<p>Synchronous Metastatic Nasopharyngeal Carcinoma: Characteristics and Survival of Patients Adding Definitive Nasopharyngeal-Neck Radiotherapy to Systematic Chemotherapy</p>

Abstract

To determine the M1 sub-staging in synchronous metastatic nasopharyngeal carcinoma (smNPC) and to examine the effect of nasopharyngeal-neck radiotherapy (RT) and local treatment of metastases on overall survival (OS) of smNPC patients. Patients and Methods: A total of 150 patients with smNPC were included. Metastatic characteristics associated with their potential prognostic significance were analyzed. Then, a stratification system of the M1 sub-staging in smNPC was provided according to metastatic features. Moreover, the OS of patients with or without nasopharyngeal-neck RT was compared by Log rank test. The OS of patients who received or did not receive local treatment of metastases was also analyzed. Results: We successfully divided the M1 stage into three sub-staging: M1a (a single site with a single lesion), M1b (a single site with multiple lesions), and M1c (multiple sites with multiple lesions). The median OS was 53.2, 25.8, and 18.9 months for M1a, M1b, and M1c, respectively (p < 0.001). Nasopharyngeal-neck RT plus systematic chemotherapy (CT) significantly improved OS compared to systematic CT (median OS, 34.0 vs 15.2 months, p = 0.002). However, incorporation of local treatment of metastases did not bring survival benefit to smNPC patients who received nasopharyngeal-neck RT plus systematic CT (median OS, 25.8 vs 35.1 months, p = 0.374). Conclusion: The sub-staging of the M1 stage in smNPC had promising prognostic value. Adding nasopharyngeal-neck RT on the basis of systematic CT markedly improved the survival of smNPC patients, while addition of local treatment of metastases to nasopharyngeal-neck RT plus systematic CT for smNPC needed further exploration.

Identifying the optimal candidates for locoregional radiation therapy in patients with de novo metastatic nasopharyngeal carcinoma

“…Retrospective data, including ours, have suggested a role of LRRT in de novo mNPC based on conventional radiotherapy 16‐21 . This phenomenon was further confirmed in the subsequent IMRT era 7‐10,22,23 . Liao et al 8 conducted a retrospective study of 150 synchronous mNPC patients and indicated that LRRT plus PCT significantly improved OS compared to PCT alone (median OS, 34.0 vs. 15.2 months, 3‐year OS 44.9% vs. 24.8%, p = 0.002).…”

“…As have been recommended in current National Comprehensive Cancer Network (NCCN) and European Society for Medical Oncology (ESMO) guidelines, palliative chemotherapy (PCT) (i.e., platinum‐based combination regimens) is commonly used as a first‐line therapy since platinum represents the most effective agent 1,2 . However, reported survival outcomes of de novo mNPC treated by PCT alone were far from satisfactory, with the indicated median overall survival (OS) time ranging from 12 to 21 months 3‐9 . Thus, how to improve the survival further in this subgroup of patients remains an urgent issue to be clarified.…”

“…Several investigators proposed that locoregional radiation therapy (LRRT) may achieve survival benefits in de novo mNPC. Published data had revealed that LRRT could increase the OS time of de novo mNPC from 13–24.5 to 21–60 months 5‐10 . However, mNPC is a heterogeneous group varying by the distribution and extent of the metastatic burden and significantly different prognosis 9 ; some argue that patients with some particular characteristics, such as detectable EBV DNA after PCT, may have no benefit from additional post‐PCT LRRT 7 .…”

Optimizing the Treatment Mode for de Novo Metastatic Nasopharyngeal Carcinoma with Bone-Only Metastasis

“…Rusthoven et al reported that compared to chemotherapy alone, local radiotherapy combined with chemotherapy was associated with improved OS (median OS 21.4 vs 15.5 months, 5-year OS 28% vs 10%), resulting in a 39% reduction of death risk [13]. Similar ndings were also found in some retrospective studies [14][15][16][17][18][19][20]. Up to now, there are only one multicenter phase 3 randomized clinical trial investigated the e cacy of LLRT in de novo mNPC.…”

“…Since there is no consensus on who should receive LLRT and / or RT to metastatic sizes after rst-line PCT, prognostic models and risk strati cations guiding the subdivisions of mNPC patients based on clinical features, therapeutic response and blood biomarkers had been widely researched to identify the optimal candidates [3,14,17,19,[22][23][24][25], as well as in mNPC with bone-only metastasis [6, 9-11, 21, 26].…”