Types Of Cancer

CANCER TYPES
Currently recognized varieties of cancer can be grouped into three basic categories according to the type of tissue from which the tumor cells have arisen,

Carcinoma– arises in epithelial tissue of the skin and mucous membranes in organs, glands, lungs, urinary bladder, nerves, etc. It is the most common major group of cancers. Some subcategories of carcinoma are:
· Adenocarcinoma – form on glandular epithelium, such as the lung, breast, prostate, ovary, or kidney.
· Basal Cell Carcinoma – arises in the small round cells of the outer layer of the skin
· Carcinoma in Situ – abnormal cell growth, stays within the area in which it started, does not spread.
· Squamous Cell – arises on the skin and inner surfaces of the body.
· Transitional Cell – develops in the lining of the bladder, ureter, and renal pelvis.

2. Sarcoma – the arises from cells of blood, bone marrow, and immune system (including lymph nodes). It is usually found in bone, muscle, cartilage, fat, and fibrous tissue. They include:
Angiosarcoma – resemble blood or lymphatic tissue.

Chondrosarcoma – arises in cells that form cartilage.
Epitheliod Sarcoma – usually found in the hand or foot.
Fibrosarcoma – arises in fibrous tissues like tendons and ligaments.
Hematological – arises from blood cell elements.
Leukemia – originates in the blood-forming tissues of the body. Acute leukemia involves an overgrowth of very immature blood cells, chronic involves an overgrowth of mature blood cells.

Lymphoma – originating in the lymphatic system, affecting the body’s immune system.
» Hodgkins – develops in white blood cells (disease fighting cells) and is caused by an overproduction of lymphoid cells.
» Non -Hodgkins – all lymphomas other than Hodgkins. NHL’s
arise in B-cell, T-cell, from true histiocytes or undefined cells.

Myeloma – usually referred to as multiple myeloma, it originates in the plasma cells of the bone marrow.
Mixed Type – Certain types of cancer that do not belong to any single category. They include:
Brain and CNS cancers include:
» Astrocytoma – involves the brain stem, cerebellum, cerebrum. May be pineal, anaplastic, diffuse, and non-infiltrating (pilocytic, subependymal).
» Choroid Plexus Carcinoma – typically occurs in one of the lateral ventricles.
» GermCell – includes germinoma, teratoma, embryonal carcinoma, yolk sac, and choriocarcinoma.
» Glioma – arises from the glia (supportive tissue). Includes brain stem, optic, astrocytic, and mixed cell.
Melanomas – stems from the pigment-forming cells (melanin) of the skin.

Cancer

Cancer

Cancer stages & Diagnosis

Cancers can be classified according to stage. Staging describes how far a cancer has progressed based on the size of the primary tumor and whether and/or where it has spread.

· Stage 1 usually means a cancer is relatively small and contained within the organ it started in

· Stage 2 usually means the cancer is localised, but the tumour is larger than in stage 1. Sometimes stage 2 means there are nearby lymph nodes that have cancer cells in.

· Stage 3 usually means the cancer is larger and there are cancer cells in the lymph nodes in the area .

· Stage 4 means the cancer has spread from where it started to another body organ, such as the liver, bones or lungs.

Cancer Diagnosis:

The diagnosis of cancer entails an attempt to accurately identify the anatomical site of origin of the malignancy and the type of cells involved. The site refers to the location of the cancer within the body. The body part in which cancer first develops is known as the primary site. A cancer's primary site may determine how the tumor will behave; whether and where it may spread (metastasize) and what symptoms it is most likely to cause.

Secondary site refers to the body part where metastasized cancer cells grow and form secondary tumors. A cancer is always described in terms of the primary site, even if it has spread to another part of the body. Cancer can arise in any organ or tissue in the body except fingernails, hair, and teeth.

A definitive diagnosis usually requires the histologic examination of tissue by a pathologist. This tissue is obtained by biopsy or surgery. Once diagnosed, cancer is usually treated with surgery, chemotherapy or radiotherapy.

Why cancer is referred a killing disease?

Quite a few cancers can be cured these days. 7 out of 10 children are cured of cancer. Testicular cancer, Hodgkin's disease, and many cases of leukaemia can all be cured in adults with chemotherapy. Most skin cancers are cured with surgery. And many cases of thyroid cancer and cancer of the larynx (voicebox) are cured with radiotherapy.Many other types of cancer are also cured if they are found early enough - 3/4 of breast cancers found at stage one for example. Of course, there is still a long way to go. Particularly with some of the commonest types of cancer - lung, breast, bowel and prostate for example.

Difficulties in dealing with cancers
· Are caused by different things, so no one strategy can prevent them
· Respond to different treatments so no one treatment can cure them

There is much research going on in all types of cancer to try and find a cure. Biological therapies such as cancer vaccines, monoclonal antibodies and gene therapies are all active areas of research. There is also research into how cancers grow their own blood supplies. Researchers are beginning to test 'anti-angiogenic' drugs that may be able to stop that happening and so stop cancers from growing. Of course you still have to find them early enough for this to be a cure. But there is hope that this treatment may also stop cancer secondaries from developing. And cancer researchers work on developing new and more effective chemotherapy drugs all the time. Work goes on into refining and improving the treatment of different types of cancer. It is an approach that has come up with the treatments and cures we already have. And we hope will come up with more. Research also goes on into cost effective ways of screening for the different common cancers so that they can be diagnosed early enough for cure to be achievable.

Radio therapy plays a very active role in treating cancer.Radiotherapy is commonly performed using cobalt. The therapy aims in the destruction of cancer cells.

Cured patients do have cancer cells in them,but the treatment aims completely in bringing down the cancer cell concentrate rather than completely eliminating them.

Cancer

Cancer is a wide range of different diseases of which there are well over a hundred types. Cancers can be classified into two broad types: haematological (malignancies of the blood) or solid tumors. The name of the cancer depends on the type of tissue or the site it develops in. For example a sarcoma is a cancer arising from bone, muscle or connective tissue, and carcinoma is cancer arising from epithelial tissue.

Origins of Cancer:

Cell division or cell proliferation is a physiological process that occurs in almost all tissues and under many circumstances. Normally the balance between proliferation and programmed cell death is tightly regulated to ensure the integrity of organs and tissues. Mutations in DNA that lead to cancer disrupt these orderly processes. The uncontrolled and often rapid proliferation of cells can lead to either a benign tumor or a malignant tumor (cancer).

Benign tumors do not spread to other parts of the body or invade other tissues, and they are rarely a threat to life unless they extrinsically compress vital structures. Malignant tumors can invade other organs, spread to distant locations (metastasize) and become life-threatening