Prognostic effect of parotid area lymph node metastases after preliminary diagnosis of nasopharyngeal carcinoma: a propensity score matching study

Abstract

Parotid area lymph node (PLN) metastasis in nasopharyngeal carcinoma (NPC) is rare, and its prognosis remains largely unknown. Our study aimed to investigate the prognostic value and staging categories of PLN metastasis in patients with NPC and treated with intensity‐modulated radiation therapy (IMRT), to provide a reference for clinical treatment for NPC with PLN metastasis. Records for 1616 untreated NPC patients without distant metastasis was retrospectively reviewed. All patients underwent magnetic resonance imaging (MRI) examination prior to treatment and then received IMRT as their primary treatment. Forty‐five NPC patients (2.8%) showed initial PLN metastasis on follow‐up MRI. PLN metastasis was significantly associated with the N classification and clinical stage. Univariate analysis showed that PLN metastasis had an unfavorable influence on overall survival (OS), progression‐free survival (PFS), distant metastasis‐free survival (DMFS), and regional relapse‐free survival (RRFS) in NPC patients. Using propensity score matching (PSM) to calibrate selection bias and confounding bias, it was observed that PLN metastasis remained an adverse prognostic factor for OS, PFS, DMFS, and RRFS. Furthermore, the 5‐year DMFS and RRFS curves for PLN metastasis were significantly separated from that for N2 disease but crossed that for N3 disease. Therefore, PLN metastasis was found to be an adverse prognostic factor for NPC and to be associated with the same DMFS as N3 disease. Therefore, more aggressive therapeutic strategies consistent with those for N3 disease are recommended for NPC with PLN metastasis to reduce distant metastasis.

Effect of marital status on survival in glioblastoma multiforme by demographics, education, economic factors, and insurance status

“…PSM has been widely used in several areas of medical research including studies to assess factors associated with cancer survival 25, 26, 27, 28, 29. In our study, after 1:1 matching, married patients showed survival advantage over unmarried patients.…”

Establishment and Validation of a Nomogram for Nasopharyngeal Carcinoma Patients Concerning the Prognostic Effect of Parotid Lymph Node Metastases

“…Zhang et et al [15] verified that PLN group had a poorer DMFS than N2 disease but was close to N3 disease. Similarly, Xu et al [16] confirmed that the 5-year DMFS and regional relapse-free survival (RRFS) rates in case with PLN involvement were significantly worse than N2 disease but similar to N3 disease. Meanwhile, the 5-year OS and PFS were consistent with N2 disease.…”

“…Initial PLN metastasis is far less common in NPC patients with an incidence rate of 1%-3.4% in previous studies [ 4 - 7 ] and 2.3% in our study. Due to the low incidence of PLN involvement, there was a paucity of data addressing the prognostic significance and appropriate clinical classification methods for PLN metastasis [ 15 , 16 ]. Zhang et et al [ 15 ] verified that PLN group had a poorer DMFS than N2 disease but was close to N3 disease.…”

“…However, PLN metastasis is not included in the current UICC/AJCC staging system for NPC [14], which leads to different classifications and treatment strategies for PLN metastasis from center to center. Additionally, due to the low incidence of PLN involvement, there was a paucity of data addressing the prognostic significance and clinical staging reference for PLN metastasis [15,16]. Therefore, we retrospectively reviewed the clinical charts of 7,084 NPC patients including 164 patients with PLN metastasis, and further combined both PLN metastasis and clinical variables to generate a nomogram model with accurate prediction, which could be useful for guiding individualized treatment.…”

Prophylactic and therapeutic parotidectomy for secondary neoplasms of the parotid gland

“…PLN metastasis of NPC was recommended to assess as N3 and treat with aggressive concurrent chemoradiotherapy to decrease the possibility of distant metastasis. Parotidectomy is a choice for treatment-resistant (CRT) cases, as the cases with NPC and Rhabdomyosarcoma in the present series [31][32][33].…”