摘要目的 研究儿童神经母细胞源性肿瘤(NT)中N-myc和C-myc基因的分子遗传学异常及其临床病理学意义.方法 应用间期荧光原位杂交(FISH)技术检测246例NT标本[神经母细胞瘤(NB)188例,节细胞神经母细胞瘤(GNB) 52例,节细胞神经瘤(GN)6例]中N-myc异常,并与组织学类型、预后进行相关性分析,同时对其中的133例NT进行C-myc基因的FISH检测.结果 246例NT中,N-myc总扩增率为11.0％(27/246),所有扩增均发生在NB中,52例GNB及6例GN中无1例存在N-myc扩增(P＜0.05).246例NT中,N-myc非扩增者占89.0％(219/246),包括N-myc的获得者(71.1％,175/246)和正常者(17.9％,44/246).单因素生存分析显示,N-myc扩增者预后比N-myc非扩增者差(P=0.012)；N-myc非扩增者中,N-myc获得者预后与N-myc正常者相比,差异无显著统计学意义(P =0.057).进行C-myc检测的133例NT中,55.6％(74/133)存在C-myc的获得,未见C-myc扩增及易位者.6/15 N-myc扩增者与57.6％(68/118) N-myc非扩增者,伴C-myc获得,两者的差异无统计学意义(P＞0.05).C-myc基因的单因素生存分析显示,C-myc获得者预后与C-myc正常者相比,差异无统计学意义(P=0.357).结论 我国儿童NT中N-myc扩增率较低,且仅存在于NB中；N-myc扩增者预后差；儿童NT中未检测到C-myc的扩增及易位,但C-myc获得较常见；N-myc扩增与C-myc获得之间无明显相关性.

abstractsObjective To investigate the molecular genetic abnormalities of N-myc and C-myc,and their clinical pathological implications in pediatric neuroblastic tumors (NTs).Methods Abnormalities of N-myc were detected by interphase fluorescence in situ hybridization (FISH) technique in 246 cases of NTs,including neuroblastoma (NB,188 cases),ganglioneuroblastoma (GNB,52 cases),ganglioneuroma (GN,6 cases),and their association with the histological typing of the tumors and prognosis was analyzed.Abnormalities of C-myc were detected by FISH in 133 cases of NTs.Results Of the 246 cases of NTs,N-myc amplification was only found in 27 cases (11.0％,27/246) of NB,but not in any cases of GNB or GN (P＜0.05).89.0％ (219/246) N-myc non-amplification were found in NTs,and it included N-myc gain in 175 cases (71.1％,175/246)and normal N-myc in 44 cases (17.9％,44/246).Univariate analysis indicated significantly (P =0.012) poorer outcome in patients with N-myc amplification than N-myc non-amplification.However no significant difference was observed between N-myc gain cases and normal N-myccases (P =0.057).C-myc gain was found in 74 of 133 cases (55.6％) of NTs; no C-myc amplification or translocation was detected.Forty percent (6/15) of cases with N-myc amplification and 57.6％ (68/118) of cases with N-myc non-amplification were accompanied by C-myc gain.The difference between N-myc amplification and non-amplification with C-myc gain was not significant (P ＞ 0.05).Univariate analysis indicated that the outcome difference was not statistically significant between C-myc gain cases and normal C-myc cases (P =0.357).Conclusions The incidence of N-myc amplification only found in NB is low in pediatric NTs in China.Patients with N-myc amplification predict poorer outcome.No amplification or translocation of C-myc is detected in NTs,whereas C-myc gain is relatively common in NTs.There is no obvious association between N-myc amplification and C-myc gain.