Aspiration Pneumonia and Pneumonitis
Among HNSCC patients, the etiology of aspiration, pneumonia, and
pneumonitis is multifactorial and remains an important and often
under-recognized source of morbidity and mortality during and following
completion of treatment. In a retrospective analysis of 374 patients who
received organ preservation therapy for locally advanced HNSCC, risk
factors for aspiration pneumonia included poor oral hygiene, advanced
N-classification, inpatient treatment, and
hypoalbuminemia.65 Treatment breaks occurred far more
often in patients with aspiration pneumonia versus those without (36%
vs. 3%, respectively; p < 0.01), which ultimately
affected survival (Table 1).65 Kawai et al. reported
similar findings and found that 21% (65 of 305) of patients developed
pneumonia at a median of 161 days following treatment; chronic alcohol
consumption, poor oral hygiene, hypoalbuminemia, coexisting malignancies
(mainly esophageal and gastric cancer), and use of sleeping pills were
independent predictors.66 Rates of post-treatment
pneumonia range from 5 to 25%, with concurrent CRT having the largest
influence on its development in most studies.5,6,65-72The sequela can be devastating with 30-day mortality rates of 20 to
30%.24,73-75 The range in incidence of pneumonia
among studies could partly be explained by patient demographics and
length of follow up. In a retrospective study of 15,894 Taiwanese
patients with HNSCC by Chu et al., the authors reported a lower
incidence of pneumonia (5%) within 90 days of RT
initiation.67 However, only 15% of the cohort was
older than age 65, in contrast to studies with a higher proportions of
elderly patients.65-67
While the risk of pneumonia in patients treated with CRT is
significantly elevated during and soon after treatment, this risk
continues to be elevated several years after
therapy.6,75 In an analysis of 3,513 patients, Xu et
al. found that nearly one-quarter of elderly patients developed
aspiration pneumonia within 5 years of CRT, with a 1 year and 5 year
cumulative incidence of 15.8% and 23.8% for patients with head and
neck malignancies, compared to 3.6% and 8.7% for noncancer controls,
respectively.75 A 42% increased risk of death was
also observed (p < 0.001) after controlling for
confounding factors. The authors showed that independent risk factors
for aspiration pneumonia included hypopharyngeal and nasopharyngeal
tumors, increased comorbidities, older age at diagnosis, and treatment
at a teaching hospital.
Notably, both of the studies from Xu et al.75 and Chu
et al.67 separately identified an increased risk of
aspiration pneumonia among patients receiving care at a teaching
institution. This finding likely reflects a higher concentration of
sicker patients with a higher degree of medical complexity at academic
teaching institutions. This is important to note as many of our HNSCC
population will undergo treatment at higher volume, academic centers
burdened by the COVID-19 pandemic.