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Monday 7 May 2012

Cancer



Cancer

is a broad group of various diseases involving unregulated cell growth. It is medically known as a malignant neoplasm. In cancer, cells divide and grow uncontrollably and invade nearby parts of the body. The cancer may also spread to more distant parts of the body through the lymphatic system or bloodstream, it is called metastasis. However, not all tumors are cancerous. Some tumors do not grow uncontrollably, do not invade neighboring tissues, and do not spread throughout the body which are called Benign tumors.

There are more than 100 types of Cancers. Follow the link to know more:
http://www.cancer.gov/cancertopics/types/alphalist
 


Classification of Cancers:
There are five broad groups that are used to classify cancer.


Carcinomas:
These are characterized by cells that cover internal and external parts of the body such as lung, breast, and colon cancer.


Sarcomas:
These are characterized by cells that are located in bone, cartilage, fat, connective tissue, muscle, and other supportive tissues.


Lymphomas:
These are cancers that begin in the lymph nodes and immune system tissues.


Leukemias:
These are cancers that begin in the bone marrow and often accumulate in the bloodstream.


Adenomas:
These are cancers that arise in the thyroid, the pituitary gland, the adrenal gland, and other glandular tissues.


Causes
Hereditary (about 5-10%)
Environmental (90-95% of cases) factors e.g.,
Tobacco (25-30%) - about 70% of the lung cancers are due to tobacco habit
Infections (15-20%)
Radiation (both ionizing and non-ionizing, up to 10%)
Obesity (30-35%) and
Pollutants,Sedentary life, poor diet etc. are likely to cause cancer.

These can directly damage genes or combine with existing genetic faults within cells to cause the disease.


Detection
Presence of certain signs and symptoms, screening tests including medical imaging etc. can be used.


Diagnosis
Cancer can be diagnosed by microscopic examination of a tissue sample called biopsy.


Treatment
Cancer is usually treated with chemotherapy, radiation therapy and surgery.


Survival
Survival depends greatly by the type and location of the cancer and the extent of disease at the start of treatment. The risk of developing cancer generally increases with age.


Young People with Cancer, visit following link for details:
http://www.cancer.gov/cancertopics/coping/youngpeople/page6

For Types of Childhood Cancer, visit the following link:
http://www.cancer.gov/cancertopics/coping/youngpeople/page13

For common medical procedures, visit the following link:
http://www.cancer.gov/cancertopics/coping/youngpeople/page6

Signs and Symptoms
Initially there will be no signs and symptoms but only appearing as the mass that continues to grow or ulcerates. The findings that result depends on the type and location of the cancer. For example, Mass effects from Lung Cancer can cause blockage of the bronchus resulting in cough (coughing up blood if there is ulceration) or pneumonia.


Oesophageal Cancer
can cause narrowing of the esophagus making it difficult or painful to swallow.


Colorectal Cancer
may lead to changes in bowel habits and bleeding leading to anemia.

 
General symptoms  may include:
Unintentional weight loss,
Fever,
Being excessively tired,
Changes to the skin,
Hodgkin disease,
Leukemias, and
Persistent fever due to Cancers of the liver or kidney.

Symptoms of metastasis  include:
Enlarged lynph nodes which can be felt or sometimes seen under the skin and are typically hard),
Enlarged liver or spleen which can be felt in the abdomen,
Pain or fracture of affected bones, and
Neurological symptoms.

It is nearly impossible to prove what caused a cancer in any individual, because most cancers have multiple possible causes. For example, lung cancer could be due to tobacco habbit or could be a result of air pollution or radiation.


Prevention
http://www.who.int/cancer/prevention/en/

Literature on Cancer:
http://www.cancer.gov/cancertopics/litsearch