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

Abstract

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.

The map of bone metastasis in nasopharyngeal carcinoma: A real‐world study

“…The study showed that these patients received more than 6 cycles of chemotherapy would have better survival and prognosis 24 . But after when these patients had been treated by palliative chemotherapy plus locoregional radiotherapy, further local radiotherapy to bone metastases would not significantly improve survival 25–27 . If performed radiotherapy to metastatic bones, the radiation dose should give radical dose rather than palliative dose 28 .…”

“… 24 But after when these patients had been treated by palliative chemotherapy plus locoregional radiotherapy, further local radiotherapy to bone metastases would not significantly improve survival. 25 , 26 , 27 If performed radiotherapy to metastatic bones, the radiation dose should give radical dose rather than palliative dose. 28 Zoledronic acid would prevent bone‐related events, but could not improve OS.…”

Assessment of bone lesions with 18F-FDG PET/MRI in patients with nasopharyngeal carcinoma

“…Bone metastasis is the most common type of organ metastasis, accounting for 54-80% of all metastatic sites [3]. The number of metastatic lesions is very important for accurate staging and the formulation of treatment strategies for metastatic NPC [3][4][5]. 99m Tc-MDP planar bone scintigraphy (PBS) is the most frequently used method for detecting bone metastasis [6].…”