Breivik J, Meling G I, Spurkland A, Rognum T O, Gaudernack G
Institute of Transplantation Immunology, National Hospital, University of Oslo, Norway.
Br J Cancer. 1994 Feb;69(2):367-71. doi: 10.1038/bjc.1994.67.
DNA from 251 primary tumours obtained from 123 male and 125 female Norwegian patients with colorectal carcinoma was analysed for the presence of K-ras point mutations at codons 12 and 13. Mutations were found in 99 (39%) of the samples. The frequency of K-ras mutations was significantly related to age and sex of the patients, and to the location of the tumours (overall: P = 0.008). K-ras mutations were much less frequent in colonic tumours from male than female patients at younger ages (< 40 years, odds ratio < 0.014). The low frequency might indicate that a different, ras-independent, pathway to neoplasia is dominating in the colon of younger males. In contrast, older men had more mutations than older women (e.g. 90 years, odds ratio = 5.8). An inverse but less pronounced relationship was seen for rectal tumours. The type of mutation was found to be associated to sex of patient and location of tumour. G-->C transversions accounted for 35% of the mutations in rectal tumours from females, in contrast to only 2.5% in the rest of the material (P = 0.0005). This may indicate that there are specific carcinogens acting in this location.
对来自123名男性和125名女性挪威结直肠癌患者的251份原发性肿瘤的DNA进行分析,以检测第12和13密码子处K-ras点突变的存在情况。在99份(39%)样本中发现了突变。K-ras突变的频率与患者的年龄、性别以及肿瘤的位置显著相关(总体:P = 0.008)。在年龄较小(<40岁)的男性患者的结肠肿瘤中,K-ras突变的频率远低于女性患者(优势比<0.014)。这种低频率可能表明在年轻男性的结肠中,一种不同的、不依赖于ras的肿瘤形成途径占主导地位。相比之下,老年男性的突变比老年女性更多(例如90岁时,优势比 = 5.8)。在直肠肿瘤中观察到一种相反但不太明显的关系。发现突变类型与患者性别和肿瘤位置有关。G→C颠换占女性直肠肿瘤突变的35%,而在其他样本中仅占2.5%(P = 0.0005)。这可能表明在这个部位有特定的致癌物起作用。