High-risk HPV related to oropharyngeal squamous cell carcinomas in nonsmoking, nondrinking patients

Laco J. Virchows Arch. 2011; doi:10.1007/s00428-010-1037-y.

Issue: February 10, 2011

Oropharyngeal squamous cell carcinomas, but not oral squamous cell carcinomas, were related to high-risk HPV infection in nonsmoking and nondrinking patients, according to researchers from Charles University in the Czech Republic.

“Traditionally, [these cancers] are associated with smoking and alcohol abuse, which still represent important risk factors,” the researchers wrote. “Since the 1980s, however, evidence has been emerging, suggesting that a subset of oropharyngeal [squamous cell carcinomas], in contrast to oral [squamous cell carcinomas], is associated with oral high-risk human papillomavirus infection.”

The researchers identified 24 patients with oral squamous cell carcinomas and 22 patients with oropharyngeal squamous cell carcinomas who had no personal history of smoking or chronic alcohol abuse. They used immunohistochemistry to analyze the cancer samples for p16^INK4a expression. They also used chromogenic in situ hybridization and polymerase chain reaction to identify the presence of high-risk HPV.

In the patients with oral squamous cell carcinoma, p16^INK4a was identified in 29% of the samples, whereas it was detected in all of the oropharyngeal squamous cell carcinoma samples. Using chromogenic in situ hybridization, researchers found high-risk HPV in 25% of the oral squamous cell carcinoma samples and in 95% of the oropharyngeal squamous cell carcinoma samples. Polymerase chain reaction revealed HPV DNA in 13% of the oral squamous cell carcinoma samples and 82% of the oropharyngeal squamous cell carcinoma samples.

The oropharyngeal squamous cell carcinoma samples more often showed basaloid morphology, lymph node involvement diffuse p16 expression and high-risk HPV DNA presence than the oral squamous cell carcinoma samples.

“Our results indicate that the majority of oropharyngeal tumors developing in these patients are related to oral HPV infection, whereas the viral etiology is responsible for a substantially smaller subset of tumors occurring in the oral cavity, stressing the need for identification of further, still unknown risk factors playing a role in the pathogenesis of squamous cell carcinoma of the oral cavity,” the researchers wrote.

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