Prognostic value of primary tumor surgery in minor salivary-gland carcinoma patients with distant metastases at diagnosis: first evidence from a SEER-based study

Xiao Shi,1,2,* Nai-Si Huang,1,2,* Rong-Liang Shi,1,2,* Wen-Jun Wei,1,2 Yu-Long Wang,1,2 Qing-Hai Ji1,2 1Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center, 2Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China *These authors contributed equally to this work Purpose: The prognostic value of primary tumor surgery (PTS) in minor salivary-gland carcinoma (MiSGC) with distant metastasis (DM) at diagnosis has never been investigated. In this study, we aimed to provide the first evidence.Patients and methods: The Surveillance, Epidemiology, and End Results (SEER) database was employed to identify MiSGC patients with DM at diagnosis. The prognostic value of PTS was evaluated by Kaplan–Meier methods, log-rank analyses, and multivariate Cox proportional-hazard regression models.Results: Of the 152 eligible patients included in our study, 50 (32.9%) had undergone PTS. Kaplan–Meier analyses showed that the PTS group had >20% increase in 1- and 2-year overall survival (OS) and cancer-specific survival (CSS) compared with their counterparts without PTS (PTS group vs no-PTS group, 1-year OS 66.1% vs 43.9%, 1-year CSS 69.9% vs 44.9%, 2-year OS 56.6% vs 24.2%, 2-year CSS 59.9% vs 25.7%). Compared with the no-PTS group, multivariate analyses also demonstrated a significantly decreased risk of overall mortality (HR 0.601, 95% CI 0.379–0.952; P=0.031) and cancer-specific mortality (HR 0.547, 95% CI 0.336–0.891; P=0.015) in the PTS group. Subgroup multivariate analyses revealed patients with T1–T3 oropharynx, nasal cavity, or paranasal sinus primary MiSGC, especially adenoid cystic carcinoma, might benefit from PTS (all P