Cell phones and cancer, followed through the numbers
US brain cancer rates have not climbed while cell phones went from rare to almost universal, and the largest human studies mostly find no link between phone use and brain tumors. A big US government rat study did find heart and brain tumors in male rats, at whole-body doses many times the public exposure limit. And the International Agency for Research on Cancer (IARC) has listed radiofrequency fields as "possibly carcinogenic to humans" since 2011. This site follows each of those statements back to the document it came from, and tells you what that document can and can't show.
- 6.1 per 100,000
- new brain and other nervous system cancers in the US each year, age-adjusted, 2019 to 2023 cases
- 98%
- US adults who own a cellphone, in a Pew survey run January to June 2026
- Group 2B
- the IARC rating for radiofrequency fields since May 2011, "possibly carcinogenic to humans"
- 63 papers
- pooled by the 2024 WHO-commissioned review, which found no raised glioma risk among phone users
Source: SEER Cancer Stat Facts (April 2026 release), Pew Research Center, IARC press release 208, Karipidis et al. 2024 in Environment International.
What the cancer registries show
The National Cancer Institute's SEER program has counted new cancers in the same eight regional registries since 1975. For cancers of the brain and other nervous system, the age-adjusted rate in those registries was 5.93 per 100,000 people in 1975. It peaked at 7.17 in 1990 and was 5.66 in 2023, the latest year in the April 2026 release. SEER's modeled trend for those registries has the rate falling about 1.4% a year from 2014 to 2023.
Phones spread to nearly everyone during the same decades. CTIA, the wireless industry association, estimated 340,213 subscriber connections at the end of 1985 and about 109 million at the end of 2000. Pew Research Center found that 62% of American adults owned a cellphone in its 2002 survey and 98% in 2026.
A registry line that stays flat for this long rules out a large effect that shows up within a decade or two. That's a real result. It is also a blunt one: a small risk could hide inside it, and so could a risk limited to very heavy users or a cancer that takes longer to appear than the data cover. Our registry article has the year-by-year numbers and the studies that tested them.
What the animal studies found
The US National Toxicology Program (NTP) exposed rats and mice to 2G and 3G phone signals for about nine hours a day, for roughly two years. Its final reports, released in November 2018, found clear evidence of malignant heart schwannomas in male rats and some evidence of brain gliomas and adrenal tumors in male rats. Results in female rats and in mice were rated equivocal.
Those rats absorbed 1.5 to 6 watts per kilogram across the whole body. The FCC's whole-body limit for the public is 0.08 W/kg. Two matched studies in Japan and Korea, published in 2026, exposed male rats at 4 W/kg for two years and found no significant increase in brain, heart or adrenal tumors. The details, including what the FDA disputed, are in our NTP explainer.
What the large reviews conclude
IARC placed radiofrequency fields in Group 2B in May 2011, citing "limited" evidence in humans for glioma and acoustic neuroma. In IARC's terms, limited means a positive association was seen and a causal reading seemed credible, but chance, bias or confounding couldn't be ruled out with reasonable confidence. The National Cancer Institute's fact sheet on cell phones, last reviewed in April 2024, puts its reading in one sentence:
"the evidence to date suggests that cell phone use does not cause brain or other kinds of cancer in humans."
In 2024 a WHO-commissioned systematic review pooled 63 papers and found moderate certainty evidence that phone use likely does not raise the risk of glioma, meningioma or acoustic neuroma. A second WHO-commissioned review, this one of animal studies, came out in 2025 and rated the evidence for gliomas and heart schwannomas in male rats as high certainty. So two reviews commissioned by the same organization point in different directions, one for people and one for rats. IARC's own advisory group has asked for a fresh evaluation in the second half of 2025 to 2029. Our review comparison puts the main studies side by side.
| Line of evidence | Main source | What it found | Main limit |
|---|---|---|---|
| US cancer registries | SEER, 1975 to 2023 | No rise in brain cancer rates; a decline since 2014 | Cannot see small or slow-to-appear risks |
| Case-control study | Interphone, 13 countries, 2010 | No overall increase; higher odds in the top tenth of call time | Recall and participation bias |
| Cohort studies | Danish cohort, Million Women Study, COSMOS | No association with brain tumors | Crude or short exposure records |
| Rodent studies | NTP, 2018 | Heart and brain tumors in male rats | Whole-body doses far above phone limits |
| Systematic review | Karipidis et al., 2024 | Moderate certainty of no raised risk | Inherits the biases of the studies it pools |
How we handle the evidence
Every number on this site comes from a document we link to. When a study has a weakness, we name it, whichever way the weakness cuts. We don't test or review products, whether that's an RF meter or EMFCALM's sticker packs, which that shop sells for phones, tablets, laptops and routers. If you have a symptom or a scan to ask about, that conversation belongs with your doctor.
The next formal re-rating will come from IARC. Its advisers asked in 2024 for a re-evaluation in the back half of the 2025 to 2029 cycle, and the Monographs meetings IARC has announced so far, running through October 2027, do not include radiofrequency fields.
The Incidence Line follows the cancer statistics and research on cell phones and radio-frequency energy, from national registries to animal studies and systematic reviews. It is not a medical practice. Talk to a doctor about any health question of your own.