A tremendous surge in vocal-cord (glottic) cancer diagnoses in young adults appears to come from infection with human papilloma virus (HPV) strains. Samples of vocal-cord cancer from 10 patients aged 30 or younger, mostly nonsmokers, were found to have HPV infection, reported Massachusetts General Hospital researchers.
For well over a century, glottic cancer was almost wholly associated with smoking and most often seen in patients older than 40. But today, nonsmokers account for close to 50% of glottic cancer patients, who are commonly diagnosed before age 40. The transformation is a significant public health concern because of the diagnostic confusion surrounding this type of cancer diagnosis, say the researchers.
The increase in glottic cancer diagnosis resembles an earlier increase in throat cancer diagnosis, which has been associated with infections by high-risk strains of HPV. Initially, researchers believed that increased travel and exposure to infectious diseases were causing glottic cancer in nonsmokers, but investigators decided to examine whether HPV infection might also explain the diagnosis in younger nonsmokers.
The researchers examined records of 353 patients treated for vocal-cord cancer from July 1990 to June 2004 and July 2004 to June 2018. None of the 112 patients from 1990 to mid-2004 were aged 30 or younger, but 11 of the 241 patients from 2004 to 2018 were 30 or younger, and only three were smokers. An analysis of tumors from 10 of the 11 younger patients revealed high-risk strains of HPV in all of them.
These high-risk-HPV-associated vocal-cord cancers are very similar to recurrent respiratory papillomatosis (RRP), a benign condition caused by common, low-risk strains of HPV. Benign RRP has been a familiar HPV disease for years and there is concern that this new HPV malignancy so closely resembles it, causing diagnostic and therapeutic confusion. The researchers point out that “these HPV-associated vocal-cord carcinomas are not a malignant degeneration of the benign disease.”
The researchers say that large-scale studies are required to determine the speed of glottic cancer increase in nonsmokers, the incidence of high-risk HPV in these cancers, and changes in the age and gender of those affected.
EurekAlert!, February 7, 2019