Editing Cancer (section)

== Signs and symptoms ==
{{Main|Signs and symptoms of cancer}}
[[File:Symptoms of cancer metastasis.svg|thumb|upright=1.35|Symptoms of cancer [[metastasis]] depend on the location of the tumor.]]

When cancer begins, it produces no symptoms. Signs and symptoms appear as the mass grows or [[ulcer (dermatology)|ulcerates]]. The findings that result depend on cancer's type and location. Few symptoms are [[non-specific symptom|specific]]. Many frequently occur in individuals who have other conditions. Cancer can be difficult to diagnose and can be considered a "[[the great imitator|great imitator]]".<ref name=Card10/>

People may become anxious or depressed post-diagnosis. The risk of suicide in people with cancer is approximately double.<ref>{{cite journal |vauthors=Anguiano L, Mayer DK, Piven ML, Rosenstein D |s2cid=45874503 |title=A literature review of suicide in cancer patients |journal=Cancer Nursing |volume=35 |issue=4 |pages=E14–26 |date=July–August 2012 |pmid=21946906 |doi=10.1097/NCC.0b013e31822fc76c|doi-access=free }}</ref>

=== Local symptoms ===
Local symptoms may occur due to the mass of the tumor or its ulceration. For example, mass effects from lung cancer can block the [[bronchus]] resulting in cough or [[pneumonia]]; [[esophageal cancer]] can cause narrowing of the [[esophagus]], making it difficult or painful to swallow; and [[colorectal cancer]] may lead to narrowing or blockages in the [[bowel]], affecting bowel habits. Masses in breasts or testicles may produce observable lumps. [[ulcer (dermatology)|Ulceration]] can cause bleeding that can lead to symptoms such as [[hemoptysis|coughing up blood]] (lung cancer), [[anemia]] or [[Lower gastrointestinal bleeding|rectal bleeding]] (colon cancer), [[Hematuria|blood in the urine]] (bladder cancer), or [[abnormal vaginal bleeding]] (endometrial or cervical cancer). Although localized pain may occur in advanced cancer, the initial tumor is usually painless. Some cancers can cause a buildup of fluid within the chest or [[Ascites|abdomen]].<ref name="Card10">Holland Chp. 1</ref>

=== Systemic symptoms ===
Systemic symptoms may occur due to the body's response to the cancer. This may include fatigue, unintentional weight loss, or skin changes.<ref>{{cite book | vauthors = O'Dell M, Stubblefield M |title=Cancer rehabilitation principles and practice |year=2009 |publisher=Demos Medical |location=New York |isbn=978-1-933864-33-4 |page=983 |url={{google books |plainurl=y |id=_JaPlNYgXkEC |page=983}}}}</ref> Some cancers can cause a systemic inflammatory state that leads to ongoing muscle loss and weakness, known as [[cachexia]].<ref>{{cite journal | vauthors = Fearon K, Strasser F, Anker SD, Bosaeus I, Bruera E, Fainsinger RL, Jatoi A, Loprinzi C, MacDonald N, Mantovani G, Davis M, Muscaritoli M, Ottery F, Radbruch L, Ravasco P, Walsh D, Wilcock A, Kaasa S, Baracos VE | title = Definition and classification of cancer cachexia: an international consensus | journal = The Lancet. Oncology | volume = 12 | issue = 5 | pages = 489–95 | date = May 2011 | pmid = 21296615 | doi = 10.1016/S1470-2045(10)70218-7 }}</ref>

Some cancers, such as [[Hodgkin's disease]], [[leukemia]]s, and [[Liver cancer|liver]] or [[kidney cancer]]s, can cause a persistent [[Fever of unknown origin|fever]].<ref name=Card10/>

Shortness of breath, called [[Shortness of breath|dyspnea]], is a common symptom of cancer and its treatment. The causes of cancer-related dyspnea can include tumors in or around the lung, blocked airways, fluid in the lungs, pneumonia, or treatment reactions including an [[allergic response]].<ref>{{Cite web |title=Shortness of Breath {{!}} Cancer-related Side Effects |url=https://www.cancer.org/cancer/managing-cancer/side-effects/shortness-of-breath.html |access-date=10 October 2023 |website=www.cancer.org |language=en}}</ref> Treatment for dyspnea in patients with advanced cancer can include [[Fan (machine)|fans]], bilevel ventilation, [[acupressure]]/[[reflexology]] and multicomponent [[Non-pharmaceutical intervention|nonpharmacological interventions]].<ref>{{Cite book | vauthors = Dy SM, Gupta A, Waldfogel JM, Sharma R, Zhang A, Feliciano JL, Sedhom R, Day J, Gersten RA, Davidson PM, Bass EB |url=http://www.ncbi.nlm.nih.gov/books/NBK565137/ |title=Interventions for Breathlessness in Patients With Advanced Cancer |date=2020 |publisher=Agency for Healthcare Research and Quality (US) |series=AHRQ Comparative Effectiveness Reviews |location=Rockville (MD) |pmid=33289989}}</ref>

Some systemic symptoms of cancer are caused by hormones or other molecules produced by the tumor, known as [[paraneoplastic syndromes]]. Common paraneoplastic syndromes include [[hypercalcemia]], which can cause [[altered mental state]], constipation and dehydration, or [[hyponatremia]], which can also cause altered mental status, vomiting, headaches, or seizures.<ref>{{cite journal | vauthors = Dimitriadis GK, Angelousi A, Weickert MO, Randeva HS, Kaltsas G, Grossman A | title = Paraneoplastic endocrine syndromes | journal = Endocrine-Related Cancer | volume = 24 | issue = 6 | pages = R173–R190 | date = June 2017 | pmid = 28341725 | doi = 10.1530/ERC-17-0036 | doi-access = free }}</ref>

=== Metastasis ===
{{Main|Metastasis}}
[[Metastasis]] is the spread of cancer to other locations in the body. The dispersed tumors are called metastatic tumors, while the original is called the primary tumor. Almost all cancers can metastasize.<ref name=metastasis/> Most cancer deaths are due to cancer that has metastasized.<ref name="What is Metastasized Cancer">{{cite web |title=What is Metastasized Cancer? |url=http://www.nccn.com/component/content/article/54-cancer-basics/925-what-is-metastasized-cancer.html |website=National Comprehensive Cancer Network |access-date=18 July 2013 |archive-url=https://web.archive.org/web/20130707200430/http://www.nccn.com/component/content/article/54-cancer-basics/925-what-is-metastasized-cancer.html |archive-date=7 July 2013}}</ref>

Metastasis is common in the late stages of cancer and it can occur via the blood or the [[lymphatic system]] or both. The typical steps in metastasis are:

# Local [[Invasion (cancer)|invasion]]
# [[Intravasation]] into the blood or lymph.
# Circulation through the body.
# [[Extravasation]] into the new tissue.
# Proliferation
# [[Angiogenesis]]

Different types of cancers tend to metastasize to particular organs. Overall, the most common places for metastases to occur are the [[lung]]s, [[liver]], brain, and the [[bone]]s.<ref name="metastasis">{{cite web |url=https://www.cancer.gov/types/metastatic-cancer |title=Metastatic Cancer: Questions and Answers |access-date=28 March 2018|publisher=National Cancer Institute |date=12 May 2015}}</ref>

While some cancers can be cured if detected early, metastatic cancer is more difficult to treat and control. Nevertheless, some recent treatments are demonstrating encouraging results.<ref>{{cite web |title=Why is cancer so hard to cure? |url=https://www.theage.com.au/national/why-is-cancer-so-hard-to-cure-20230626-p5djiw.html |access-date=17 July 2023 |website=The Age|date=15 July 2023 }}</ref>