Cancer Classification and Staging
Nursing Times.Net
As
indicated, cancer is a collection of diseases with certain common
features. Patients often view cancer as a single disease and use the
term generically (Varmus and Weinberg, 1993).
The difficulty with such a
generic term is that it is loaded with meanings for people and these
are inevitably negative.
There are, in fact, more than 200 different
types of cancer (Souhami and Tobias, 1995).
All cancers begin as an
individual cell and because each cell in the body is unique, each cancer
is also unique (Morgan, 2001).
Any tumour may be classified by a
behaviouristic classification and/or the histogenic classification.
- Behaviouristic classification: The greatest distinction between tumour types depends on the degree of malignancy. Both truly benign and truly malignant tumours exist. There are, however, benign tumours that predispose to malignant change, such as adenomas of the large intestine, and there are some in situ carcinomas that progress so slowly that they never achieve malignancy, such as certain in situ carcinomas of the uterine cervix. Thus, a spectrum of types of tumour behaviour exists.
- Histogenic classification: The most widely employed classification of tumours is based on their histogenesis and defines a tumour according to the tissues or cells from which it arises (Gowing and Fisher, 1988). Thus malignant neoplasms can be described as carcinomas (cancer of the epithelial cells), sarcomas (cancer of connective tissue) and leukaemia (cancer of white blood cells) (Morgan, 2001).
WIKIPEDIA
Cancers are classified by the type of cell that the tumor cells resemble and is therefore presumed to be the origin of the tumor. These types include:
- Carcinoma: Cancers derived from epithelial cells. This group includes many of the most common cancers, particularly in the aged, and include nearly all those developing in the breast, prostate, lung, pancreas, and colon.
- Sarcoma: Cancers arising from connective tissue (i.e. bone, cartilage, fat, nerve), each of which develop from cells originating in mesenchymal cells outside the bone marrow.
- Lymphoma and leukemia: These two classes of cancer arise from hematopoietic (blood-forming) cells that leave the marrow and tend to mature in the lymph nodes and blood, respectively. Leukemia is the most common type of cancer in children accounting for about 30%.[83]
- Germ cell tumor: Cancers derived from pluripotent cells, most often presenting in the testicle or the ovary (seminoma and dysgerminoma, respectively).
- Blastoma: Cancers derived from immature "precursor" cells or embryonic tissue. Blastomas are more common in children than in older adults.
Cancers are usually named using -carcinoma, -sarcoma or -blastoma as a suffix, with the Latin or Greek word for the organ or tissue of origin as the root. For example, cancers of the liver parenchyma arising from malignant epithelial cells is called hepatocarcinoma, while a malignancy arising from primitive liver precursor cells is called a hepatoblastoma, and a cancer arising from fat cells is called a liposarcoma.
For some common cancers, the English organ name is used. For example, the most common type of breast cancer is called ductal carcinoma of the breast. Here, the adjective ductal refers to the appearance of the cancer under the microscope, which suggests that it has originated in the milk ducts.
Benign tumors (which are not cancers) are named using -oma as a suffix with the organ name as the root. For example, a benign tumor of smooth muscle cells is called a leiomyoma (the common name of this frequently occurring benign tumor in the uterus is fibroid). Confusingly, some types of cancer use the -noma suffix, examples including melanoma and seminoma.
Some types of cancer are named for the size and shape of the cells under a microscope, such as giant cell carcinoma, spindle cell carcinoma, and small-cell carcinoma.
National Cancer institute
Staging describes the severity of a person’s cancer based on the size and/or extent (reach) of the original (primary) tumor and whether or not cancer has spread in the body. Staging is important for several reasons... More Information
American Cancer Society
Staging is the process of finding out how much cancer there is in a person’s body and where it’s located. It’s how the doctor learns the stage of a person’s cancer. Doctors use staging information to plan treatment and to help predict a person’s outlook (prognosis).
Cancers with the same stage tend to have similar outlooks and are often treated the same way. The cancer stage is also a way for doctors to describe the extent of the cancer when they talk with each other about a person’s cancer. More Information