Detrimental impact of late-onset pneumonia on long-term prognosis in oesophageal cancer survivors

Backgroud Oesophageal cancer patients are prone to early- and late-onset pneumonia after oesophagectomy. We aimed to investigate the incidence rate and impact on the long-term prognosis of late-onset pneumonia in oesophageal cancer survivors who survived for at least one year after oesophagectomy without cancer recurrence. Methods We retrospectively reviewed 233 patients with thoracic oesophageal cancer who underwent oesophagectomy with gastric conduit reconstruction between September 2009 and June 2019 at a tertiary referral hospital in Japan. Pneumonia that occurred ≥1 year after oesophagectomy was defined as late-onset pneumonia. Results Among the 185 oesophageal cancer survivors, 31 (17%) developed late-onset pneumonia. The cumulative incidence rates of late-onset pneumonia 24, 36, and 60 months after oesophagectomy were 6.4%, 10%, and 21%, respectively, whereas pneumonia recurred at 21%, 31%, and 52% within 6, 12, and 24 months, respectively, after the first pneumonia. Chronic obstructive pulmonary disease, postoperative anastomotic leakage, and loss of skeletal muscle mass were independently associated with late-onset pneumonia, and a combination of these factors further increased the risk. Late-onset pneumonia with hospitalisation had the greatest negative impact on the long-term prognosis as non-cancer deaths (HR, 21; p < 0.001), followed by recurrent late-onset pneumonia (HR, 18; p < 0.001). Conclusions Late-onset pneumonia in oesophageal cancer survivors is significantly associated with an increased risk of recurrent infections and non-cancer deaths. Chronic obstructive pulmonary disease and postoperative muscle loss are risk factors for late-onset pneumonia, and more intensive pharmacological and nutritional interventions should be considered to improve long-term prognosis after oesophagectomy.