Detection of bone metastasis in nasopharyngeal carcinoma by bone scintigraphy: A retrospective study in perspective of limited resource settings

Background: Nasopharyngeal carcinoma (NPC) is an aggressive tumor with a significant proportion of patients presenting with distant metastasis. The skeleton is one of the most common sites of distant failure. This retrospective study was performed to analyze the incidence and patterns of skeletal metastasis in NPC detected by bone scintigraphy in resource-poor settings. Materials and Methods: We analyzed records of 301 NPC patients attending our oncology outpatient department from January 2002 to December 2012. Of these, 33 patients who presented with bony pain underwent bone scan (BS) for suspect of skeletal metastasis. In patients with positive scans, histological diagnosis to confirm metastasis was attempted. Results: Bone metastasis (BM) was found in 19 patients (57.6% of patients undergoing BS, 6.3% of total NPC patients). About 36.8% and 15.8% of BM cases were in the age group 20-29 and 30-39 years, respectively (P = 0.27). 63.1% of metastatic cases were of World Health Organization type-II histology (P = 0.021). Of the patients diagnosed with BM, 52.6% belonged to stage IV at presentation (P = 0.022). Spine was involved in 56% of the positive cases, followed by the pelvis (32%), and ribs (24%). On univariate analysis, histology (P < 0.001), stage at diagnosis (P = 0.007) and age group (P = 0.001) were identified as significant factors affecting BM. However, on multivariate analysis, only stage (P = 0.001) was a significant factor. Conclusion: Bone scintigraphy can be considered in limited resource settings for the evaluation of distant metastasis in the patients of advanced NPC.