OBJECTIVES/HYPOTHESIS:

Tonsillectomy is related to increased risk of certain types of cancer. This study evaluates the possible association between tonsillectomy and cancer in Taiwan.

METHODS:

Data from the National Health Insurance system of Taiwan was used. A cohort study consisting of 997 patients with a new diagnosis of tonsillectomy from 2000 to 2005 and a comparison cohort of 3,988 subjects without tonsillectomy were used in the Poisson regression analysis to estimate the incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of cancers.

RESULTS:

The incidence rate of all cancer types was higher in the tonsillectomy group than in the control group (4.28 vs. 2.97 per 1,000 person-years, respectively), with an IRR = 1.54 and 95% CI of 1.05 to 2.25, but the significant difference was limited to patients with more than 3 years follow-up. Site-specific analysis found no significant association between tonsillectomy and any individualcancer after adjusting for age, sex, hyperlipidemia, hypertension, and diabetes; however, tonsillectomy patients with more than 3 years follow-up had a marginally significantly higher risk for breast cancer development (adjusted IRR = 2.62; CI = 0.97-7.03).

CONCLUSION:

Our study found that Taiwanese people with tonsillectomy have a significantly higher overall risk of developing cancerand a marginally higher risk of developing breast cancer when follow-up is longer than 3 years.