Chronic rhinosinusitis may be linked to an increased risk for cancer, according to a study of patients in Asia. 

The study found that chronic rhinosinusitis was linked to an 18% increased risk for cancer in Korean patients and a 63% increased risk for cancer in patients from Japan. The results provide the first large-scale evidence for an association between chronic rhinosinusitis and the risk for cancer, suggesting a possible role for cancer surveillance in patients with the inflammatory condition, researchers said.

“This study suggests that certain chronic inflammatory conditions may be associated with an increased risk of cancer development and could warrant heightened cancer surveillance, particularly in middle-aged and older populations,” Seong H. Cho, MD, professor of medicine and pediatrics at the University of South Florida Health Morsani College of Medicine in Tampa, Florida, said. “While the consistency across both Asian populations strengthens the validity of the findings, confirmation in the US and other Western populations is essential before broad global application.”

Cho presented the findings at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2026 Annual Meeting.

The researchers looked at adults aged 40 years or older in South Korea and Japan with a history of chronic rhinosinusitis, either with or without nasal polyps. An additional analysis used overlap weighted propensity scores, a statistical method that reduces potential bias when comparing two countries.

Cho and his colleagues used diagnostic codes from the South Korean National Health Insurance Service and the Japanese Medical Data Center to identify the incidence of epithelial and other cancers, including lung and colorectal malignancies. 

In the South Korean group (n = 587,661), chronic rhinosinusitis was associated with a 15% increased risk for cancer (adjusted hazard ratio [aHR], 1.15; 95% CI, 1.06-1.23), with the strongest associations for hematologic malignancies (aHR, 2.02; 95% CI, 1.34-3.04) and lung cancer (aHR, 1.32; 95% CI, 1.01-1.73), according to Cho.

The Japanese group (n = 4,885,282) showed similar patterns, with chronic rhinosinusitis associated with a 63% increased risk for overall cancer (aHR, 1.63; 95% CI, 1.58-1.69). The strongest associations were for hematologic malignancies (aHR, 2.32; 95% CI, 2.04-2.65), thyroid cancer (aHR, 2.05; 95% CI, 1.65-2.54), and lung cancer (aHR, 1.99; 95% CI, 1.75-2.27).

The overlap weighted analysis included 62,336 Koreans. In this group, chronic rhinosinusitis was associated with an 18% increased risk for any cancer (aHR, 1.18; 95% CI, 1.09-1.27) and a 28% increased risk for lung cancer (aHR, 1.28; 95% CI, 1.04-1.57). These associations were significant for people with chronic rhinosinusitis without nasal polyps for overall cancer (aHR, 1.19; 95% CI, 1.10-1.28) and lung cancer (aHR, 1.26; 95% CI, 1.02-1.55), but not for those with rhinosinusitis with nasal polyps.

“This is an important area of research with potentially broad implications,” Jennifer Mulligan, PhD, an associate professor in the Department of Otolaryngology – Head & Neck Surgery at the University of Florida in Gainesville, Florida, said.

Obesity, smoking, and age over 40 years are risk factors for the development of cancer and chronic rhinosinusitis, making the association between the two conditions “biologically plausible,” Mulligan, whose research interests include rhinosinusitis and tumor immunology, said.

“Although the study is well powered, it does not fully address these shared risk factors,” added Mulligan, the vice chair for research and co-director of the UF Health Smell Disorders Program.

The results may be relevant to the US, where two thirds of patients with chronic rhinosinusitis do not develop nasal polyps, she said. In the new research, chronic rhinosinusitis without nasal polyps was associated with cancer risk.

“Although the study did not identify a strong link between chronic rhinosinusitis without nasal polyps and cancer risk, additional research is needed to determine how well these results apply to individuals in the US,” she said.

Cho said his group is now conducting a similar analysis of patients in the US.

“If these findings are replicated in the US population, enhanced vigilance for cancer surveillance may be warranted in patients newly diagnosed with chronic rhinosinusitis after age 40,” he said.

Cho and Mulligan reported no financial conflicts of interest.

Veronica Hackethal, MD, MSc, is a science communicator based in New York City. Her work has appeared in Medscape, Nature Medicine News, Scientific American, The New York Times, and others.