生物谷报道：一项新的研究发现，一种基因突变能够急剧改变前列腺癌患者的存活几率。携带BRCA2基因的一种突变形式的男性可能更易患上这种类型的癌症，其发病时间要比携带最常见的该基因版本的人早10年。这项研究的结果公布在近期的Journal of the National Cancer Institute杂志上。
专家表示，筛查BRCA2基因突变可能有助于改善前列腺肿瘤治疗的结果。人们对BRCA2的认识可以追随到1995年。当时，研究人员首次确定处这种基因并开始了解它对乳腺癌的影响。携带BRCA2或BRCA1基因突变的女性，其患乳腺癌的风险增加了七倍。
近年来，研究人员开始逐渐了解BRCA2突变如何影响男性健康。大量研究发现携带BRCA2特定变异体的男性，其患上前列腺癌的风险翻倍，并且患上胰腺癌的风险比携带正常基因版本的人高出6倍。
冰岛的Laufey Tryggvadóttir 博士和她的同事决定分析BRCA2突变对已经患上的前列腺癌病情恶化情况的影响。她解释说，目前面临的一个最大的挑战就是区分致死性前列腺癌和无害形式。
该研究组找到527名患者的前列腺癌活组织切片，并分析了这些样本的DNA。他们发现其中三十个男性显示出了BRCA2突变（即999del5）阳性。而且，携带这种突变的男性在癌症确诊后的平均存活时间为2.1年——比携带该基因正常版本的前列腺癌患者存活时间少了十年左右！
这项新研究显示，携带这种基因突变的人被确诊的年龄平均为69岁，比不携带这种突变的人早了5年。
原始出处:
Journal of the National Cancer Institute Advance Access published online on June 12, 2007
JNCI Journal of the National Cancer Institute, doi:10.1093/jnci/djm005
ARTICLES
Prostate Cancer Progression and Survival in BRCA2 Mutation Carriers
Laufey Tryggvadóttir, Linda Vidarsdóttir, Tryggvi Thorgeirsson, Jon Gunnlaugur Jonasson, Elinborg Jona Ólafsdóttir, Gudridur Helga Ólafsdóttir, Thorunn Rafnar, Steinunn Thorlacius, Eirikur Jonsson, Jorunn Erla Eyfjord, Hrafn Tulinius
Affiliations of authors: Icelandic Cancer Registry, Reykjavik, Iceland (LT, JGJ, EJO, GHO, HT); Molecular and Cell Biology Laboratory, University of Iceland and the Icelandic Cancer Society, Reykjavik, Iceland (LV, JEE); Department of Medicine, University of Iceland, Reykjavik, Iceland (LT, LV, TT, JGJ, JEE); Iceland Genomics Corporation, Reykjavik, Iceland (TR, ST); Department of Urology, Landspitali University Hospital, Reykjavik, Iceland (EJ)
Correspondence to: Laufey Tryggvadóttir, MSc, Icelandic Cancer Registry, Skógarhlíð 8, PO Box 5420, Iceland (e-mail: laufeyt@krabb.is ).
Background: Mutations in the BRCA2 gene are associated with an increased risk of prostate cancer, but it is not known whether they are associated with progression of the disease. We compared prostate cancer–specific survival, disease stage, and tumor grade between prostate cancer patients carrying the Icelandic BRCA2 999del5 founder mutation and noncarriers.
Methods: Using population-based registries, we identified all 596 prostate cancer patients who were diagnosed in Iceland during 1955 through 2004 among 29603 male relatives of unselected breast cancer probands. BRCA2 mutation status could be determined for 527 patients (88.4%). Stage and grade were abstracted from original records, blindly with respect to mutation status, for a subgroup of 89 patients that included all mutation carriers and, for each carrier, two control patients without the BRCA2 999del5 mutation who were matched to the carrier on years of diagnosis and birth. Hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer–specific survival were estimated using multivariable regression models. All statistical tests were two-sided.
