Editing Cancer (section)

== Screening ==
{{Main|Cancer screening}}
Unlike diagnostic efforts prompted by [[symptom]]s and [[medical sign]]s, cancer screening involves efforts to detect cancer after it has formed, but before any noticeable symptoms appear.<ref name=NIH>{{cite web |url=https://www.cancer.gov/about-cancer/screening/patient-screening-overview-pdq |title=Cancer Screening Overview (PDQ®)–Patient Version |publisher=National Cancer Institute |access-date=28 March 2018 |date=13 January 2010}}</ref> This may involve [[physical examination]], [[blood test|blood]] or [[urinalysis|urine tests]] or [[medical imaging]].<ref name=NIH/>

[[Cancer biomarker|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.<ref name=Wilson>Wilson JMG, Jungner G. (1968) [https://web.archive.org/web/20110604205519/http://whqlibdoc.who.int/php/WHO_PHP_34.pdf Principles and practice of screening for disease.] Geneva: [[World Health Organization]]. Public Health Papers, No. 34.</ref> ''Selective screening'' identifies people who are at higher risk, such as people with a family history.<ref name=Wilson/> Several factors are considered to determine whether the benefits of screening outweigh the risks and the costs of screening.<ref name=NIH/> 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 a suitable treatment is available
* Whether early detection improves treatment outcomes
* Whether 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.<ref name=Wilson/>
* 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.<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspscerv.htm |title=Screening for Cervical Cancer |year=2003 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101223103447/http://www.uspreventiveservicestaskforce.org/uspstf/uspscerv.htm |archive-date=23 December 2010|access-date=21 December 2010 }}</ref>
* Recommend that Americans be screened for [[colorectal cancer]] via [[fecal occult blood]] testing, [[sigmoidoscopy]], or [[colonoscopy]] starting at age 50 until age 75.<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspscolo.htm |title=Screening for Colorectal Cancer |year=2008 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20150207110937/http://www.uspreventiveservicestaskforce.org/uspstf/uspscolo.htm |archive-date=7 February 2015|access-date=21 December 2010 }}</ref>
* Evidence is insufficient to recommend for or against screening for [[skin cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsskca.htm |title=Screening for Skin Cancer |year=2009 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20110108054103/http://www.uspreventiveservicestaskforce.org/uspstf/uspsskca.htm |archive-date=8 January 2011|access-date=21 December 2010 }}</ref> [[oral cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsoral.htm |title=Screening for Oral Cancer |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101024144627/http://www.uspreventiveservicestaskforce.org/uspstf/uspsoral.htm |archive-date=24 October 2010|access-date=21 December 2010 }}</ref> lung cancer,<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspslung.htm |title=Lung Cancer Screening |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101104055403/http://www.uspreventiveservicestaskforce.org/uspstf/uspslung.htm |archive-date=4 November 2010|access-date=21 December 2010 }}</ref> or [[prostate cancer]] in men under 75.<ref name="USPSTFPr08">{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsprca.htm |title=Screening for Prostate Cancer |year=2008 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101231105229/http://www.uspreventiveservicestaskforce.org/uspstf/uspsprca.htm |archive-date=31 December 2010|access-date=21 December 2010 }}</ref>
* Routine screening is not recommended for [[bladder cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsblad.htm |title=Screening for Bladder Cancer |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20100823053849/http://www.uspreventiveservicestaskforce.org/uspstf/uspsblad.htm |archive-date=23 August 2010|access-date=21 December 2010 }}</ref> [[testicular cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspstest.htm |title=Screening for Testicular Cancer |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=http://arquivo.pt/wayback/20160515181437/http://www.uspreventiveservicestaskforce.org/uspstf/uspstest.htm |archive-date=15 May 2016|access-date=21 December 2010 }}</ref> [[ovarian cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsovar.htm |title=Screening for Ovarian Cancer |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101023221553/http://www.uspreventiveservicestaskforce.org/uspstf/uspsovar.htm |archive-date=23 October 2010|access-date=21 December 2010 }}</ref> [[pancreatic cancer]],<ref>{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspspanc.htm |title=Screening for Pancreatic Cancer |year=2004 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20101121030321/http://www.uspreventiveservicestaskforce.org/uspstf/uspspanc.htm |archive-date=21 November 2010|access-date=21 December 2010 }}</ref> or [[prostate cancer]].<ref name="USPSTF-20111007">{{cite journal | vauthors = Chou R, Croswell JM, Dana T, Bougatsos C, Blazina I, Fu R, Gleitsmann K, Koenig HC, Lam C, Maltz A, Rugge JB, Lin K | title = Screening for prostate cancer: a review of the evidence for the U.S. Preventive Services Task Force | journal = Annals of Internal Medicine | volume = 155 | issue = 11 | pages = 762–71 | date = December 2011 | pmid = 21984740 | doi = 10.7326/0003-4819-155-11-201112060-00375 | publisher = [[United States Preventive Services Task Force]]| doi-access = free}}</ref>
* Recommends [[mammography]] for breast cancer screening every two years from ages 50–74, but does not recommend either [[breast self-examination]] or [[Breast cancer screening|clinical breast examination]].<ref name="USPSTFBr09">{{cite web |url=http://www.uspreventiveservicestaskforce.org/uspstf/uspsbrca.htm |title=Screening for Breast Cancer |year=2009 |website=[[U.S. Preventive Services Task Force]] |archive-url=https://web.archive.org/web/20130102015424/http://www.uspreventiveservicestaskforce.org/uspstf/uspsbrca.htm |archive-date=2 January 2013|access-date=21 December 2010 }}</ref> A 2013 [[Cochrane review]] concluded that breast cancer screening by mammography had no effect in reducing mortality because of overdiagnosis and overtreatment.<ref>{{cite journal | vauthors = Gøtzsche PC, Jørgensen KJ | title = Screening for breast cancer with mammography | journal = The Cochrane Database of Systematic Reviews | issue = 6 | pages = CD001877 | date = June 2013 | volume = 2013 | pmid = 23737396 | doi = 10.1002/14651858.CD001877.pub5 | pmc = 6464778 }}</ref>

==== Japan ====
Screens for [[gastric cancer]] using [[photofluorography]] due to the high incidence there.<ref name=Epi11/>

=== Genetic testing ===
{{See also|Cancer syndrome}}
{| class="wikitable floatright" style="text-align:center" width="50%"
|-
! Gene
! Cancer types
|-
| [[BRCA1]], [[BRCA2]]
| Breast, ovarian, pancreatic
|-
| [[Hereditary nonpolyposis colorectal cancer|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.<ref name=pmid24176569/><ref name=BRCA08>{{cite journal |vauthors=Gulati AP, [[Susan Domchek|Domchek SM]] |s2cid=29630942 |title=The clinical management of BRCA1 and BRCA2 mutation carriers |journal=Current Oncology Reports |volume=10 |issue=1 |pages=47–53 |date=January 2008 |pmid=18366960 |doi=10.1007/s11912-008-0008-9}}</ref> Carriers of these mutations may then undergo enhanced surveillance, chemoprevention, or preventative surgery to reduce their subsequent risk.<ref name=BRCA08/>