Impact of childhood/adolescent cancer history on prognosis in parotid mucoepidermoid carcinoma.

Our goal was to assess the impact of childhood/adolescent cancer history on overall survival (OS) and disease-specific survival (DSS) in patients with parotid mucoepidermoid carcinoma (MEC). Patients who underwent surgical treatment for primary parotid MEC and those with a second malignancy of parotid MEC were retrospectively identified from the Surveillance, Epidemiology, and End Results (SEER) database. The primary outcome variables were OS and DSS. The hazard ratios (HRs) of these survival rates associated with cancer history were analysed using Cox regression models. In total, 2681 patients were included, 263 of whom had a second malignancy. The 10-year OS rates in the primary (72%) and second malignancy groups (59%) were significantly different. Cox regression confirmed that a history of cancer tended to decrease OS (p = 0.062, HR: 1.28, 95% confidence interval: 0.99 to 1.64). Subgroup analyses showed that a history of solid tumour as opposed to haematological cancer predicted worse OS, with central nervous system tumours exhibiting a more significant influence than others (p = 0.030 vs p = 0.088). Cancer history was not related to DSS. A history of childhood/adolescent cancer negatively influenced the prognosis of patients with parotid MEC, and this effect was primarily driven by a history of solid malignancy.