Having your tonsils out will get you ice cream ― and perhaps protection from tonsil cancer. The finding from a large Danish population-based study seems intuitive, but really had not been shown before.

But lead researcher Carole Fakhry, MD, of Johns Hopkins School of Medicine, Baltimore, Maryland, said she “would not encourage people to get a tonsillectomy” in the hope of reducing their risk for this type of oral cancer, which is rare. However, a “side benefit” of tonsillectomy might be the reduction in risk for these cancers, she told Medscape Medical News.

The study was published online April 20 in Cancer Prevention Research.
The incidence of oropharyngeal carcinoma, which includes cancers arising from the tonsils, oropharynx, pharynx, Waldeyers’ ring, and branchial cleft, is increasing globally, particularly in younger age groups, driven largely by sexually transmitted human papillomavirus (HPV) infection, Dr Fakhry and colleagues note in their article.

For example, about 77% of tonsil cancers in Denmark, which is the data source for the new study, occurring between 2000 and 2010 were related to HPV. At the same time, tonsillectomy for hypertrophic tonsils and recurrent tonsillitis has “lost previously held general acceptance,” they point out about Western countries.

“We are asked this question all of the time by patients: ‘Could I have prevented this [oropharyngeal cancer] by having a tonsillectomy?’ ” Dr Fakhry said.

So she and her colleagues decided to investigate.

Using data from 1977 to 2012 on more than 3.8 million adults in the Danish Cancer Registry, they analyzed the incidence of tonsillectomies and oropharyngeal carcinoma and whether tonsillectomy reduces the future risk for oropharyngeal carcinoma.
Since 1977, the incidence of tonsillectomy has fallen significantly (P < .001), most markedly after 1995, they report. The rate of tonsillectomy has declined by 1.1% annually, on average. During a 35-year period, this corresponds to a 33.8% decrease in the incidence of tonsillectomies.

During the same period, the incidence of oropharyngeal carcinoma increased “dramatically,” the researchers report.

Importantly, tonsillectomy was not associated with the risk for oropharyngeal carcinoma or cancer of other anatomic sites, including the base of tongue. However, tonsillectomy was associated with a 60% reduction in risk for tonsil cancer (rate ratio [RR], 0.40; 95% confidence interval [CI], 0.22 – 0.70).

“Notably,” say the researchers, the risk for diagnosis of tonsil carcinoma before age 60 years was significantly reduced after tonsillectomy (adjusted RR, 0.15; 95% CI, 0.06 – 0.41).

Tonsillectomy within 1 year of diagnosis of tonsil carcinoma was associated with significantly improved overall survival (hazard ratio, 0.53; 95% CI, 0.38 – 0.74).

“Tonsillectomy likely reduces the palatine lymphoid tissue susceptible to carcinogenic factors, and subsequent potential for malignant transformation,” the researchers say.

But again, they do not recommend prophylactic tonsillectomy for the general population. For one thing, tonsil carcinoma is rare, as noted above. If a biomarker of “high predictive value” for the development of oropharyngeal cancer could be identified, people with such a marker might benefit from tonsillectomy, although that would require study, they suggest.

“If early tonsil lesions could be identified through a combination of biomarkers for risk stratification, imaging, and cytologic evaluation, then tonsillectomy in a select well-defined population may reduce the incidence of tonsil carcinoma,” they add.

Limitations of the study include the lack of some “clinically relevant information,” including HPV tumor status, stage, and tobacco use, which introduces the potential for residual confounding, the researchers note.

Also, the limited number of oropharyngeal carcinoma cases overall (n = 52) and of tonsil carcinomas (n = 12) following tonsillectomy could imply that the observed associations were by chance. “Although the estimates of the effect of tonsillectomy may have low precision and relatively wide CIs, the significant point estimates are far from null and highly significant, therefore supporting a true association,” they say.

This study “provides the first insight into the association of tonsillectomy with risk of oropharyngeal cancers,” Anil Chaturvedi, PhD, with the Division of Cancer Epidemiology at the National Institutes of Health, notes in an accompanying editorial.

It shows “an ecologic correlation” between declining incidence of tonsillectomies in Denmark and rising oropharyngeal cancer incidence over time, he points out. Still, the question remains regarding the extent to which a decline in tonsillectomies has contributed to the rise in tonsil cancer incidence in recent years, he adds.

Echoing the authors, Dr Chaturvedi says, “at this time, prophylactic tonsillectomies should not be considered as a secondary prevention strategy for oropharyngeal cancers.”

“Although a common surgical procedure, tonsillectomy is not without minor complications, such as postoperative bleeding, pain, and nausea, as well as major complications, such as hemorrhage and death,” he writes.