Monday, January 5, 2009

Skin cancer


Skin cancer is a malignant growth on the skin which can have many causes. The most common skin cancers are basal cell cancer, squamous cell cancer, and melanoma. Skin cancer generally develops in the epidermis (the outermost layer of skin), so a tumor is usually clearly visible. This makes most skin cancers detectable in the early stages. There are three common types of skin cancer, each of which is named after the type of skin cell from which it arises. Unlike many other cancers, including those originating in the lung, pancreas, and stomach, only a small minority of those afflicted will actually die of the disease.(citation needed) Skin cancers are the fastest growing type of cancer in the United States. Skin cancer represents the most commonly diagnosed malignancy, surpassing lung, breast, colorectal and prostate cancer. Melanoma is the least common skin cancer but it is potentially the most serious: there are over 8,000 new cases each year in the UK and 1,800 deaths. More people now die of Melanoma in the UK than in Australia. It is the second most common cancer in the young population (20 – 39 age group). It is estimated that approximately 85% of cases are caused by too much sun. Non-melanoma skin cancers are the most common skin cancers. The majority of these are called Basal Cell Carcinomas. These are usually localised growths caused by excessive cumulative exposure to the sun and do not tend to spread.


Colorectal cancer



Colorectal cancer, also called colon cancer or large bowel cancer, includes cancerous growths in the colon, rectum and appendix. With 655,000 deaths worldwide per year, it is the third most common form of cancer and the second leading cause of cancer-related death in the Western world.[1] Many colorectal cancers are thought to arise from adenomatous polyps in the colon. These mushroom-like growths are usually benign, but some may develop into cancer over time. The majority of the time, the diagnosis of localized colon cancer is through colonoscopy. Therapy is usually through surgery, which in many cases is followed by chemotherapy.
To Read More About This Article:http://en.wikipedia.org/wiki/Colon_cancer

Cancer




Cancer (medical term: malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age. Cancer causes about 13% of all deaths. According to the American Cancer society 7.6 million people died from cancer in the world during 2007. Cancers can affect all animals.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation,chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers are usually affected by complex interactions between carcinogens and the host's genome. New aspects of the genetics of cancer pathogenesis. DNA methylation, and microRNAs are increasingly recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system. Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy, and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologic grading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.

Breast cancer

Breast cancer is a cancer that starts in the cells of the breat in women and men. Worldwide, breast cancer is the second most common type of cancer after lung cancer (10.4% of all cancer incidence, both sexes counted) and the fifth most common cause of cancer death. In 2005, breast cancer caused 502,000 deaths worldwide (7% of cancer deaths; almost 1% of all deaths).

Breast cancer also occurs in males. Incidences of breast cancer in men are approximately 100 times less common than in women, but men with breast cancer are considered to have the same statistical survival rates as women.



Brain tumor




A brain tumor (brain tumour in the UK and Canada; see spelling differences) is any intracranial tumor created by abnormal and uncontrolled cell division, normally either in the brain itself (neurons, glial cells(astrocytes,oligodendrocytes,ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain. In the United States in the year 2005, it was estimated that there were 43,800 new cases of brain tumors (Central Brain Tumor Registry of the United States, Primary Brain Tumors in the United States, Statistical Report, 2005–2006), which accounted for 1.4 percent of all cancers, 2.4 percent of all cancer deaths, and 20–25 percent of pediatric cancers. Ultimately, it is estimated that there are 13,000 deaths per year in the United States alone as a result of brain tumors.

MESOTHELIOMA TREATMENTS

Malignant mesothelioma is an uncommon form of cancer typically associated with prolonged asbestos exposure. A rare yet serious disease, malignant mesothelioma attacks the mesothelium (membrane lining the heart sac and the lung and abdominal cavities), typically causing death within one to two years of diagnosis. Malignant mesothelioma types include:

Pleural Mesothelioma: The most common type of malignant mesothelioma, pleural mesothelioma attacks the thoracic cavity (lungs).

Peritoneal Mesothelioma: The second most common type of malignant mesothelioma, peritoneal
mesothelioma attacks the abdominal cavity (stomach).

Pericardial Mesothelioma: The least common type of malignant mesothelioma, pericardial mesothelioma attacks the heart sac.
A plethora of treatment options are available for the 2,000 to 3,000 cases of malignant mesothelioma diagnosed yearly throughout the United States.
Traditional Treatment Options There are three traditional ways to treat malignant mesothelioma:
Surgery
Chemotherapy
Radiation therapy (radiotherapy)
Doctors will often use a combination of two or more treatments (chemotherapy or radiotherapy is commonly used to stunt the growth of a malignant tumor prior to a surgical procedure).

Surgery: Surgical treatment of malignant mesothelioma is the physical removal of a cancerous tumor. The most proactive approach to treating any form of cancer, surgery is split into three categories:

Diagnostic surgery: A precursor to treatment rather than a method of treatment, diagnostic surgery helps confirm and stage malignant mesothelioma. In a procedure called a biopsy, tissue is removed from an area in question and examined by a pathologist.

Palliative surgery: As opposed to aggressively treating malignant mesothelioma, palliative surgery is the process of solely treating the disease's symptoms. For example, fluid build-up (pleural effusion) is a common symptom of malignant mesothelioma. Relief of pleural effusion requires draining of the fluid (thoracentesis). Because pleural effusion often recurs, the only way to eliminate the problem is through surgical closure of the pleural space.

Curative surgery: The goal of curative surgery is to remove all instances of malignant mesothelioma. More often than not, microscopic mesothelioma residue will remain following curative surgery, so it is typically followed by some other treatment (adjuvant therapy) such as chemotherapy or radiotherapy.

Chemotherapy: Treatment of mesothelioma using chemical substances is commonly referred to as chemotherapy. Cancer cells divide at a faster rate than normal cells, fostering a rapid spread of the disease. Although chemotherapy is not a curative procedure, it works to slow the spread of cancer cells throughout the body. Chemotherapy is used for various purposes in treating malignant mesothelioma:
Slowing the growth and spread of cancer cells throughout the body.
Shrinking tumors prior to surgical treatment (neoadjuvant chemotherapy).
Killing microscopic mesothelioma residue following surgery (adjuvant chemotherapy).
Treating the symptoms, using chemical substances (palliative chemotherapy).
Cisplatin has been used in the treatment of cancers since the 1970s when studies demonstrated its effectiveness in combating various sarcomas implanted in rats. A platinum-based chemotherapy drug, cisplatin is currently used for the treatment of sarcomas, carcinomas, lymphomas and germ cell tumors. Cisplatin was the first of a group of platinum-based chemotherapy drugs that now includes carboplatin and oxaliplatin. Although a traditional chemotherapy drug, cisplatin is often used in conjunction with various new treatment modalities or chemotherapy drugs. Both cisplatin and carboplatin are being tested in conjunction with pemetrexed (Alimta) for the treatment of malignant mesothelioma.

Radiation Therapy: Commonly called radiotherapy, radiation therapy uses high-energy rays such as x-rays to kill malignant mesothelioma cells. Somewhat similar to chemotherapy, radiotherapy is not typically viewed as a curative procedure; rather, it is used in combination with surgical procedures and for the purpose of treating the symptoms. Usually, radiotherapy is applied solely to a localized area of concern, as opposed to the entire body.

MESOTHELIOMA DIAGNOSIS

Mesothelioma diagnosis typically begins with a sufferer's visit to the doctor complaining of chronic chest pain. This pain is caused as a result of a buildup of fluid inside the pleural space; this is called pleural effusion and is the most common presenting symptom of malignant mesothelioma.

Preliminary mesothelioma detection can be achieved through a chest imagery scan (CT scan, x-ray); however, mesothelioma is often misdiagnosed as viral pneumonia at this stage because of certain symptomatic similarities between the two. The only way to definitively verify a suspected case of malignant mesothelioma is through a biopsy.
A biopsy is a relatively minor procedure (dependent on the location of the tumor) during which a small section of suspect tissue is removed. The removed section is examined by a histopathologist, an expert in the study of diseased tissue.

Histopathological examination can confirm a case of malignant mesothelioma while also typing and staging it. Understanding the type and stage can help doctors suggest the best of treatment.

Histopathological Examination

Histopathologists are focused on the microscopic study of diseased tissue. A field of pathology, histopathology is a particularly useful tool in forming an accurate diagnosis of cancer and other diseases. The first step in performing a histopathological examination is excising a section of suspect tissue from the patient in question (biopsy). In order to prevent the excised tissue from decaying, it is placed in a fixative (something that increases tissue durability), the most common of which is called formalin (formaldehyde mixed with water).
In order to be prepped for viewing under a high-powered microscope, tissue samples are bathed in a number of increasingly concentrated solutions of ethanol so as to dehydrate the tissue prior to it being dipped in a type of wax called paraffin. By undergoing this procedure, the tissue sample is transformed from a soft and moist section of tissue into a hard paraffin block. This process is called embedding and is performed for the purpose of making it possible to slice the tissue into incredibly thin sections (approximately five micrometers). The ultra-thin slices allow histopathologists to view the size and structure of individual tumor cells.
A tissue section with a thickness of five micrometers is virtually transparent, forcing histopathologists to "stain" the tissue with various types of pigments (hematoxylin and eosin are common) designed to make it viewable under the microscope. Once a section of tissue has been embedded and stained, it is ready for examination.

Mesothelioma Cellular Types

Histopathological examination provides a definitive mesothelioma diagnosis in addition to providing detailed information about the type of mesothelioma (pleural, peritoneal or pericardial) such as its cellular makeup. Mesothelioma cancer cells can be found in three distinct types: epithelioid, sarcomatoid and biphasic.
Epithelioid mesothelioma is the most common type of mesothelioma cancer cell, accounting for 50% to 70% of all mesothelioma cancer cells. Epithelioid cancer cells are distinguished by their unique cellular pattern. They are relatively uniform in shape with a tubular pattern and a clearly defined cell nucleus under magnification.
Sarcomatoid mesothelioma is the least common type of mesothelioma cancer cell, accounting for 10% to 15% of all mesothelioma cancer cells. Sarcomatoid cancer cells are typically oval shaped, but more irregular with a less visible cell nucleus under magnification.

Biphasic mesothelioma is the second most common type of mesothelioma cancer cell, accounting for 25% to 60% of all mesothelioma cancer cells. Biphasic cancer cells do not have a unique pattern because they are a combination of epithelioid cells and sarcomatoid cells. Biphasic mesothelioma cancer cells can be intertwined or isolated from one another across the tumor mass. The latter configuration can lead to a misdiagnosis of cellular type if an excised section of tissue contains only epithelioid or sarcomatoid cells.

TYPES OF MESOTHELIOMA

Types of Mesothelioma include pleural mesothelioma, peritoneal mesothelioma and pericardial mesothelioma. Mesothelioma cancer affects the mesothelial tissue lining of the body's three largest cavities; the pleura (lung cavity), the peritoneum (abdominal cavity) and the pericardium (heart sac). A type of malignant mesothelioma is based on the section of the mesothelium that it affects.
Pleural Mesothelioma

Pleural mesothelioma is the most common type of malignant mesothelioma (accounting for an approximate 75% of all documented cases of the disease) and affects the section of the mesothelium called the pleura. Although the most common type of malignant mesothelioma, the disease is still somewhat of a rarity. As a result, pleural mesothelioma is often confused with other types of diseases, such as lung cancer and viral pneumonia. Lung cancer can be caused by asbestos (asbestos lung cancer), though it differs from pleural mesothelioma in that it is a malignancy of the lung tissue itself, as opposed to pleural mesothelioma which is a malignancy of the tissue casing of the lungs. Viral pneumonia shares certain symptomatic similarities with pleural mesothelioma and is often misdiagnosed as such.

The most common presenting symptom of pleural malignant mesothelioma is chronic chest pain. A buildup of fluid inside the pleural space can cause severe and chronic chest pains; this is called pleural effusion. Steps can be taken to drain the fluid and relieve the pain (with the possibility of recurrence) or surgery can be performed to close the pleural space (with virtually no possibility of recurrence). Some of the other notable symptoms associated with pleural mesothelioma include:
Shortness of breath

Chronic coughing
Weight loss
Fever

Pericardial Mesothelioma

Pericardial mesothelioma is much less common than malignant mesothelioma of the pleura or peritoneum. In fact there are only about 150 cases ever reported in the medical literature. It affects the section of the mesothelium called the pericardium (the mesothelial lining of the heart). People in the fourth to seventh decades of life are most likely to have this cancer, and there is a 2:1 male to female ratio. Currently, surgical excision (removal) of the pericardium is the treatment for pericardial mesothelioma, primarily to lessen symptoms of constriction around the heart.

Symptoms that are associated with pericardial mesothelioma include:

Chest pain

Fluid buildup around the heart

A mass in the space between the lungs

Abnormal or difficult breathing (dyspnea)

Chronic coughing

Irregular heartbeat (palpitations)

Mesothelioma of the Tunica Vaginalis Testis
Mesothelioma of the tunica vaginalis testis is the least common type of malignant mesothelioma (amounting to less than 100 of all documented cases of the disease) and affects the section of the mesothelium called the tunica vaginalis testis (the mesothelial lining around the testes). Most patients are in their 50s or older, but about ten percent of the patients are younger than 25 years. Patients generally present with a hydrocele (an accumulation of serous fluid in a sac-like cavity (as the scrotum)) or hernia. Treatment is usually a high inguinal orchiectomy (surgical excision of the entire affected testis through an incision in the lower abdomen - called also orchidectomy). Prognosis is somewhat better than for pleural mesothelioma.
Symptoms that are associated with this cancer include:
Hydrocele (a fluid filled sac attached to a testicle)
Suspected hernia

Peritoneal Mesothelioma
Peritoneal mesothelioma is the second most common type of malignant mesothelioma (accounting for an approximate 10% to 20% of all documented cases of the disease) and affects the section of the mesothelium called the peritoneum (the mesothelial lining of the abdomen). Peritoneal mesothelioma is most often caused by the ingestion of carcinogenic asbestos fibers. Inhaled asbestos fibers can become lodged in mucous lining the mouth and esophagus. Once swallowed, it travels through the digestive system where it can potentially become lodged and develop into a tumor.
Some of the notable symptoms that are associated with peritoneal mesothelioma include:
Swelling
Abdominal pain (resulting from fluid buildup in peritoneal space)
Weight loss
Abdominal mass
Lowered red blood cell count (anemia)
Fever
Bowel obstruction
Blood clotting problems

Types of Asbestos

Chrysotile asbestos - Also called white asbestos, chrysotile asbestos is viewed to be the safest of the six because it is less friable (less brittle / likely to produce airborne microbes) and therefore less likely to be inhaled. More than 95% of asbestos used today is of the chrysotile variety. Some early evidence suggested that chrysotile asbestos did not pose a health hazard even when inhaled, though more recent animal studies have dispelled this myth. Chrysotile is the only type of asbestos classed as a serpentine mineral (fibers making up chrysotile are of a curled variety).

The remaining five types of asbestos are amphibole minerals, meaning that they are made up of straight, needle-like fibers.

Tremolite asbestos - Tremolite asbestos is not often used industrially, though it was sometimes found in certain commercial products such as talcum powder.

Actinolite asbestos - Like tremolite, actinolite asbestos is not often used industrially. Airborne actinolite asbestos fibers are easily inhaled and severely damaging to the lungs.

Amosite asbestos - Also called brown asbestos, amosite asbestos is used for a variety of commercial purposes such as pipe and cement sheet insulation.

Crocidolite asbestos - Also called blue asbestos, crocidolite asbestos viewed as the most dangerous of the six.

Anthophyllite asbestos - Like tremolite and actinolite, anthophylite asbestos is not often used industrially, though it can occasionally be found in certain types of vermiculite (natural minerals that expand with the application of heat).
Resource

About Asbestos

Asbestos is a group of six naturally occurring fibrous metamorphic minerals: chrysotile, tremolite, actinolite, amosite, crocidolite and anthophyllite. Of the hydrous magnesium silicate variety, asbestos has long been used for a variety of industrial and commercial purposes. Once viewed as a "miracle mineral," asbestos was commonly used as an insulator. Resistant to heat and fire and high in tensile strength, asbestos was used for insulation in buildings, automobile parts and the shipbuilding trades. Miners, harvesting the hazardous mineral on a daily basis, were most at risk of developing mesothelioma because of the amount of direct asbestos exposure they faced.

The health hazards associated with asbestos have been known since the late nineteenth century, though they were ignored for the purpose of business prosperity. A result of increased public awareness and growing health concerns, asbestos was finally regulated under section 112 of the Clean Air Act in 1970.

MESOTHELIOMA CAUSES

Mesothelioma causes are limited to direct and secondary asbestos exposure. Asbestos exposure is known to be responsible for a variety of health issues, including:

Malignant mesothelioma

Asbestos lung cancer

Asbestosis

Diffuse pleural thickening

Fibrosis

Asbestos as a cause of mesothelioma was discovered in connection with occupational exposure to the mineral. Asbestos miners, factory workers, shipyard workers and construction workers were the most likely to contract the deadly disease and amongst the first victims. Mesothelioma is a latent disease that can take anywhere from 30 to 40 years to become symptomatic. A number of cases of mesothelioma where therefore reported within similar windows of time, displaying similar occupational backgrounds. Establishing the link back to asbestos (which was already linked to a number of aforementioned diseases) was a relatively simple task.
Although other causes of mesothelioma have not been ruled out, asbestos exposure is the only known cause thus far.