History of tonsillectomy and risk of oropharyngeal cancer.

Objective: To investigate whether palatine tonsillectomy in youth influences the risk of oropharyngeal cancers (OPC) by assessing the association between history of tonsillectomy and risk of tonsillar, base of tongue (BOT) cancer, and other head and neck cancers (HNC).

Materials And Methods: RACKAM was a case-case study comparing frequency of tonsillectomy history in individuals diagnosed with HNC from 2013 to 2018 in 15 centers across France. History of tonsillectomy was defined using combined assessment of patients' recollections and surgeons' visualizations of tonsil area. OPC subsite-specific odds ratios (OR) of tonsillectomy were calculated using multinomial logistic regression with non-oropharyngeal HNC as reference.

Results: 1045 patients were included in the study. Frequency of tonsillectomy was 19.5% in patients with tonsillar cancer (N = 85), 49.3% in BOT (N = 76), 33.8% in other oropharyngeal cancers (N = 202) and 38.0% in non-oropharyngeal HNC (N = 682). History of tonsillectomy was inversely associated with tonsillar cancer (adjusted OR 0.4; 95% CI 0.2-0.8), and positively associated with BOT cancer (adjusted OR 1.8; 95% CI 1.1-3.1), but was not associated with all OPC combined (adjusted OR 1.1; 95% CI 0.8-1.4). Sensitivity analyses considering only patients' or surgeons' assessments of tonsillectomy provided comparable results.

Conclusion: We confirm the long-term protective effect of tonsillectomy performed in youth on future risk of tonsillar cancer, and our study is the second to report a concurrent increased risk of BOT cancer. Our data suggest that tonsillectomy in youth shifts the site of the first diagnosed oropharyngeal tumor and has a limited impact on overall risk of OPC.