Editing Cervix (section)

===Cancer===
{{Main|Cervical cancer}}
In 2008, cervical cancer was the third-most common cancer in women worldwide, with rates varying geographically from less than one to more than 50 cases per 100,000 women.{{Update after|2021|3|17}}<ref name=ARBYN2011>{{cite journal | vauthors = Arbyn M, Castellsagué X, de Sanjosé S, Bruni L, Saraiya M, Bray F, Ferlay J | title = Worldwide burden of cervical cancer in 2008 | journal = Annals of Oncology | volume = 22 | issue = 12 | pages = 2675–2686 | date = December 2011 | pmid = 21471563 | doi = 10.1093/annonc/mdr015 | doi-access = free }}</ref> It is a leading cause of cancer-related death in poor countries, where delayed diagnosis leading to poor outcomes is common.<ref name="who fact sheet">{{cite web |author=World Health Organization |date=February 2014 |title=Fact sheet No. 297: Cancer |url=https://www.who.int/mediacentre/factsheets/fs297/en/index.html |access-date=23 July 2014|author-link=World Health Organization }}</ref> The introduction of routine screening has resulted in fewer cases of (and deaths from) cervical cancer, however this has mainly taken place in developed countries. Most developing countries have limited or no screening, and 85% of the global burden occurs there.<ref name="Vaccarella13">{{cite journal | vauthors = Vaccarella S, Lortet-Tieulent J, Plummer M, Franceschi S, Bray F | title = Worldwide trends in cervical cancer incidence: impact of screening against changes in disease risk factors | journal = European Journal of Cancer | volume = 49 | issue = 15 | pages = 3262–3273 | date = October 2013 | pmid = 23751569 | doi = 10.1016/j.ejca.2013.04.024 }}</ref>

Cervical cancer nearly always involves human papillomavirus (HPV) infection.<ref name=WAHL2007>{{cite book| vauthors = Wahl CE |title=Hardcore pathology|date=2007|publisher=Lippincott Williams & Wilkins|location=Philadelphia, PA |isbn=9781405104982|page=72|url=https://books.google.com/books?id=JZtr6cmJhvgC&q=transformation+zone+vaginal+pH&pg=PA72}}</ref><ref name=ROBBINS2007/> HPV is a virus with numerous strains, several of which predispose to precancerous changes in the cervical epithelium, particularly in the transformation zone, which is the most common area for cervical cancer to start.<ref name=LOWE2005>{{cite book| vauthors = Lowe A, Stevens JS |title=Human histology|year=2005|publisher=Elsevier Mosby|location=Philadelphia, PA; Toronto, ON|isbn=0-323-03663-5|edition=3rd|pages=350–51}}</ref> [[HPV vaccines]], such as [[Gardasil]] and [[Cervarix]], reduce the incidence of cervical cancer, by inoculating against the viral strains involved in cancer development.<ref name=HARRISONS2010B>{{cite book| veditors = Fauci AS, Braunwald E, Kasper DL, Hauser SL, Longo DL, Jameson JL, Loscalzo J |title=Harrison's Principles of Internal Medicine|url=https://archive.org/details/harrisonsprincip00asfa |url-access=limited |date=2008|publisher=McGraw-Hill Medical|location=New York [etc.]|isbn=978-0-07-147692-8|pages=[https://archive.org/details/harrisonsprincip00asfa/page/n646 608]–09|edition=17th}}</ref>

Potentially precancerous changes in the cervix can be detected by [[cervical screening]], using methods including a [[Pap smear]] (also called a cervical smear), in which [[epithelium|epithelial]] cells are scraped from the surface of the cervix and [[cytopathology|examined under a microscope]].<ref name=HARRISONS2010B/> The [[Colposcopy|colposcope]], an instrument used to see a magnified view of the cervix, was invented in 1925. The Pap smear was developed by [[Georgios Papanikolaou]] in 1928.<ref name=GASPARINI2009 /> A [[loop electrical excision procedure|LEEP procedure]] using a heated loop of [[platinum]] to excise a patch of cervical tissue was developed by [[Aurel Babes]] in 1927.<ref>{{cite journal | vauthors = Diamantis A, Magiorkinis E, Androutsos G | title = Different strokes: Pap-test and Babes method are not one and the same | journal = Diagnostic Cytopathology | volume = 38 | issue = 11 | pages = 857–859 | date = November 2010 | pmid = 20973044 | doi = 10.1002/dc.21347 | s2cid = 823546 }}</ref> In some parts of the developed world, including the UK, the Pap test has been superseded with [[liquid-based cytology]].<ref>{{cite book |url= https://books.google.com/books?id=eqC-0qjzl_AC&q=nice+lbc&pg=PA614 |title= Diagnostic Cytopathology | veditors = Gray W, Kocjan G |year=2010 |page=613 |publisher= Churchill Livingstone|isbn= 9780702048951 }}</ref>

An inexpensive, cost-effective and practical alternative in poorer countries is [[Cervical screening#Visual inspection to detect pre-cancer or cancer|visual inspection with acetic acid]] (VIA).<ref name="who fact sheet"/> Instituting and sustaining cytology-based programs in these regions can be difficult, due to the need for trained personnel, equipment and facilities and difficulties in follow-up. With VIA, results and treatment can be available on the same day. As a screening test, VIA is comparable to cervical cytology in accurately identifying precancerous lesions.<ref name=sherris>{{cite journal | vauthors = Sherris J, Wittet S, Kleine A, Sellors J, Luciani S, Sankaranarayanan R, Barone MA | title = Evidence-based, alternative cervical cancer screening approaches in low-resource settings | journal = International Perspectives on Sexual and Reproductive Health | volume = 35 | issue = 3 | pages = 147–154 | date = September 2009 | pmid = 19805020 | doi = 10.1363/3514709 | doi-access = free }}</ref>

A result of [[dysplasia]] is usually further investigated, such as by taking a [[cone biopsy]], which may also remove the cancerous lesion.<ref name=HARRISONS2010B/> [[Cervical intraepithelial neoplasia]] is a possible result of the biopsy and represents dysplastic changes that may eventually progress to invasive cancer.<ref name=NEJM1996>{{cite journal | vauthors = Cannistra SA, Niloff JM | title = Cancer of the uterine cervix | journal = The New England Journal of Medicine | volume = 334 | issue = 16 | pages = 1030–1038 | date = April 1996 | pmid = 8598842 | doi = 10.1056/NEJM199604183341606 }}</ref> Most cases of cervical cancer are detected in this way, without having caused any symptoms. When symptoms occur, they may include vaginal bleeding, discharge, or discomfort.<ref name=DAVIDSONS2010>{{cite book | veditors = Colledge NR, Walker BR, Ralston SH |others= Illustrated by Britton R |title= Davidson's Principles and Practice of Medicine |url= https://archive.org/details/davidsonsprincip00frcp |url-access= limited |year=2010 |publisher= Churchill Livingstone/Elsevier |location= Edinburgh |isbn=978-0-7020-3084-0 |edition= 21st |page=[https://archive.org/details/davidsonsprincip00frcp/page/n292 276] }}</ref>