Peritonsillar abscess as a clinical sign of oropharyngeal cancer - a Swedish national cohort study.

PURPOSE: Patients older than 40 years with peritonsillar abscess may routinely undergo follow-up to detect oropharyngeal cancer, but this approach lacks scientific evidence. This study aimed to assess the hypothesis that oropharyngeal cancer is not overrepresented in patients with peritonsillar abscess.

METHODS

This population-based, nationwide Swedish cohort study compared all patients diagnosed with peritonsillar abscess during 2005-2023 with an age-, date-, and sex-matched non-exposed group from the same cohort. Conditional logistic regression provided odds ratios (OR) with 95% confidence intervals (CI) for oropharyngeal cancer within 1 year after peritonsillar abscess diagnosis, or matching date. Except for the three matching variables, the OR were adjusted for tobacco smoking, alcohol overconsumption, and comorbidity in a multivariable model.

RESULTS

Oropharyngeal cancer was diagnosed in 30 patients out of 64,244 occurrences of peritonsillar abscess (0.05%), compared to 9 out of 642,440 individuals in the comparison group (0.0014%). All 39 oropharyngeal cancers occurred in individuals aged 40 or older. Peritonsillar abscess was associated with an increased 1-year risk of oropharyngeal cancer (adjusted OR 3.51, 95% CI 2.75-4.26). In substrata of age, the strongest association was observed for patients aged 60 years and above (adjusted OR 4.54, 95% CI 3.07-6.02), corresponding to 2.8 cases per 1000 patients, while the age group 40-59 years had an OR of 2.76 (95% CI 1.80-3.72).

CONCLUSION

Peritonsillar abscess may indicate an underlying oropharyngeal cancer only in rare cases. Given the low incidence of oropharyngeal cancer after peritonsillar abscess, routine follow-up is questionable or may be limited to older patients.