Head and neck cancers vary by HPV infection status
MedWire News: Head and neck tumors associated with human papillomavirus infection (HPV) have a different etiologic and clinical profile from non-HPV-related tumors, a US study shows.
The findings suggest that HPV tumor status should be taken into account when making treatment decisions, say Lauren Cole (Louisiana State University, New Orleans) and fellow researchers writing in PLoS ONE.
The epidemiology of head and neck cancer (HNC) is known to differ widely by gender and race, and recent evidence has implicated HPV in the pathogenesis of the disease.
To explore this further, Cole's team used the North American Association of Central Cancer Registries' database to analyze HNC trends for 1995-2005 from 40 population-based cancer registries.
A total of 273,273 HNC cases were included in the database. The majority of patients were male (73.4%) and non-Hispanic White (80.7%), with the most frequent age at diagnosis being 65 years and above (47.0%).
As HPV status was not known for individual tumors, the researchers instead classified all HNC cases into two groups based on proclivity for HPV infection at the anatomic subsite.
Based on the available literature, they classified the tonsil, base of tongue, and lingual tonsil, and parts of the oropharynx as HPV-associated sites, while all other subsites were classified as non-HPV-associated.
The overall age-adjusted incidence rate of HPV-associated HNC was 2.88 per 100,000 people while the corresponding rate for non-HPV-associated HNC was 8.56 per 100,000. These rates varied by age group, however, being lowest in people aged 0-44 years and highest in those aged 45 years and over, irrespective of HPV status.
Interestingly, over the 11-year study period, the incidence of HPV-associated HNC rose in all age groups while the incidence of non-HPV-associated disease declined in all age groups.
Again, however, these trends varied among subgroups. For instance, the increase in HPV-associated HNC was relatively greater among younger people, non-Hispanic Whites, and Hispanic individuals, whereas the incidence of HNC declined in non-Hispanic Blacks independent of HPV status.
In addition, the incidence of HPV-associated HNC increased at the greatest rate in non-Hispanic White males aged 45-54, whereas the greatest decline in non-HPV-associated HNC was seen in non-Hispanic Black males aged 0-44 years and in women aged 55-64 years.
Taken together, the data indicate that infection with HPV has dramatically affected the disease distribution of HNC, say Cole et al.
"In light of an overall decrease in HNC over the past two decades, HNC subsites most strongly associated with HPV have demonstrated a significant increase in incidence over time relative to non HPV-associated sites," the researchers conclude.
"This study provides evidence that HPV-associated tumors are disproportionately affecting certain age, sex and race/ethnicity groups, representing a different disease process for HPV-associated tumors compared to non HPV-associated tumors. Our study suggests that HPV tumor status should be incorporated into treatment decisions for HNC patients to improve prognosis and survival."
In a press statement, study co-author Edward Peters, also from Louisiana State University, New Orleans, remarked: "With the introduction of the HPV vaccine, this study suggests that the vaccine can not only be used to help prevent cervical cancer, but head and neck cancer as well."
By Joanna Lyford