Paraneoplastic thrombocytosis is associated with increased mortality and increased rate of lymph node metastasis in oesophageal adenocarcinoma.

Paraneoplastic thrombocytosis has been associated with adverse outcomes in several cancers, but has not been described in oesophageal adenocarcinoma. The aim of our study was to examine the prognostic value of platelet counts in patients with oesophageal adenocarcinoma. A cohort of 584 patients who underwent oesophagectomy for oesophageal adenocarcinoma was identified. Platelet counts, history of neoadjuvant chemoradiation, and clinicopathological factors such as T and N stage, and overall survival were recorded. Patients with elevated platelet count (>450,000/μL) had a higher mortality rate than patients with normal platelet count (150,000-450,000/μL) (hazard ratio = 2.60, p = 0.0013). This effect was seen in patients with and without neoadjuvant chemoradiation therapy. Paraneoplastic thrombocytosis was also associated with increased likelihood of lymph node metastasis compared to normal platelet count (69% versus 31%, p < 0.01). Paraneoplastic thrombocytosis is associated with increased rate of lymph node metastasis and mortality in oesophageal adenocarcinoma. Further studies are needed to examine the mechanisms behind this phenomenon.