Histological subtype remains a prognostic factor for survival in nasopharyngeal carcinoma patients.

OBJECTIVES: There is currently no consensus on the prognostic significance of the histological subtype of nasopharyngeal carcinoma (NPC). The aim of the current study was to evaluate the impact of histological subtype on survival in NPC patients based on the Surveillance, Epidemiology, and End Results (SEER) Program. METHODS: Patients with NPC were identified within the SEER database (2004-2015). The effects of histological subtype on cause-specific survival (CSS) in NPC patients were evaluated using univariate and multivariate Cox regression analyses. Subgroup analysis according to histological subtype in NPC patients was carried out by 1:1 propensity score matching (PSM). RESULTS: A total of 4085 NPC patients were selected from the SEER database, including 1929 with keratinizing squamous cell carcinoma (KSCC), 2203 with nonkeratinizing carcinoma (NKC), and 53 with basaloid squamous cell carcinoma (BSCC). The 3-year and 5-year CSS rates were 61.76% and 55.07% for KSCC patients, 79.57% and 72.09% for NKC patients, and 77.55% and 74.03% for BSCC patients, respectively. Multivariate analysis identified sex, age, marital status, race, T stage, N stage, M stage, radiotherapy, chemotherapy, and histological subtype as significant prognostic factors for CSS in NPC patients. KSCC was found to be associated with worse CSS than NKC on Kaplan-Meier analysis and subgroup analysis after 1:1 PSM. CONCLUSIONS: Histological subtype determines the long-term survival outcomes of patients with NPC. Moreover, the NKC subtype has the best prognosis, while the KSCC subtype has the worst prognosis. LEVEL OF EVIDENCE: NA Laryngoscope, 130:E83-E88, 2020.

A simplified T classification based on the 8th edition of the UICC/AJCC staging system for nasopharyngeal carcinoma.

Objective: This study aimed to establish a simplified T classification based on the 8th edition of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system for nasopharyngeal carcinoma (NPC). Methods: In total, 325 patients with NPC were included in this study. All patients underwent magnetic resonance imaging, and the staging criteria were recorded. These patients were subjected to staging with the 8th edition of the UICC/AJCC staging system for NPC. Results:  Involvement of the oropharynx, nasal cavity, adjacent soft tissue (medial pterygoid, lateral pterygoid, and prevertebral muscles), cervical vertebra, orbit, and hypopharynx were always accompanied by other equivalently or more advanced T-stage classifications. All cases with involvement of the paranasal sinuses showed skull base erosion. The majority of cases with involvement of the pterygoid structure showed skull base erosion. Conclusion: According to the simplification principle, the following new T classification based on the 8th edition of the UICC/AJCC staging system was established: T1, tumor confined to nasopharynx, or beyond the nasopharynx without parapharyngeal involvement; T2, tumor with extension to the parapharyngeal space; T3, tumor with infiltration to bony structures at the skull base; T4, tumor with intracranial extension, involvement of the cranial nerves or parotid gland, and/or extensive soft tissue infiltration beyond the lateral surface of the lateral pterygoid muscle. Validation with a large series of patients is needed.