TP53 Mutations In Patients Research Articles

Minimal Residual Disease (MRD) Status in FCR-Treated CLL Patients at the End of Treatment Influences Progression Free Survival (PFS), Results of the Ctrial-IE (ICORG) 07-01/ CLL Ireland Study, with Mutational Analysis Providing Additional Insight

Fludarabine, cyclophosphamide and rituximab (FCR) therapy results in a complete remission (CR) rate of 72% and a median progression free survival (PFS) of 80 months in non-del (17P) CLL1. Achieving an MRD negative (MRD-ve) CR after completing therapy is an early surrogate marker for overall survival (OS) and PFS2. Specific genetic CLL subtypes determined by fluorescent in-situ hybridisation (FISH) analysis, immunoglobulin mutation IgVH, NOTCH1 and SF3B1 status determine response to chemotherapy3,4.We completed a multi-centre prospective study between 2008 and 2012, with a median follow up of 62.6 months using MRD status to determine length of therapy. Patients who achieved an MRD-veCR after 4 courses of FCR received no further therapy and the remaining patients completed 6 cycles of FCR. MRD status was tracked 6 monthly in patients who became MRD-veuntil MRD was detected. The genetic subtype was also analysed but did not influence treatment.Fifty-two patients {35M;17F, median age 61years (range 37-73)} were enrolled. Forty-six patients completed the MRD assessment after 4 cycles. Eleven patients discontinued assigned FCR therapy for the following reasons: prolonged cytopenia (4); non-compliance (1); autoimmune haemolytic anaemia (2); renal impairment (1); pleural effusion (1); not recorded (2).Eighteen (34.6%) patients achieved an MRD-veCR after 4 cycles and a further11 after 6cycles resulting in 29/52 (55.8%) MRD-veCRs in total. The median PFS was 72.3 months (95% Confidence Interval 61.3-84.1 months) and the median OS has not been reached. Patients who attained an MRD-veversusMRD+vestatus had a prolonged PFS (81.1 vs 46.2 months, p<0.0002). No difference in PFS was observed between patients reaching an MRD-veCR after 4 versus 6 cycles (median PFS81.1 vs 84.1 months,p=0.29).FISH results were available for 48 patients; del(13q) in 16/48 (33%), del(11q) in 15/48 (31%) no abnormality in 12/48 (25%), trisomy 12 in 4 (8%) and other abnormality in 1 patient. The IgVH status was unfavourable in 34/52 (65%), SF3B1 mutations were detected in 5/51 (9.8%) and NOTCH1 mutations in 10/52(19.2%) patients respectively, comparable to published studies of first-line treatment in CLL3,4.The median PFS for patients with good risk IgVH was not reached. Del(11q) did not impact on PFS (median PFS 66.5 vs 78.9 months, p=0.7301). SF3B1 and NOTCH1 mutated patients had a shortened PFS (median PFS 38.4 vs 71.1 months, p=0.038 and median PFS 62.4 vs 82.2 months p=0.0302, respectively).In conclusion abbreviated FCR therapy is effective for patients achieving MRD-veremission after 4 cycles. SF3B1 and NOTCH1 mutated patients had a short PFS and may benefit from alternative first-line treatment. This finding emphasizes the role mutational profiling will play in optimising and personalising therapy in CLL in the future.Reference:Tam C, O'Brien S, WierdaW, et al. “Long-term results of the fludarabine, cyclophosphamide and rituximab regimen as initial therapy of chronic lymphocytic leukemia” Blood 2008 Aug 15;112(4):975-80Böttcher S, Ritgen M, Fischer K, et al. "Minimal Residual Disease Quantification is an Independent Predictor of Progression-Free and Overall Survival in Chronic Lymphocytic Leukemia: A Multivariate Analysis From the Randomized GCLLSG CLL8 Trial" J Clin Onc 2012 Mar 20; 30(9):980-8.StilgenbauerS,SchnaiterA,PaschkaP, et al. "Gene mutations and treatment outcome in chronic lymphocyticleukemia: results from the CLL8 trial" Blood 2014 May 22;123(21):3247-54Chiaretti S, Marinelli M, Del Giudice I, et al."NOTCH1, SF3B1, BIRC3 and TP53 mutations in patients with chronic lymphocytic leukaemia undergoing first-line treatment: correlation with biological parameters and response to treatment"LeukLymphoma 2014 Dec; 55(12):2785-92 [Display omitted] [Display omitted] [Display omitted] DisclosuresCrotty:BMS, Takeda, Novartis, Janssen, Roche: Honoraria. O'Dwyer:Glycomimetics: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding.

Therapy-related myeloid neoplasms: does knowing the origin help to guide treatment?

Therapy-related myeloid neoplasms (t-MN) combine t-MDS and therapy related acute myeloid leukemia (t-AML) patients in one entity because of their similar pathogenesis, rapid progression from t-MDS to t-AML, and their equally poor prognosis. Treatment with epipodophyllotoxins like etoposide has been associated with a short interval between treatment and development of t-AML, with fusion oncogenes like KMT2A/MLL-MLLT3 and a better prognosis. In contrast, treatment with alkylating agents has been associated with a longer latency, an initial MDS phase, adverse cytogenetics, and a poor prognosis. The pathogenesis of t-MN can be explained by direct induction of an oncogene through chromosomal translocations, induction of genetic instability, or selection of a preexisting treatment-resistant hematopoietic stem cell clone. Recent evidence has highlighted the importance of the last mechanism and explains the high frequency of TP53 mutations in patients with t-MN. After previous cytotoxic therapy, patients present with specific vulnerabilities, especially evident from the high nonrelapse mortality in patients with t-MN after allogeneic hematopoietic cell transplantation. Here, the prognostic impact of currently known risk factors and the therapeutic options in different patient subgroups will be discussed.

Prognostic and Predictive Effect of TP53 Mutations in Patients with Non–Small Cell Lung Cancer from Adjuvant Cisplatin–Based Therapy Randomized Trials: A LACE-Bio Pooled Analysis

IntroductionTumor protein p53 gene (TP53) mutations are common in stage I through III non–small cell lung cancer, but clinical trials have shown inconsistent results regarding their relationship to the effects of adjuvant therapy. The objective is to clarify their putative prognostic and predictive effects. MethodsA pooled analysis of TP53 mutations (exons 5–8) was conducted in four randomized trials (the International Adjuvant Lung Cancer Trial, J BRonchus 10, Cancer and Leukemia Group B-9633, and Adjuvant Navelbine International Trialist Association trial) of platinum-based adjuvant chemotherapy (ACT) versus observation (OBS). Hazard ratios (HRs) and 95% confidence intervals (CIs) of mutant versus wild-type (WT) TP53 for overall survival (OS) and disease-free survival (DFS) were estimated using a multivariable Cox model stratified on trial and adjusted on sex, age, and clinicopathological variables. Predictive value was evaluated with an interaction between treatment and TP53. ResultsA total of 1209 patients (median follow-up 5.5 years) were included. There were 573 deaths (47%) and 653 DFS events (54%). Mutations (434 [36%]) had no prognostic effect (OBS HROS = 0.99, 95% CI: 0.77–1.28, p = 0.95; HRDFS = 0.99, 95% CI: 0.78–1.25, p = 0.92) but were marginally predictive of benefit from ACT for OS (test for interaction: OS, p = 0.06; DFS, p = 0.11). Patients with WT TP53 had a tendency toward better outcomes with ACT than did those in the OBS group (HROS = 0.77, 95% CI: 0.62–0.95, p = 0.02; HRDFS = 0.75, 95% CI: 0.62–0.92, p = 0.005). In the ACT arm, a deleterious effect of mutant versus WT TP53 was observed (HROS = 1.40, 95% CI: 1.10–1.78, p = 0.006; HRDFS = 1.31, 95% CI: 1.04–1.64, p = 0.02). ConclusionsTP53 mutation had no prognostic effect but was marginally predictive for survival from ACT. In patients who received ACT, TP53 mutation tended to be associated with shorter survival than wild-type TP53.

TP53 mutation in patients with high-risk acute myeloid leukaemia treated with allogeneic haematopoietic stem cell transplantation.

Treatment success in patients with acute myeloid leukaemia (AML) is heterogeneous. Cytogenetic and molecular alterations are strong prognostic factors, which have been used to individualize treatment. Here, we studied the impact of TP53 mutations on the outcome of AML patients with adverse cytogenetic risk treated with allogeneic haematopoietic stem cell transplantation (HSCT). Samples of 97 patients with AML and adverse-risk cytogenetics who had received a HSCT within three randomized trials were analysed. Complete sequencing of the TP53 coding region was performed using next generation sequencing. The median age was 51 years. Overall, TP53 mutations were found in 40 patients (41%). With a median follow up of 67 months, the three-year probabilities of overall survival (OS) and event-free survival for patients with TP53 wild type were 33% [95% confidence interval (CI), 21% to 45%] and 24% (95% CI, 13% to 35%) compared to 10% (95% CI, 0% to 19%) and 8% (95% CI, 0% to 16%) (P = 0·002 and P = 0·007) for those with mutated TP53, respectively. In multivariate analysis, the TP53-mutation status had a negative impact on OS (Hazard Ratio = 1·7; P = 0·066). Mutational analysis of TP53 might be an important additional tool to predict outcome after HSCT in patients with adverse karyotype AML.

A36: The TP53 mutations in the Russian patients with de novo DLBCL

Background TP53 dysfunction is implicated in lymphomagenesis and disease progression. Information about the frequency and spectrum of TP53 mutations in the Russian pathients with diffuse large B-cell lymphoma (DLBCL) in the current version of the IARC TP53 Mutation Database R17 is not represented. The goal of this work was to study the frequency, spectrum and functional significance of TP53 mutations in Russian patients with DLBCL. Material and methods At the present time the pilot group of 14 patients were included in the study. Diagnosis was assessed according to the criteria of the WHO classification system. Genomic DNA was isolated from formalin-fixed, paraffin embedded tissue blocks. Direct sequence analysis of gene TP53 was performed according to the IARC protocol, 2010 update. Results In two patients were identified single nucleotide substitutions that are not described in the current version of the PubMed database. All of mutations occurred in the DNA-binding domain of p53. The nonsense mutation Arg196Ter was detected in one patient. Previously it was shown that formation of this premature stop codon might activate the nonsense-mediated RNA decay pathway. The second patient had two missense mutations – Leu130Phe and Arg156Cys. The first of them leads to p53 inactivation according to the analysis of the functional importance of amino acid substitutions using service PolyPhen-2. Conclusion We detected TP53 mutation in 14% cases. The mutational rate in our study is in good agreement with other studies where the frequency of the TP53 mutations in patients with DLBCL ranged mostly from 13% to 23%.

Analysis of K-ras codon 12 and TP53 mutations in patients with advanced colorectal carcinoma.

Colorectal cancer (CRC) is one of the most common types of cancer, affecting 3 - 5% of the global population. K-ras protooncogene and TP53 tumour suppressor gene mutations are among the most common genetic alterations detected in advanced colorectal tumours. To investigate the role of K-ras codon 12 and TP53 exons 5 - 9 mutations in late-stage CRC patients. Blood samples were collected from 249 CRC patients, of whom 147 presented with advanced carcinoma. K-ras codon 12 mutations were analysed using polymerase chain reaction-restriction fragment length polymorphism, while direct sequencing was used in screening for TP53 exons 5 - 9 mutations. No significant changes were observed in TP53 exons 5 - 9, except for two cases in which nucleotide replacements were observed in the non-coding regions in intron 4 (c.376-19C&gt;T) and intron 9 (c.993+12T&gt;C). Heterozygous mutations in K-ras codon 12 were observed in 79 individuals suffering from advanced CRC (53.7%). Colon and rectal tumours were equally distributed among the heterozygotes, but colon tumours were mostly present in wild-type homozygotes (84.6%). There was also a predominance of Caucasians among heterozygotes and a predominance of Asians among the wild-type homozygotes. Analysis of peripheral blood samples of CRC patients suffering from advanced carcinoma has prognostic value only for K-ras codon 12 mutations, and not for TP53 mutations.

Clinical Impact of TP53 Mutations in Patients with MDS and Isolated Deletion 5(q) Treated with Lenalidomid: Results from the German Prospective Le-Mon-5 Trial

Introduction: MDS with isolated deletion 5(q) accounts for approximately 5% of all MDS cases. A recent retrospective analysis has found a cumulative progression rate of 18% after 5 years in patients with MDS deletion 5(q) without an increased medullary blast count[1]. Retrospective analyses have indicated that mutations in TP53 have an adverse impact on the clinical course of affected patients and their response to Len treatment. Here we report on the results of the German multi-center, prospective Le-Mon-5 trial that investigated the safety and efficacy of lenalidomide (Len) in patients with MDS and isolated deletion 5(q).Methods: Le-Mon-5 is a trial of Len in patients with MDS with isolated 5q abnormality, a blast count of < 5% in the bone marrow, a platelet count > 50.000/µl and absolute neutrophil counts of > 500/µl in the peripheral blood. Patients were treated with the standard dose of 10 mg Len for 21 days q28 days. The primary endpoint was safety. Secondary endpoints included response according to IWG criteria (2000), time to response, duration of transfusion independency and incidence and time to AML-transformation, respectively. All patients gave written informed consent to the trial including additional molecular genetic analyses. Central cytologic, cytogenetic and histologic review was performed. Mutational analysis of TP53 was done by next generation sequencing (NGS). For generation of PCR amplicon libraries TP53 primer plate assays were used and technically validated within the IRON-II (Interlaboratory Robustness Of Next generation sequencing) study network. Amplicon sequencing of TP53 was performed on a Roche 454 GS Junior system. Mean coverage of sequenced exons was about 800-fold allowing an approximate detection sensitivity of 2% mutational burden.Results: A total of 91 patients were enrolled into the trial. Of those, 71 patients (male, n=13) were analyzed for TP53 mutations. Median age was 71 years (range 40-88 years). TP53 mutations prior to treatment initiation with Len were found in 7 patients (10%). There was no difference between the TP53 mutated (TP53mut) versus TP53 wildtype patients (TP53WT) with regard to age, IPSS risk, hemoglobin levels, absolute neutrophil counts and platelet counts at baseline. Transfusion independence was achieved in a significantly lower proportion of patients in the TP53mut group versus TP53WT group (43% vs. 62%, p=0.036). Moreover, median survival was significantly shorter in the TP53mut group as compared to TP53WT group (533 days vs. not reached, p=0.0002). No difference was seen with regard to cytologic and cytogenetic response. Data on evolution into AML are currently being collected. Of 2 patients we had follow-up samples available. Both patients showed no difference with regard to the mutation frequency after a follow-up of 4-17 months on Len treatment (27% and 51%, respectively), although one of the patients achieved a complete cytogenetic response during Len treatment.Conclusions: Using the NGS technique on a routine basis, we achieved high quality runs with a high mean coverage of analyzed exons of TP53. Presence of TP53 mutations adversely affected response to Len with regard to transfusion independence. Moreover, TP53mut patients had a shorter overall survival as compared to TP53WT patients underlining the prognostic relevance of TP53 mutations in this patient cohort. Therefore, mutation analysis of TP53 might guide treatment decisions in the future, e.g. consideration of combination regimens. Since the TP53 clone obviously prevails during Len treatment, careful monitoring for signs of transformation should be performed. DisclosuresPlatzbecker:Celgene Corp.: Honoraria, Research Funding. Götze:Celgene Corp, Novartis Pharma: Honoraria. Schlenk:Celgene Corp.: Research Funding, Speakers Bureau. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Bug:Celgene: Honoraria, Research Funding. Germing:Celgene Corp.: Honoraria, Research Funding. Nolte:Celgene Corp., Novartis Pharma: Honoraria, Research Funding.

Utilization of Targeted Exome Sequencing to Determine Implications of TP53 Mutation Status in Relation to 17p Deletion in Chronic Lymphocytic Leukemia (CLL)

Background:Advances in molecular genetics have changed the risk stratification and treatment of patients with Chronic Lymphocytic Leukemia (CLL). Previous studies have shown the worst patient outcomes associated with 17p deletion from diminished overall and progression free survival, in addition to lack of response to conventional Fludarabine based chemotherapy regimens. More recently, analyses of the role of TP53 mutation utilizing next generation sequencing (NGS) in CLL patients has shown that it may also be associated with poor prognosis and similar outcomes to those patients with 17p deletion. This study seeks to characterize the role of TP53 mutation and 17p deletion with overall survival (OS) of CLL patients treated at H. Lee Moffitt Cancer Center who underwent Targeted Exome Sequencing (TES).Methods:We utilized the Total Cancer Care/H. Lee Moffitt Cancer Center (MCC) database containing 844 CLL patients of diverse ethnic backgrounds and long survival follow up to determine the rates and outcomes of 17p deletion within our population. A subset of 93 patients treated between 2004 and 2010 at MCC were randomly chosen for TES. Bone marrow and/or peripheral blood samples were subjected to genomic capture and massive parallel sequencing of 1,321 cancer-related genes. Sequences were aligned to the hs37d5 human reference. Insertion/deletion realignment, quality score recalibration, and variant identification were performed with the Genome Analysis ToolKit (GATK). Sequence variants for TP53 and 17p deletion were annotated with ANNOVAR. Alignments using BWA and Stampy were manually inspected with Samtools View. The primary objective was to determine OS stratified into four groups: 1) TP53 positive/17p deletion positive (tp53+/17pdel+), 2) TP53 negative/17p deletion positive (tp53-/17pdel+), 3) TP53 positive/17p deletion negative (tp53+/17pdel-), and lastly 4) TP53 negative/17p deletion negative (tp53-/17pdel-).Results:Analysis of patients with genetic data available in our larger population of CLL patients at MCC (n=844), revealed the median OS of patients with 17pdel+ (n=46) was 6 years vs. 13 years for 17pdel- patients (Figure 1, p<0.001). These results were comparable to our CLL patients that underwent TES. Among patients who underwent TES (n=93), the median age was 58 (34-87) years and the male/female ratio was 63/30. Sixteen patients had Rai Stage III/IV disease (17.3%). ZAP70 and CD38 were positive in 41 (44.1%) and 11 patients (11.8%), respectively. Recurrent CLL mutations by FISH showed 13qdel in 54 (58.1%), 11qdel in 19 (20.4%), trisomy 12 in 18 (19.4%), and 17pdel in 12 (12.9%) cases. By TES, TP53 mutation was the most frequent mutation and detected in 18/93 (19.4%) of patients. The median OS for 17pdel+ vs. 17pdel- in this population were 9.6 and 14 years, respectively (p=0.023). When patients were divided by subgroups the frequencies were as follows: tp53+/17p+ in 10 (10.8%), tp53-/17p+ in 2 (2.2%), tp53+/17p- in 8 (8.6%), and tp53-/17p- in 73 (78.5%). The median OS for patients with tp53+/17pdel+, tp53+/17pdel-, and tp53-/17pdel- were 2, 9, and 13 years, respectively (Figure 2, p=0.028). Due to the small number in the tp53-/17pdel+ subgroup, the median OS could not be determined.Conclusion:The impact of TP53 mutations detected by NGS in CLL patients is still under investigation. TP53 mutation and 17p deletion are associated with a very poor prognosis. The impact of TP53 mutation in the absence of 17p deletion is not well understood. Within our study, our findings clearly show the 84.6% reduction in OS (11 years) of tp53+/17p+ patients when compared to tp53-/17pdel- patients. TP53 mutation in the absence of 17p deletion did reduce OS by 4 years (30.8%) when compared to patients who lack the 17p deletion or TP53 mutation. TP53 mutation does appear to impact and shorten OS most strikingly in the presence of 17p deletion, suggesting that 17p deletion may play a greater role in prognosis than TP53 alone. Larger number of patients will be needed in order to confirm these findings and to determine the impact of 17p deletion in patients lacking TP53 mutations. Further analyses of CLL patients utilizing NGS technologies and functional analyses to determine if these mutations fully inactivate TP53 will need to be performed to help further elucidate the role of TP53 mutation in patients with high-risk CLL. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

NOTCH1, SF3B1, BIRC3 and TP53 mutations in patients with chronic lymphocytic leukemia undergoing first-line treatment: correlation with biological parameters and response to treatment

In chronic lymphocytic leukemia, NOTCH1, SF3B1, BIRC3 and TP53 disruptions are recurrent and affect survival. To define their incidence and clinical impact in patients undergoing first-line treatment, we evaluated 163 cases enrolled in the GIMEMA (Gruppo Italiano Malattie EMatologiche dell’Adulto) LLC0405 protocol (fludarabine plus alemtuzumab or fludarabine plus cyclophosphamide), for young patients, or in the ML21445 protocol (chlorambucil plus rituximab), for elderly patients. NOTCH1, SF3B1, BIRC3 and TP53 disruptions were detected in 15.9%, 12.2%, 8.6% and 10.4% of cases. NOTCH1 mutations correlated with a shorter treatment-free interval (p = 0.058), an unmutated immunoglobulin heavy variable gene (IGHV) status (p < 0.0001), CD38 and ZAP-70 expression (p = 0.0025 and 0.026, respectively) and trisomy 12 (p = 0.0028), SF3B1 mutations with an unmutated IGHV status (p = 0.02), and BIRC3 disruptions with an unmutated IGHV configuration (p = 0.01) and 11q deletion (p < 0.0001). NOTCH1 and SF3B1 did not appear to impact on overall response, while an inferior response was observed for BIRC3- and TP53-disrupted cases in the LLC0405 and ML21445 protocols, respectively. Progression-free survival, evaluable in the LLC0405 protocol – not affected by NOTCH1, SF3B1 and TP53 – appeared inferior for BIRC3 disruption. NOTCH1 and SF3B1 mutations may be overcome by aggressive regimens, while BIRC3 might impact on outcome also in intensive regimens.

Screening the APC, MLH1, MSH2 and TP53 Mutations in Patients with Early Onset of Colorectal Cancer

Objective: A molecular-genetic study of early onset colorectal cancer (CRC) patients in Kazakhstan. Methods: The direct sequencing of crucial regions of key CRC genes (APC codons between nucleotides 967-1386 and 1286–1513; exons 8 and 16 of MLH1 and exon 7 of MSH2; exons 5-9 of TP53) was performed for early cancer-onset and suspected familial cases. Results: Blood was collected from 249 patients diagnosed with rectal or colon cancer. There were 32 patients with early onset CRC (28-50 yrs), including 10 patients with a family history of cancer. Two types of nucleotide replacements were detected in intron 4 (c.376-19C>T) and intron 9 (c.993+12T>C) of TP53, both in the heterozygous state. Another nucleotide substitution was present in 15 patients in intron 15 of MLH1 (c.1732-90C>A) while known coding polymorphisms were observed in exon 8 of MLH1 (rs1799977-A655G/Ile219Val), in exon 7 of MSH2 (rs5028341-C1168T/Leu390Phe), in exon 15 of APC (rs1801166-G3949C/p.Glu1317Gln and rs41115–4479G>A). The single deletion, c.3613delA (p.Ser1205fs), located in exon 15 of APC gene, was found in the heterozygous state in two patients with a family history of adenomatous polyposis. Conclusion: We suggest a possible role of MLH1 655A>G, MSH2 1168C>T, APC 4479G>A, and APC 3949G>C polymorphisms in the susceptibility to early onset of CRC. A single base pair deletion at codon 1205 (c.3613delA) of APC gene seems to be differentially associated with early-onset cases depending on having a family history of CRC.

TP53 Mutations In Patients With High-Risk Acute Myeloid Leukemia Treated With Allogeneic Hematopoietic Stem Cell Transplantation

PurposeThe treatment success in patients (pts) with acute myeloid leukemia (AML) is very heterogeneous. Cytogenetic and molecular alterations present at diagnosis are strong prognostic factors, which have been used to individualize treatment. As shown by several groups, the subgroup of pts with deletion of the short arm of chromosome 17 are at high risk for treatment failure (e.g. Seifert, Leukemia 2009), which persists even after allogeneic hematopoietic stem cell transplantation (HSCT) (Middeke, Blood 2012; Mohr, Br J Haematol 2013). Besides allelic loss of TP53 located on the short arm of chromosome 17, other mechanisms of inactivation have been shown for this key tumor suppressor gene, most importantly missense point mutations or small deletions. These alterations have also been linked to poor outcome in AML after chemotherapy (Grossmann, Blood 2012). Here, we studied the impact of TP53 mutations on the outcome of AML pts with adverse cytogenetic risk treated with HSCT. Patients and MethodsWe selected AML pts with complex karyotype (CK), monosomy 7, monosomy 5/del5q and/or abnl(17p) who had received HSCT within 3 randomized controlled trials (NCT numbers 00180115, 00180102, and 00180167). All pts were treated with intensive induction chemotherapy and HSCT according to a risk adapted strategy.Complete sequencing of the TP53coding region was done using next generation sequencing (NGS) on a 454 GS Junior instrument (Roche) using the IRONII-study amplicon panel. Amplicons were generated from genomic DNA isolated at the time of diagnosis. Data analysis was done using the Sequence Pilot software package (JSI Medical Systems), a 10% cut-off was used for mutation calling.Nonsynonymous mutations were classified into bi-allelic TP53 mutations if detected allelic frequency as determined by NGS was >50% and mono-allelic TP53 mutations for frequencies between 10% and 50%. All samples with synonymous mutations or no detectable mutations according to the predefined cut-off of 10% were classified as TP53wild type (wt).Overall survival (OS), event-free survival (EFS), cumulative incidence of relapse (CIR) and non-relapse-mortality (NRM) after HSCT were analyzed according to the mutational status. ResultsSamples from 97 pts with AML were analysed, the median age was 51 years (range 18 to 67), 83% suffered from de novo AML, while 13% had sAML and 3% therapy-related myeloid neoplasms. CK and monosomal karyotype (MK) were present in 61% and 42% of the pts, respectively. Twenty-nine pts (30%) had abnl(17p) detected by conventional karyotyping or FISH analysis. Twenty-six pts (27%) were treated with standard myeloablative conditioning (MAC) regimens while the remaining pts received reduced intensity conditioning (RIC). Donors were siblings in 36 pts (37%) and matched or mismatched unrelated donors in all other pts.Overall, TP53 mutations were found in 40 pts (41%). Twenty-eight (29%) pts had a bi-allelic TP53 mutation while 12 (12%) pts had a mono-allelic TP53 mutation. We identified 15 pts with TP53 mutations without abnl(17p). Four pts with abnl(17p) had wt TP53. Pts with TP53 mutations were significantly older than pts with wt TP53 AML (median age 55 vs. 43, p=.004). Donor type, type of conditioning and the rate of transplantation in first complete remission were not statistically different among pts with or without TP53mutations.With a median follow up of 67 months the three-year probabilities of OS and EFS for pts with wt TP53 were 33% (95% CI, 21% to 45%) and 24% (95% CI, 13% to 35%) compared to 10% (95% CI, 0% to 19%) and 8% (95% CI, 0% to 16%) (p=.002 and p=.007) for those with mutated TP53, respectively. CIR at three years was 42% for pts with wt TP53 and 60% for those with mutated TP53 (p=.05). NRM was not different in both groups. In multivariate analysis including age, donor type (sibling vs. all other), type of conditioning (RIC vs. MAC) and disease status (CR1 vs. advanced disease) only the TP53-mutation status had a significant influence on EFS (HR=1.72; p=.03). In our analysis, classification according to MK did not significantly influence OS, EFS, CIR or NRM. ConclusionIn this cohort of pts with cytogenetic adverse risk abnormalities, who had received HSCT, TP53 mutations were present in 41% of the pts. OS and EFS were significantly worse in pts with mutated TP53. Mutational analysis of TP53 might be an important additional tool to predict outcome after HSCT in pts with adverse karyotype AML. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

P-316 TP53 mutations in patients with myelodysplastic syndrome and isolated deletion (5q) treated with lenalidomide: Results from the German Le-Mon-5 trial

P-316 TP53 mutations in patients with myelodysplastic syndrome and isolated deletion (5q) treated with lenalidomide: Results from the German Le-Mon-5 trial

Detection of KRAS Codon 12 Mutations is not Associated with Concurrent Detection of TP53 Mutations in Patients With Rectal Cancer

Detection of KRAS Codon 12 Mutations is not Associated with Concurrent Detection of TP53 Mutations in Patients With Rectal Cancer

Abstract P3-06-02: Prevalence of TP53 p.R337H Mutation in Cases of Breast Phyllodes Tumours in Southern Brazil

Abstract Background: Previous studies in Brazilian patients diagnosed with the core-cancers of Li-Fraumeni syndrome (LFS) and its variants (LFL) indicate that a particular germline mutation, TP53 p.R337H, may be highly prevalent and strongly associated with pediatric adrenocortical tumors in Southern Brazil. However, other tumours types, including breast cancer, have been observed in carriers, raising the possibility that the TP53 p.R337H mutation may also contribute to breast tumorigenesis. Breast phyllodes tumour, a very rare and aggressive breast neoplasia that accounts for less than 1% of all breast cancer cases, may be associated with LFS, and has suggested by some to be particularly frequent in TP53 mutation carriers. Methods: Formalin fixed paraffin-embedded (FFPE) tissue from disease-free lymph nodes of an unselected consecutive series of women diagnosed with benign and malignant phyllodes tumours between 2000 and 2010, was obtained from 7 Pathology Laboratories in Southern Brazil. Genomic DNA was isolated from FFPE with the QIAamp DNA Tissue Kit. Genotyping was performed by qPCR using TaqMan technology and direct bi-directional sequencing for confirmation in mutation-positive cases. Results: Analysis of the first 48 cases included in the study (9 malignant, 3 borderline and 36 benign phyllodes tumors) resulted in identification of the TP53 p.R337H mutation in the germline of a 61 year-old patient with malignant phyllodes and a 38 year-old patient with a benign phyllodes tumor of the breast. Conclusion: Preliminary analysis of a case series of breast phyllodes tumors indicates that germline the founder mutation TP53 p.R337H may be particularly common in women with these tumors in Southern Brazil. Further analysis of the entire TP53 coding region and evaluation of the founder haplotype in the mutation-positive cases is ongoing. The identification of germline TP53 mutations in patients diagnosed with phyllodes tumors of the breast has important implications for disease management and in cancer risk counseling for these patients and families. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-06-02.

Associations between polymorphisms in DNA repair genes and TP53 mutations in non-small cell lung cancer

This study was conducted to identify genetic factors predisposing to TP53 mutations in patients with non-small cell lung cancer (NSCLC). A comprehensive panel of potentially functional single nucleotide polymorphisms (SNPs) in DNA repair genes was evaluated in relation to TP53 mutations. Thirty-seven SNPs in 28 DNA repair genes were genotyped by a sequenome mass spectrometry-based genotyping assay in 173 NSCLCs and the associations with TP53 mutations in the entire coding exons (exons 2–11), including splicing sites of the gene, were analyzed. Four SNPs (XPA rs1800975, OGG1 rs1052133, ADPRT rs1136410, and NBS1 rs1805794) were significantly associated with the prevalence of TP53 mutations in multivariate analysis for each SNP. When the 4 SNPs were combined, the prevalence of TP53 mutations was increased as the number of bad genotypes increased (Ptrend=0.001). Patients with 3 and 4 bad genotypes had a significantly higher frequency of TP53 mutations than those with 0–1 bad genotypes (adjusted odds ratio=5.18, 95% confidence interval=1.51–17.81, P=0.01 and adjusted odds ratio=18.26, 95% confidence interval=2.87–116.09, P=0.002, respectively). These findings suggest that the 4 SNPs may modulate the occurrence of TP53 mutations and contribute to lung carcinogenesis. However, larger studies are required to confirm our findings in other ethnic populations.

P53- The Molecular Guardian Crashes in Gastric Adenocarcinomas - A Study in an Ethnic Kashmiri Population

Genetic instability underlies the etiology of multistep gastric carcinogenesis. The p53 mutations observed in tumors represent the expression of such instability by allowing the accumulation of genetic alterations caused by multiple mechanisms. The present study was conducted to investigate the nature and frequency of TP53 mutations in patients with gastric adenocarcinomas of Kashmir valley. Tumor samples from 30 patients with primary gastric adenocarcinomas undergoing radical gastrectomy were evaluated. The mutational status of the p53 (exons 5 to 8) was screened by PCR-SSCP analysis followed by direct sequencing. Of all 30 gastric adenocarcinomas including ten intestinal types and twenty diffuse types, 20% patients (6/30) harbored mutations in the p53 gene. Overall, twenty-one mutations were found in TP53 in 30 patients included in this study. Mutations were found at codon 142 (3 cases) of exon 5, codon 144 (1 case) in exon 5, codon 147 (1 case) in exon 5, codon 157 (1 case) in exon 5, codon 169 (2 cases) in exon 5, codon 170 (3 cases) in exon 5, codon 172 (1 case) in exon 5, codon 173 (3 cases) in exon 5, codon 179 (3 cases) in exon 5, codon 180 (1 case) in exon 5, codon 213 (1 case) in exon 6, the insertional mutation was between codon 216 & 217 (1 case) in exon 6 and codon 287 in exon 8 (1 case). The mutation pattern comprised of 12 insertions, 6 substitutions (all transversions) and 3 deletions. All the twelve insertions represented frame-shift mutations. The six single-base substitutions leading to aminoacid substitution included four missense mutations and a single silent mutation. The mutation effect data was found to be significant (p< 0.05). This study exhibited signifi cant amount of mutation in exon 5 (OR=90.25 and p<0.05 within the CI of 12.47-652.89) of TP53 in the gastric adenocarcinoma patients from Kashmir valley. Comparison of mutation profi le with other ethnic populations and regions refl ected both differences and similarities indicating co-exposure to a unique set of risk factors. The differences could be due to exposure to explicit environmental carcinogens, different lifestyle, dietary or cultural practices of Kashmiris being an ethnic population that need further investigations. The direct sequencing results, therefore, shall help in understanding the molecular events associated with progression and metastasis in gastric carcinoma. Conclusions: p53 gene mutation incites the pathogenesis of human gastric adenocarcinomas.

TP53 Mutations and Outcome in Osteosarcoma: A Prospective, Multicenter Study

Mutations of the TP53 gene have been associated with resistance to chemotherapy as well as poor prognosis in many different malignancies. This is the first prospective study of the prognostic value of somatic TP53 mutations in patients with newly diagnosed extremity osteosarcoma. One hundred ninety-six patients with high-grade, nonmetastatic osteosarcoma of the extremities were enrolled from seven tertiary care institutions and observed prospectively for tumor recurrence (median follow-up duration, 44 months). All patients received neoadjuvant or adjuvant chemotherapy and surgery. Tumors were analyzed for the presence of TP53 mutations by polymerase chain reaction single-strand conformation polymorphism analysis and direct DNA sequencing. The association of the status of the TP53 gene with the risk of systemic recurrence was examined using survival analyses with traditional and histologic markers as prognostic factors. Patient age was the only factor that varied with TP53 gene status (P = .05). No relationship was identified between TP53 status and systemic relapse (relative risk, 1.24; P = .41). Analyses based on missense or nonsense mutations gave similar results (P > .10). In multivariate analysis, large (> 9 cm) tumor size (relative risk, 1.9; P = .006) and poor histologic response (< or = 90% necrosis) to chemotherapy (relative risk, 2.14; P = .02) were the only significant independent predictors of systemic outcome. We found no evidence that TP53 mutations predict for development of metastases in patients with high-grade osteosarcoma. Identification of other genes that influence chemotherapy response and clinical outcome in osteosarcoma is needed to facilitate further improvements in patient outcomes.

Screening for TP53 mutations in patients and tumours from 109 Swedish breast cancer families.

To estimate the prevalence of TP53 mutations in familial breast cancer, constant denaturant gel electrophoresis (CDGE) was used to screen exons 5-8 of the TP53 gene for germline mutations. Genomic DNA from 128 breast cancer patients belonging to 109 families with familial cancer were screened. No germline mutations were found in any of the patients. We also studied TP53 mutations in tumour DNA from 51 of the same individuals and found mutations in 14%. This is similar to what has been reported in sporadic breast cancer.