The Complexity of Defining Postoperative Pneumonia After Esophageal Cancer Surgery: A Spectrum of Lung Injury Rather Than a Simple Infective Complication?

OBJECTIVE: To analyze the spectrum of Centers for Disease Control and Prevention (CDC)-defined pneumonia after esophageal cancer surgery. SUMMARY BACKGROUND DATA: Pneumonia is commonly documented after esophageal cancer surgery, and reducing its incidence is central to both ERAS development and to the evidence-base for minimally invasive approaches. The existing definitions of pneumonia based on hospital acquired pneumonia classifications may be suboptimal in this context and merits strict academic scrutiny. METHODS: Patients (2013-2018) treated with curative intent by open surgery were studied. Pneumonia was defined per the CDC definition. Risk factors and associations were analyzed, as was the implications of positive cultures. Multivariable logistic regression examined independently predictive factors of pneumonia and oncologic outcomes. RESULTS: Of 343 patients, 56 (16%) had defined pneumonia, 22 (39%) with positive cultures. Preoperative respiratory disease predicted pneumonia ( P = 0.043). Neoadjuvant therapy was significantly ( P = 0.004) associated with culture negative pneumonia, and age ( P = 0.001) with culture positive pneumonia. In multivariable analysis, pneumonia was associated ( P < 0.05) with respiratory comorbidity, tumor site, and neoadjuvant chemoradiation. Pneumonia did not impact on overall survival (P = 0.807). DISCUSSION: CDC-defined pneumonia occurred in 16% of cases. Culture-negative pneumonia accounted for 61% of cases and was significantly associated with neoadjuvant chemoradiation. Pneumonia as currently defined seems to represent a spectrum of etiology and severity in the post-esoph-agectomy patient, with infection per se rarely proven, suggesting a need to reevaluate its definition, severity classification, and preventive and treatment strategies.