Nasopharyngeal carcinoma with paranasal sinus invasion: the prognostic significance and the evidence-based study basis of its T-staging category according to the AJCC staging system

Abstract

BackgroundTo evaluate the prognostic significance of paranasal sinus invasion for patients with NPC and to provide empirical proofs for the T-staging category of paranasal sinus invasion according to the AJCC staging system for nasopharyngeal carcinoma.MethodsThe clinical records and imaging studies of 770 consecutive patients with newly diagnosed, untreated, and nondisseminated NPC were reviewed retrospectively. The overall survival, distant metastasis-free survival, and local relapse-free survival of these patients were analyzed using the Kaplan-Meier method, and the differences were compared using the log-rank test.ResultsThe incidence of paranasal sinus invasion was 23.6%, with the rate of incidence of sphenoid sinus invasion being the highest. By multivariate analysis, paranasal sinus invasion was shown to be an independent prognostic factor for overall survival, distant metastasis-free survival, and local relapse-free survival (p < 0.05 for all). No significant differences in overall survival, distant metastasis-free survival, and local relapse-free survival were observed between patients with sphenoid sinus invasion alone and those with maxillary sinus and ethmoid sinus invasion (p = 0.87, p = 0.80, and p = 0.37, respectively). The overall survival, distant metastasis-free survival, and local relapse-free survival for patients with stage T3 disease with paranasal sinus invasion were similar to the survival rates for patients with stage T3 disease without paranasal sinus invasion (p = 0.22, p = 0.15, and p = 0.93, respectively). However, the rates of overall survival and local relapse-free survival were better for patients with stage T3 disease with paranasal sinus invasion than for patients with stage T4 disease (p < 0.01, and p = 0.03, respectively).ConclusionsParanasal sinus invasion is an independent negative prognostic factor for NPC, regardless of which sinus is involved. Our results confirm that it is scientific and reasonable for the AJCC staging system for nasopharyngeal carcinoma to define paranasal sinus invasion as stage T3 disease.

Impact of paranasal sinus invasion on advanced nasopharyngeal carcinoma treated with intensity‐modulated radiation therapy: the validity of advanced T stage of AJCC/UICC eighth edition staging system

“…Tian et al. retrospectively analyzed 770 patients with stage I–IV disease (by the AJCC seventh edition staging system). They reported paranasal sinus invasion in 182 of 770 (23.6%) patients, with invasion of the sphenoid, maxillary, and ethmoid sinuses being seen in 162 of 770 (21.0%), 86 of 770 (11.2%), and 38 of 770 (4.9%) patients, respectively.…”

“…Sphenoid sinus involvement was most common (163/943, 17.3%); ethmoid, maxillary, and frontal sinus involvements were seen in 50 of 943 (5.3%), 27 of 943 (2.6%), and two of 943 (0.2%), respectively. Tian et al [16] retrospectively analyzed 770 patients with stage I-IV disease (by the AJCC seventh edition staging system). They reported paranasal sinus invasion in 182 of 770 (23.6%) patients, with invasion of the sphenoid, maxillary, and ethmoid sinuses being seen in 162 of 770 (21.0%), 86 of 770 (11.2%), and 38 of 770 (4.9%) patients, respectively.…”

Paranasal sinus invasion suggested T4 classification of patients of nasopharyngeal carcinoma: A two‐center retrospective investigation

“…T staging, including involvement of the paranasal sinuses, can reflect the risk of local failure . Paranasal sinus involvement is common; previous studies showed an incidence of 16%‐39.4% . However, there is no consensus on the staging of paranasal sinus invasion in the current staging systems.…”

“…NPC with paranasal sinus invasion is considered T3 classification in the eighth edition of the AJCC staging system, whereas the Chinese 2008 staging system, which is widely used in southern China, defines it as T4 disease . There are limited studies about the prognostic value and staging classification of NPC with paranasal sinus invasion, especially in the IMRT era with the current AJCC staging system . Whether different types of paranasal sinus invasion should be classified as the same T classification is still controversial .…”

“…11,12 Paranasal sinus involvement is common; previous studies showed an incidence of 16%-39.4%. [13][14][15][16] However, there is no consensus on the staging of paranasal sinus invasion in the current staging systems. NPC with paranasal sinus invasion is considered T3 classification in the eighth edition of the AJCC staging system, whereas the Chinese 2008 staging system, which is widely used in southern China, defines it as T4 disease.…”