Souza Gabriele Nunes, Kersting Nathália, Gonçalves Thomaz Abramsson, Pacheco Daphne Louise Oliveira, Saraiva-Pereira Maria-Luiza, Camey Suzi Alves, Saute Jonas Alex Morales, Jardim Laura Bannach
Programa de Pós-Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul, Brazil.
Escola de Enfermagem, Universidade Federal do Rio Grande do Sul, Brazil.
Cancer Genet. 2017 Apr;212-213:19-23. doi: 10.1016/j.cancergen.2017.03.008. Epub 2017 Mar 30.
Since polyglutamine diseases have been related to a reduced risk of cancer, we aimed to study the 15 years cumulative incidence of cancer (CIC) (arm 1) and the proportion of cancer as a cause of death (arm 2) in symptomatic carriers of spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD). SCA3/MJD and control individuals from our state were invited to participate. A structured interview was performed. CIC as published by the Brazilian National Institute of Cancer, was used as populational control. Causes of death were obtained from the Public Information System on Mortality. We interviewed 154 SCA3/MJD patients and 80 unrelated controls: CIC was 7/154 (4.5%) and 5/80 (6.3%), respectively. The interim analysis for futility showed that the number of individuals required to detect a significant difference between groups (1938) would be three times larger than the existing local SCA3/MJD population (625), for an absolute risk reduction of 1.8%. Then this study arm was discontinued due to lack of power. In the same period, cancer was a cause of death in 9/101 (8.9%) SCA3/MJD and in 52/202 (26.2%) controls, with an absolute reduction risk of 17.3% (OR 0.27, 95%CI 0.13 to 0.58, p = 0.01). A significant reduction of cancer as cause of death was observed in SCA3/MJD, suggesting a common effect to all polyglutamine diseases.
由于多聚谷氨酰胺疾病与癌症风险降低有关，我们旨在研究脊髓小脑共济失调3型/马查多-约瑟夫病（SCA3/MJD）有症状携带者的15年癌症累积发病率（CIC）（第1组）以及癌症作为死亡原因的比例（第2组）。邀请了来自我们所在州的SCA3/MJD患者和对照个体参与。进行了结构化访谈。巴西国家癌症研究所公布的CIC被用作总体对照。死亡原因来自公共死亡率信息系统。我们采访了154名SCA3/MJD患者和80名无关对照：CIC分别为7/154（4.5%）和5/80（6.3%）。无效性的中期分析表明，要检测出组间显著差异所需的个体数量（1938）将比现有的当地SCA3/MJD人群数量（625）大三倍，绝对风险降低1.8%。然后，由于缺乏检验效能，该研究组停止。同期，9/101（8.9%）的SCA3/MJD患者和52/202（26.2%）的对照个体死于癌症，绝对风险降低17.3%（OR 0.27，95%CI 0.13至0.58，p = 0.01）。在SCA3/MJD患者中观察到癌症作为死亡原因的显著减少，这表明对所有多聚谷氨酰胺疾病都有共同影响。
