Mark H F, Brown S, Taylor W, Bassily N, Sun C L, Samy M, Bland K I
Lifespan Academic Medical Center Cytogenetics Laboratory, Rhode Island Hospital, Providence 02903, USA.
Cancer Genet Cytogenet. 1999 Jan 1;108(1):26-31. doi: 10.1016/s0165-4608(98)00104-6.
Trisomy 12 is the most frequent numerical chromosomal abnormality reported in chronic lymphocytic leukemia (CLL). Its significance in other cancers, however, has not been extensively investigated until recently. Less than 20 cases of polysomy for chromosome 12 have been studied thus far. The most recent data in the literature suggest that gain of chromosome 12 may be a recurrent and sometimes early event in breast carcinogenesis. To test the hypothesis that a subset of breast cancer may be characterized by chromosome 12 trisomy, we conducted a retrospective study of 40 specimens. Of these, ten were stage I, ten were stage II, ten were stage III, and ten were stage IV. Out of the total sample, 12 cases (30%) were found to be presumably trisomic, if a conservative cutoff point of greater than or equal to 15% cells with three signals is adopted. Furthermore, some, but not all, of the 12 cases were found to be likely triploid, when data from a control chromosome 17 probe were taken into account. Thus, our data support the hypothesis that a subset of breast cancer exists which is characterized by an abnormal copy of chromosome 12, in either a diploid or a triploid background.
12号染色体三体是慢性淋巴细胞白血病（CLL）中报道的最常见的染色体数目异常。然而，直到最近，其在其他癌症中的意义尚未得到广泛研究。迄今为止，仅有不到20例12号染色体多体的病例被研究。文献中的最新数据表明，12号染色体的增加可能是乳腺癌发生过程中的一个反复出现且有时较早出现的事件。为了验证一部分乳腺癌可能以12号染色体三体为特征这一假设，我们对40个标本进行了一项回顾性研究。其中，10个为I期，10个为II期，10个为III期，10个为IV期。在整个样本中，如果采用大于或等于15%的细胞具有三个信号这一保守的截断点，有12例（30%）被发现可能为三体。此外，当考虑来自对照17号染色体探针的数据时，12例中的部分（但不是全部）病例被发现可能为三倍体。因此，我们的数据支持这样一种假设，即存在一部分乳腺癌，其特征是在二倍体或三倍体背景下12号染色体的拷贝异常。
