Pharyngeal squamous cell carcinoma has been linked to later squamous cell carcinoma of the esophagus, but it is unclear if risks are similar to that of Barrett’s esophagus and would justify routine gastroscopy surveillance.

Data on pharyngeal and esophageal cancers in 1980–2016 were retrieved through histopathology reports from Sweden’s 28 pathology departments and linked to national population-based healthcare registers. We calculated hazard ratios (HRs) for esophageal cancer and death in patients with pharyngeal carcinoma compared to a matched general population, and in a secondary analysis also compared to siblings of patients.

We identified 1055 adults with pharyngeal cancer without prior or concomitant cancer. 78 % were men and median age at diagnosis of pharyngeal cancer was 64 years. During a median follow-up of 2.5 years four (0.4 %) patients developed esophageal squamous cell carcinoma, equal to 1 in 263 patients (HR = 14.3; 95 % CI = 1.6–132.3). In a competing risk analysis, the risk estimate for ESCC dropped and did not attain statistical significance (subdistribution HR=1.9 (95 % CI=0.7–5.2)). Some 855 patients (81 %) died during follow-up, representing a 7.7-fold increased risk of death among patients with pharyngeal cancer (Cox regression: HR=7.7; 95 % CI = 6.8–8.6).

The yearly risk of developing esophageal squamous cell carcinoma was 0.07 %. This is lower than in Barrett’s esophagus and argues against long-term endoscopic surveillance among patients with pharyngeal cancer.