American Journal of Hematology ( IF 10.1 ) Pub Date : 2024-10-11 , DOI: 10.1002/ajh.27497 Yiannis Petros Dimopoulos, Wei Wang, Sa A. Wang, Sanam Loghavi, Courtney D. DiNardo, Yoheved Gerstein, Shimin Hu, Zhenya Tang, Charmaine Joyce Lim Ilagan, Beenu Thakral, Siba El Hussein, Jie Xu, Shaoying Li, Pei Lin, Keyur P. Patel, Chi Young Ok, L. Jeffrey Medeiros, Hong Fang
Li-Fraumeni syndrome (LFS) is a rare inherited disorder associated with germline pathogenic TP53 variants. The absence of the functional gene product, p53 protein, results in failure to activate programmed cell death in the appropriate context and leads to uncontrolled cell proliferation. LFS patients present with a high incidence of various malignancies, often at young ages. In contrast to the high occurrence rate of solid tumors, hematologic neoplasms in LFS patients are relatively rare and not systemically described. A few previous studies showed that leukemias developed in about 2%–4% of LFS patients, whereas lymphomas are less frequent, seen in approximately 2% of LFS patients.1-3
This study explored the clinicopathologic spectrum of hematologic neoplasms in LFS patients. Eighteen patients with a well-established clinical diagnosis of LFS and confirmatory TP53 genetic testing as well as a hematologic neoplasm were included, spanning the time interval from 1/1/2000 through 8/5/2023. Their LFS diagnosis was further confirmed by our LFS Progeny Database and/or Clinical Cancer Genetics (CCG) team that runs the LFS program in our institution. Four previously reported patients (cases #1, 2, 6, 7 in that cohort)4 were included in this study. To the best of our knowledge, this is the largest cohort described to date.
The cohort included 12 (67%) women and 6 (33%) men. Their clinical history and hematologic diagnoses are presented in Table 1. All patients had a confirmed germline pathogenic variant of TP53 at MD Anderson Cancer Center and/or an outside institution, although the detailed nomenclature of TP53 germline mutation in 4 patients (cases #1, 8, 14, 18) tested at an outside institution was not available. All 18 patients had an extensive family history of malignancies (Supplementary Table 1). Seventeen (94%) patients had other malignant or pre-malignant neoplasms in additional to hematologic malignancy; 7 (39%) patients had one neoplasm and 10 (56%) patients had ≥2 neoplasms. The most common non-hematologic malignancies were breast cancer (9/18, 50%), sarcoma (8/18, 44%), and gastrointestinal tumors (5/18, 28%). The only patient without any other neoplasm (case #18) was diagnosed with B-lymphoblastic leukemia/lymphoma (B-ALL/LBL) at the age of 11 years and died 4 years later.
Case number | Sex | Germline TP53 mutation | Age at diagnosis of first neoplasm | Treatment of non-hematologic neoplasm | History of cytotoxic exposure prior to development of hematologic neoplasm | Latency between cytotoxic exposure and hematologic neoplasm (months) | Original hematologic diagnosis | Age at diagnosis of hematologic neoplasm | Ch17 alterations by conventional cytogenetics | TP53 FISH or aCGH | TP53 mutation(s) by NGS | Variant allele frequency | Presumed biallelic TP53? | Subsequent second hematologic neoplasm | Interval between original and subsequent hematologic neoplasm (months) |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | F | N/Aa | 43 | Surgery | No | — | MDS | 52 | No | Not performed | c.412G>C p.A138Pb | 7.8 | N/A | AML | 14 |
2 | F | c.626_627del p.R209fs | 16 | Chemotherapy | Yes | 78 | MDS | 22 | Yes | Not performed | c.626_627del p.R209fs (germline) | N/A | Yes | — | — |
3 | M | c.743G>A p.R248Q | 25 | Chemotherapy | Yes | 3 | MDS | 25 | Yes | Monosomy 17 | c.743G>A p.R248Q (germline) | 77 | Yes | — | — |
4 | F | c.733G>A p.G245S | 40 | Chemotherapy, surgery, radiation | Yes | 163 | MDS | 73 | Yes | Negative | c.733G>A p.G245S (germline); c.681del p.D228fs (somatic) | 60; <5 | Yes | — | — |
5 | M | c.524G>A p.R175H | 24 | Surgery | No | — | T-ALL/LBL | 24 | Yes | Loss of one TP53 | c.524G>A p.R175H (germline) | 25 | Yes | — | — |
6 | F | c.844C>T p.R282W | 49 | Chemotherapy, herceptin | Yes | 100 | MDS | 57 | No | Monosomy 17 | c.844C>T p.R282W (germline) | 91.7 | Yes | — | — |
7 | F | c.325T>G p.F109V | 34 | None | No | — | B-ALL/LBL | 34 | Yes | Monosomy 17 | c.325T>G p.F109V (germline) | 68.3 | Yes | — | — |
8 | M | N/Aa | 11 | Chemotherapy, IFN-gamma | Yes | 49 | MDS | 15 | No | Loss of one TP53 | c.324_328delinsAAA p.F109fsb | 25.5 | Yes | MS/AML | 3 |
9 | F | c.184G>T p.E62a | 36 | Chemotherapy | Yes | 27 | MDS | 38 | No | Not performed | c.184G>T p.E62a (germline); c.764T>C p.I255T (somatic) | 51.3; 31.3 | Yes | — | — |
10 | F | c.448_460del p.T150fs | 26 | Chemotherapy, radiation | Yes | 183 | MDS | 41 | Yes | Negative | c.448_460del p.T150fs (germline); c.726C>A p.C242a (somatic) | 39.9; 44.1 | Yes | AML | 11 |
11 | F | c.374C>T p.T125M | 54 | Surgery, hormonal | No | — | MPN | 60 | No | Not performed | c.374C>T p.T125M (germline) | 42.2 | N/A | — | — |
12 | F | c.659A>G p.Y220C | 34 | Chemotherapy, surgery, radiation | Yes | 197 | MDS | 50 | No | Loss of one TP53 | c.659A>G p.Y220C (germline) | 63.7 | Yes | AML | 15 |
13 | M | c.733G>A p.G245S | 41 | Surgery | No | — | PCN | 41 | No | Negative | c.733G>A p.G245S (germline) | 93.7 | Yes | — | — |
14 | F | N/Aa | 1 | Chemotherapy | Yes | N/A | MDS | 47 | No | Not performed | c.552del p.D184fsb | 85 | Yes | AML | 8 |
15 | F | c.743G>A p.R248Q | 30 | Chemotherapy, surgery, radiation | Yes | 240 | AML | 49 | No | Not performed | c.743G>A p.R248Q (germline) | 68.9 | Yes | — | — |
16 | F | Large deletion involving exons 10–11 | 30 | Chemotherapy, surgery, radiation | Yes | 121 | AML | 40 | Yes | Not performed | Nonec | — | Yes | — | — |
17 | M | c.743G>A p.R248Q | 46 | Surgery | No | — | PCN | 46 | No | Trisomy 17, negative for loss of TP53 | c.743G>A p.R248Q (germline) | 52.6 | No | — | — |
18 | M | N/Aa | 11 | Not applicable | No | — | B-ALL/LBL | 11 | Yes | Not performed | N/Ab | N/A | N/A | MDS | 43 |
- Abbreviations: AML, acute myeloid leukemia; B-ALL/LBL, B-lymphoblastic leukemia/lymphoma; MDS, myelodysplastic syndrome; MPN, myeloproliferative neoplasm; MS, myeloid sarcoma; N/A, not available; PCN, plasma cell neoplasm; T-ALL/LBL, T-lymphoblastic leukemia/lymphoma.
- a These patients had an outside confirmatory germline TP53 mutation but the detailed nomenclature was not available.
- b Outside confirmed TP53 germline mutations but without detailed nomenclature.
- c Confirmed germline mutation (large deletion involving exons 10–11), not detectable by NGS.
The median age at diagnosis of the first malignancy was 32 years (range, 1–54 years) and the median age at diagnosis of hematologic neoplasm was 41 years (range, 11–73 years). The initial presenting hematologic neoplasms included myelodysplastic syndrome (MDS) (n = 10, 56%), “de novo” acute myeloid leukemia (AML) developing in patients without a prior history of MDS or other hematologic neoplasms (n = 2, 11%), B-ALL/LBL (n = 2, 11%), plasma cell neoplasms (PCN) (n = 2, 11%), T-lymphoblastic leukemia/lymphoma (T-ALL/LBL) (n = 1, 6%), and myeloproliferative neoplasm (MPN) (n = 1, 6%). Fifteen (83%) hematologic neoplasms occurred after the diagnosis of other tumors. In the remaining 3 patients, 1 T-ALL/LBL (case #5) was diagnosed with a synchronous astrocytoma, 1 B-ALL/LBL (case #7) was followed by high grade dysplasia in a gastric adenoma, and another B-ALL/LBL (case #18) was diagnosed in a 11-year-old patient without any other malignancies.
At initial presentation of hematologic neoplasm, 11 (61%) patients had a history of exposure to chemotherapy or radiation therapy (“cytotoxic exposure”) for other tumors. This exposure occurred with a median interval of 111 months (range: 3–240 months) prior to the diagnosis of the hematologic neoplasm. All these 11 patients presented with a myeloid neoplasm, including 9 MDS and 2 “de novo” AML. Among 9 MDS cases, 4 developed secondary AML with a median interval of 9.5 months (range, 3–15 months). The 7 patients without a history of cytotoxic exposure included 1 MDS, 1 T-ALL/LBL, 2 B-ALL/LBL, 1 MPN, and 2 PCN. Among this group, 1 patient (case #18) presented initially with B-ALL/LBL, was treated with chemoradiation and developed MDS 43 months later.
Cytogenetic findings from bone marrow aspirate samples are summarized in Table 1 (detailed karyotype in Supplementary Table 2). Conventional cytogenetic analysis showed a complex karyotype in all MDS (n = 10), AML (n = 2) and T-ALL/LBL (n = 1) cases. The 2 B-ALL/LBL cases had a hypodiploid (case #18) and a possible hypodiploid (case #7) karyotype, respectively. The remaining 3 cases (1 MPN and 2 PCN) showed a normal karyotype. By conventional cytogenetic analysis, chromosome 17 alterations were seen in 4 MDS, 2 B-ALL/LBL, 1 AML, and 1 T-ALL/LBL cases. Fluorescence in situ hybridization (FISH) or microarray-based comparative genomic hybridization (aCGH) results were available for 10 neoplasms, showing monosomy 17 and/or loss of one TP53 allele in 6 neoplasms. Incorporating conventional cytogenetic and FISH/aCGH data, 9 patients had TP53 deletion at cytogenetic level (monosomy 17 or loss of TP53 signal).
Targeted next generation sequencing (NGS) data from bone marrow aspirate samples were available for 17 cases (Table 1). Three patients showed an additional somatic TP53 mutation besides the germline TP53 mutation (cases #4, 9, 10). Of the 14 patients with detailed information on germline TP53 variants, 10 (71%) germline mutations occurred in the DNA binding domain (exons 5–8), including 2 in exon 5, 2 in exon 6, 5 in exon 7, and 1 in exon 8. The remaining 4 germline mutations included 3 in exon 4 and 1 involving exons 10 and 11. Missense mutations were most common (n = 10, 71%), followed by frameshift (n = 3, 21%) and nonsense (n = 1, 7%). Among the missense mutations, TP53 p.R248Q was most common, detected in 3 patients (cases #3, 15, 17). Of the 4 patients without a detailed germline TP53 mutational profile, 3 (cases #1, 8, 14) had a TP53 mutation (possibly germline) detected by NGS. The remaining 1 case (#18) did not have material to perform the analysis.
In the newly published WHO and ICC classifications of myeloid neoplasms, great emphasis was placed on TP53 status, with a separate category of MDS/AML proposed to include cases with biallelic alterations of TP53. Integrating cytogenetic and molecular data, 14 cases in this cohort demonstrated a presumed biallelic TP53 alteration (Table 1) based on a high variant allele frequency of the mutant TP53 (cases #3, 6, 7, 13, 14, 15), two separate TP53 mutations (cases #4, 9, 10), or a TP53 mutation paired with a cytogenetic alteration involving the TP53 locus at chromosome 17p (cases #2, 3, 4, 5, 6, 7, 8, 10, 12, and 16). In the remaining 4 cases, 3 did not have FISH study performed for evaluation of TP53 deletion status, thus their biallelic TP53 status is uncertain. The remaining one case (#17) showed no TP53 deletion by FISH, arguing against biallelic TP53 alteration.
The treatment regimens and survival data for the hematologic neoplasms are summarized in Supplementary Table 3. Nine patients underwent stem cell transplant (SCT), including 5 MDS, 1 AML, 2 B-ALL/LBL, and 1 T-ALL/LBL. At the time of last clinical follow up, 9 (50%) patients died, including 5 MDS, 2 AML, 1 T-ALL/LBL, and 1 B-ALL/LBL. The median overall survival (OS) time from the diagnosis of the first malignancy was 198.0 months and the median OS from the diagnosis of the hematologic neoplasm was 28.8 months. To explore the prognosis of patients with MDS or AML, we compared the OS of these patients with TCGA cohort of AML patients stratified by using the European LeukemiaNet standardized system for cytogenetic risk.5 Only patients younger than 55 years were included to achieve a group of similar median age to this cohort. The analyses showed that the MDS/AML patients in this cohort showed a poorer OS than the TCGA AML patients with favorable cytogenetic risk (median, 19.7 months vs. not reached, p = .0002) and a similar OS to TCGA AML patients with intermediate cytogenetic risk (median, 19.7 vs. 27.0 months, p = .89) and those with unfavorable cytogenetic risk (median, 19.7 vs. 12.2 months, p = .60).
In contrast to previous studies which showed that hematologic neoplasms in LFS patients mainly occurred in children with B-ALL/LBL being the most common,2 the majority of our cohort had myeloid neoplasms (MDS or AML) with a median age of 41 years. These discrepancies are potentially due to selection bias, as our institution is a tertiary referral cancer hospital with a predominant patient population of adults.
Both B-ALL/LBL patients in our cohort exhibited a low hypodiploid or pseudo-hyperdiploid karyotype, highlighting the association of a hypodiploid karyotype in B-ALL/LBL and alterations in TP53. This association is particularly notable for low hypodiploid B-ALL/LBL in children in up to 50% of whom with this karyotype are found to have LFS.6
In our cohort, 11 (61%) patients had a history of cytotoxic exposure, and all developed MDS/AML. Only one MDS patient (case #1) had no history of cytotoxic therapy. These findings highlight the strong association between exposure to cytotoxic treatment and subsequent development of MDS/AML. These findings have clinical implications regarding the follow-up of LFS patients receiving cytotoxic therapy, given the high risk of transformation to aggressive leukemia and poor prognosis.
In summary, in this largest cohort of predominantly adult LFS patients with hematologic neoplasms, MDS and AML were most common, frequently associated with a prior non-hematologic malignancy, a history of cytotoxic exposure, complex karyotype, and poor prognosis. Missense mutation was the most observed TP53 germline mutation, followed by frameshift mutation. Many of the myeloid neoplasms would fall into the category of neoplasms with biallelic TP53 alterations, additionally supporting the aggressive nature of these neoplasms seen in LFS patients.
中文翻译:
Li-Fraumeni 综合征患者血液系统肿瘤谱
Li-Fraumeni 综合征 (LFS) 是一种罕见的遗传性疾病,与种系致病性 TP53 变异相关。功能性基因产物 p53 蛋白的缺失导致无法在适当的环境中激活程序性细胞死亡,并导致细胞增殖不受控制。LFS 患者各种恶性肿瘤的发病率很高,通常年轻时。与实体瘤的高发生率相比,LFS 患者的血液系统肿瘤相对罕见,并且没有系统描述。以前的一些研究表明,大约 2%-4% 的 LFS 患者患白血病,而淋巴瘤不太常见,大约有 2% 的 LFS 患者出现。1-3
本研究探讨了 LFS 患者血液系统肿瘤的临床病理谱。纳入了 18 名临床诊断为 LFS 和确诊性 TP53 基因检测以及血液系统肿瘤的患者,时间跨度从 2000 年 1 月 1 日到 2023 年 8 月 5 日。他们的 LFS 诊断得到了我们的 LFS 后代数据库和/或在我们机构运行 LFS 计划的临床癌症遗传学 (CCG) 团队的进一步确认。本研究包括 4 名先前报告的患者(该队列中的病例 #1、2、6、7)4。据我们所知,这是迄今为止描述的最大队列。
该队列包括 12 名 (67%) 女性和 6 名 (33%) 男性。他们的临床病史和血液学诊断见 表 1。所有患者在 MD 安德森癌症中心和/或外部机构均已确认 TP53 种系致病性变异,尽管在外部机构检测的 4 例患者 (病例 #1 、 8 、 14 、 18) 的 TP53 种系突变的详细命名不可用。所有 18 例患者都有广泛的恶性肿瘤家族史 (补充表 1)。17 例 (94%) 患者除血液系统恶性肿瘤外,还患有其他恶性或癌前肿瘤;7 例 (39%) 患者有 1 个肿瘤,10 例 (56%) 患者有 ≥2 个肿瘤。最常见的非血液系统恶性肿瘤是乳腺癌 (9/18, 50%) 、肉瘤 (8/18, 44%) 和胃肠道肿瘤 (5/18, 28%)。唯一没有任何其他肿瘤的患者 (病例 #18) 在 11 岁时被诊断出患有 B 淋巴细胞白血病/淋巴瘤 (B-ALL/LBL),并在 4 年后死亡。
案例编号 | 性 | 种系 TP53 突变 |
诊断为首次肿瘤的年龄 |
非血液系统肿瘤的治疗 |
血液系统肿瘤发展前的细胞毒暴露史 |
细胞毒性暴露与血液系统肿瘤之间的潜伏期(月) |
原始血液学诊断 |
诊断为血液系统肿瘤的年龄 |
常规细胞遗传学的 Ch17 改变 |
TP53 系列FISH 或 aCGH |
NGS 的 TP53 突变 |
变异等位基因频率 | 推测的双等位基因 TP53? | 随后的第二血液系统肿瘤 |
原始血液肿瘤和后续血液系统肿瘤之间的间隔(月) |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | F | 不适用a | 43 | 手术 | 不 | — | MDS | 52 | 不 | 未执行 | c.412G>C p.A138Pb | 7.8 | 不适用 | AML | 14 |
2 | F | c.626_627del p.R209fs | 16 | 化学疗法 | 是的 | 78 | MDS | 22 | 是的 | 未执行 | c.626_627del p.R209fs (种系) |
不适用 | 是的 | — | — |
3 | M | c.743G>A p.R248Q | 25 | 化学疗法 | 是的 | 3 | MDS | 25 | 是的 | 17 号单体 | c.743G>A p.R248Q (种系) |
77 | 是的 | — | — |
4 | F | c.733G>A p.G245S | 40 | 化疗、手术、放疗 |
是的 | 163 | MDS | 73 | 是的 | 阴性 | c.733G>A p.G245S(种系);c.681del p.D228fs (体细胞) |
60;<5 | 是的 | — | — |
5 | M | c.524G>A p.R175H | 24 | 手术 | 不 | — | T-ALL/LBL | 24 | 是的 | 损失 1 个 TP53 |
c.524G>A p.R175H (种系) |
25 | 是的 | — | — |
6 | F | c.844C>T p.R282W | 49 | 化疗、赫赛汀 | 是的 | 100 | MDS | 57 | 不 | 17 号单体 | c.844C>T p.R282W (种系) |
91.7 | 是的 | — | — |
7 | F | c.325T>G p.F109V | 34 | 没有 | 不 | — | B-全部/LBL | 34 | 是的 | 17 号单体 | c.325T>G p.F109V (种系) |
68.3 | 是的 | — | — |
8 | M | 不适用a | 11 | 化疗、IFN-γ | 是的 | 49 | MDS | 15 | 不 | 损失 1 个 TP53 |
c.324_328delinsAAA p.F109fsb | 25.5 | 是的 | 多发性硬化症/急性髓系 AML | 3 |
9 | F | c.184G>T p.E62a | 36 | 化学疗法 | 是的 | 27 | MDS | 38 | 不 | 未执行 | c.184G>T p.E62a(种系); c.764T>C p.I255T (体细胞) |
51.3; 31.3 | 是的 | — | — |
10 | F | c.448_460del p.T150fs | 26 | 化疗、放疗 | 是的 | 183 | MDS | 41 | 是的 | 阴性 | c.448_460del p.T150fs (种系);c.726C>A p.C242a (体细胞) |
39.9; 44.1 | 是的 | AML | 11 |
11 | F | c.374C>T p.T125M | 54 | 手术、激素 | 不 | — | MPN | 60 | 不 | 未执行 | c.374C>T p.T125M (种系) |
42.2 | 不适用 | — | — |
12 | F | c.659A>G p.Y220C | 34 | 化疗、手术、放疗 |
是的 | 197 | MDS | 50 | 不 | 损失 1 个 TP53 |
c.659A>G p.Y220C (种系) |
63.7 | 是的 | AML | 15 |
13 | M | c.733G>A p.G245S | 41 | 手术 | 不 | — | PCN | 41 | 不 | 阴性 | c.733G>A p.G245S (种系) |
93.7 | 是的 | — | — |
14 | F | 不适用a | 1 | 化学疗法 | 是的 | 不适用 | MDS | 47 | 不 | 未执行 | c.552del p.D184fsb | 85 | 是的 | AML | 8 |
15 | F | c.743G>A p.R248Q | 30 | 化疗、手术、放疗 |
是的 | 240 | AML | 49 | 不 | 未执行 | c.743G>A p.R248Q (种系) |
68.9 | 是的 | — | — |
16 | F | 涉及外显子 10-11 的大缺失 |
30 | 化疗、手术、放疗 |
是的 | 121 | AML | 40 | 是的 | 未执行 | 无c | — | 是的 | — | — |
17 | M | c.743G>A p.R248Q | 46 | 手术 | 不 | — | PCN | 46 | 不 | 17 三体,TP53 缺失阴性 |
c.743G>A p.R248Q (种系) |
52.6 | 不 | — | — |
18 | M | 不适用a | 11 | 不適用 | 不 | — | B-全部/LBL | 11 | 是的 | 未执行 | 不适用b | 不适用 | 不适用 | MDS | 43 |
缩写:AML,急性髓性白血病;B-ALL/LBL、B-淋巴细胞白血病/淋巴瘤;MDS,骨髓增生异常综合征;MPN,骨髓增生性肿瘤;MS,髓系肉瘤;N/A, 不可用;PCN,浆细胞肿瘤;T-ALL/LBL,T 淋巴细胞白血病/淋巴瘤。
a 这些患者具有外部确认性种系 TP53 突变,但无法获得详细的命名法。
b 外部确认的 TP53 种系突变,但没有详细的命名法。
c 确认的种系突变(涉及外显子 10-11 的大缺失),NGS 无法检测到。
首次恶性肿瘤诊断的中位年龄为 32 岁 (范围,1-54 岁),血液系统肿瘤诊断的中位年龄为 41 岁 (范围,11-73 岁)。最初表现的血液系统肿瘤包括骨髓增生异常综合征 (MDS) (n = 10, 56%)、无 MDS 或其他血液系统肿瘤既往病史的患者发生的“新发”急性髓系白血病 (AML) (n = 2, 11%)、B-ALL/LBL (n = 2, 11%)、浆细胞肿瘤 (PCN) (n = 2, 11%)、T 淋巴细胞白血病/淋巴瘤 (T-ALL/LBL) (n = 1, 6%) 和骨髓增生性肿瘤 (MPN) (n = 1, 6%) (n= 1, 6%)。15 例 (83%) 血液系统肿瘤发生在诊断其他肿瘤之后。在其余 3 名患者中,1 例 T-ALL/LBL(病例 #5)被诊断为同步星形细胞瘤,1 例 B-ALL/LBL(病例 #7)随后出现胃腺瘤高度异型增生,另一例 B-ALL/LBL(病例 #18)诊断为一名 11 岁患者,无任何其他恶性肿瘤。
在血液系统肿瘤的初次表现中,11 例 (61%) 患者有其他肿瘤的化疗或放疗暴露史(“细胞毒性暴露”)。这种暴露发生在血液系统肿瘤诊断之前的中位间隔为 111 个月(范围:3-240 个月)。所有这 11 例患者均表现为髓系肿瘤,包括 9 例 MDS 和 2 例“新发”AML。在 9 例 MDS 病例中,4 例发展为继发性 AML,中位间隔为 9.5 个月 (范围,3-15 个月)。7 例无细胞毒性暴露史的患者包括 1 例 MDS 、 1 例 T-ALL/LBL 、 2 例 B-ALL/LBL 、 1 例 MPN 和 2 例 PCN。在该组中,1 例患者 (病例 #18) 最初表现为 B-ALL/LBL,接受放化疗,43 个月后发展为 MDS。
骨髓穿刺物样本的细胞遗传学结果总结于表 1 中(详细核型见补充表 2)。常规细胞遗传学分析显示,所有 MDS (n = 10) 、 AML (n = 2) 和 T-ALL/LBL (n = 1) 病例均具有复杂的核型。2 例 B-ALL/LBL 病例分别具有亚二倍体 (病例 #18) 和可能的亚二倍体 (病例 #7) 核型。其余 3 例 (1 例 MPN 和 2 例 PCN) 显示正常核型。通过常规细胞遗传学分析,在 4 例 MDS 、 2 例 B-ALL/LBL 、 1 例 AML 和 1 例 T-ALL/LBL 病例中观察到 17 号染色体改变。10 个肿瘤的荧光原位杂交 (FISH) 或基于微阵列的比较基因组杂交 (aCGH) 结果可用,显示 6 个肿瘤中单体 17 和/或一个 TP53 等位基因缺失。结合常规细胞遗传学和 FISH/aCGH 数据,9 例患者在细胞遗传学水平上存在 TP53 缺失 (17 单体或 TP53 信号丢失)。
来自 17 例骨髓抽吸物样本的靶向下一代测序 (NGS) 数据可用(表 1)。除了种系 TP53 突变外,3 名患者还显示额外的体细胞 TP53 突变(病例 #4、9、10)。在了解种系 TP53 变体详细信息的 14 例患者中,10 例 (71%) 种系突变发生在 DNA 结合域(外显子 5-8),其中外显子 5 例 2 例,外显子 6 例 2 例,外显子 7 例 5 例,外显子 8 例 1 例。其余 4 个种系突变包括 3 个外显子 4 和 1 个涉及外显子 10 和 11。错义突变最常见 (n = 10, 71%),其次是移码 (n = 3, 21%) 和无义 (n = 1, 7%)。在错义突变中,TP53 p.R248Q 最常见,在 3 例患者 (病例 #3 、 15 、 17) 中检测到。在没有详细种系 TP53 突变谱的 4 例患者中,3 例 (病例 #1 、 8 、 14) 通过 NGS 检测到 TP53 突变 (可能是种系)。其余 1 个案例 (#18) 没有进行分析的材料。
在新发布的 WHO 和 ICC 髓系肿瘤分类中,非常重视 TP53 状态,并提出了一个单独的 MDS/AML 类别,以包括 TP53 双等位基因改变的病例。整合细胞遗传学和分子数据,该队列中的 14 例表现出基于突变 TP53 的高变异等位基因频率(病例 #3、6、7、13、14、15)、两个独立的 TP53 突变(病例 #4、9、10)或 TP53 突变与涉及 TP53 的细胞遗传学改变配对的推测双等位基因 TP53 改变(表 1)染色体 17p 位点(病例 #2、3、4、5、6、7、8、10、12 和 16)。在其余 4 例中,3 例未进行 FISH 研究以评估 TP53 缺失状态,因此他们的双等位基因 TP53 状态不确定。其余一个案例 (#17) 显示 FISH 没有 TP53 缺失,反对双等位基因 TP53 改变。
血液系统肿瘤的治疗方案和生存数据总结在补充表 3 中。9 例患者接受了干细胞移植 (SCT),包括 5 例 MDS、1 例 AML、2 例 B-ALL/LBL 和 1 例 T-ALL/LBL。在最后一次临床随访时,9 例 (50%) 患者死亡,包括 5 例 MDS、2 例 AML、1 例 T-ALL/LBL 和 1 例 B-ALL/LBL。诊断为首次恶性肿瘤的中位总生存期 (OS) 为 198.0 个月,诊断为血液系统肿瘤的中位 OS 为 28.8 个月。为了探讨 MDS 或 AML 患者的预后,我们将这些患者的 OS 与使用欧洲 LeukemiaNet 细胞遗传学风险标准化系统分层的 AML 患者的 TCGA 队列进行了比较。5 仅纳入 55 岁以下的患者,以达到与该队列相似的中位年龄组。分析显示,该队列中的 MDS/AML 患者的 OS 比具有良好细胞遗传学风险的 TCGA AML 患者差(中位数,19.7 个月与未达到,p = .0002),并且与具有中等细胞遗传学风险的 TCGA AML 患者相似(中位数,19.7 个月对 27.0 个月,p = .89)和具有不良细胞遗传学风险的患者(中位数, 19.7 个月对 12.2 个月,p = .60)。
与先前的研究表明 LFS 患者的血液系统肿瘤主要发生在 B-ALL/LBL 最常见的儿童中相比,2 我们队列中的大多数患有髓系肿瘤(MDS 或 AML),中位年龄为 41 岁。这些差异可能是由于选择偏倚造成的,因为我们机构是一家三级转诊癌症医院,患者群体主要是成人。
我们队列中的 B-ALL/LBL 患者均表现出低亚二倍体或假高二倍体核型,突出了 B-ALL/LBL 中亚二倍体核型与 TP53 改变的关联。这种关联对于儿童中的低亚二倍体 B-ALL/LBL 尤其明显,其中高达 50% 的具有这种核型的人被发现患有 LFS。6
在我们的队列中,11 例 (61%) 患者有细胞毒暴露史,并且都发生了 MDS/AML。只有一名 MDS 患者 (病例 #1) 没有细胞毒性治疗史。这些发现强调了暴露于细胞毒性治疗与随后发生 MDS/AML 之间的密切关联。鉴于转化为侵袭性白血病的高风险和不良预后,这些发现对接受细胞毒治疗的 LFS 患者的随访具有临床意义。
总之,在这个最大的以成人为主的血液系统肿瘤 LFS 患者队列中,MDS 和 AML 最常见,通常与既往非血液系统恶性肿瘤、细胞毒性暴露史、复杂核型和不良预后有关。错义突变是观察到最多的 TP53 种系突变,其次是移码突变。许多髓系肿瘤属于具有双等位基因 TP53 改变的肿瘤类别,此外还支持在 LFS 患者中看到的这些肿瘤的侵袭性。