The Rising Mystery of Early-Onset Colorectal Cancer
For decades, medical professionals have been puzzled by the increasing rates of colorectal cancer among people under 50 in affluent countries. Known as early-onset colon and rectal cancer (EOCRC), this rise over the last 20 years cannot be fully explained by traditional risk factors such as obesity, smoking, poor diet, and lack of exercise.
A New Hypothesis: Cell Phones Carried Below the Waist
Dr. De-Kun Li’s Proposition
Five years ago, Dr. De-Kun Li, a senior epidemiologist at Kaiser Permanente in Oakland, CA, suggested a novel possibility: carrying a cell phone below the waist might increase the risk of EOCRC. He theorized that when a phone is placed in a pocket below the belt, it transmits radiofrequency (RF) radiation into the abdomen, potentially causing cancer—as demonstrated in some animal experiments.
The Pilot Study and Findings
Despite initial skepticism, Dr. Li conducted a pilot study involving 50 EOCRC cases and 50 matched controls. The study found that individuals who carried a phone below the waist were four times more likely to develop tumors.
Ipsilateral vs. Contralateral Carrying
The link was strongest when the phone was kept on the same side as the tumor (ipsilateral carrying). Those who carried a phone on the left side for more than 30,000 hours were 12 times more likely to develop a tumor on that side of the colon—a statistically significant finding. In contrast, carrying the phone on the right side (contralateral carrying) showed only a slight increase in left-side colon cancer risk.
Expert Opinions: Skepticism and Debate
Dr. Kurt Straif’s Perspective
Dr. Kurt Straif, formerly the head of the IARC Monograph Section and now affiliated with Boston College and ISGlobal, expressed skepticism about Dr. Li’s findings. He pointed to the small sample size, wide confidence intervals, and the timing of cell phone usage relative to the rise in EOCRC. Dr. Straif believes that established risk factors, particularly obesity, remain plausible explanations.
Dr. Li’s Response
Dr. Li acknowledged the limitations of the pilot study but emphasized the significant difference between ipsilateral and contralateral risks. He also contested the timing issue, noting that cell phone use became widespread before the steady rise in EOCRC incidence and that latency periods are uncertain.
The American Cancer Society’s View
Rebecca Siegel, a senior researcher at the American Cancer Society, also questioned the timing, suggesting that EOCRC rates have been increasing since the 1970s and 1980s, prior to widespread cell phone use. However, Dr. Li cited studies indicating that the significant rise began in the mid-1990s, coinciding with the surge in cell phone adoption.
The Timing Debate: Cell Phone Usage vs. EOCRC Increase
Evidence of Cell Phone Proliferation
Cell phone usage in the United States escalated from about 11 million users in 1992 to over 44 million in 1996 and nearly 110 million by 2000, according to CTIA, the wireless trade association.
EOCRC Incidence Trends
Studies, such as a 2022 review by Frank Sinicrope of the Mayo Clinic, point to a clear change in EOCRC incidence beginning around 1994, with similar trends observed in other high-income countries. For instance, research published in Gut, a BMJ journal, found that colorectal cancer incidence increased by an average of 7.9% per year among individuals aged 20–29 from 2004 to 2016 across 20 European countries.
Next Steps: Larger Studies and Public Health Implications
Dr. Li plans to apply for federal funding to conduct a larger, more statistically reliable study. He stresses that if his hypothesis is correct, the public health implications are significant because the risk factor is easily preventable through public education about cell phone carrying habits.
An Early Warning: Historical Cases
An incident from the 1990s may have foreshadowed these findings. In January 1997, the UK Sunday Times reported that three members of an elite police unit who concealed radio transmitters near their lower back or kidneys died of colon cancer, raising concerns about radiofrequency exposure.
Conclusion: The Need for Further Research
While experts remain divided, the potential link between cell phone carrying habits and EOCRC underscores the need for further research. As traditional risk factors fail to fully explain the rise in EOCRC, exploring new environmental factors could be key to understanding and preventing this growing health issue.