#162 Axial Metastasis in Nasopharyngeal Carcinoma
Poster Presented by: N.S. Kumar
N.S. Kumar (1,2)
J. Tan (1)
J. Lim (1)
A.S. Zaw (1)
(1) National University Health System, Orthopaedic Surgery, Singapore, Singapore
(2) National University Hospital, Orthopaedic Surgery, Singapore, Singapore
Summary: Axial metastasis is common in nasopharyngeal carcinoma (NPC), affecting 13% of patients in our study. It usually presents within 3years from diagnosis of NPC. NPC seems to have an affinity for lumbar and thoracic vertebrae in its spread to axial skeleton.
Introduction: Axial metastasis is commonly found in patients with nasopharyngeal carcinoma.1We have evaluated axial metastasis in nasopharyngeal carcinoma (NPC), with regard to the time of diagnosis of NPC, its presentation and geographic distribution in the axial skeleton.
Patients and Methods: 814 patients with the diagnosis of NPC who presented to the National University Hospital (NUH), Singapore, over a 5-year period (2007-2011) were recruited for this study. Case records from clinics, wards, operating theatres at NUH and nationwide electronic records of polyclinics and Emergency Medical Department (EMD) were obtained and reviewed. The data collected included demographics, medical history, radiologic and histopathology reports.
Results: A total of 814 NPC cases were studied of which 99(12.2%) cases had spinal metastases. The male:female ratio for patients with skeletal metastasis was 4.2:1. There was a preponderance of Chinese patients (84.9%). The spine was the most common site of metastases with 90 (90.9%) of patients having spine metastases of which 77(85.6%) had multiple spine metastases. 84(84.9%) of patients had metastases to other sites of the axial skeleton, with 71(84.5%) having multiple sites of non-spinal axial skeleton metastases. Appendicular metastases were less common with only 42(42.4%) having appendicular metastases. 23 had skeletal metastasis at the time of diagnosis of NPC (23.2%). 47 developed skeletal involvement within 3 years (46.5%), 29 did so beyond 3years (29.3%). Metastasis to the spine, had a predilection for the lumbar vertebrae -76.8%, followed by the thoracic vertebrae- 72.7% sacrum 41.4%, and finally the cervical vertebrae 32.3%. Out of the 99 patients with axial metastasis only 8 of them had spinal metastasis requiring surgery (8.1%).
Conclusion: Axial metastasis is common in NPC, affecting 12.2% of patients in our study. The most common time of presentation is within 3years from diagnosis of NPC. Skeletal metastasis tends to be widespread, with 40.4% affecting both the axial and appendicular bones and 85.6% affecting more than 1 spinal segment. NPC seems to have an affinity for the lumbar and thoracic vertebrae in its spread to the axial skeleton.