[Clinical analysis of adult Philadelphia chromosome-positive acute lymphoblastic leukemia with p16 gene deletion]

目的

探讨p16基因缺失在成人Ph染色体阳性急性淋巴细胞白血病（Ph⁺ ALL）中的临床意义。

方法

回顾性分析80例Ph⁺ALL伴p16基因缺失患者的临床特征、免疫表型、细胞遗传学、分子生物学改变及其预后。

结果

31.3% Ph⁺ALL患者合并p16基因缺失；p16基因缺失组与非缺失组相比，初诊时高白细胞计数（WBC≥30×10⁹/L）更常见，高表达CD20，更易出现附加染色体异常，其中以累及7、8、19号染色体以及der（22）较为常见；两组诱导缓解率比较差异无统计学意义（P=0.033），p16基因缺失组患者治疗3个疗程后获BCR-ABL融合基因主要分子学反应（MMR）率和完全分子学反应（CMR）率均明显低于非缺失组（P值分别为0.034和0.036），且复发率明显高于非缺失组（P=0.033）；p16基因缺失组使用伊马替尼联合化疗者和使用达沙替尼联合化疗者的MMR、CMR率及复发率差异均无统计学意义（P值均>0.05）；p16基因缺失组患者3年总体生存（OS）率及无病生存（DFS）率分别为37.1%和12.4%，显著低于非缺失组的54.1%和45.9%（P值分别为0.037和0.026）；25例p16基因缺失患者中14例行异基因造血干细胞移植（allo-HSCT），其中位OS时间为21个月，明显长于非移植组患者的12个月（P=0.030）。

结论

成人Ph⁺ALL伴p16基因缺失患者预后相对较差，二代酪氨酸激酶抑制剂不能明显改善其疗效，但allo-HSCT能够改善部分患者的生存，明确p16基因缺失状态对于评估预后和指导临床治疗有重要意义。

Primary malignant lymphoma of the brain: demonstration of frequent p16 and p15 gene deletions

The p16 (MTS-1) gene, a candidate tumor suppressor gene, was examined by means of Southern blot, PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) and nucleotide analyses in 5 cases of primary malignant lymphoma of the brain. By Southern blot analysis, the p16 gene was found to be deleted in at least 4 cases, homozygously (3 cases) or hemizygously (1 case). The p15 (MTS-2) gene, another candidate tumor suppressor gene located in the vicinity of the p16 gene, to which it shows structural and functional similarity, was also found to be deleted in 4 cases. Our frequent detection (80%) of p16 and p15 gene deletions might suggest that these deletions are closely related to carcinogenesis in primary malignant lymphoma of the brain. SSCP and nucleotide analyses revealed no mutations of the p16 gene in any of the cases.