Cancer Classification & Metastasis | NCLEX Review
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Cancer Classification & Metastasis | NCLEX Review

Welcome to this video tutorial on cancer classification
and metastasis. Cancer is a group of diseases in which abnormal
cells grow and divide uncontrollably, destroying body tissue. Cancers are classified according to the type
of tissue in which the cancer originates and by the primary location where the cancer first
developed. Based on tissue type, cancers are classified
into six major categories: 1. Carcinoma is a malignant tumor of epithelial
cells, which are found in skin and the covering and lining of organs and internal passageways,
such as the GI tract. Carcinomas usually affect organs capable of
secretion including breast, lung, bladder, prostate, and colon. There are two types of carcinomas adenocarcinoma
and squamous cell carcinoma. Adenocarcinoma develops in mucus-secreting
glands and is rapidly spreading. Squamous cell carcinoma is one of the main
types of skin cancer. 2. Sarcoma is a malignant tumor of connective
and supportive tissue cells, including muscles, tendons, fat, cartilage, blood & lymph vessels,
nerves, and tissue around joints. Sarcoma can also originate in the bone. Soft tissue and bone sarcomas are the main
types of sarcomas. 3. Myeloma is a cancer originating in the plasma
cells of bone marrow. Plasma cells are white blood cells that produce
antibodies. When myeloma cells prevent the normal production
of antibodies, the immune system is weakened and there is an interference with the normal
production and function of red and white blood cells. Patients often have bone pain or fractures,
anemia, and susceptibility to infection. A single cell plasma cell tumor is called
an isolated (or solitary) plasmacytoma, and more than one plasmacytoma is called multiple
myeloma. 4. Leukemia is cancer of the blood involving
the bone marrow and lymph nodes. When cancerous, the bone marrow produces abnormal
white blood cells that fail to provide immunity, causing the patient to be prone to infection. Leukemia also affects red blood cells and
can cause poor blood clotting and fatigue from anemia. 5. Lymphoma is cancer of the lymphatic system
and develops in the glands or lymph nodes. There are two types Hodgkin’s lymphoma and
Non-Hodgkin’s lymphoma. The cancerous cells of Hodgkin’s lymphoma
crowd out normal white cells, and the immune system is unable to effectively guard against
infection. The difference between the two types of lymphomas
is determined during a biopsy of a lymph node; the presence of Reed-Sternberg cells (huge
mutated B lymphocytes) distinguishes Hodgkin’s lymphoma from Non-Hodgkin lymphoma. 6. Mixed types have two or more components of
cancer, such as carcinosarcoma or teratocarcinoma. Whereas medical professionals refer to cancers
based on their tissue type, the general public is more familiar with cancer names based on
their primary body sites. The most common sites in which cancer develops
include… Skin, lungs, female breasts, prostate, uterus,
colon, and rectum. Cancer names based on their primary site are
often not as accurate as those based on tissue type. However, cancer can be classified by either
the tissue cell type or its primary site. For example, uterine cancer is the same as
carcinoma of the uterus. Cancers can also be classified by grade, in
which the cancer is examined for its cellular maturity and characteristics. Cells that are undifferentiated are highly
abnormal, or immature and primitive, with respect to surrounding tissues. Grade 0 Normal tissue
Grade 1 Well differentiated cells with slight abnormality
Grade 2 Moderately differentiated cells that have more abnormalities
Grade 3 Poorly differentiated cells that are very abnormal
Grade 4 Very undifferentiated and immature cells, meaning there is no resemblance to
the tissue of origin Cancers are also classified according to their
stage. The most commonly used method is called the
TNM staging. “T” stands for tumor size, “N” is the degree
of regional spread or node involvement, and “M” stands for distant metastasis. T0 represents no evidence of tumor, T1 to
T4 represents increasing tumor size and involvement, and Tis represents carcinoma in situ (or abnormal
cells that remain in the place where they first formed). N0 represents no nodal involvement and N1
to N4 signifies increasing degrees of lymph node involvement. Nx indicates that node involvement cannot
be assessed. M0 represents no evidence of distant metastasis
and M1 represents evidence of metastatic involvement. For many cancers, the TNM combinations are
grouped into five less-detailed stages. Stage 0 Also called carcinoma in situ, abnormal
cells are present but have not spread to nearby tissue. Stage 1, 2, and 3 Cancer is present; the higher
the number, the larger the tumor and the more it has spread into nearby tissues. Stage 4 The cancer has spread to distant parts
of the body. Cancer cells do not serve any useful function,
and they can migrate through blood vessels and tissues, spreading and growing in other
body locations. This process is called metastasis and is the
major cause of cancer death. Cancer can spread by moving into or invading
nearby normal tissue. The cancer cells break away from where they
first formed (primary cancer), move through the blood vessels or lymph nodes, traveling
to other parts of the body. At a distant location the cancer cells again
go through the vessel walls, moving into the surrounding tissue and forming a new tumor
(metastatic tumor). Metastatic cancer cells have features like
that of the primary cancer, and therefore have the same name as the primary cancer. For example, breast cancer that spreads to
the brain is called metastatic breast cancer, not brain cancer. Cancer can spread to any part of the body,
but different types of cancer are more likely to spread to certain areas than others. The most common sites where cancer spreads
include bone, liver, and lung. Some common sites of metastasis include the
following: Breast cancer metastasizes to bone, brain,
liver, & lung. Colon, ovary, pancreas, rectal, and stomach
cancer metastasize to liver, lung, and peritoneum. Bladder cancer goes to bone, liver, and lung. Kidney cancer can move to adrenal gland, bone,
brain, liver, or lung. Lung cancer goes to adrenal gland, bone, brain,
liver, or other lung. Melanoma can go to bone, brain, liver, lung,
skin, or muscle. Prostate cancer metastasizes to adrenal gland,
bone, liver, and lung. Thyroid cancer to bone, liver, or lung. Uterine cancer can move to vagina, bone, liver,
lung, or peritoneum. Once cancer spreads, it can be hard to control. Most types of metastatic cancer cannot be
cured with current treatment, but there are treatments with the goal of stopping or slowing
the growth of the cancer or relieving symptoms to help prolong life. If the metastatic cancer can no longer be
controlled, end-of-life care needs to be discussed. Thank you for watching this video on the classification
and metastasis of cancer.


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