[First-line chemotherapy and its survival analysis of 394 patients with extensive-stage small cell lung cancer in a single institute]

Small cell lung cancer (SCLC) is the most malignant neuroendocrine tumor but highly sensitive to chemotherapy and radiotherapy. At present, the standard first-line chemotherapy regimen of extensive-stage SCLC is platinum combined etoposide regimen. However, most patients who receive first-line chemotherapy will relapse within one to two years. Once recurrent, it indicates poor prognosis. In this study, we analyzed the survival among all extensive-stage SCLC and patients who received first-line chemotherapy and determined prognostic factors.Total of 394 patients who were diagnosed as extensive-stage small cell lung cancer from February 2001 to December 2011 hospitalized in Peking Union Medical College Hospital were collected. Kaplan-Meier method was used to calculate the overall survival (OS) and progression-free survival (PFS). Univariate analysis and Cox regression analysis were used to detect the influence factors of survival.The median OS of all extensive-stage small cell lung cancer was 14.8 months; 1-year, 2-year and 5-year survival rates were 58.9%, 27.2% and 7.8%, respectively. According to the results of univariate and Cox multivariate analysis, OS of extensive-stage SCLC was closely associated with age (P=0.006), ECOG PS (P=0.021), liver metastasis (P0.001), bone metastasis (P0.001) and chemotherapy (P0.001). The mortality risk of patients who didn't receive chemotherapy was 4.919 times higher than that who received; the mortality risk of patients without liver, bone metastasis was reduced by approximately 50 percent. The first-line chemotherapy was mainly EP (DDP+VP-16) or CE (CBP+VP-16) regimens (accounting for 82.8%) with 4-6 cycles. The median OS and PFS in first-line chemotherapy were 15.1 months and 7.5 months, respectively. The result of Cox regression analysis indicated that OS in first-line chemotherapy was remarkably related to smoking history (P=0.041), liver metastasis (P0.001), bone metastasis (P0.001), chemotherapy cycle number (P0.001); PFS was relevant with smoking history (P=0.003), liver metastasis (P=0.001), bone metastasis (P0.001), chemotherapy cycle number (P0.001). Thoracic radiotherapy was not an independent influence factor of OS and PFS in extensive-stage small cell lung cancer.The patients who were younger than 60-year old, with good KPS, absence of liver and bone metastasis had better prognosis. Patients should receive chemotherapy with first-line standard regimen (CE/EP regimen). It was beneficial to survival if the effect of first-line chemotherapy was SD or PR-CR and the proper chemotherapy cycle number was 4-6 cycles. The role of thoracic radiotherapy in extensive-stage small cell lung cancer needed to be investigated further.背景与目的 小细胞肺癌（small cell lung cancer, SCLC）是恶性程度极高的神经内分泌肿瘤，对放化疗敏感。目前，广泛期SCLC的一线标准化疗方案为铂类联合依托泊苷方案，但大多数接受一线化疗的患者在1年-2年内复发。一旦疾病复发，预后不良。本研究旨在研究广泛期SCLC总体和一线化疗的生存情况及其影响因素。方法 收集2001年2月-2011年12月经病理学或细胞学确诊为广泛期的SCLC患者394例，采用Kaplan-Meier法计算总生存时间（overall survival, OS）和无进展生存时间（progression-free survival, PFS）并绘制生存曲线，单因素及Cox回归多因素分析各种因素对生存期的影响。结果 全组中位OS为14.8个月，1年、2年、5年生存率分别为58.9%、27.2%、7.8%。全组OS与年龄（P=0.006）、ECOG评分（P=0.021）、肝转移（P0.001）、骨转移（P0.001）、是否化疗（P0.001）密切相关。一线化疗广泛期SCLC患者的中位OS为15.1个月，中位PFS为7.5个月。多因素分析结果显示一线化疗广泛期SCLC的OS与吸烟（P=0.041）、肝转移（P0.001）、骨转移（P0.001）、化疗疗程数（P0.001）相关；一线化疗PFS与吸烟（P=0.003）、肝转移（P=0.001）、骨转移（P0.001）、化疗疗程数（P0.001）相关。胸部放疗并非广泛期SCLC OS和PFS的独立影响因素。结论 年龄60岁、体能状况好、无肝、骨转移的广泛期SCLC患者预后更好。广泛期SCLC患者应积极进行化疗，一线化疗的化疗疗效达到部分缓解-完全缓解有益于生存；适合的化疗疗程数目是4-6疗程。胸部放疗在广泛期SCLC治疗中的作用需要进一步研究。