Types of cancer

Types of cancer

Cancer cells within a tumor are the descendants of a single cell, even after it has metastasized. Hence, a cancer can be classified by the type of cell in which it originates and by the location of the cell.
Carcinomas originate in epithelial cells (e.g. the digestive tract or glands). Hematological malignancies, such as leukemia and lymphoma, arise from cells of hematopoeitic origin, such as blood and bone marrow. Sarcoma arises from connective tissue, bone or muscle. Malignant tumors usually end in suffix "-carcinoma" for epithelial cancers, and "-sarcomas" for connective tissue tumors. Otherwise, benign tumors of both origins are denoted as "-omas." For instance, benign tumor of fat cells are known as "lipoma," while its malignant form is known as "liposarcoma."
Adult cancersIn the USA and other developed countries, cancer is presently responsible for about 25% of all deaths[1]. On a yearly basis, 0.5% of the population is diagnosed with cancer.
For adult males in the United States, the most common cancers are prostate cancer (33% of all cancer cases), lung cancer (13%), colorectal cancer (10%), bladder cancer (7%) and cutaneous melanoma (5%). As a cause of death lung cancer is the most common (31%) cause, followed by prostate cancer (10%), colorectal cancer (10%), pancreatic cancer (5%) and leukemia (4%)[1].
For adult females in the United States, breast cancer is the most common cancer (32% of all cancer cases) followed by lung cancer (12%), colorectal cancer (11%), endometrial cancer (6%, uterus) and non-Hodgkin's lymphoma (4%). By cause of death, lung cancer is again the most common (27% of all cancer deaths), followed by breast cancer (15%), colorectal cancer (10%), ovarian cancer (6%) and pancreatic cancer (6%)[1].
These statistics vary substantially in other countries.
Other cancers not mentioned:
Epithelial tumors: skin cancer (this is in fact the most common cancer but often not classified as such in health statistics), cervical cancer, anal carcinoma, esophageal cancer, hepatocellular carcinoma (in the liver), laryngeal cancer, renal cell carcinoma (in the kidneys), stomach cancer, many testicular cancers, and thyroid cancer. Hematological malignancies (blood and bone marrow): leukemia, lymphoma, multiple myeloma. Sarcomas: osteosarcoma (in bone), chondrosarcoma (arising from cartilage), rhabdomyosarcoma (in muscle) Miscellaneous origin: brain tumors, gastrointestinal stromal tumors (GIST), mesothelioma (in the pleura or pericardium), thymoma and teratomas, melanoma
Childhood cancersCancer can also occur in young children and adolescents. Here, the aberrant genetic processes that fail to safeguard against the clonal proliferation of cells with unregulated growth potential occur early in life and can progress quickly.
The age of peak incidence of cancer in children occurs during the first year of life. Leukemia (usually ALL) is the most common infant malignancy (30%), followed by the central nervous system cancers and neuroblastoma. The remainder consists of Wilms' tumor, lymphomas, rhabdomyosarcoma (arising from muscle), retinoblastoma, osteosarcoma and Ewing's sarcoma[1].
Female infants and male infants have essentially the same overall cancer incidence rates, but white infants have substantially higher cancer rates than black infants for most cancer types. Relative survival for infants is very good for neuroblastoma, Wilms' tumor and retinoblastoma, and fairly good (80%) for leukemia, but not for most other types of cancer.
Causes and pathophysiologyMain article: Carcinogenesis
Origins of cancerCell division (proliferation) is a physiological process that occurs in almost all tissues and under many circumstances. Normally the balance between proliferation and 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.

Diagnosing cancer

Diagnosing cancer

Most cancers are initially recognized either because signs or symptoms appear or through screening. Neither of these lead to a definitive diagnosis, which usually requires the opinion of a pathologist.
Signs and symptomsRoughly, cancer symptoms can be divided into three groups:Local symptoms: unusual lumps or swelling (tumor), hemorrhage (bleeding), pain and/or ulceration. Compression of surrounding tissues may cause symptoms such as jaundice. Symptoms of metastasis (spreading): enlarged lymph nodes, cough and hemoptysis, hepatomegaly (enlarged liver), bone pain, fracture of affected bones and neurological symptoms. Although advanced cancer may cause pain, it is often not the first symptom. Systemic symptoms: weight loss, poor appetite and cachexia (wasting), excessive sweating (night sweats), anemia and specific paraneoplastic phenomena, i.e. specific conditions that are due to an active cancer, such as thrombosis or hormonal changes. Every single item in the above list can be caused by a variety of conditions (a list of which is referred to as the differential diagnosis). Cancer may be a common or uncommon cause of each item.
BiopsyA cancer may be suspected for a variety of reasons, but the definitive diagnosis of most malignancies must be confirmed by histological examination of the cancerous cells by a pathologist. Tissue can be obtained from a biopsy or surgery. Many biopsies (such as those of the skin, breast or liver) can be done in a doctor's office. Biopsies of other organs are performed under anesthesia and require surgery in an operating room.The tissue diagnosis indicates the type of cell that is proliferating, its histological grade and other features of the tumor. Together, this information is useful to evaluate the prognosis of this patient and choose the best treatment. Cytogenetics and immunohistochemistry may provide information about future behavior of the cancer (prognosis) and best treatment.
ScreeningCancer screening is an attempt to detect unsuspected cancers in the population. Screening tests suitable for large numbers of healthy people must be relatively affordable, safe, noninvasive procedures with acceptably low rates of false positive results. If signs of cancer are detected, more definitive and invasive followup tests are performed to confirm the diagnosis.Screening for cancer can lead to earlier diagnosis. Early diagnosis may lead to extended life. A number of different screening tests have been developed. Breast cancer screening can be done by breast self-examination. Screening by regular mammograms detects tumors even earlier than self-examination, and many countries use it to systematically screen all middle-aged women. Colorectal cancer can be detected through fecal occult blood testing and colonoscopy, which reduces both colon cancer incidence and mortality, presumably through the detection and removal of premalignant polyps. Similarly, cervical cytology testing (using the Pap smear) leads to the identification and excision of precancerous lesions. Over time, such testing has been followed by a dramatic reduction of cervical cancer incidence and mortality. Testicular self-examination is recommended for men beginning at the age of 15 years to detect testicular cancer. Prostate cancer can be screened for by a digital rectal exam along with prostate specific antigen (PSA) blood testing.Screening for cancer is controversial in cases when it is not yet known if the test actually saves lives. The controversy arises when it is not clear if the benefits of screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example: when screening for prostate cancer, the PSA test may detect small cancers that would never become life threatening, but once detected will lead to treatment. This situation, called overdiagnosis, puts men at risk for complications from unnecessary treatment such as surgery or radiation. Followup procedures used to diagnose prostate cancer (prostate biopsy) may cause side effects, including bleeding and infection. Prostate cancer treatment may cause incontinence (inability to control urine flow) and erectile dysfunction (erections inadequate for intercourse). Similarly, for breast cancer, there have recently been criticisms that breast screening programs in some countries cause more problems than they solve. This is because screening of women in the general population will result in a large number of women with false positive results which require extensive follow-up investigations to exclude cancer, leading to having a high number-to-treat (or number-to-screen) to prevent or catch a single case of breast cancer early.Cervical cancer screening via the Pap smear has the best cost-benefit profile of all the forms of cancer screening from a public health perspective as, being a cancer, it has clear risk factors (sexual contact), and the natural progression of cervical cancer is that it normally spreads slowly over a number of years therefore giving more time for the screening program to catch it early. Moreover, the test itself is easy to perform and relatively cheap.For these reasons, it is important that the benefits and risks of diagnostic procedures and treatment be taken into account when considering whether to undertake cancer screening.Use of medical imaging to search for cancer in people without clear symptoms is similarly marred with problems. There is a significant risk of detection of what has been recently called an incidentaloma - a benign lesion that may be interpreted as a malignancy and be subjected to potentially dangerous investigations.

Cancer

Cancer

When normal cells are damaged beyond repair, they are eliminated by apoptosis. Cancer cells avoid apoptosis and continue to multiply in an unregulated manner.Cancer is a class of diseases characterized by uncontrolled cell division and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue (invasion) or by implantation into distant sites (metastasis). This unregulated growth is caused by damage to DNA, resulting in mutations to genes that control cell division. Several mutations are required to transform a normal cell into a malignant cell. These mutations are often caused by chemicals or physical agents called carcinogens, the best known being tobacco smoke. Some mutations can be inherited.
Tumor ("swelling" in Latin) is a more general term that describes an abnormal mass of tissue. Tumors can be malignant or benign. Cancer is synonymous with malignant tumor.
The word cancer is not used in Medicine as it lacks accuracy, but remains the common name for this group of diseases in most languages. Malignant tumors are classified as such:
Carcinoma: malignant tumors derived from epithelial cells. This group represent the most common cancers, including the common forms of breast, prostate, lung and colon cancer. Lymphoma and Leukemia: malignant tumors derived from blood and bone marrow cells Sarcoma: malignant tumors derived from connective tissue, or mesenchymal cells Glioma: tumors derived from brain cells germ cell tumours: tumors derived from germ cells, normally found in the testicle and ovary Choriocarcinoma: malignant tumors derived from the placenta Cancer can cause many different symptoms, depending on the site and character of the malignancy and whether there is metastasis. Usually, cancer is painless at an early stage. A definitive diagnosis usually requires the histologic examination of tissue by a specialized physician called a pathologist. This tissue is obtained by biopsy or surgery. Once diagnosed, cancer is usually treated with surgery, chemotherapy and/or radiation.
If untreated, most cancers eventually cause death; cancer is one of the leading causes of death in developed countries. Most cancers can be treated and many cured, especially if treatment begins early. Many forms of cancer are associated with environmental factors, which may be avoidable. Cigarette smoking leads to more cancers than any other environmental factor.

Distiller Water Filters

Water distillers use electricity to heat tap water to boiling point. Generally the Impurities are left in the container and the purified contents go back to a clean container. They need a higher level of efficiency and cannot give immediate supply, because the boiling process must be over before water is present. There are a number of reports in that distilled water is not fit for health because it takes away nutrients from the body, being the most 'unnatural' of water.

Ionized Water Filters
These are generally filtered using an acid and an alkaline. They run between the positive and the negative ends of the electrodes and get the charged and acidic water. They are formed using 70% alkaline water and 30% Acid water. Alkaline and Acidic waters have unusual properties and benefits, but anyway their respective uses could not be more different.

Back flush Water Filters
They are costlier compared to charcoal filter units, but justify this by their claims of longevity. They are highly durable and efficient.

Waste Water Treatment

A standard wastewater treatment train would typically consist of a primary clarifier system to remove solid and floating materials, a secondary treatment system consisting of an aeration basin followed by flocculation and sedimentation or an activated sludge system and a secondary clarifiers, a tertiary biological nitrogen removal system, and a final tertiary disinfections unit.

The aeration basin/activated sludge system removes organic material by growing bacteria (activated sludge). The secondary clarifier removes the activated sludge from the water. The tertiary system is becoming more prevalent to remove nitrogen and phosphorus and do final disinfections of the water prior to its discharge to a surface water stream or ocean outfall. Before reentering into a body of water, the wastewater gets treated under a multi-stage process then only the water gets renovated and it is used for application. The process is the removal of wastewater pollutants, organic matter, disease-causing organisms, solids and nutrients.

Most wastewater is treated in industrial-scale wastewater treatment plants, which may include physical, chemical and biological treatment processes. However, the use of septic tanks is widespread in rural areas, serving up to one quarter of the homes in the U.S. The most important aerobic treatment system is the activated sludge process, based on the maintenance and recirculation of a complex biomass composed by microorganisms able to degrade the organic matter carried in the wastewater.

Anaerobic processes are widely applied in the treatment of industrial wastewaters and biological sludge. Some wastewater may be highly treated and reused as reclaimed water. For some wastewaters ecological approaches using reed bed systems such as constructed wetlands may be appropriate. Modern systems include tertiary treatment by micro filtration or synthetic membranes. After membrane filtration, the treated wastewater is indistinguishable from waters of natural origin of drinking quality.