicines
travel throughout the entire body. It is a necessary treatment for some
forms of leukemia and lymphoma. Chemotherapy treatment occurs in cycles
so the body has time to heal between doses. However, there are still
common side effects such as hair loss, nausea, fatigue, and vomiting.
Combination therapies often include multiple types of chemotherapy or
chemotherapy combined with other treatment options.
Immunotherapy
Immunotherapy aims to get the body's immune system to fight the tumor.
Local immunotherapy injects a treatment into an affected area, for
example, to cause inflammation that causes a tumor to shrink. Systemic
immunotherapy treats the whole body by administering an agent such as
the protein interferon alpha that can shrink tumors. Immunotherapy can
also be considered non-specific if it improves cancer-fighting abilities by
stimulating the entire immune system, and it can be considered targeted if
the treatment specifically tells the immune system to destroy cancer cells.
These therapies are relatively young, but researchers have had success with
treatments that introduce antibodies to the body that inhibit the growth of
breast cancer cells. Bone marrow transplantation (hematopoetic stem cell
transplantation) can also be considered immunotherapy because the donor's
immune cells will often attack the tumor or cancer cells that are present in
the host.
Hormone therapy
Several cancers have been linked to some types of hormones, most notably
breast and prostate cancer. Hormone therapy is designed to alter hormone
production in the body so that cancer cells stop growing or are killed
completely. Breast cancer hormone therapies often focus on reducing
estrogen levels (a common drug for this is tamoxifen) and prostate cancer
hormone therapies often focus on reducing testosterone levels. In addition,
some leukemia and lymphoma cases can be treated with the hormone
cortisone.
Gene therapy
The goal of gene therapy is to replace damaged genes with ones that work
to address a root cause of cancer: damage to DNA. For example,
researchers are trying to replace the damaged gene that signals cells to
stop dividing (the p53 gene) with a copy of a working gene. Other gene-
based therapies focus on further damaging cancer cell DNA to the point
where the cell commits suicide. Gene therapy is a very young field and has
not yet resulted in any successful treatments.
Using cancer-specific immune system cells to treat cancer
Scientists from the RIKEN Research Centre for Allergy and Immunology in
Yokohama, Japan, explained in the journal Cell Stem Cell (January 2013
issue) how they managed to make cancer-specific immune system cells
from iPSCs (induced pluripotent stem cells) to destroy cancer cells .
The authors added that their study has shown that it is possible to clone
versions of the patients’ own cells to enhance their immune system so that
cancer cells could be destroyed naturally.
Hiroshi Kawamoto and team created cancer-specific killer T-lymphocytes
from iPSCs. They started off with mature T-lymphocytes which were
specific for a type of skin cancer and reprogrammed them into iPSCs with
the help of “Yamanaka factors”. The iPSCs eventually turned into fully
active, cancer-specific T-lymphocytes - in other words, cells that target
and destroy cancer cells.
Get the fullstory at :www.medicalnewstoday.com
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