Clinical Importance and Risk Factors for Postoperative Late-Onset Pneumonia After Major Oral Cancer Surgery With Microvascular Reconstruction

BACKGROUND: Pulmonary complications are common among patients who have undergone major oral cancer surgery with microvascular reconstruction. Current literatures focused on early-onset pneumonia in the postoperative acute stage. In contrast, we are aiming to identify the clinical importance and the risk factors associated with late-onset pneumonia in oral cancer patients after acute stage. METHODS: In total, 195 patients were included from May 2014 to December 2016 and followed up for up to 1 year after surgery. Their medical histories were reviewed to identify the risk factors of late-onset pneumonia and outcome. Primary outcome was late-onset pneumonia. Other outcome measures included early-onset pneumonia, tumor recurrence, and death within 1 year after surgery. RESULTS: Patients with late-onset pneumonia have demonstrated a significantly higher rate of tumor recurrence (P < 0.001) and death within 1 year (P < 0.001). Independent risk factors of late-onset pneumonia identified were age (P = 0.031), previous radiotherapy (P = 0.017), postoperative radiotherapy (P = 0.002), flap size (P = 0.001), flap type other than osteocutaneous fibula flap (P = 0.009), and tumor recurrence (P < 0.001). CONCLUSIONS: Late-onset pneumonia can act as a warning sign for oral cancer patients who have received microsurgical reconstruction, for its high correlation with tumor recurrence and mortality rate.