Cancer:::: screening, management, prognosis, epidemiology, history, society and culture!!!!!

Main article: Cancer screening
Unlike diagnostic efforts prompted by symptoms and medical signs, cancer screening involves efforts to detect cancer after it has formed, but before any noticeable symptoms appear.[120] This may involve physical examination, blood or urine tests or medical imaging.[120]

Cancer screening is not available for many types of cancers. Even when tests are available, they may not be recommended for everyone. Universal screening or mass screening involves screening everyone.[121] Selective screening identifies people who are at higher risk, such as people with a family history.[121] Several factors are considered to determine whether the benefits of screening outweigh the risks and the costs of screening.[120] These factors include:

Possible harms from the screening test: for example, X-ray images involve exposure to potentially harmful ionizing radiation
The likelihood of the test correctly identifying cancer
The likelihood that cancer is present: Screening is not normally useful for rare cancers.
Possible harms from follow-up procedures
Whether suitable treatment is available
Whether early detection improves treatment outcomes
Whether the cancer will ever need treatment
Whether the test is acceptable to the people: If a screening test is too burdensome (for example, extremely painful), then people will refuse to participate.[121]
Cost
Recommendations
U.S. Preventive Services Task Force
The U.S. Preventive Services Task Force (USPSTF) issues recommendations for various cancers:

Strongly recommends cervical cancer screening in women who are sexually active and have a cervix at least until the age of 65.[122]
Recommend that Americans be screened for colorectal cancer via fecal occult blood testing, sigmoidoscopy, or colonoscopy starting at age 50 until age 75.[123]
Evidence is insufficient to recommend for or against screening for skin cancer,[124] oral cancer,[125] lung cancer,[126] or prostate cancer in men under 75.[127]
Routine screening is not recommended for bladder cancer,[128] testicular cancer,[129] ovarian cancer,[130] pancreatic cancer,[131] or prostate cancer.[132]
Recommends mammography for breast cancer screening every two years from ages 50–74. Do not recommend either breast self-examination or clinical breast examination.[133] (A 2011 Cochrane review came to slightly different conclusions with respect to breast cancer screening stating that routine mammography may do more harm than good.[134][needs update])
Japan
Screens for gastric cancer using photofluorography due to the high incidence there.[21]

Genetic testing
See also: Cancer syndrome
Gene Cancer types
BRCA1, BRCA2 Breast, ovarian, pancreatic
HNPCC, MLH1, MSH2, MSH6, PMS1, PMS2 Colon, uterine, small bowel, stomach, urinary tract
Genetic testing for individuals at high-risk of certain cancers is recommended by unofficial groups.[119][135] Carriers of these mutations may then undergo enhanced surveillance, chemoprevention, or preventative surgery to reduce their subsequent risk.[135]

Main articles: Management of cancer and oncology
Many treatment options for cancer exist. The primary ones include surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy and palliative care. Which treatments are used depends on the type, location and grade of the cancer as well as the patient’s health and preferences. The treatment intent may or may not be curative.

Chemotherapy
Chemotherapy is the treatment of cancer with one or more cytotoxic anti-neoplastic drugs (chemotherapeutic agents) as part of a standardized regimen. The term encompasses a variety of drugs, which are divided into broad categories such as alkylating agents and antimetabolites.[136] Traditional chemotherapeutic agents act by killing cells that divide rapidly, a critical property of most cancer cells.

Targeted therapy is a form of chemotherapy that targets specific molecular differences between cancer and normal cells. The first targeted therapies blocked the estrogen receptor molecule, inhibiting the growth of breast cancer. Another common example is the class of Bcr-Abl inhibitors, which are used to treat chronic myelogenous leukemia (CML).[137] Currently, targeted therapies exist for breast cancer, multiple myeloma, lymphoma, prostate cancer, melanoma and other cancers.[138]

The efficacy of chemotherapy depends on the type of cancer and the stage. In combination with surgery, chemotherapy has proven useful in cancer types including breast cancer, colorectal cancer, pancreatic cancer, osteogenic sarcoma, testicular cancer, ovarian cancer and certain lung cancers.[139] Chemotherapy is curative for some cancers, such as some leukemias,[140][141] ineffective in some brain tumors,[142] and needless in others, such as most non-melanoma skin cancers.[143] The effectiveness of chemotherapy is often limited by its toxicity to other tissues in the body. Even when chemotherapy does not provide a permanent cure, it may be useful to reduce symptoms such as pain or to reduce the size of an inoperable tumor in the hope that surgery will become possible in the future.

Radiation
Radiation therapy involves the use of ionizing radiation in an attempt to either cure or improve symptoms. It works by damaging the DNA of cancerous tissue, killing it. To spare normal tissues (such as skin or organs, which radiation must pass through to treat the tumor), shaped radiation beams are aimed from multiple exposure angles to intersect at the tumor, providing a much larger dose there than in the surrounding, healthy tissue. As with chemotherapy, cancers vary in their response to radiation therapy.[144][145][146]

Radiation therapy is used in about half of cases. The radiation can be either from internal sources (brachytherapy) or external sources. The radiation is most commonly low energy x-rays for treating skin cancers, while higher energy x-rays are used for cancers within the body.[147] Radiation is typically used in addition to surgery and or chemotherapy. For certain types of cancer, such as early head and neck cancer, it may be used alone.[148] For painful bone metastasis, it has been found to be effective in about 70% of patients.[148]
Surgery
Surgery is the primary method of treatment for most isolated, solid cancers and may play a role in palliation and prolongation of survival. It is typically an important part of definitive diagnosis and staging of tumors, as biopsies are usually required. In localized cancer, surgery typically attempts to remove the entire mass along with, in certain cases, the lymph nodes in the area. For some types of cancer this is sufficient to eliminate the cancer.[139]

Palliative care
Palliative care refers to treatment that attempts to help the patient feel better and may be combined with an attempt to treat the cancer. Palliative care includes action to reduce physical, emotional, spiritual and psycho-social distress. Unlike treatment that is aimed at directly killing cancer cells, the primary goal of palliative care is to improve quality of life.

People at all stages of cancer treatment typically receive some kind of palliative care. In some cases, medical specialty professional organizations recommend that patients and physicians respond to cancer only with palliative care.[149] This applies to patients who:[150]

display low performance status, implying limited ability to care for themselves[149]
received no benefit from prior evidence-based treatments[149]
are not eligible to participate in any appropriate clinical trial[149]
no strong evidence implies that treatment would be effective[149]
Palliative care may be confused with hospice and therefore only indicated when people approach end of life. Like hospice care, palliative care attempts to help the patient cope with their immediate needs and to increase comfort. Unlike hospice care, palliative care does not require people to stop treatment aimed at the cancer.

Multiple national medical guidelines recommend early palliative care for patients whose cancer has produced distressing symptoms or who need help coping with their illness. In patients first diagnosed with metastatic disease, palliative care may be immediately indicated. Palliative care is indicated for patients with a prognosis of less than 12 months of life even given aggressive treatment.[151][152][153]

Immunotherapy
Main article: Cancer immunotherapy
A variety of therapies using immunotherapy, stimulating or helping the immune system to fight cancer, have come into use since 1997. Approaches include antibodies, checkpoint therapy and adoptive cell transfer.[154]

Alternative medicine
Complementary and alternative cancer treatments are a diverse group of therapies, practices and products that are not part of conventional medicine.[155] “Complementary medicine” refers to methods and substances used along with conventional medicine, while “alternative medicine” refers to compounds used instead of conventional medicine.[156] Most complementary and alternative medicines for cancer have not been studied or tested using conventional techniques such as clinical trials. Some alternative treatments have been investigated and shown to be ineffective but still continue to be marketed and promoted. Cancer researcher Andrew J. Vickers stated, “The label ‘unproven’ is inappropriate for such therapies; it is time to assert that many alternative cancer therapies have been ‘disproven’.”[157]
See also: List of cancer mortality rates in the United States and Cancer survivor
Survival rates vary by cancer type and by the stage at which it is diagnosed, ranging from majority survival to complete mortality five years after diagnosis. Once a cancer has metastasized, prognosis normally becomes much worse. About half of patients receiving treatment for invasive cancer (excluding carcinoma in situ and non-melanoma skin cancers) die from that cancer or its treatment.[21]

Survival is worse in the developing world,[21] partly because the types of cancer that are most common there are harder to treat than those associated with developed countries.[158]

Those who survive cancer develop a second primary cancer at about twice the rate of those never diagnosed.[159] The increased risk is believed to be due to the random chance of developing any cancer, the likelihood of surviving the first cancer, the same risk factors that produced the first cancer, unwanted side effects of treating the first cancer (particularly radiation therapy), and to better compliance with screening.[159]

Predicting short- or long-term survival depends on many factors. The most important are the cancer type and the patient’s age and overall health. Those who are frail with other health problems have lower survival rates than otherwise healthy people. Centenarians are unlikely to survive for five years even if treatment is successful. People who report a higher quality of life tend to survive longer.[160] People with lower quality of life may be affected by depression and other complications and/or disease progression that both impairs quality and quantity of life. Additionally, patients with worse prognoses may be depressed or report poorer quality of life because they perceive that their condition is likely to be fatal.

Cancer patients have an increased risk of blood clots in veins. The use of heparin appears to improve survival and decrease the risk of blood clots.[161]

Main article: Epidemiology of cancer
See also: List of countries by cancer rate

Death from cancer per million persons in 2012
135-367
368-443
444-521
522-588
589-736
737-968
969-1,567
1,568-2,085
2,086-2,567
2,568-3,320
In 2008, approximately 12.7 million cancers were diagnosed (excluding non-melanoma skin cancers and other non-invasive cancers)[21] and in 2010 nearly 7.98 million people died.[162] Cancers account for approximately 13% of deaths. The most common are lung cancer (1.4 million deaths), stomach cancer (740,000), liver cancer (700,000), colorectal cancer (610,000) and breast cancer (460,000).[163] This makes invasive cancer the leading cause of death in the developed world and the second leading in the developing world.[21] Over half of cases occur in the developing world.[21]

Deaths from cancer were 5.8 million in 1990.[162] Deaths have been increasing primarily due to longer lifespans and lifestyle changes in the developing world.[21] The most significant risk factor for developing cancer is age.[164] Although it is possible for cancer to strike at any age, most patients with invasive cancer are over 65.[164] According to cancer researcher Robert A. Weinberg, “If we lived long enough, sooner or later we all would get cancer.”[165] Some of the association between aging and cancer is attributed to immunosenescence,[166] errors accumulated in DNA over a lifetime[167] and age-related changes in the endocrine system.[168] Aging’s effect on cancer is complicated by factors such as DNA damage and inflammation promoting it and factors such as vascular aging and endocrine changes inhibiting it.[169]

Some slow-growing cancers are particularly common, but often are not fatal. Autopsy studies in Europe and Asia showed that up to 36% of people have undiagnosed and apparently harmless thyroid cancer at the time of their deaths and that 80% of men develop prostate cancer by age 80.[170][171] As these cancers do not cause the patient’s death, identifying them would have represented overdiagnosis rather than useful medical care.

The three most common childhood cancers are leukemia (34%), brain tumors (23%) and lymphomas (12%).[172] In the United States cancer affects about 1 in 285 children.[173] Rates of childhood cancer increased by 0.6% per year between 1975 and 2002 in the United States[174] and by 1.1% per year between 1978 and 1997 in Europe.[172] Death from childhood cancer decreased by half since 1975 in the United States.[173]

Main article: History of cancer

Engraving with two views of a Dutch woman who had a tumor removed from her neck in 1689
Cancer has existed for all of human history.[175] The earliest written record regarding cancer is from circa 1600 BC in the Egyptian Edwin Smith Papyrus and describes breast cancer.[175] Hippocrates (ca. 460 BC – ca. 370 BC) described several kinds of cancer, referring to them with the Greek word καρκίνος karkinos (crab or crayfish).[175] This name comes from the appearance of the cut surface of a solid malignant tumor, with “the veins stretched on all sides as the animal the crab has its feet, whence it derives its name”.[176] Galen stated that “cancer of the breast is so called because of the fancied resemblance to a crab given by the lateral prolongations of the tumor and the adjacent distended veins”.[177]:738 Celsus (ca. 25 BC – 50 AD) translated karkinos into the Latin cancer, also meaning crab and recommended surgery as treatment.[175] Galen (2nd century AD) disagreed with the use of surgery and recommended purgatives instead.[175] These recommendations largely stood for 1000 years.[175]

In the 15th, 16th and 17th centuries, it became acceptable for doctors to dissect bodies to discover the cause of death.[178] The German professor Wilhelm Fabry believed that breast cancer was caused by a milk clot in a mammary duct. The Dutch professor Francois de la Boe Sylvius, a follower of Descartes, believed that all disease was the outcome of chemical processes and that acidic lymph fluid was the cause of cancer. His contemporary Nicolaes Tulp believed that cancer was a poison that slowly spreads and concluded that it was contagious.[179]

The physician John Hill described tobacco snuff as the cause of nose cancer in 1761.[178] This was followed by the report in 1775 by British surgeon Percivall Pott that chimney sweeps’ carcinoma, a cancer of the scrotum, was a common disease among chimney sweeps.[180] With the widespread use of the microscope in the 18th century, it was discovered that the ‘cancer poison’ spread from the primary tumor through the lymph nodes to other sites (“metastasis”). This view of the disease was first formulated by the English surgeon Campbell De Morgan between 1871 and 1874.[181]

Though many diseases (such as heart failure) may have a worse prognosis than most cases of cancer, cancer is the subject of widespread fear and taboos. The euphemism “after a long illness” is still commonly used (2012), reflecting an apparent stigma.[182] This deep belief that cancer is necessarily a difficult and usually deadly disease is reflected in the systems chosen by society to compile cancer statistics: the most common form of cancer—non-melanoma skin cancers, accounting for about one-third of cancer cases worldwide, but very few deaths[183][184]—are excluded from cancer statistics specifically because they are easily treated and almost always cured, often in a single, short, outpatient procedure.[185]

Cancer is regarded as a disease that must be “fought” to end the “civil insurrection”; a War on Cancer was declared in the US. Military metaphors are particularly common in descriptions of cancer’s human effects and they emphasize both the state of the patient’s health and the need to take immediate, decisive actions himself, rather than to delay, to ignore, or to rely entirely on others. The military metaphors also help rationalize radical, destructive treatments.[186][187]

In the 1970s, a relatively popular alternative cancer treatment in the US was a specialized form of talk therapy, based on the idea that cancer was caused by a bad attitude.[188] People with a “cancer personality”—depressed, repressed, self-loathing and afraid to express their emotions—were believed to have manifested cancer through subconscious desire. Some psychotherapists said that treatment to change the patient’s outlook on life would cure the cancer.[188] Among other effects, this belief allowed society to blame the victim for having caused the cancer (by “wanting” it) or having prevented its cure (by not becoming a sufficiently happy, fearless and loving person).[189] It also increased patients’ anxiety, as they incorrectly believed that natural emotions of sadness, anger or fear shorten their lives.[189] The idea was ridiculed by Susan Sontag, who published Illness as Metaphor while recovering from treatment for breast cancer in 1978.[188] Although the original idea is now generally regarded as nonsense, the idea partly persists in a reduced form with a widespread, but incorrect, belief that deliberately cultivating a habit of positive thinking will increase survival.[189] This notion is particularly strong in breast cancer culture.[189]

One idea about why people with cancer are blamed or stigmatized, called the just-world hypothesis, is that blaming cancer on the patient’s actions or attitudes allows the blamers to regain a sense of control. This is based upon the blamers’ belief that the world is fundamentally just and so any dangerous illness, like cancer, must be a type of punishment for bad choices, because in a just world, bad things would not happen to good people.[190]
Economic effect
In 2007, the overall costs of cancer in the US—including treatment and indirect mortality expenses (such as lost productivity in the workplace)—was estimated to be $226.8 billion. In 2009, 32% of Hispanics and 10% of children 17 years old or younger lacked health insurance; “uninsured patients and those from ethnic minorities are substantially more likely to be diagnosed with cancer at a later stage, when treatment can be more extensive and more costly.”[191]…….