Cancer::first    Journal::title    Cancer::pages    Author::volume    Issue::cancers    Cause::breast

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Cancer, also known as a malignant tumor or malignant neoplasm, is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.<ref name=WHO2014/><ref name=NCI2014>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Not all tumors are cancerous; benign tumors do not spread to other parts of the body.<ref name=NCI2014/> Possible signs and symptoms include: a new lump, abnormal bleeding, a prolonged cough, unexplained weight loss, and a change in bowel movements among others.<ref name=NHS2012>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> While these symptoms may indicate cancer, they may also occur due to other issues.<ref name=NHS2012/> There are over 100 different known cancers that affect humans.<ref name=NCI2014/>

Tobacco use is the cause of about 22% of cancer deaths.<ref name=WHO2014>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Another 10% is due to obesity, a poor diet, lack of physical activity, and consumption of alcohol.<ref name=WHO2014/><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants.<ref name=Enviro2008>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> In the developing world nearly 20% of cancers are due to infections such as hepatitis B, hepatitis C, and human papillomavirus (HPV).<ref name=WHO2014/> These factors act, at least partly, by changing the genes of a cell.<ref name=WCR2014Bio>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> Typically many such genetic changes are required before cancer develops.<ref name=WCR2014Bio/> Approximately 5–10% of cancers are due to genetic defects inherited from a person's parents.<ref name="ACS-heredity">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Cancer can be detected by certain signs and symptoms or screening tests.<ref name=WHO2014/> It is then typically further investigated by medical imaging and confirmed by biopsy.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Many cancers can be prevented by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating plenty of vegetables, fruits and whole grains, being vaccinated against certain infectious diseases, not eating too much processed and red meat, and avoiding too much exposure to sunlight.<ref name=Kushi2012>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref><ref>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> Early detection through screening is useful for cervical and colorectal cancer.<ref name=WCR2014Scr>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> The benefits of screening in breast cancer are controversial.<ref name=WCR2014Scr/><ref name=Got2013>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> Cancer is often treated with some combination of radiation therapy, surgery, chemotherapy, and targeted therapy.<ref name=WHO2014/><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Pain and symptom management are an important part of care. Palliative care is particularly important in those with advanced disease.<ref name=WHO2014/> The chance of survival depends on the type of cancer and extent of disease at the start of treatment.<ref name="WCR2014Bio"/> In children under 15 at diagnosis the five-year survival rate in the developed world is on average 80%.<ref name=WCR2014Peads>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> For cancer in the United States the average five-year survival rate is 66%.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

In 2012 about 14.1 million new cases of cancer occurred globally (not including skin cancer other than melanoma).<ref name="WCR2014Bio"/> It caused about 8.2 million deaths or 14.6% of all human deaths.<ref name="WCR2014Bio">{{#invoke:citation/CS1|citation |CitationClass=book }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The most common types of cancer in males are lung cancer, prostate cancer, colorectal cancer, and stomach cancer, and in females, the most common types are breast cancer, colorectal cancer, lung cancer, and cervical cancer.<ref name="WCR2014Bio"/> If skin cancer other than melanoma were included in total new cancers each year it would account for around 40% of cases.<ref>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref><ref name=Cak2012>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> In children, acute lymphoblastic leukaemia and brain tumors are most common except in Africa where non-Hodgkin lymphoma occurs more often.<ref name=WCR2014Peads/> In 2012, about 165,000 children under 15 years of age were diagnosed with cancer. The risk of cancer increases significantly with age and many cancers occur more commonly in developed countries.<ref name="WCR2014Bio"/> Rates are increasing as more people live to an old age and as lifestyle changes occur in the developing world.<ref name=Epi11>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> The financial costs of cancer have been estimated at $1.16 trillion US dollars per year as of 2010.<ref name="WCR2014Eco">{{#invoke:citation/CS1|citation |CitationClass=book }}</ref>

Cancer sections
Intro  Definitions  Signs and symptoms  Causes  Pathophysiology  Diagnosis  Prevention  Screening  Management  Prognosis  Epidemiology  History  Society and culture  Research  Pregnancy  Other animals  Notes  Further reading  External links  

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