Analysis of risk factors for 1-year survival rate in patients with spinal metastasis secondary to lung cancer / 中华骨科杂志

ABSTRACT

Objective:To investigate the risk factors for 1-year survival rate in patients with spinal metastasis secondary to lung cancer.Methods:The data of 343 patients with spinal metastases secondary to lung cancer from January 2011 to December 2018 were retrospectively studied. There were 188 males (54.8%) and 155 females (45.2%) with an average age of 59.47±10.21 years old (range 23-91 years). The patients were divided into operation group (150 cases, 43.7%) and non operation group (193 cases, 56.3%). The demographics, types of primary tumor, non spinal metastasis, visceral metastasis, spinal metastasis and segments, pathological fractures of vertebra, Frankel classification, physical function status (Karnofsky performance scale, KPS), visual analogue score (VAS), the spinal instability neoplastic score (SINS) were recorded and analyzed. The impact of different treatments on the survival prognosis of patients with spinal metastasis was evaluated. The independent factors affecting survival in those patients were analyzed by Cox proportional hazards regression model.Results:The peak incidence of spinal metastases was found in the age group of 46-60 years (43.7%, 150/343). 38.5% (132/343) of the patients had pathological fractures of the involved vertebral body. 58.3% (200/343) of the patients had extraspinal bone metastasis. 36.2% (124/343) of the patients had visceral metastasis. Among the primary tumors, adenocarcinoma was the most common tpye (61.5%, 211/343), followed by large cell lung cancer (12.5%, 43/343), small cell lung cancer (6.4%, 22/343), squamous cell cancer (6.1%, 21/343) and mixed cell lung cancer (5.3%, 18/343). The type of lung cancer cells in about 8.2 (28/343) patients was unknown. Among the surgical patients, 21 patients underwent minimally invasive surgery (14.0%), 28 patients underwent simple decompression surgery (18.7%), 76 patients underwent separation surgery (50.7%), and 25 patients underwent radical surgery (16.6%). 59.3% (89/150) of the patients had a better neurological function than before surgery. The average survival time of all patients was 9.88 months with the median survival time of 8 (5,14) months. The survival rates were 62.1% (213/343), 30.0% (103/343), and 3.8% (13/343) at 6, 12, and 24 months, respectively. The average survival time of patients in the operation group was 10.24 months with the median survival time of 9 (5, 15) months, and the average survival time of patients in the non operation group was 9.41 months with the median survival time of 7 (5, 13) months with no significant difference between the groups (χ 2=0.300, P=0.584). Multivariate Cox proportional hazard regression model analysis showed that radiotherapy [ HR=1.913, 95% CI(1.471, 2.488), P<0.001], chemotherapy [ HR=1.313, 95% CI(1.040, 1.658), P=0.022], targeted drug therapy [ HR=1.683, 95% CI(1.221, 2.319), P=0.001], KPS [ HR=1.593, 95% CI(1.140, 2.225), P=0.006] and pathological type (non-small cell lung cancer) were independent factors affecting the 1-year survival rate of patients with spinal metastasis secondary to lung cancer [ HR=0.322, 95% CI(0.225, 0.460), P<0.001] with significant difference. Conclusion:Surgical treatment can improve both the neurological function and general status of patients with spinal metastasis. Treatments of radiotherapy, chemotherapy, and targeted drug therapy can significantly improve 1-year survival rate, while a KPS less than 50 points and a primary lung cancer other than adenocarcinoma were independent risk factors reducing 1-year survival rate.