Abstract
BackgroundThe current World Health Organization (WHO) classification of nasopharyngeal carcinoma (NPC) conveys little prognostic information. This study aimed to propose an NPC histopathologic classification that can potentially be used to predict prognosis and treatment response.MethodsWe initially developed a histopathologic classification based on the morphologic traits and cell differentiation of tumors of 2716 NPC patients who were identified at Sun Yat-sen University Cancer Center (SYSUCC) (training cohort). Then, the proposed classification was applied to 1702 patients (retrospective validation cohort) from hospitals outside SYSUCC and 1613 patients (prospective validation cohort) from SYSUCC. The efficacy of radiochemotherapy and radiotherapy modalities was compared between the proposed subtypes. We used Cox proportional hazards models to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS).ResultsThe 5-year OS rates for all NPC patients who were diagnosed with epithelial carcinoma (EC; 3708 patients), mixed sarcomatoid-epithelial carcinoma (MSEC; 1247 patients), sarcomatoid carcinoma (SC; 823 patients), and squamous cell carcinoma (SCC; 253 patients) were 79.4%, 70.5%, 59.6%, and 42.6%, respectively (P < 0.001). In multivariate models, patients with MSEC had a shorter OS than patients with EC (HR = 1.44, 95% CI = 1.27–1.62), SC (HR = 2.00, 95% CI = 1.76–2.28), or SCC (HR = 4.23, 95% CI = 3.34–5.38). Radiochemotherapy significantly improved survival compared with radiotherapy alone for patients with EC (HR = 0.67, 95% CI = 0.56–0.80), MSEC (HR = 0.58, 95% CI = 0.49–0.75), and possibly for those with SCC (HR = 0.63; 95% CI = 0.40–0.98), but not for patients with SC (HR = 0.97, 95% CI = 0.74–1.28).ConclusionsThe proposed classification offers more information for the prediction of NPC prognosis compared with the WHO classification and might be a valuable tool to guide treatment decisions for subtypes that are associated with a poor prognosis.
Highlights
The current World Health Organization (WHO) classification of nasopharyngeal carcinoma (NPC) con‐ veys little prognostic information
Based on the current World Health Organization (WHO) pathologic classification, NPCs are grouped into keratinizing squamous cell carcinoma (KSCC) and non-keratinizing carcinoma
Clinicians have continued to appeal to pathologists to propose an NPC histopathologic classification system that better predicts prognosis and that enables personalized treatment of NPC patients
Summary
The current World Health Organization (WHO) classification of nasopharyngeal carcinoma (NPC) con‐ veys little prognostic information. Based on the current World Health Organization (WHO) pathologic classification, NPCs are grouped into keratinizing squamous cell carcinoma (KSCC) and non-keratinizing carcinoma. The latter group is further subdivided into non-keratinizing differentiated carcinoma (NKDC) and non-keratinizing undifferentiated carcinoma (NKUC). Pathologists have observed that NPC tumor cells have obvious morphologic variations, with cells that are small and round, large and round, spindleshaped, with or without vesicular nuclei, or mixed round and spindle-shaped Despite this morphologic heterogeneity, proposed NPC histopathologic classifications to date have not demonstrated clinically relevant improvement in prognostic prediction beyond the WHO classification [11]. Clinicians have continued to appeal to pathologists to propose an NPC histopathologic classification system that better predicts prognosis and that enables personalized treatment of NPC patients
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
