Editing Cancer (section)

== Etymology and definitions ==
The word comes from the ancient Greek καρκίνος, meaning 'crab' and 'tumor'. Greek physicians [[Hippocrates]] and [[Galen]], among others, noted the similarity of crabs to some tumors with swollen veins. The word was introduced in English in the modern medical sense around 1600.<ref>{{Cite web |title=cancer |url=https://www.etymonline.com/word/cancer |url-status=live |archive-url=https://web.archive.org/web/20221107103233/https://www.etymonline.com/word/cancer |archive-date=7 November 2022 |website=www.etymonline.com}}</ref>

Cancers comprise a large family of diseases that involve abnormal [[cell growth]] with the potential to invade or spread to other parts of the body.<ref name=WHO2018/><ref name=WhatIsCancerNCI/> They form a subset of [[neoplasm]]s. A neoplasm or tumor is a group of cells that have undergone unregulated growth and will often form a mass or lump, but may be distributed diffusely.<ref name=ACSglossary>{{cite web |title=Cancer Glossary |website=cancer.org |publisher=American Cancer Society |url=http://www.cancer.org/cancer/cancerglossary/index |access-date=11 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20130901160014/http://www.cancer.org/cancer/cancerglossary/index |archive-date=1 September 2013}}</ref><ref name=NCIdefinition>{{cite web |title=What is cancer? |website=cancer.gov |publisher=National Cancer Institute |access-date=28 March 2018 |url=https://www.cancer.gov/about-cancer/understanding/what-is-cancer|date=17 September 2007}}</ref>
 
All tumor cells show the [[The Hallmarks of Cancer|six hallmarks of cancer]]. These characteristics are required to produce a malignant tumor. They include:<ref name=Han2000/>
* [[Cell growth]] and division absent the proper signals
* Continuous growth and division even given contrary signals
* Avoidance of [[apoptosis|programmed cell death]]
* [[Biological immortality|Limitless number of cell divisions]]
* Promoting [[angiogenesis|blood vessel construction]]
* [[Invasion (cancer)|Invasion]] of tissue and formation of [[metastasis|metastases]]<ref name=Han2000/>

The progression from normal cells to cells that can form a detectable mass to cancer involves multiple steps known as malignant progression.<ref name=Han2000>{{cite journal |vauthors=Hanahan D, Weinberg RA |s2cid=1478778 |title=The hallmarks of cancer |journal=Cell |volume=100 |issue=1 |pages=57–70 |date=January 2000 |pmid=10647931 |doi=10.1016/S0092-8674(00)81683-9 |author-link1=Douglas Hanahan |author-link2=Robert Weinberg (biologist)|doi-access=free }}</ref><ref name=Han2011>{{cite journal |vauthors=Hanahan D, Weinberg RA |title=Hallmarks of cancer: the next generation |journal=Cell |volume=144 |issue=5 |pages=646–74 |date=March 2011 |pmid=21376230 |doi=10.1016/j.cell.2011.02.013|doi-access=free }}</ref>