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.