Objective: To identify the clinical outcome and prognostic factors of synchronous multicentric osteosarcoma (SMOS). Methods: The clinical data of 2 602 conventional osteosarcoma patients admitted to Beijing Jishuitan Hospital from January 1995 to June 2018 were retrospectively analyzed. Finally, 56 (2.1%) cases were confirmed as SMOS according to clinical and imaging database, medical record and pathological results.All epidemiological data of SMOS cases,initial diagnosis time, tumor site, number of lesions, chemotherapy, surgical treatment, alkline phosphatase (AKP),lactate dehydrogenase (LDH) and oncological results were collected in our institution. The Survival rate, comparison of various parameters, univariate analysis and multivariate Cox regression were performed with statistical software. Results: There were 41 males and 15 females enrolled in this research, the median and mean ages were 15 and 18 years (range, 8-50 years) respectively. All of them were multi-site involved, whereas the initial complaints of sites distribution were 32 cases of femur, 13 cases of tibia, 4 cases of humerus, 3 cases of fibula, 2 cases of spine, 1 case of sternum and 1 case of calcaneus. Forty-four of 56 cases performed adjuvant chemotherapy and 31 of them underwent surgical treatment. The mean follow-up time was 15.4 (range, 1-186) months. Thirty-five cases died of disease at the end of the follow-up. The 5-year survival rate was 10.4%. According to the number of lesions stratification, the 2-year survival rates in patients with low (<5 sites) and high (≥5 sites) tumor load was 33.6% and 0, respectively (χ(2)=6.697, P=0.010). The 2-year survival rate of chemotherapy and non-chemotherapy patients was 20.8% and 0, respectively (χ(2)=6.998, P=0.008), the value of AKP after chemotherapy(median: 272 IU/L) significantly decreased when compared with that at the initial diagnosis (median: 454 U/L) (Z=-3.274, P=0.001).The 2-year survival rate in patients with and without standard chemotherapy was 55.6% and 0, respectively (χ(2)=8.798, P=0.003). The 2-year survival rate was 25.0% in the surgical group and 0 in the non-surgical group, respectively (χ(2)=7.942, P=0.005). Multivariate cox regression analysis with the forward Wald method indicated that standard chemotherapy was the only variable contributor to survival and prognosis of multifocal osteosarcoma. Conclusions: SMOS has low survival rate and poor prognosis. Chemotherapy and surgery can improve the survival rate, standard chemotherapy is an independent prognostic factor.
目的： 研究同时性多中心骨肉瘤（MOS）的治疗结果和预后影响因素。 方法： 回顾性分析1995年1月至2018年6月北京积水潭医院收治的2 602例经典型骨肉瘤患者的临床资料。通过临床和影像数据库资料、病历记录、病理结果核实筛选。确诊为同时性MOS(SMOS)56例（2.1%），组织学诊断均为高级别恶性骨肉瘤。记录所有SMOS病例流行病学资料、初诊时间、发病部位和数量、化疗和手术方案、AKP和LDH、肿瘤学随访结果等指标。并进行各参数生存分析比较和预后多因素回归分析。 结果： 本组患者男41例，女15例，年龄8~50岁，中位和平均年龄分别为15和18岁，均为多部位发病，但初诊主诉部位分别为股骨32例，胫骨13例，肱骨4例，腓骨3例，脊柱2例，胸骨和跟骨各1例。44例接受化疗，12例未化疗，31例接受手术治疗，25例未手术。随访时间1~186个月，平均15.4个月，至随访期末35例死亡。本组总体5年生存率为10.4%。根据病灶数量分层，病灶<5处和≥5处两组2年生存率分别为33.6%和0(χ(2)=6.697，P=0.010)；化疗与非化疗患者2年生存率分别为20.8%和0(χ(2)=6.998，P=0.008)。接受化疗者化疗后AKP(中位：272 U/L）较初诊时（中位：454 U/L）显著下降（Z=-3.274，P=0.001)。化疗患者中规范化疗与不规范化疗两组2年生存率分别为55.6%和0(χ(2)=8.798，P=0.003)。手术和非手术患者2年生存率分别为25.0%和0(χ(2)=7.942，P=0.005)。多因素回归分析显示是否规范化疗是影响预后的独立危险因素。 结论： 同时性多中心骨肉瘤生存率低预后差，化疗和手术可提高生存率，是否规范化疗是影响SMOS生存的独立预后因素。.
Keywords: Chemotherapy; Prognosis; Surgical treatment; Synchronous multicenter osteosarcoma.