Introduction
Hypo-pharyngeal carcinoma is often difficult to be diagnosed in its early stages because of its occulted incidence site. Regional metastases such as lymphatic metastases are easy to be found at the time of tumor diagnosed1. Though there is a high incidence rate of lymphatic metastases; the detection of distant metastases is still rare in hypo-pharyngeal carcinoma.
Only 8.5% patients were observed to have distant metastases in head and neck squamous cell carcinoma. Among them, 16.3% of the patients suffered from hypo-pharyngeal carcinoma. The metastatic organs are relatively limited as reported: the lungs (77 %), bone (19 %), mediastinal and other lymph nodes (4 %), as well as the brain, liver1,2. Although distant metastases in hypo-pharyngeal carcinoma are not common, they play an important role. Lymphatic metastases are most often the cause of mortality due to hypo-pharyngeal carcinoma1.
Population-level estimates for prognosis among patients including newly diagnosed hypo-pharyngeal carcinoma and lung metastases or other organs’ metastases are extremely rare, however the incidence of lung metastases or other organ metastases combined with hypo-pharyngeal carcinoma occurs less frequently than newly diagnosed hypo-pharyngeal carcinoma. Data was sourced from a single institution or case report. The purpose of this study was to use the Surveillance, Epidemiology, and End Results (SEER) database to characterize the incidence of lung metastases among patients with hypo-pharyngeal cancer on a population-based level. We also quantified survival estimates and assessed other potential risk factors that influence survival among patients with hypo-pharyngeal cancer and lung metastases present at the time diagnosis.