Susceptibility to Adverse Respiratory Outcomes

Patients with HNSCC are at high risk for poor respiratory outcomes due to underlying respiratory comorbidities. Kawakita et al. performed the first population-based analysis designed to compare the incidence of respiratory disease in HNSCC patients compared to the general population. In a study of 1901 head and neck cancer patients within the Utah Cancer Registry matched to 7796 noncancer patients, the authors discovered that risks of respiratory infection (HR 1.63), COPD and bronchiectasis (HR 2.65), and aspiration pneumonitis (HR 6.21) were higher among head and neck cancer survivors, even after adjusting for baseline smoking status.6 Interestingly, this increased risk persisted more than 5 years after diagnosis (Table 1 ).6 Specifically, risks of COPD and aspiration pneumonitis were more than 3-times higher among this population. Moreover, the authors demonstrated that triple modality therapy was the strongest risk factor for aspiration pneumonia. Age at diagnosis, baseline body mass index, sex, smoking status, treatment modality, primary tumor site, and stage were also identified as significant risk factors for adverse respiratory outcomes.
The risk of severe pulmonary complications remains elevated in both the immediate and long-term perioperative period. In a review of 3932 patients from a national database who underwent head and neck surgical procedures, postoperative pneumonia was the most common medical complication (3.26%) and was associated with a mortality rate of 10.9% (OR for mortality, 4.4).39 Buitelaar et al. showed comparable outcomes in a retrospective series of 469 patients undergoing primary major head and neck ablation with cardiovascular (12%) and respiratory (11%) complications being the most frequent. Significant risk factors for pulmonary complications included preexisting pulmonary disease, prior myocardial infarction, and ASA grade.40The incidence of new respiratory comorbidities including pneumonia, asthma, and COPD has been found to be highest within the first 6 to 12 months following treatment and remains nearly two-fold higher compared to non-cancer patients. Similar findings were reported by Baxi et al. who demonstrated that mortality from COPD, pneumonia, and influenza continued to rise among HNSCC survivors who had lived at least 3 years after diagnosis (Table 1).3
These findings highlight several key considerations. First, early dysphagia intervention programs may be useful in mitigating the adverse functional impacts of surgery and radiation-induced fibrosis and prevent aspiration pneumonitis.41 Second, adherence to smoking cessation is critical to reducing the risk of recurrence, second primary malignancies, and comorbid respiratory diseases.42Finally, in general, frequent disease surveillance and multidisciplinary care should remain central to the treatment and prevention of adverse pulmonary outcomes among higher risk HNSCC survivors.