Postoperative Pneumonia Is a Prognostic Factor of Long-Term Survival for Recurrence-Free Esophageal Cancer Patients

Background Long-term outcomes of esophageal cancer surgery are commonly reported based on the 5-year overall survival rate and relapse-free survival rate, which serve as indicators of oncological efficacy following esophagectomy. However, there is limited research on the impact of highly invasive esophageal cancer surgery and perioperative complications on survival outcomes beyond 5 years. This study aims to investigate the influence of esophageal cancer surgery and associated perioperative complications on ultra-long-term survival exceeding 5 years. A single-center retrospective analysis was conducted using the database at Kobe University Hospital, focusing on esophageal cancer patients who underwent curative esophagectomy. Methods This study retrospectively analyzed 640 cases of esophageal cancer surgery performed at Kobe University Hospital between April 2010 and July 2024. Additionally, patients who underwent curative esophagectomy were independently analyzed, excluding cases of cancer recurrence and short-term mortality within 90 days. Patient characteristics, including sex, age, comorbidities, smoking history, Brinkman index, tumor location, surgical procedures, reconstruction route and organ, operative time, thoracic operative time, intraoperative blood loss, length of hospital stay, and pathological findings, were systematically collected. The impact of each individual parameter on ultra-long-term outcomes, specifically those extending beyond 5 years, was statistically assessed. Results Postoperative complications occurred in 424 cases (66.3%), including anastomotic leakage in 144 cases (22.5%), recurrent nerve palsy in 192 cases (30.0%), and pneumonia in 139 cases (21.7%). While overall complications (P = 0.382), anastomotic leakage (P = 0.061), and recurrent nerve palsy (P = 0.607) did not significantly affect ultra-long-term survival rate, pneumonia significantly worsened overall survival rate (P < 0.05). In a subgroup of 391 recurrence-free patients, 250 cases (63.9%) had postoperative complications, with pneumonia observed in 81 cases (20.7%). Postoperative pneumonia significantly impacted ultra-long-term survival rate (P < 0.01), and patients with pneumonia had a higher incidence of respiratory disease-related mortality (P < 0.05). Conclusion Although overall complications, postoperative anastomotic leakage, and recurrent nerve palsy did not significantly affect survival prognosis, postoperative pneumonia was strongly associated with a marked reduction in ultra-long-term survival in both the entire cohort and recurrence-free patients. Prevention of postoperative pneumonia is critical for improving survival outcomes following curative esophageal cancer surgery, particularly in patients without recurrence. Further research is warranted to explore the impact of preventing postoperative pneumonia on ultra-long-term survival outcomes.