scholarly journals Artificial Intelligence Substantially Supports Chromosome Banding Analysis Maintaining Its Strengths in Hematologic Diagnostics Even in the Era of Newer Technologies

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 47-48
Author(s):  
Claudia Haferlach ◽  
Siegfried Hänselmann ◽  
Wencke Walter ◽  
Sarah Volkert ◽  
Melanie Zenger ◽  
...  

Background: Chromosome banding analysis (CBA) is one of the most important techniques in diagnostics and prognostication in hematologic neoplasms. CBA is still a challenging method with very labor-intensive wet lab processes and karyotyping that requires highly skilled and experienced specialists for tumor cytogenetics. Short turnaround times (TAT) are becoming increasingly important to enable genetics-based treatment stratification at diagnosis. Aim: Improve TAT and quality of CBA by automated wet lab processes and AI-based algorithms for automatic karyotyping. Methods: In the last 15 years the CBA workflow has gradually been automated with focus on the wet lab and metaphase capturing processes. Now, a retrospective unselected digital data set of 100,000 manually arranged karyograms (KG) with normal karyotype (NKG) from routine diagnostics was used to train a deep neural network (DNN) classifier to automatically determine the class/number and orientation of the respective chromosomes (AI based classifier normal, AI-CN). With a total of 6 Mio parameters, the DNN uses two distinct output layers to simultaneously predict the chromosome number (24 classes) and the angle that is required to rotate the chromosome in its correct, vertical position (360 classes). Training of the DNN took 16 days on a Nvidia RTX 2080 Ti graphic card with 4352 cores. AI-CN was implemented into the routine workflow (including ISO 15189) after 7 months of development and intensive testing. Results: The AI-CN was tested by highly experienced staff in an independent prospective validation set of 500 NKG: 22,675/23,000 chromosomes (98.6%) were correctly assigned by AI-CN. In 369/500 (73.8%) of cells all chromosomes were correctly assigned, in an additional 20% only 2 chromosomes were interchanged. The chromosomes accounting for the majority of misclassifications were chromosomes 14 and 15 as well as 4 and 5, which are difficult to distinguish in poor quality metaphases also for humans. The 1st AI-CN was implemented into routine diagnostics in August 2019 and the 2nd AI-CN - optimized for chromosome orientation - was used since November 2019. Since then more than 17,500 cases have been processed with AI-CN (>350,000 metaphases) in routine diagnostics resulting in the following benefits: 1) Reduced working time: an experienced cytogeneticist needs - depending on chromosome quality - between 1 and 3 minutes to arrange a KG, while AI-CN needs only 1 second and the cytogeneticist about 30 seconds to review the KG. 2) Shorter TAT: The proportion of cases reported within 5 days increased from 30% before AI-CN (2019) to 36% with AI-CN1 (2019) and 45% with AI-CN2 (2019/2020), while the proportion of cases reported >7 days was reduced to 28%, 21%, and 17%, respectively (figure). Using AI-CN for aberrant karyotypes results in correct assignment of normal chromosomes and thus also correct KG in cases with solely numerical chromosome abnormalities. Derivative chromosomes derived from structural abnormalities (SA) that differ clearly from any normal chromosome are not automatically assigned but are left out for manual classification. Thus, even in cases with SA, using AI-CN saves time. To allow AI based SA assignment, two additional classifiers normal/aberrant (CNA) were built: AI-CNA1 was trained on 54,634 KG encompassing 10 different SA (AKG) and 100,000 NKG and AI-CNA2 was trained on all AKG and an equal number of NKG. First validation tests are promising and optimization is ongoing. Once the CNA has been optimized, a standardized high quality of chromosome aberration detection is feasible. A fully automated separation of chromosomes is currently in progress and will reduce the TAT by another 12-24 hours. In a fully automated workflow the detection of small subclones can be further optimized by increasing today's standard of 20 metaphases to several hundred, even without any delay in TAT and need for additional personnel. Conclusions: Implementation of AI in CBA substantially improves the quality of results and shortens turnaround times even in comparison to highly trained and experienced cytogeneticists. In the majority of cases a complete karyotype analysis can be guaranteed within 3 to 7 days, allowing CBA based treatment strategies at diagnosis. This fully automated workflow can be implemented worldwide, is rapidly scalable, can be performed cloud based and requires in the near future fewer experienced tumor cytogeneticists. Figure Disclosures Hänselmann: MetaSystems: Current Employment. Lörch:MetaSystems: Current equity holder in private company.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2064-2064
Author(s):  
Claudia Schoch ◽  
Frank Dicker ◽  
Susanne Schnittger ◽  
Wolfgang Kern ◽  
Torsten Haferlach

Abstract 13q14 deletions are the most frequent abnormality in CLL and are overall associated with a favourable prognosis. However, the clinical course of the disease is heterogeneous within this subgroup of CLL. In order to characterize this subgroup, which is identified in routine diagnostics by interphase FISH, in more detail we performed chromosome banding analysis in addition. By improving the cultivation technique using the immunostimulatory CpG-oligonucleotide, DSP30, and IL-2 we reached a high success rate in routine diagnostics. Since August 2005 416 CLL were analyzed in parallel with chromosome banding analysis (CBA) and interphase-FISH. The FISH panel included probes for the detection of trisomy 12, IGH-rearrangements, and deletions of 6q21, 11q22.3 (ATM), 13q14 (D13S25 and D13S319), and 17p13 (TP53). 411/416 (98.8%) cases could be successfully stimulated for metaphase generation. 348/411 (84.7%) cases showed chromosomal aberrations in CBA while abnormalities were detected by FISH in 332 of 416 (79.8%) successfully evaluated cases. In 229 cases (55%) a 13q14 deletion was detected by FISH, including 58 patients with a homozygous deletion. CBA was not evaluable in 4/229 cases. A normal karyotype was observed in 9/229, due to a small size of the aberrant clone missed by CBA (20% of interphase nuclei) in 1 case and due to the small size of the deletion not visible in CBA in 8 cases (growth of the aberrant clone was confirmed by FISH on metaphases). In 108 cases a deletion 13q was the only abnormality detected in CBA. 29 cases showed one other abnormality in addition to del(13q) (del(11q) n=13, +12 n=2, der(17p) n=3, other abnormalities not detectable by the used FISH panel n=11). In 51 cases 2 or more abnormalities were observed in addition to the 13q deletion. Interestingly, 28 cases did not show a 13q-deletion but a reciprocal translocation or insertion with a breakpoint in 13q14. In all these cases FISH on metaphases was performed with a whole chromosome painting probe for chromosome 13 and a probe for either D13S25 or D13S319, demonstrating a loss of one D13S25/D13S319 signal from the derivative chromosome 13 and the partner. In 9 cases D13S25/D13S25 was also lost from the homologous chromosome 13 (homozygous 13q14 deletion). The translocation partner was confirmed in a second FISH analysis also confirming the reciprocal nature of the abnormality. The breakpoints of the partner chromosomes were distributed all over the genome (1p13, 1q23, 1q24, 1q42, 1q42, 3q21, 3q21, 4p16, 4q23, 5q13, 5q15, 6q11, 6q23, 7p21, 8p23, 8q21, 8q22, 9p22, 9q21, 9q33, 10p15, 10q24, 11p15, 11q23, 13q34, 15q15, 16q24, 16q24). In conclusion, CBA offers important information in addition to interphase FISH in CLL. 1) CBA detects chromosome abnormalities in addition to 13q14 deletion which can not be detected with a standard interphase FISH panel. 2) CBA provides new biological insights into different mechanisms leading to loss of 13q14. Prospective clinical trials have to evaluate the prognostic impact of the different subclasses of CLL with 13q14 deletion that now can be identified by chromosome banding analysis.


Cytometry ◽  
1989 ◽  
Vol 10 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Marty F. Bartholdi ◽  
Julie Meyne ◽  
Roger G. Johnston ◽  
L. Scott Cram

1994 ◽  
Vol 72 (5) ◽  
pp. 958-964 ◽  
Author(s):  
Vitaly T. Volobouev ◽  
Constantinus G. van Zyll de Jong

The chromosomes of Sorex haydeni are described for the first time and their banding pattern (R- and C-bands) compared with that of Sorex cinereus. The karyotype of S. haydeni differs from that of S. cinereus in its diploid (64 vs. 66) and fundamental numbers (66 vs. 70). These differences are the result of one tandem translocation and one pericentric inversion. The size and form of the Y chromosomes are also quite different in these taxa. The karyotypic differences strongly support the status of independent species, proposed for these taxa earlier on the basis of gross morphological characters.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2016-2016 ◽  
Author(s):  
Claudia Schoch ◽  
Mirjam Klaus ◽  
Susanne Schnittger ◽  
Wolfgang Hiddemann ◽  
Wolfgang Kern ◽  
...  

Abstract In AML karyotype abnormalities are not detected in 40 to 45% of cases using classical chromosome banding analysis. For several reasons false negative results might occur in chromosome banding analysis: 1. no proliferation of the aberrant clone in vitro, 2. low resolution due to technical problems or limitations of the method itself, 3. real cryptic rearrangements. In order to determine the proportion of “false negative” karyotypes by chromosome banding analysis we conducted a study using interphase-FISH and comparative genomic hybridization in addition to chromosome banding analysis. In total, chromosome banding analysis have been performed in 3849 AML at diagnosis. Of these 1748 showed a normal karyotype (45.4%). Out of these in 3 cases cytomorphology revealed an APL and in 2 cases an AML M4eo. Using interphase FISH with a PML-RARA or CBFB probe we detected cryptic PML-RARA or CBFB-rearrangements, respectively, in all 5 cases, which were cytogenetically invisible due to submicroscopic insertions. 480 cases of AML with normal karyotype were analyzed for MLL gene rearrangements using FISH with an MLL-probe. 11 cases with a cryptic MLL-rearrangement were detected (FAB-subtypes: M5a: 7, M2: 2, M0: 2). In 273 patients interphase-FISH screening with probes for ETO, ABL, ETV6, RB, P53, AML1 and BCR was performed. In 6 out of 273 (2.2%) pts an abnormality was detectable. In two cases the aberrant clone did not proliferate in vitro: 1 case each with monosomy and trisomy 13. Due to limitations of resolution in chromosome banding analysis translocations or deletions of very small chromosome fragments were only detected with FISH in n=4 cases (ETV6 rearrangements: t(11;12)(q24;p13), t(12;22)(p13;q12), ETV6 deletions: del(12)(p13), n=2). Like interphase-FISH comparative genomic hybridization (CGH) does not rely on proliferating tumor cells but in contrast to interphase-FISH allows the detection of all genomic imbalances and not only of selected genomic regions. Therefore, we selected 48 cases with normal karyotype and low in vitro proliferation (less than 15 analyzable metaphases in chromosome banding analysis). In 8 of 48 cases (16.7%) an aberrant CGH-pattern was identified which was verified using interphase-FISH with suitable probes. In 3 cases a typical pattern of chromosomal gains and losses observed in complex aberrant karyotypes was detected. In one case each a trisomy 4 and 13 was observed, respectively. In one case trisomy 13 was accompanied by gain of material of the long arm of chromosome 11 (11q11 to 11q23). One case each showed loss of chromosome 19 and gain of the long arm of chromosome 10, respectively. In conclusion, CGH in combination with interphase-FISH using probes for the detection of balanced rearrangements is a powerful technique for identifying prognostically relevant karyotype abnormalities in AML assigned to normal karyotype by chromosome banding analysis. Especially this is true in cases with a low yield of metaphases and in AML with a high probability of carrying a specific, cytogenetically cryptic fusion-gene. Thus, in these cases interphase-FISH and CGH should be performed in a diagnostic setting to classify and stratify patients best.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4143-4143
Author(s):  
Claudia Haferlach ◽  
Alexander Kohlmann ◽  
Sonja Rauhut ◽  
Frank Dicker ◽  
Wolfgang Kern ◽  
...  

Abstract Chromosomal rearrangements involving the MLL gene occur in 3–5% of adult AML. More than 50 different partner genes have been described in acute leukemia with 11q23-abnormalities. Although MLL-rearrangements per se have a high leukemic potential, additional genetic aberrations occur. This study was intended to decipher MLLrearrangements and their accompanying genetic lesions at the molecular level. Therefore, Affymetrix SNP 6.0 microarray analyses were performed in 47 newly diagnosed AML with 11q23 aberrations. First, as a proof of principle, all gains and losses of chromosomal material as observed by cytogenetics were also detected by the SNP technology. This included recurring gains of whole chromosomes; 4 (n=3), 8 (n=7), and 19 (n=2). In addition, the following unbalanced abnormalities were detected: gain of 1q31.3 to 1q43 (n=5) and a gain of 3q (n=2). In 40/47 cases the following partner genes had been identified based on the translocation observed in chromosome banding analysis and RTPCR: AF9 (n=27), AF6 (n=4), AF10 (n=3), ELL (n=2), AF4 (n=1), AF17 (n=1), ENL (n=1), SEPT5 (n=1). In 4/47 cases results from chromosome banding analysis suggested partner genes to be located at 11q13 (n=1), 10p11 (n=1), and 19p13 (n=2). In 3/47 cases the MLL rearrangement was cryptic and only suspected by FISH analysis. Two of those (#1, #2) showed a del(11)(q23q25) in chromosome banding analyses and FISH analyses demonstrated a loss of the 3′ flanking MLL probe. In the remaining case (#3) cytogenetics showed an i(21)(q10). FISH analysis on metaphase spreads identified an additional copy of the 5′ flanking MLL probe which localized on 6q27. SNP analyses were able to resolve all three cases: #1) The deletion was fine-mapped by SNP microarray data and ranged from physical map position 117,859,541 to 11qter including exons 10 to 28 of the MLL gene. In addition, SNP microarray data revealed a gained segment on 6q ranging from physical map position 167,977,103 to 6qter including exons 2 to 28 of AF6. #2) In this case the 11q deletion spans from physical map position 117,859,541 to 121,033,713 including exons 10 to 28 of the MLL gene. SNP microarray data revealed a gained segment on 6q ranging from physical map position 168,036,784 to 168,457,799 including exons 9 to 28 of AF6. #3) Corresponding to FISH analysis SNP microarray data revealed a gained segment on 11q ranging from physical map position 117,760,488 to 117,859,673, including exons 1 to 9 of MLL. Moreover, on chromosome 6 a small deletion of 177 kb was detected, starting at physical map position 167,804,673 towards 167,982,457. This deletion included exon 1 of AF6 and a small adjacent centromeric region. In all 3 cases, subsequent RT-PCR analyses confirmed the predicted MLL-AF6 fusion. Analyzing the MLL gene further in the remaining cases revealed copy number changes in 2 cases showing gains of 11q starting from exon 12 of the MLL gene to 11qter (physical map position 117,863,291 to 11qter and 117,862,916 to 11qter). These were due to an extra copy of der(4)t(4;11)(q21;q23) and der(19)t(11;19)(q23;p13.3), respectively. In two additional cases very small deletions within MLL with a size of 4.831 kb including exons 10 and 11 (physical map position 117,859,541 to 117,864,372) and 1.699 kb including exons 10 and 11 (physical map position 117,859,541 to 117,861,240) were observed (MLL-AF6- and MLL-AF4-rearrangement). With respect to the various MLL partner genes, deletions starting in the partner genes were observed in 2 cases with MLL-AF9 rearrangement (size: 8 MB and 6.1 MB, physical map position 20,334,335 to 28,350,412 and 20,342,604 to 26,451,390). The region deleted in both cases spanned 37 genes, including several genes of the interferon alpha family and the tumor suppressor candidate TUSC1. Copy number gains were observed in the region of the partner genes in both cases with a doubling of der(4)t(4;11)(q21;q23) and der(19)t(11;19)(q23;p13.3). In conclusion, using high resolution SNP arrays we identified three novel mechanisms leading to MLL-AF6 fusions which are cytogenetically cryptic and associated with atypical FISH signal constellations. Furthermore, a distinct pattern of additional aberrations was observed showing trisomies of chromosomes 4, 8 and 19. SNP microarray data also revealed a small deletion on the short arm of chromosome 9 as a recurrent additional genetic change in AML with MLL-AF9-rearrangements.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1394-1394
Author(s):  
Vera Grossmann ◽  
Claudia Haferlach ◽  
Susanne Schnittger ◽  
Ulrike Bacher ◽  
Franziska Poetzinger ◽  
...  

Abstract Abstract 1394 Background: Acute erythroid leukemia (AEL) is characterized by a predominant erythroid population and is comprising <5% of adult AML cases. Because of the relative rarity of AEL, few large studies have examined underlying clinical and genetic features. Aims: Molecular and cytogenetic characterization of AEL and identification of genes with prognostic impact. Patients and Methods: We studied an unselected cohort of 94 AEL patients including 32 female and 62 male cases; median age was 69.0 yrs (range: 21.3–88.3 yrs). Survival data was available in 73 cases; median survival was 15.9 months. First, chromosome banding analysis (n=94) was performed. In addition, all cases with normal karyotype (NK) were investigated by CGH arrays (n=32) (Human CGH 12×270K Whole-Genome Tiling Array, Roche NimbleGen, Madison, WI). Further, mutation screening for ASXL1 (n=87), CEBPA (n=94), DNMT3A (n=94), FLT3 (both internal tandem duplication (ITD) (n=93), and tyrosine-kinase domain (TKD) mutations (n=85)), IDH1 (n=93), IDH2 (n=65), NRAS (n=91), KRAS (n=93), MLL-PTD (n=79), NPM1 (n=94), RUNX1 (n=94), TP53 (n=94), and WT1 (n=90) was performed by 454 amplicon deep-sequencing (Roche, Branford, CT), Sanger sequencing or melting curve analyses. CGH array data analysis was performed using Nexus Copy Number 6.0 (BioDiscovery Inc, El Segundo, CA). Results: Cytogenetic data was available for all cases: 48 cases (51.1%) presented an intermediate-risk and 46 (48.9%) cases an unfavorable cytogenetic category according to the MRC Classification. By CGH array analysis 30/32 cases retained a NK, whereas in two cases small aberrations were detected: case 1: deletion of the CEBPA gene, case 2: duplication 11q13.3 to 11q25 including the ATM and MLL gene. Molecular mutations were detected in 85/94 patients (90.4%). 63.5% (54/85) of mutated patients carried one, whereas 36.5% (31/85) of cases harbored two (n=22) or more (n=9) mutations. In detail, TP53 was the most frequently mutated gene (41 cases, 43.6%). Other alterations were detected in NPM1 (15/94; 16.0%); DNMT3A (12/94; 12.8%); ASXL1 (8/87; 9.2%); MLL-PTD (7/79; 8.9%); RUNX1 (8/94; 8.5%); IDH1 (6/93; 6.5%); WT1 (5/90; 5.6%); IDH2 (3/65; 4.6%); NRAS (3/91; 3.3%); KRAS (3/93; 3.2%); FLT3-ITD (3/93, 3.2%), FLT3-TKD (3/85, 3.5%), and CEBPA (1/94). First, we were interested in any correlation with the respective karyotype and observed that NPM1, RUNX1, and WT1 mutations correlated with an intermediate-risk karyotype (NPM1: 15/48 vs 0/46, P<0.001; RUNX1: 8/48 vs 0/46, P=0.006; WT1: 5/46 vs 0/44, P=0.056), whereas TP53mut correlated with the unfavorable karyotype (38/46 vs 3/48, P<0.001). Within the cytogenetically adverse subset TP53mut were associated with complex karyotype (36/38 vs 2/8, P<0.001). In addition, NPM1mut correlated with lower age (56±15 vs 67±13 yrs, P=0.002), whereas mutations in ASXL1, DNMT3A, and TP53 correlated with higher age (73±4 vs 64±15, P=0.001; 71±6 vs 65±14, P=0.015; 71±8 vs 61±15, P<0.001). NPM1mut were associated with longer, and RUNX1mut and TP53mut with shorter OS (OS after 2 yrs: NPM1mut vs wt: 85.1% vs 28.3%, P=0.001; RUNX1mut vs wt: 0% vs 45.2%, P=0.007; TP53mut vs wt: 9.4% vs 61.6%, P=0.001). In the univariable Cox regression analyses mutations in NPM1 (HR 0.12; P=0.004), RUNX1 (HR 3.99; P=0.013), TP53 (HR 3.19; P=0.001), age (HR 4.24, P=0.001) and adverse cytogenetics (HR 2.98, P=0.002) were significantly associated with OS. Independent prognostic factors in multivariable Cox regression analysis were: age (HR 2.6, P=0.047) and RUNX1mut (HR 6.3, P=0.006). Of note, when separating MRC intermediate from MRC adverse cases, we confirmed the longer OS of NPM1 and shorter OS of RUNX1 mutated cases in comparison to NPM1, RUNX1 wt cases (OS after 2 yrs: NPM1mut vs wt: 85.1% vs 46.3%, P=0.027; RUNX1mut vs wt: 0% vs 69.0%, P<0.001). Conclusions: (1) The frequency of cases with complex or other adverse karyotypes within the AEL cohort is very high (48.9%), (2) 93.7% of cases with NK also showed a NK using high-resolution CGH arrays. (3) Overall, a remarkably high mutation frequency of 90.4% was found. (4) NPM1 and RUNX1mut were exclusively detected in the cytogenetically intermediate-risk MRC, TP53 mut predominantly in the MRC adverse group and mainly in cases with complex karyotype. (5) In addition to chromosome banding analysis mutation screening of RUNX1 and NPM1 in cases with intermediate-risk karyotype should be considered for better prognostication. Disclosures: Grossmann: MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Bacher:MLL Munich Leukemia Laboratory: Employment. Poetzinger:MLL Munich Leukemia Laboratory: Employment. Weissmann:MLL Munich Leukemia Laboratory: Employment. Roller:MLL Munich Leukemia Laboratory: Employment. Eder:MLL Munich Leukemia Laboratory: Employment. Fasan:MLL Munich Leukemia Laboratory: Employment. Zenger:MLL Munich Leukemia Laboratory: Employment. Staller:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 968-968 ◽  
Author(s):  
Claudia Haferlach ◽  
Melanie Zenger ◽  
Tamara Alpermann ◽  
Susanne Schnittger ◽  
Wolfgang Kern ◽  
...  

Abstract Abstract 968 Background and Aim: The karyotype is one of the most important prognostic factors in MDS with respect to survival and evolution to AML and may change during the course of the disease. The aim of this study was to evaluate 1. the frequency of acquisition of additional chromosome abnormalities during the course of the disease (clonal evolution), 2. the pattern of acquired genetic abnormalities, 3. the association of karyotype at diagnosis and clonal evolution and 4. the impact of clonal evolution on transformation to AML and overall survival (OS). Patients and Methods: 988 MDS patients were evaluated by chromosome banding analysis (CBA) during the course of their disease. According to IPSS 729 (73.8%) cases showed a favorable karyotype, 146 (14.8%) patients an intermediate karyotype and 113 (11.4%) cases an unfavorable karyotype at first investigation. Progression to AML occurred in 180 of 988 patients during follow-up. Results: 2,454 chromosome banding analyses were performed in 988 cases (mean: 2.48 per case, range: 2–9). The median time between the first and the last evaluation was 12.5 months (range 1–60.6 months). Overall, in 171 of 988 patients (17.3%) clonal evolution was observed. Clonal evolution was detected between 1 and 56 months (median 14.3 months) after first evaluation and occurred later in patients with favorable than in patients with intermediate or unfavorable karyotype (mean 19.8 mo vs 15.5 mo vs 10.5 mo, favorable vs intermediate p=0.07, intermediate vs unfavorable p=0.05 and favorable vs unfavorable p<0.001). The abnormalities most frequently acquired during the course of the disease were +8, 7q−/−7, and gain of 21q detected in 29 cases each, followed by loss of 12p (n=22), 5q (n=14), 17p (n=19), and 20q (n=12). Other recurrently acquired abnormalities were +13 (n=12), +1q (n=12), +3q (n=12), −3q (n=10). Clonal evolution was strongly associated with cytogenetic IPSS category: Clonal evolution occurred in 100/729 cases with upfront favorable cytogenetics (13.7%), in 32/146 patients (21.9%) with upfront intermediate cytogenetics, but in 39/113 cases (34.5%) with upfront unfavorable cytogenetics (p<0.001). In 100 patients with favorable cytogenetics and clonal evolution karyotype was intermediate at second evaluation in 43 cases (43%), unfavorable in 25 cases (25%) and stayed favorable in the remaining 32 patients (32%). In 32 patients with intermediate cytogenetics and clonal evolution karyotype shifted to unfavorable at second evaluation in 11 cases (34.4%) and stayed intermediate in 21 patients (65.6%). Progression to AML was more frequent in patients with clonal evolution as compared to patients without (52/171 (30.4%) vs 128/817 (15.7%); p<0.001). In Cox regression analysis the IPSS karyotype at first evaluation, the IPSS karyotype at second evaluation, clonal evolution and progression to AML were associated with OS (relative risk: 2.12, 2.15, 1.87, and 6.6; p<0.001, p<0.001, p=0.011, p<0.001, respectively). In multivariate Cox regression analysis the IPSS karyotype at second evaluation and progression to AML were independently associated with shorter OS (relative risk: 2.0, and 6.1; p=0.013, p<0.001, respectively). Clonal evolution was associated with shorter OS (median 130.4 months vs not reached, OS at 5 years 72.3%vs 82.9%, p=0.01). Also in the subset of patients without transformation to AML outcome was inferior in patients with clonal evolution as compared to those without clonal evolution (OS at 5 years 78.2% vs 83.0%, p=0.05). Conclusions: 1. Clonal evolution was observed in 17.3% of patients with MDS. 2. The pattern of acquired abnormalities resembles the pattern observed in MDS at primary evaluation. 3. A higher frequency of clonal evolution and a shorter time to clonal evolution is observed in higher cytogenetic IPSS scores determined at first evaluation. 4. Clonal evolution is significantly associated with transformation to AML and shorter OS. 5. Sequential cytogenetic analyses allow the identification of subsets of MDS patients with a higher risk for transformation to AML and thus might guide treatment decisions in future. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Zenger:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1516-1516
Author(s):  
Claudia Haferlach ◽  
Melanie Zenger ◽  
Marita Staller ◽  
Andreas Roller ◽  
Kathrin Raitner ◽  
...  

Abstract Background In MDS, cytogenetic aberrations play an important role for classification and prognostication. The original IPSS and the revised IPSS classifiers have clearly demonstrated the prognostic impact of distinct cytogenetic abnormalities. The vast majority of chromosome aberrations in MDS are gains or losses of chromosomal material while balanced rearrangements are rare. However, more than 50% of MDS and even more in low risk MDS harbor a normal karyotype. Chromosome banding analysis can only detect gains and losses of more than 10 Mb size due to its limited resolution and is dependent on proliferation of the MDS clone in vitro to obtain metaphases. Array CGH has a considerably higher resolution and does not rely on proliferating cells. Aims In this study we addressed the question whether MDS with normal karyotype harbor cytogenetically cryptic gains and losses. Patients and Methods 520 MDS patients with normal karyotype were analyzed by array CGH (Human CGH 12x270K Whole-Genome Tiling Array, Roche NimbleGen, Madison, WI). For all patients cytomorphology and chromosome banding analysis had been performed in our laboratory. The cohort comprised the following MDS subtypes: RA (n=22), RARS (n=43), RARS-T (n=27), RCMD (n=124), RCMD-RS (n=111), RAEB-1 (n=104), and RAEB-2 (n=89). Median age was 72.2 years (range: 8.9-90.1 years). Subsequently, recurrently deleted regions detected by array CGH were validated using interphase-FISH. Results In 52/520 (10.0%) patients copy number changes were identified by array CGH. Only eight cases (1.5%) harbored large copy number alterations >10 Mb in size, as such generally detectable by chromosome banding analysis. These copy number alterations were confirmed by interphase-FISH. They were missed by chromosome banding analysis due to small clone size (n=2), insufficient in vitro proliferation (n=3) or poor chromosome morphology (n=3). In the other 44 patients with submicroscopic copy number alterations 18 gains and 32 losses were detected. The sizes ranged from 193,879 bp to 1,690,880 bp (median: 960,176 bp) in gained regions and 135,309 bp to 3,468,165 bp (median: 850,803 bp) in lost regions. Recurrently deleted regions as confirmed by interphase-FISH encompassed the genes TET2 (4q24; n=9), DNMT3A (2p23; n=3), ETV6 (12p13; n=2), NF1 (17q11; n=2), RUNX1 (21q22; n=2), and STAG2 (Xq25, deleted in 2 female patients). No recurrent submicroscopic gain was detected. In addition, we performed survival analysis and compared the outcome of patients with normal karyotype also proven by array CGH (n=462) to patients with aberrant karyotype as demonstrated by array CGH (n=52). No differences in overall survival were observed. However, overall survival in 35 patients harboring deletions detected solely by array CGH was significantly shorter compared to all others (median OS: 62.1 vs 42.4 months, p=0.023). Conclusions 1. Array CGH detected copy number changes in 10.0% of MDS patients with cytogenetically normal karyotype as investigated by the gold standard method, i.e. chromosome banding analysis. 2. Most of these alterations were submicroscopic deletions encompassing the genes TET2, ETV6, DNMT3A, NF1, RUNX1, and STAG2. 3. Interphase-FISH for these loci can reliably pick up these alterations and is an option to be easily performed in routine diagnostics in MDS with normal karyotype. 4. Patients harboring deletions detected solely by array-CGH showed worse prognosis. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Zenger:MLL Munich Leukemia Laboratory: Employment. Staller:MLL Munich Leukemia Laboratory: Employment. Roller:MLL Munich Leukemia Laboratory: Employment. Raitner:MLL Munich Leukemia Laboratory: Employment. Holzwarth:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.


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