Air pollution linked with higher rates of head and neck cancer

A study published yesterday has linked the incidence of head and neck cancer with exposure to PM2.5 pollution at a variety of time intervals, with the effects being most pronounced five years after the exposure.

The study was led by John Cramer, Ph.D., associate professor of otolaryngology, and John Peleman, M.D., medical resident in the Department of Otolaryngology, in the Wayne State University School of Medicine. They collaborated with Mass General Brigham, an integrated academic health care system.

PM2.5 exposure is associated with increased incidence of breast cancer and lung cancer, particularly in non-smokers however the team felt that research into the link between linking air pollution and the development of head and neck cancers was more limited.

Cramer said: ‘There has been previous research on air pollution, but the effects mostly were connected to cancers within the lower respiratory system. Head and neck cancer is a harder link to show, and it has a much lower occurrence than lung cancers, but since they also occur as a result of smoking, similar to lung cancers, we wanted to explore any connections. Presumably, the link to head and neck cancer comes from what we breathe to that material affecting the lining in the head and neck. We see a lot of occurrences of where carcinogens touch or pool in the body to where cancers can occur.

‘We are looking at a certain size of air pollution particulates. The size of the particles is relevant because the classic model for studying the upper airways is that the nose and throat act as filters before it gets into the lungs. Larger particles are being filtered out, but we are conceptualizing that different types of pollution hit different parts of the airways.’

The research drew on data from the U.S. Surveillance Epidemiology and End Results (SEER) national cancer database from 2002 to 2012. They found the greatest association between PM2.5 exposure and head and neck cancer after a five-year lag period but such associations were identified up to 20 years following exposure.

Senior author Stella Lee, M.D., of the Center for Surgery and Public Health at Brigham and Women’s Hospital said: ‘While there has been substantial research investigating the effects of air pollutants on lung disease, few studies have focused on air pollution exposure as a risk factor for the upper airway, including the development of head and neck cancer.

‘These findings shed light on the significant role of environmental pollution in cancers of the upper aerodigestive tract, highlighting the need for further awareness, research and mitigation efforts.’

The research can be read here.