Ognjanovic Simona, Linabery Amy M, Charbonneau Bridget, Ross Julie A
Division of Pediatric Epidemiology and Clinical Research, Department of Pediatrics, University of Minnesota, Masonic Cancer Center, Minneapolis, Minnesota 55455, USA.
Cancer. 2009 Sep 15;115(18):4218-26. doi: 10.1002/cncr.24465.
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents aged<20 years; its etiology remains largely unknown. It is believed that embryonal (ERMS) and alveolar rhabdomyosarcoma (ARMS), the most common subtypes, arise through distinct biologic mechanisms. The authors of this report evaluated incidence and survival trends by RMS demographic subgroups to inform future etiologic hypotheses.
Incidence and survival trends in RMS among children and adolescents aged<20 years were analyzed using data from the Surveillance, Epidemiology, and End Results Program. Frequencies, age-adjusted incidence and survival rates, and joinpoint regression results, including annual percentage change (APC) and 95% confidence interval (CI), were calculated.
Between 1975 and 2005, the incidence of ERMS was stable, whereas a significant increase in the incidence of ARMS was observed (APC, 4.20%; 95% CI, 2.60%-5.82%). This trend may have been attributable in part to shifts in diagnosis, because a significant negative trend in RMS, not otherwise specified was observed concurrently. A bimodal age peak for ERMS was observed, with the second, smaller peak in adolescence noted for males only; ARMS incidence did not vary by age or sex. Five-year survival rates for RMS and ERMS increased during the period from 1976 to 1980 (52.7% and 60.9%, respectively) to the period from 1996 to 2000 (61.8% and 73.4%, respectively), whereas there was little improvement for ARMS (40.1% and 47.8%, respectively).
Observed differences in incidence and survival for 2 major RMS subtypes across sex and age subgroups further supported the hypothesis that there are unique underlying etiologies for these tumors. Exploration of these differences presents an opportunity to increase current knowledge of RMS.
横纹肌肉瘤（RMS）是20岁以下儿童和青少年中最常见的软组织肉瘤；其病因在很大程度上仍不清楚。人们认为，最常见的亚型胚胎型横纹肌肉瘤（ERMS）和腺泡状横纹肌肉瘤（ARMS）是通过不同的生物学机制产生的。本报告的作者评估了RMS各人口统计学亚组的发病率和生存趋势，以为未来的病因假说提供依据。
使用监测、流行病学和最终结果计划的数据，分析20岁以下儿童和青少年中RMS的发病率和生存趋势。计算了频率、年龄调整发病率和生存率，以及连接点回归结果，包括年度百分比变化（APC）和95%置信区间（CI）。
1975年至2005年期间，ERMS的发病率稳定，而ARMS的发病率显著增加（APC，4.20%；95%CI，2.60%-5.82%）。这种趋势可能部分归因于诊断的变化，因为同时观察到未另作说明的RMS有显著的负趋势。观察到ERMS有双峰年龄高峰，第二个较小的高峰仅在青春期男性中出现；ARMS的发病率在年龄或性别上没有差异。RMS和ERMS的五年生存率从1976年至1980年期间（分别为52.7%和60.9%）提高到1996年至2000年期间（分别为61.8%和73.4%），而ARMS的生存率几乎没有改善（分别为40.1%和47.8%）。
在2种主要RMS亚型的发病率和生存方面，观察到的性别和年龄亚组差异进一步支持了这些肿瘤存在独特潜在病因的假说。对这些差异的探索为增加当前对RMS的认识提供了一个机会。
