Prognosis of non-small cell lung cancer patients with bone oligometastases treated concurrently with thoracic three-dimensional radiotherapy and chemotherapy

Background: To evaluate the efficacy of three-dimensional radiotherapy for non-small cell lung cancer (NSCLC) patients with bone metastases. Methods: Clinical data for 95 NSCLC patients with bone metastases were collected and prognostic factors were analyzed. All patients received radiation to their thoracic primary tumor and >= 2 cycles of chemotherapy. Results: Of these 95 patients, 47 patients had only bone metastases and 48 had both bone metastases and other organ metastases. Univariate analysis showed that factors that statistically significantly contributed to patients having longer overall survival (OS) included receiving a radiation dose to the primary tumor >= 63 Gy, responding to treatment and receiving >= 4 cycles of chemotherapy (p = 0.001, p = 0.037 and p = 0.009, respectively). A radiation dose to the primary tumor >= 63 Gy remained significant for patients with bone metastases only as well as those with bone and other organ metastases when they were analyzed separately (p = 0.045 and p = 0.012, respectively). For patients with bone metastases only, those with T1-2 tumors had longer OS than those with T3-4 (p = 0.048); and patients who received >= 4 cycles chemotherapy compared with those who received <4 cycles had similar OS (p = 0.385). On multivariate analysis, only a radiation dose >= 63 Gy (p = 0.028) and having only bone metastases (p = 0.006) were independent prognostic factors for better OS. Conclusions: A radiation dose to the primary tumor >= 63 Gy and having only bone metastases were associated with better OS in NSCLC patients with bone metastases. For patients with bone metastases only, besides radiation dose, T status was also correlated with OS, whereas the number of chemotherapy cycles was not. Therefore, aggressive thoracic radiation may play an important role in improving OS.