Editing Cancer cluster

{{Use dmy dates|date=December 2017}}
{{Use British English|date=December 2017}}

A '''cancer cluster''' is a [[disease cluster]] in which a high number of [[cancer]] cases occurs in a group of people in a particular geographic area over a limited period of time.<ref name="CDC">{{Cite web |last=CDC |date=2024-05-16 |title=About Unusual Patterns of Cancer |url=https://www.cdc.gov/cancer-environment/about/index.html |access-date=2024-06-23 |website=Unusual Patterns of Cancer, the Environment, and Community Concerns |language=en-us}}</ref>

Historical examples of work-related cancer clusters are well documented in the medical literature.  Notable examples include: scrotal cancer among [[chimney sweep]]s in 18th-century London; [[osteosarcoma]] among [[Radium Girls|female watch dial painters]] in the 20th century; [[skin cancer]] in farmers; [[bladder cancer]] in dye workers exposed to [[aniline]] compounds; and [[leukemia]] and [[lymphoma]] in chemical workers exposed to [[benzene]].<ref name="NCI">[http://cis.nci.nih.gov/fact/3_58.htm Cancer Facts] {{webarchive|url=https://web.archive.org/web/20041010003350/http://cis.nci.nih.gov/fact/3_58.htm |date=10 October 2004 }}. National Cancer Institute.  U.S. National Institutes of Health.</ref>

Cancer cluster suspicions usually arise when members of the general public report that their family members, friends, neighbors, or coworkers have been diagnosed with the same or related cancers.  State or local health departments will investigate the possibility of a cancer cluster when a claim is filed.<ref name="Thun">{{Citation |last1=Thun |first1=M. J. |last2=Sinks |first2=T. |name-list-style=amp |year=2004 |title=Understanding Cancer Clusters |journal=CA Cancer J Clin |volume=54 |issue=5 |pages=273–280 |doi=10.3322/canjclin.54.5.273 |pmid=15371285 |doi-access=free }}</ref>  In order to justify investigating such claims, health departments conduct a preliminary review.  Data will be collected and verified regarding: the types of cancer reported, numbers of cases, geographic area of the cases, and the patients clinical history.  At this point, a committee of medical professionals will examine the data and determine whether or not an investigation (often lengthy and expensive) is justified.<ref name="Devier">{{Citation |last1=Devier |first1=J. R. |last2=Brownson |first2=R. C. |last3=Bagby |first3=J. R. Jr. |last4=Carlson |first4=G. M. |last5=Crellin |first5=J. R. |name-list-style=amp |year=1990 |title=A public health response to cancer clusters in Missouri |journal=Am J Epidemiol |volume=132 |issue=1 |pages=S23–31 |url=http://aje.oxfordjournals.org/cgi/content/abstract/132/supp1/23 |archive-url=https://web.archive.org/web/20090927075529/http://aje.oxfordjournals.org/cgi/content/abstract/132/supp1/23  |archive-date=2009-09-27 |author6=C |doi=10.1093/oxfordjournals.aje.a115784 |pmid=2356832 |url-access=subscription }}</ref>

In the U.S., state and local health departments respond to more than 1,000 inquiries about suspected cancer clusters each year.  It is possible that a suspected cancer cluster may be due to chance alone; however, only clusters that have a disease rate that is statistically significantly greater than the disease rate of the general population are investigated. Given the number of inquiries it is likely that many of these are due to chance alone. It is a well-known problem in interpreting data that random cases of cancer can appear to form clumps that are misinterpreted as a cluster.<ref name="Go Figure: How can you explain cancer clusters?">{{cite news|last1=Blastland|first1=Michael|title=Go Figure: How can you explain cancer clusters?| work=BBC News | date=12 May 2011 |url=https://www.bbc.com/news/magazine-13374325|access-date=7 April 2016}}</ref>

A cluster is less likely to be coincidental if the case consists of one type of cancer, a rare type of cancer, or a type of cancer that is not usually found in a certain age group.  Between 5% and 15% of suspected cancer clusters are [[statistical significance|statistically significant]].<ref name="Thun" />

==Examples==
[[File:Texas Sharpshooter Fallacy illustration.png|thumb|Statisticians examining data for cancer clusters must beware of random coincidences, which [[Texas sharpshooter fallacy|seem to form a pattern]].<ref name="Go Figure: How can you explain cancer clusters?" /> In this randomly generated scatter graph, arcs and patterns appear to exist that have formed only by coincidence.]]
{{main|List of cancer clusters}}

Some of the larger or more well known cancer clusters include:
* At least 700 cases of [[clear-cell carcinoma]] caused by the prenatal exposure to [[diethylstilbestrol]] in the US in the mid-1900s.<ref>{{cite web|title=Role of DES Cohort Studies|url=https://www.cdc.gov/DES/consumers/research/understanding_cohort.html|website=www.cdc.gov}}</ref>
* The [[Camp Lejeune water contamination]] incident in which multiple chemicals were found in drinking water. The CDC found that marines stationed at the base had a 10% higher rate of cancer deaths than those stationed elsewhere.<ref>{{cite news | author=Fox, Maggie |url=https://www.nbcnews.com/healthmain/contamination-nc-marine-base-lasted-60-years-1c8880227 | title=Camp Lejeune Study Finds Higher Cancer Death Risk | publisher=NBC News |date=March 14, 2013}}</ref>

==See also==
* [[Biostatistics]]
* [[Cancer Alley]]
* [[Cancer epidemiology]]
* [[Cuzick–Edwards test]]
* [[Environmental racism]]
* ''[[Fooled by Randomness]]''
* ''[[Toms River (book)|Toms River: A Story of Science and Salvation]]''

==References==
{{Reflist|30em}}

==External links==
* [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797849/ Pub Med - latest standards for evaluating cancer clusters]
* [https://web.archive.org/web/20041015033041/http://www3.cancer.gov/atlasplus/new.html Cancer Mortality Maps & Graphs: U.S., 1950-94]
* [http://www.niehs.nih.gov/ National Institute of Environmental Health Sciences (NIEHS)]
* [https://www.cdc.gov/nceh/clusters/default.htm U.S. Centers for Disease Control]
* [http://www.epa.gov/region02/health/cancer_clusters.htm U.S. Environmental Protection Agency]
* [http://www.abc.net.au/austory/content/2007/s1870108.htm Australian Story about a cluster of breast cancer cases in the workplace]

{{Portal bar|Medicine}}

[[Category:Cancer clusters| ]]
[[Category:Spatial epidemiology]]
[[Category:Medical statistics]]