Detection bias may explain chronic sinusitis, HNC link
medwireNews: Elderly patients with chronic sinusitis have an elevated risk of developing certain head and neck cancers (HNCs), but the risk is mostly confined to a short interval after sinusitis diagnosis, suggesting a role for detection bias or other artefacts, say US researchers.
Using the linked Surveillance, Epidemiology, and End Results–Medicare database, which only includes patients aged over 65 years, they identified 21,716 cases of HNC diagnosed between 2004 and 2011.
The risk of the infection-related tumours nasopharyngeal cancer (NPC) and human papillomavirus-related oropharyngeal cancer (HPV-OPC) was significantly higher for patients with versus without a prior diagnosis of chronic sinusitis, with adjusted hazard ratios (HRs) of 3.71 and 1.33, respectively.
Moreover, the risk of some non-infection-related malignancies, namely nasal cavity and paranasal sinus cancer (NCPSC) and laryngeal cancer, was also significantly higher for chronic sinusitis patients, with HRs of 5.49 and 1.54, respectively.
However, these associations were mainly driven by an increased risk in the year following chronic sinusitis diagnosis, say the study authors. For instance, chronic sinusitis patients had a significant 8.88- and 1.99-fold increased NPC and HPV-OPC risk, respectively, in the year immediately after diagnosis, while the association was not significant 1 or more years post-diagnosis.
Similarly, the association between NCPSC and chronic sinusitis was stronger within the first year after diagnosis, with an adjusted HR of 12.53 compared with 2.47 for the time period encompassing 1 or more years after chronic sinusitis diagnosis.
The researchers note that for NCPSC, they found “a significant association up to 3 years after chronic sinusitis diagnosis”, suggesting that “chronic sinusitis, especially if present over an extended period, could induce genetic damage to the epithelium lining these spaces, which, when cumulative, could promote carcinogenesis.”
But generally they believe that the associations can be explained by artefacts such as detection or surveillance bias, such that chronic sinusitis patients are “more likely to undergo medical evaluation of the head and neck, including diagnostic imaging, which would increase the probability of identifying an indolent HNC tumor”.
It is also possible for an undiagnosed HNC to be misdiagnosed as chronic sinusitis or to cause the condition, say Daniel Beachler and Eric Engels, both from the National Cancer Institute in Bethesda, Maryland.
They continue: “Whereas an etiologic contribution of sinusitis-related inflammation or immunodeficiency to HNC cannot be excluded, this study suggests that they do not play a large role in promoting the early or intermediate carcinogenic stages of HNC.”
Furthermore, the cumulative incidence of each of the three subtypes was less than 0.07% at 8 years after the diagnosis of chronic sinusitis. “[G]iven the low absolute risk, our findings do not support a need for HNC screening in individuals with chronic sinusitis”, Beachler and Engels conclude in JAMA Otolaryngology–Head & Neck Surgery.
In an accompanying commentary, however, Elisabeth Ference and Jeffrey Suh, from University of California–Los Angeles in the USA, remark that the study “may underestimate the association between sinusitis and cancer because of the older age of included patients”.
They point out that inflammation- and infection-related cancers tend to be more common in younger patients, and say that more research is required “to consider whether inflammation in patients with sinusitis contributes to tumorigenesis, especially in middle-aged adults.”
The commentators conclude: “Sinusitis may be a weak but modifiable risk factor in the development of head and neck cancer, and the association should be further explored in order to better inform patients in regards to surveillance and treatment.”
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