Molecular Characteristics of Cohorts Relative to Presence or Not of Chromosomal Instability (CIN).

CIN+ was indicated by the presence of LOH. This was scored for overall CIN+ if a cancer had 1 of the 12 markers showing greater than 40% loss in intensity of one allele compared to its paired normal. CIN- was assigned if 40% (5 of 12) markers were informative and none of these showed LOH. For individual regions, CIN+ was scored if 1 marker showed LOH, and CIN- if 2of the 3 markers were informative and neither had LOH. CIMP high was scored if 3 of the 5 markers were positive for methylation.*CIN and corresponding p53 mutational status was analysed using CIN data at the 5q, 8p and 18q loci only.

染色体不稳定性阳性（CIN+）以杂合性丢失（LOH）的存在作为判定依据。若某一癌症的12个检测标记物中，有1个标记物的某一等位基因强度较其配对正常组织降低超过40%，则将该癌症整体判定为CIN+。若40%的标记物（即12个标记物中的5个）可提供有效信息，且其中未出现LOH，则将该癌症判定为染色体不稳定性阴性（CIN-）。针对单个区域而言，若存在1个标记物出现LOH，则判定为CIN+；若3个标记物中有2个可提供有效信息，且二者均未出现LOH，则判定为CIN-。若5个标记物中有3个呈现甲基化阳性，则判定为高CpG岛甲基化表型（CIMP-high）。* 本研究仅采用5q、8p及18q染色体位点的CIN数据，对染色体不稳定性（CIN）及其对应的p53突变状态进行分析。