When Should ⁹⁹mTc Bone Scintigraphy Be Performed in cT1N0 Non-Small Cell Lung Cancer Patients?

The aim of this retrospective study was to investigate the risk factors for bone metastases (BM) in clinical T1N0 non-small cell lung cancer (NSCLC) patients.From January 2010 to June 2012, 739 patients with primary diagnosed cT1N0 NSCLC were eligible for this study. Clinical variables, including sex, smoking history, age at diagnosis, tumor size, pathologic subtype, preoperative serum Carcino embryonie antigen (CEA) level, lesion imaging performance, and skeletal system symptom, were collected.BM were found in 7 patients (0.95%), in whom 6 patients had skeletal system symptom and 1 had silent metastasis. The frequency of BM was significantly high in younger patients (P = 0.007) and in patients with higher preoperative serum CEA level (P = 0.05). In multivariate analysis, age less than 50 years old (OR = 2.23, 95% CI: 1.56-4.21, P = 0.02), presence of clinical symptom (OR = 3.15, 95% CI: 1.98-6.42, P = 0.008), and CEA level over 5 μg/mL (OR = 2.14, 95% CI: 1.37-3.53, P = 0.03) were independently associated with BM in cT1N0 NSCLC patients.Presence of skeletal system symptom is not the unique criteria for performing BS. Younger age at diagnosis and higher preoperative serum CEA level are also risk factors for BM in cT1N0 NSCLC patients. Therefore, the selection of early-stage NSCLC patients being performed BS should be more precise in the future.