What is cancer
Cancer is a class of diseases in which cells grow and divide uncontrollably. There are more than 200 different types of cancer. Each type is classified by the type of cell that is initially affected. Cancer can start in the lungs, the breast, the colon, or even in the blood.
There are many types of cancer that can’t be included
in one single article, but they can be divided into categories. These are the
most specific types of cancers found in each category.
Sarcoma: Cancer that begins in bone, cartilage, fat, muscle,
blood vessels, or other connective or supportive tissue
Carcinoma: Cancer that begins in the skin or in tissues that
line or cover internal organs.
Leukemia: Cancer that starts in blood forming tissue such as
the bone marrow and causes large numbers of abnormal blood cells to
be produced and enter the blood.
Lymphoma and myeloma: Cancers that begin in the cells of the
Central nervous system cancers: Cancers that begin in the
tissues of the brain and spinal cord.
Metastatic cancers arise from a
Diagnosis of cancer
Cancers might be
diagnosed during routine screening examinations which are commonly done at a
certain age. Cancer is nearly always diagnosed
by a pathologist who has examined a tissue sample under a microscope. In laboratory
tests, high or low levels of some markers in the body
can be a sign of cancer like in blood, urine, or other body fluids, these tests
permit measuring those markers.Also, imaging procedures create pictures
of zones that help detecting whether a tumor is present. These pictures can be
made in several ways:·CT Scan:
With an XRAY machine, a series of detailed pictures of the organs is created.·Nuclear scan:
A radioactive material is injected: a tracer. It flows through the bloodstream
and collects in certain organs. A scanner detects the radioactivity and creates
pictures of organs on a computer.·Ultrasound:
A computer uses sounds and echoes to create a picture of areas inside the body:
a sonogram. ·MRI:
A strong magnet is used to make detailed pictures of the organs. The pictures
are viewed on a monitor.·PET scan:
A tracer is injected and a machine makes 3-D pictures that show where the
tracer collects in the body.·X-rays:
X-rays use low doses of radiation to create pictures of the organs.A biopsy is a
procedure in which a sample of tissue is collected; under a microscope, the pathologist looks at
the tissue to see if it contains cancer cells. The sample can be removed in different
ways: ·The physician uses a needle to have a sample
from the tissue or the fluid. ·The physician explores areas inside the body
using a thin tube called an endoscope which is inserted through a natural
opening, such as the mouth. Then, the physician uses a tool to take a sample. ·Surgery may be excisional or incisional:
in an excisional biopsy, the surgeon removes
the entire tumor. Often some of the normal tissue around the tumor also is removed. In
an incisional biopsy, the surgeon removes just part of the tumor.