CXCL8 and CXCR4 expression in synchronous bone metastasis in nasopharyngeal cancer

Introduction : Nasopharyngeal cancer is the most common head-and-neck cancer in Indonesia. It occurs in the mucosal epithelium of the nasopharyngeal region. This study aimed to evaluate the role of gene expression in the occurrence of synchronous bone metastasis in nasopharyngeal cancer. Materials and methods : This was a cross-sectional study of patients with nasopharyngeal cancer conducted at Cipto Mangunkusumo Hospital, Jakarta, from 2018 to 2023. Gene expression differences were assessed using NanoString technology, with genetic material extracted from paraffin-embedded tissue samples. The analysis used a fold-change value of 1.5 to −1.5 and an adjusted p -value ( p -adj) of <0.05. Results : Ninety-five patients with nasopharyngeal cancer were included in the study. Most were male and the most common sites of bone metastasis were the vertebrae (70.2%), ribs and sternum (57.4%), and pelvis (27.7%). Most bone metastases were characterized by 2–5 lesions and were predominantly osteoblastic (71.4%). The CXCL8 gene was downregulated to 0.29 (0.16–0.54, p -adj=0.009), while the CXCR4 gene was upregulated to 1.45 (1.16–1.82, p -adj=0.049), in the group with bone metastasis compared to the group without metastasis. Among patients with only bone metastasis, the CXCR4 gene showed a further increase in expression levels, up to 1.61 (1.25–2.07, p -adj=0.02). Conclusions : The results of this study showed that out of the 80 genes, 2 genes play a role in primary bone metastasis. In the group with bone-involvement metastasis, CXCR4 was upregulated and CXCL8 was downregulated. In the bone-only metastasis group, only the CXCR4 gene was found to be upregulated.