Our sources & how we verify
Everything on Cancer Explained is built from trusted, publicly available sources — above all the National Cancer Institute (NCI), the U.S. government’s principal agency for cancer research. This page accounts for every kind of content on the site and the sources behind it.
2,841
Articles
462
Q&A pages
382
Glossary terms
20
Clinical summaries
459
Spanish articles
2,588
Distinct sources cited
Where each part of the site comes from
| Part of the site | Source |
|---|---|
| Explanations & articles | National Cancer Institute (cancer.gov) — the specific NCI page is linked on every article. |
| Glossary definitions | NCI Dictionary of Cancer Terms and the NCI pages the terms appear on. |
| Knowledge checks & flashcards | Written only from our NCI-based articles — every knowledge check answer traces to the article's NCI source. |
| SOAP-style cancer summaries | The NCI cancer-type page for that cancer, linked in each summary. |
| Spanish articles (/es/temas) | Official Spanish sources such as cancer.gov/espanol when available; expanded Spanish explainers are source-linked adaptations of the English guides and are clearly connected to their original source pages. |
| Other language hubs | MedlinePlus (U.S. National Library of Medicine) for verified health information in many languages. |
| News & culture posts | NCI for all medical facts; reputable news outlets (e.g. Associated Press) for public, biographical facts — cited on each post. |
| Resources & helpline info | NCI Cancer Information Service, ClinicalTrials.gov, MedlinePlus, and Smokefree.gov. |
| Worldwide statistics | WHO, IARC Global Cancer Observatory, and NCI economic-burden resources — linked on each statistics page. |
| Insurance, pets, prayer, and translation pages | NCI, CDC, FDA, CMS, NAIC, HealthCare.gov, AAHA, Cochrane, and MedlinePlus, depending on the topic — each page lists its sources. |
| The AI assistant | Answers only from our indexed NCI-based passages, and links the source for each answer. |
Every source we cite
Across the whole site we cite 2,588 distinct pages, referenced 7,019 times. Here is the full breakdown by publisher:
National Cancer Institute (cancer.gov)
cancer.gov
760 pages4629 citations
fda.gov
fda.gov
132 pages198 citations
Instituto Nacional del Cáncer (cancer.gov/espanol)
cancer.gov/espanol
90 pages165 citations
seer.cancer.gov
seer.cancer.gov
31 pages162 citations
pubmed.ncbi.nlm.nih.gov
pubmed.ncbi.nlm.nih.gov
142 pages148 citations
accessdata.fda.gov
accessdata.fda.gov
106 pages111 citations
MedlinePlus — U.S. National Library of Medicine
medlineplus.gov
80 pages97 citations
cancer.org
cancer.org
72 pages97 citations
eutils.ncbi.nlm.nih.gov
eutils.ncbi.nlm.nih.gov
71 pages73 citations
ClinicalTrials.gov — U.S. National Library of Medicine
clinicaltrials.gov
60 pages63 citations
dailymed.nlm.nih.gov
dailymed.nlm.nih.gov
48 pages54 citations
uspreventiveservicestaskforce.org
uspreventiveservicestaskforce.org
12 pages47 citations
npr.org
npr.org
43 pages43 citations
cdc.gov
cdc.gov
30 pages38 citations
theguardian.com
theguardian.com
38 pages38 citations
ncbi.nlm.nih.gov
ncbi.nlm.nih.gov
35 pages36 citations
nbcnews.com
nbcnews.com
27 pages27 citations
medicare.gov
medicare.gov
15 pages24 citations
usccb.org
usccb.org
3 pages23 citations
today.com
today.com
23 pages23 citations
epa.gov
epa.gov
19 pages23 citations
api.fda.gov
api.fda.gov
22 pages23 citations
upi.com
upi.com
23 pages23 citations
cms.gov
cms.gov
17 pages21 citations
vatican.va
vatican.va
7 pages20 citations
nhs.uk
nhs.uk
18 pages20 citations
cnn.com
cnn.com
19 pages20 citations
who.int
who.int
11 pages19 citations
variety.com
variety.com
19 pages19 citations
bbc.com
bbc.com
18 pages18 citations
radiologyinfo.org
radiologyinfo.org
10 pages17 citations
healthcare.gov
healthcare.gov
9 pages16 citations
govinfo.gov
govinfo.gov
15 pages16 citations
monographs.iarc.who.int
monographs.iarc.who.int
4 pages15 citations
dol.gov
dol.gov
9 pages15 citations
iarc.who.int
iarc.who.int
12 pages15 citations
nccih.nih.gov
nccih.nih.gov
10 pages14 citations
abcnews.go.com
abcnews.go.com
14 pages14 citations
bbc.co.uk
bbc.co.uk
14 pages14 citations
pmc.ncbi.nlm.nih.gov
pmc.ncbi.nlm.nih.gov
13 pages13 citations
cbsnews.com
cbsnews.com
13 pages13 citations
ssa.gov
ssa.gov
10 pages12 citations
acr.org
acr.org
6 pages12 citations
eeoc.gov
eeoc.gov
1 page12 citations
ntp.niehs.nih.gov
ntp.niehs.nih.gov
10 pages11 citations
prevention.cancer.gov
prevention.cancer.gov
7 pages11 citations
pbs.org
pbs.org
11 pages11 citations
prescancerpanel.cancer.gov
prescancerpanel.cancer.gov
1 page9 citations
mskcc.org
mskcc.org
8 pages9 citations
nia.nih.gov
nia.nih.gov
6 pages8 citations
oehha.ca.gov
oehha.ca.gov
6 pages8 citations
hhs.gov
hhs.gov
4 pages8 citations
abcnews.com
abcnews.com
8 pages8 citations
caregiver.org
caregiver.org
6 pages7 citations
healthcaredelivery.cancer.gov
healthcaredelivery.cancer.gov
3 pages7 citations
medicaid.gov
medicaid.gov
3 pages6 citations
ecfr.gov
ecfr.gov
6 pages6 citations
merck.com
merck.com
4 pages6 citations
nobelprize.org
nobelprize.org
6 pages6 citations
dceg.cancer.gov
dceg.cancer.gov
4 pages5 citations
ganjoho.jp
ganjoho.jp
1 page5 citations
Associated Press
apnews.com
5 pages5 citations
goodmorningamerica.com
goodmorningamerica.com
5 pages5 citations
nejm.org
nejm.org
5 pages5 citations
rollingstone.com
rollingstone.com
5 pages5 citations
pancan.org
pancan.org
5 pages5 citations
niddk.nih.gov
niddk.nih.gov
4 pages4 citations
ada.gov
ada.gov
3 pages4 citations
ods.od.nih.gov
ods.od.nih.gov
4 pages4 citations
nih.gov
nih.gov
3 pages4 citations
gco.iarc.who.int
gco.iarc.who.int
1 page4 citations
healthit.gov
healthit.gov
2 pages4 citations
genome.gov
genome.gov
4 pages4 citations
odphp.health.gov
odphp.health.gov
2 pages4 citations
ascopost.com
ascopost.com
4 pages4 citations
cuidadodesalud.gov
cuidadodesalud.gov
3 pages4 citations
pressroom.cancer.org
pressroom.cancer.org
4 pages4 citations
nps.gov
nps.gov
4 pages4 citations
cbc.ca
cbc.ca
4 pages4 citations
sabr.org
sabr.org
4 pages4 citations
aljazeera.com
aljazeera.com
4 pages4 citations
ostomy.org
ostomy.org
3 pages3 citations
lourdes-france.org
lourdes-france.org
1 page3 citations
childrensoncologygroup.org
childrensoncologygroup.org
3 pages3 citations
wcrf.org
wcrf.org
1 page3 citations
recist.eortc.org
recist.eortc.org
1 page3 citations
va.gov
va.gov
2 pages3 citations
asco.org
asco.org
3 pages3 citations
aarp.org
aarp.org
3 pages3 citations
foxnews.com
foxnews.com
3 pages3 citations
hollywoodreporter.com
hollywoodreporter.com
3 pages3 citations
aad.org
aad.org
3 pages3 citations
leginfo.legislature.ca.gov
leginfo.legislature.ca.gov
3 pages3 citations
law.cornell.edu
law.cornell.edu
3 pages3 citations
washingtonpost.com
washingtonpost.com
3 pages3 citations
publications.iarc.who.int
publications.iarc.who.int
2 pages2 citations
nida.nih.gov
nida.nih.gov
1 page2 citations
womenshealth.gov
womenshealth.gov
2 pages2 citations
acl.gov
acl.gov
2 pages2 citations
askjan.org
askjan.org
1 page2 citations
irs.gov
irs.gov
2 pages2 citations
ed.gov
ed.gov
2 pages2 citations
atsdr.cdc.gov
atsdr.cdc.gov
2 pages2 citations
cancerresearchuk.org
cancerresearchuk.org
2 pages2 citations
cancer.org.au
cancer.org.au
2 pages2 citations
niehs.nih.gov
niehs.nih.gov
2 pages2 citations
roswellpark.org
roswellpark.org
1 page2 citations
cancercontrol.cancer.gov
cancercontrol.cancer.gov
2 pages2 citations
ahrq.gov
ahrq.gov
2 pages2 citations
aafp.org
aafp.org
2 pages2 citations
p65warnings.ca.gov
p65warnings.ca.gov
2 pages2 citations
dctd.cancer.gov
dctd.cancer.gov
2 pages2 citations
curetoday.com
curetoday.com
2 pages2 citations
nidcr.nih.gov
nidcr.nih.gov
2 pages2 citations
thyroid.org
thyroid.org
1 page2 citations
pubs.rsna.org
pubs.rsna.org
2 pages2 citations
hrsa.gov
hrsa.gov
2 pages2 citations
chausa.org
chausa.org
1 page2 citations
es.medicare.gov
es.medicare.gov
2 pages2 citations
bostonglobe.com
bostonglobe.com
2 pages2 citations
nationalcancerplan.cancer.gov
nationalcancerplan.cancer.gov
1 page2 citations
jamanetwork.com
jamanetwork.com
2 pages2 citations
nfl.com
nfl.com
2 pages2 citations
profiles.nlm.nih.gov
profiles.nlm.nih.gov
2 pages2 citations
reginfo.gov
reginfo.gov
2 pages2 citations
health.ec.europa.eu
health.ec.europa.eu
2 pages2 citations
ascopubs.org
ascopubs.org
2 pages2 citations
osp.od.nih.gov
osp.od.nih.gov
2 pages2 citations
dncr.nc.gov
dncr.nc.gov
2 pages2 citations
fullfact.org
fullfact.org
1 page2 citations
deseret.com
deseret.com
2 pages2 citations
colorectalcancer.org
colorectalcancer.org
2 pages2 citations
deadline.com
deadline.com
2 pages2 citations
nbc.com
nbc.com
2 pages2 citations
hepb.org
hepb.org
2 pages2 citations
wusf.org
wusf.org
1 page2 citations
nba.com
nba.com
2 pages2 citations
statnews.com
statnews.com
2 pages2 citations
assets.espn.com
assets.espn.com
2 pages2 citations
britannica.com
britannica.com
2 pages2 citations
warnerbros.com
warnerbros.com
2 pages2 citations
scientificamerican.com
scientificamerican.com
2 pages2 citations
NCI Breast Cancer Risk Assessment Tool
bcrisktool.cancer.gov
2 pages2 citations
billboard.com
billboard.com
2 pages2 citations
cancerschmancer.org
cancerschmancer.org
2 pages2 citations
sirbobbyrobsonfoundation.org.uk
sirbobbyrobsonfoundation.org.uk
2 pages2 citations
health.gov
health.gov
1 page1 citations
samhsa.gov
samhsa.gov
1 page1 citations
osha.gov
osha.gov
1 page1 citations
sites.ed.gov
sites.ed.gov
1 page1 citations
nice.org.uk
nice.org.uk
1 page1 citations
bfmed.org
bfmed.org
1 page1 citations
journals.sagepub.com
journals.sagepub.com
1 page1 citations
midus.wisc.edu
midus.wisc.edu
1 page1 citations
rsa.ed.gov
rsa.ed.gov
1 page1 citations
oig.hhs.gov
oig.hhs.gov
1 page1 citations
cancercare.org
cancercare.org
1 page1 citations
uniformlaws.org
uniformlaws.org
1 page1 citations
theovon.com
theovon.com
1 page1 citations
nichd.nih.gov
nichd.nih.gov
1 page1 citations
hcvguidelines.org
hcvguidelines.org
1 page1 citations
usa.gov
usa.gov
1 page1 citations
ccr.cancer.gov
ccr.cancer.gov
1 page1 citations
fsis.usda.gov
fsis.usda.gov
1 page1 citations
publications.iarc.fr
publications.iarc.fr
1 page1 citations
sirweb.org
sirweb.org
1 page1 citations
iifa-aifi.org
iifa-aifi.org
1 page1 citations
rabbis.org
rabbis.org
1 page1 citations
vanityfair.com
vanityfair.com
1 page1 citations
triagecancer.org
triagecancer.org
1 page1 citations
acf.hhs.gov
acf.hhs.gov
1 page1 citations
cuh.nhs.uk
cuh.nhs.uk
1 page1 citations
thebraintumourcharity.org
thebraintumourcharity.org
1 page1 citations
psnet.ahrq.gov
psnet.ahrq.gov
1 page1 citations
library.samhsa.gov
library.samhsa.gov
1 page1 citations
echa.europa.eu
echa.europa.eu
1 page1 citations
storycorps.org
storycorps.org
1 page1 citations
altamontenterprise.com
altamontenterprise.com
1 page1 citations
acsm.org
acsm.org
1 page1 citations
cochrane.org
cochrane.org
1 page1 citations
alexslemonade.org
alexslemonade.org
1 page1 citations
osha.europa.eu
osha.europa.eu
1 page1 citations
link.springer.com
link.springer.com
1 page1 citations
hospicefoundation.org
hospicefoundation.org
1 page1 citations
mypcnow.org
mypcnow.org
1 page1 citations
hematology.org
hematology.org
1 page1 citations
auanet.org
auanet.org
1 page1 citations
evsexplore.semantics.cancer.gov
evsexplore.semantics.cancer.gov
1 page1 citations
training.seer.cancer.gov
training.seer.cancer.gov
1 page1 citations
ncihub.cancer.gov
ncihub.cancer.gov
1 page1 citations
european-union.europa.eu
european-union.europa.eu
1 page1 citations
nhlbi.nih.gov
nhlbi.nih.gov
1 page1 citations
ons.org
ons.org
1 page1 citations
ghadvances.org
ghadvances.org
1 page1 citations
neurology.org
neurology.org
1 page1 citations
aan.com
aan.com
1 page1 citations
news.umich.edu
news.umich.edu
1 page1 citations
jaist.ac.jp
jaist.ac.jp
1 page1 citations
x.com
x.com
1 page1 citations
latimes.com
latimes.com
1 page1 citations
aol.com
aol.com
1 page1 citations
developers.google.com
developers.google.com
1 page1 citations
cancerletter.com
cancerletter.com
1 page1 citations
frontiersin.org
frontiersin.org
1 page1 citations
childrensnational.org
childrensnational.org
1 page1 citations
eurekalert.org
eurekalert.org
1 page1 citations
sciencedaily.com
sciencedaily.com
1 page1 citations
packers.com
packers.com
1 page1 citations
obamawhitehouse.archives.gov
obamawhitehouse.archives.gov
1 page1 citations
oag.ca.gov
oag.ca.gov
1 page1 citations
pcf.org
pcf.org
1 page1 citations
web.archive.org
web.archive.org
1 page1 citations
columbiasurgery.org
columbiasurgery.org
1 page1 citations
lib.arizona.edu
lib.arizona.edu
1 page1 citations
guides.loc.gov
guides.loc.gov
1 page1 citations
millercenter.org
millercenter.org
1 page1 citations
content.time.com
content.time.com
1 page1 citations
gildasclubchicago.org
gildasclubchicago.org
1 page1 citations
wbur.org
wbur.org
1 page1 citations
legislation.gov.uk
legislation.gov.uk
1 page1 citations
murrow.wsu.edu
murrow.wsu.edu
1 page1 citations
csts.ua.edu
csts.ua.edu
1 page1 citations
englandfootball.com
englandfootball.com
1 page1 citations
itv.com
itv.com
1 page1 citations
nostomachforcancer.org
nostomachforcancer.org
1 page1 citations
stat.berkeley.edu
stat.berkeley.edu
1 page1 citations
news.harvard.edu
news.harvard.edu
1 page1 citations
tobaccofreekids.org
tobaccofreekids.org
1 page1 citations
theglobeandmail.com
theglobeandmail.com
1 page1 citations
nhlpa.com
nhlpa.com
1 page1 citations
headandneck.org
headandneck.org
1 page1 citations
blog.ted.com
blog.ted.com
1 page1 citations
ncsd.org
ncsd.org
1 page1 citations
myelomaactionmonth.org
myelomaactionmonth.org
1 page1 citations
copingmag.com
copingmag.com
1 page1 citations
us.movember.com
us.movember.com
1 page1 citations
espnpressroom.com
espnpressroom.com
1 page1 citations
hpvca.org
hpvca.org
1 page1 citations
news.cuanschutz.edu
news.cuanschutz.edu
1 page1 citations
kidneycancer.org
kidneycancer.org
1 page1 citations
nprillinois.org
nprillinois.org
1 page1 citations
phillyvoice.com
phillyvoice.com
1 page1 citations
adamsmith.house.gov
adamsmith.house.gov
1 page1 citations
history.com
history.com
1 page1 citations
spinmagazine.com
spinmagazine.com
1 page1 citations
abc7ny.com
abc7ny.com
1 page1 citations
v.org
v.org
1 page1 citations
web.musc.edu
web.musc.edu
1 page1 citations
newsweek.com
newsweek.com
1 page1 citations
rollcall.com
rollcall.com
1 page1 citations
foundationforwomenscancer.org
foundationforwomenscancer.org
1 page1 citations
acsjournals.onlinelibrary.wiley.com
acsjournals.onlinelibrary.wiley.com
1 page1 citations
ecan.org
ecan.org
1 page1 citations
espn.com
espn.com
1 page1 citations
abc7chicago.com
abc7chicago.com
1 page1 citations
spokesman.com
spokesman.com
1 page1 citations
eonline.com
eonline.com
1 page1 citations
england.nhs.uk
england.nhs.uk
1 page1 citations
nsjonline.com
nsjonline.com
1 page1 citations
thefa.com
thefa.com
1 page1 citations
mlb.com
mlb.com
1 page1 citations
kansasreflector.com
kansasreflector.com
1 page1 citations
arizzofoundation.org
arizzofoundation.org
1 page1 citations
news.med.miami.edu
news.med.miami.edu
1 page1 citations
barrymanilow.com
barrymanilow.com
1 page1 citations
worldcancerday.org
worldcancerday.org
1 page1 citations
hbo.com
hbo.com
1 page1 citations
ilpost.it
ilpost.it
1 page1 citations
smithsonianmag.com
smithsonianmag.com
1 page1 citations
marvel.com
marvel.com
1 page1 citations
20thcenturystudios.com
20thcenturystudios.com
1 page1 citations
emmys.com
emmys.com
1 page1 citations
bremfoundation.org
bremfoundation.org
1 page1 citations
scottcares.org
scottcares.org
1 page1 citations
scholar.lib.vt.edu
scholar.lib.vt.edu
1 page1 citations
supremecourt.gov
supremecourt.gov
1 page1 citations
cancerhealth.com
cancerhealth.com
1 page1 citations
axios.com
axios.com
1 page1 citations
prnewswire.com
prnewswire.com
1 page1 citations
nargisduttfoundation.com
nargisduttfoundation.com
1 page1 citations
nationalheraldindia.com
nationalheraldindia.com
1 page1 citations
kirkusreviews.com
kirkusreviews.com
1 page1 citations
nhl.com
nhl.com
1 page1 citations
mariolemieux.org
mariolemieux.org
1 page1 citations
royal.uk
royal.uk
1 page1 citations
uk.news.yahoo.com
uk.news.yahoo.com
1 page1 citations
nbcboston.com
nbcboston.com
1 page1 citations
tvinsider.com
tvinsider.com
1 page1 citations
thecurrent.org
thecurrent.org
1 page1 citations
skysports.com
skysports.com
1 page1 citations
aacr.org
aacr.org
1 page1 citations
minnpost.com
minnpost.com
1 page1 citations
abc.com
abc.com
1 page1 citations
cnbc.com
cnbc.com
1 page1 citations
deltagoodremfoundation.org
deltagoodremfoundation.org
1 page1 citations
factcheck.org
factcheck.org
1 page1 citations
news.cornell.edu
news.cornell.edu
1 page1 citations
bobmarley.com
bobmarley.com
1 page1 citations
bcan.org
bcan.org
1 page1 citations
visit.archives.gov
visit.archives.gov
1 page1 citations
ford.blogs.archives.gov
ford.blogs.archives.gov
1 page1 citations
mountsinai.org
mountsinai.org
1 page1 citations
fredhutch.org
fredhutch.org
1 page1 citations
mayoclinicproceedings.org
mayoclinicproceedings.org
1 page1 citations
scmp.com
scmp.com
1 page1 citations
Our primary source
For medical content, NCI (cancer.gov) is our single source of truth. If a fact isn’t supported by the NCI page a topic is based on, it doesn’t go on the page — we never invent, estimate, or guess at medical information. The few other sources above are used only for non-medical, supporting roles (verified health information in other languages, clinical-trial search, or public biographical facts in news posts), and are always clearly identified.
Attribution and reuse
Cancer Explained links to and cites source organizations; those organizations do not endorse this site unless a separate written partnership says so. Third-party names, marks, pages, images, and publications remain the property of their owners.
Our own explanations are written as original plain-language education from cited sources. For reuse limits, short excerpts, copyright notices, and IP concerns, see our terms of use.
How we verify each page
- We draft each explanation from a specific NCI source page.
- We re-fetch that live NCI page and compare every statement — summaries, key takeaways, quiz questions, glossary terms — against the source.
- Anything not supported is corrected to match the source, softened to match NCI’s own wording, or removed. Nothing is replaced with a guess.
- We confirm the citation link works and record the NCI review date.
Our most recent full accuracy review covered all 2841 articles, their questions, quizzes, glossary, and news posts. NCI updates its pages over time, so please treat the original NCI page — linked on every article — as the most current and complete source.
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