Optimizing the treatment mode for de novo metastatic nasopharyngeal carcinoma with bone-only metastasis

Background No standard radiotherapy regimens have been established for the treatment of de novo metastatic nasopharyngeal carcinoma (mNPC) with bone-only metastasis. The current study aimed to investigate the efficacy of palliative chemotherapy (PCT) plus locoregional radiotherapy (LRRT) with or without local radiotherapy (RT) for metastatic bone lesions in mNPC. Methods We retrospectively analysed 131 de novo patients with mNPC who had bone-only metastasis and received at least two cycles of PCT with LRRT. The difference in survival was evaluated by the log-rank test. Univariable and multivariable analyses were performed by Cox regression. Results The median overall survival (OS) and progression-free survival (PFS) were 33.0 months and 24.0 months, respectively. Patients with five or fewer metastatic bone lesions had significantly longer OS (72.0 months vs. 23.0 months, Hazard ratios (HR) = 0.45, p < 0.001) and PFS (48.0 months vs. 15.0 months, HR = 0.52, p = 0.004) than those who had more than five metastatic bone lesions. Patients who received four or more cycles of chemotherapy were associated with significantly longer OS (unreached vs. 19.0 months, HR = 0.27, p < 0.001) and PFS (66 months vs. 16.0 months, HR = 0.32, p < 0.001). Multivariate analysis confirmed that fewer bone metastases (≤ 5) and more chemotherapy cycles (≥ 4) were favourable prognostic factors for OS. Subgroup analysis revealed that RT to metastatic bone lesions tended to prolong OS (83.0 months vs. 45.0 months) and PFS (60 months vs. 36.5 months) in patients with five or fewer metastatic bone lesions than in those without RT to metastatic bone lesions (p > 0.05). Patients who received a RT dose > 30 Gy had neither better OS (63.5 months vs. 32.0 months, p = 0.299) nor PFS (48.0 months vs. 28.0 months, p = 0.615) than those who received a RT dose ≤30 Gy. Conclusions Local RT to bone metastases may not significantly improve survival in patients with de novo mNPC with bone-only metastasis who have already received PCT plus LRRT. Receiving four or more cycles of chemotherapy can significantly prolong survival and is a favourable independent protective factor.

Taxane/gemcitabine-containing chemotherapy plus locoregional IMRT for patients with de novo metastatic nasopharyngeal carcinoma: the treatment outcomes and prognostic factors analysis

Purpose To evaluate treatment outcomes of de novo metastatic nasopharyngeal carcinoma (mNPC) patients receiving taxane/gemcitabine-containing chemotherapy followed by locoregional intensity-modulated radiotherapy (IMRT) and analyze potential prognostic factors. Methods A total of 118 patients between March 2008 and November 2018 were retrospectively analyzed. All the patients were treated with taxane/gemcitabine-containing systemic chemotherapy followed by definitive locoregional IMRT. Potential prognostic factors including baseline absolute lymphocyte count (ALC) and the subdivision of metastasis were analyzed. Results The median follow-up time for the whole group was 31.5 months (range 5–138 months). Of the 118 patients, 9 (7.6%) patients experienced local regional failure and 60 (50.8%) patients had progression of distant metastasis. At the time of the last follow-up, 61 (51.7%) patients were dead. The 5-year actuarial progression free survival (PFS), overall survival (OS),distant metastasis relapse free survival (DMFS) and local regional recurrence free survival (LRFS) were 34.2%, 44%, 41.1% and 82.6%, respectively. Baseline lymphocyte count ≥ 1600/μl prior to the treatment conferred better locoregional control (5y-LRFS 96% vs. 64.7%, p < 0.001) and distant metastasis control (5y-MFS 50.4% vs. 32.4%, p = 0.023). The multivariate analysis showed that high lymphocyte count was the most relevant predictor of superior PFS (HR = 0.236, p < 0.001) and OS (HR = 0.518, p = 0.04). M subdivision was found as another independent prognostic factor for OS but not for PFS. Conclusion Taxane/gemcitabine-containing chemotherapy combined with IMRT represents an effective treatment modality for mNPC. Baseline ALC is an independent significant prognostic factor for PFS and OS.

Efficacy, safety, and biomarker analysis of Camrelizumab in Previously Treated Recurrent or Metastatic Nasopharyngeal Carcinoma (CAPTAIN study)

BackgroundThis study aimed to evaluate the antitumor activity of camrelizumab, an antiprogrammed cell death-1 antibody, in pretreated recurrent or metastatic nasopharyngeal carcinoma (NPC) and to explore predictive biomarkers.MethodsPatients with recurrent (not amenable to locally curative treatment) or metastatic NPC who had failed at least two lines of chemotherapy were eligible to receive camrelizumab (200 mg intravenously every 2 weeks) for 2 years or until disease progression, intolerable adverse events, withdrawal of consents, or investigator decision. The primary endpoint was objective response rate (ORR) assessed by an independent review committee (IRC). Programmed cell death-ligand 1 (PD-L1) expression was assessed by immunohistochemistry. Other immune-related biomarkers including major histocompatibility complex class I and major histocompatibility complex class II (MHC-II) were assessed by multiplex immunofluorescence staining.ResultsBetween August 14, 2018, and December 30, 2019, a total of 156 patients were enrolled. The IRC-assessed ORR was 28.2% (95% CI 21.3% to 36.0%). The median progression-free survival was 3.7 months (95% CI 2.0 to 4.1) per IRC, and the median overall survival was 17.4 months (95% CI 15.2 to 21.9). The ORRs were 35.2% (95% CI 25.3% to 46.1%) vs 19.4% (95% CI 10.4% to 31.4%) in patients with tumor PD-L1 expression of ≥10% and<10%, respectively. Patients with durable clinical benefit (DCB), which was defined as complete response, partial response or stable disease of ≥18 weeks, had higher density of MHC-II+ cell in stroma than patients without DCB (median 868.1 (IQR 413.4–2854.0) cells/mm2 vs median 552.4 (IQR 258.4 to 1242.1) cells/mm2). MHC-II+ cell density did not correlate with PD-L1 expression, and a composite of high stromal MHC-II+ cell density and tumor PD-L1 expression further enriched patients who could benefit from camrelizumab.ConclusionsCamrelizumab had clinically meaningful antitumor activity in patients with recurrent or metastatic NPC. The composition of both MHC-II+ cell density and PD-L1 expression could result in better patient selection.