p53 nuclear expression correlates with hemizygous TP53 deletion and predicts an adverse outcome for patients with relapsed/refractory multiple myeloma treated with lenalidomide.

del(17p13)(TP53) seems to be an independent poor prognostic factor in patients with relapsed/refractory multiple myeloma (MM) receiving lenalidomide. However, whether aberrant p53 nuclear expression detected by immunohistochemical analysis can be used as a surrogate marker for del(17p13)(TP53) in prognostic evaluation of lenalidomide-treated relapsed/refractory MM remains unclear. The p53 expression in myeloma cells from 88 patients was evaluated by immunohistochemical analysis, and 17p13(TP53) gene status was examined by fluorescence in situ hybridization (FISH). FISH detected hemizygous del(17p13)(TP53) in 13 (15%), and immunohistochemical analysis detected p53 nuclear expression in 11 cases (13%). del(17p13) (TP53) and p53 expression were strongly correlated (P < .0001). Furthermore, patients with aberrant p53 nuclear expression had significantly shorter progression-free and overall survival than patients without this abnormality. Our results suggest that p53 nuclear expression is associated with adverse outcome in patients with relapsed/refractory MM receiving lenalidomide-based therapy and that p53 immunohistochemical analysis may serve as a simple, rapid method to predict del(17p13)(TP53) in this patient subgroup.

Analysis of chromosome 12p deletion in plasma cell dyscrasias.

The prognostic relevance of 12p deletion is controversial in multiple myeloma (MM) and the status of 12p deletion is unknown in other plasma cell disorders. We investigated 12p deletion in 88 patients with MM, 19 patients with monoclonal gammopathy of undetermined significance (MGUS), and 17 patients with plasma cell leukemia (PCL). Cytoplasmic immunoglobulin light chain immunofluorescence with simultaneous FISH analysis (cIg-FISH) detected hemizygous 12p deletion in 8% of MM and 24% of PCL, respectively, but in none of the MGUS cases (p=0.0366). 12p deletions were found in 5 of 7 (71%) MM patients at diagnosis with stage III disease (Durie-Salmon), 2 of 7 (28%) with stage I or II. Of 11 cases with 12p deletions, 6 (55%) had coexistence of p53 deletions, including 3 of 7 (42%) MM, and 3 of 4 (75%) PCL cases. There were no significant differences in progression free or overall survivals in MM patients with or without 12p deletions. Our results do not support the use of 12p deletion as a prognostic marker in MM, rather, it tends to occur in advanced disease, may represent a secondary change associated with the disease progression.

Cyclin kinase subunit 1B nuclear expression predicts an adverse outcome for patients with relapsed/refractory multiple myeloma treated with bortezomib.

Amplification of cyclin kinase subunit 1B gene on chromosome 1q21 resulting in overexpression of cyclin kinase subunit 1B has been associated with disease progression in multiple myeloma. Bortezomib is a proteasome inhibitor that induces apoptosis in various cancer cells and has been shown to be effective as a salvage therapy for relapsed/refractory multiple myeloma. Our group has recently reported the adverse effect of 1q21 gains in relapsed and refractory multiple myeloma treated with bortezomib. However, whether nuclear cyclin kinase subunit 1B protein expression correlates with 1q21 gains and has prognostic value in patients with multiple myeloma receiving bortezomib regimen remains unclear. We, therefore, evaluated the nuclear expression of cyclin kinase subunit 1B protein in patients with relapsed/refractory multiple myeloma undergoing bortezomib therapy by immunohistochemistry. The 1q21 amplification status of the same cohort was examined by interphase cytoplasmic immunoglobulin fluorescence in situ hybridization. Of 60 cases, 19 (32%) were positive for cyclin kinase subunit 1B nuclear expression by immunohistochemistry. Seventeen (89%) of the immunohistochemistry-positive cases had 1q21 gain detected by cytoplasmic immunoglobulin fluorescence in situ hybridization, and 17 (77%) of the 22 cases with 1q21 gain showed increased cyclin kinase subunit 1B protein expression. cyclin kinase subunit 1B expression and 1q21 gain were strongly correlated (P < .0001). There was no significant difference in response rate between patients with and without cyclin kinase subunit 1B nuclear expression. However, patients with cyclin kinase subunit 1B expression had a significantly shorter progression-free survival (1.9 versus 5.6 months; P < .0001) and overall survival (4.9 versus 22.4 months; P = .012) compared with those without cyclin kinase subunit 1B expression. Our results indicated that cyclin kinase subunit 1B nuclear expression detected by immunohistochemistry is an adverse prognostic factor for patients with multiple myeloma treated with bortezomib therapy.

Genomic aberrations and survival of patients with light-chain-only multiple myeloma undergoing autologous stem cell transplantation.

The majority of patients with multiple myeloma (MM) have intact immunoglobulin, but in a subset of patients (∼15%), their tumors produce monoclonal light chains only (LCO). Although specific genomic aberrations have emerged as a major prognostic factor in MM, their incidence and prognostic impact on LCO myeloma patients are not clear. We therefore investigated a cohort of 86 LCO MM cases diagnosed and treated with autologous stem cell transplantation at our institution. Overall, genomic risk factors del(13q), del(17p), t(4;14), 1p loss, and 1q21 gain were detected by cytoplasmic fluorescence in situ hybridization (cIg-FISH) in 40.6%, 18.5%, 11.9%, 18.8%, and 25% of the cases, respectively. Patients with del(13q) and 1q gains had a significantly shorter overall survival (OS) (median 80.4 vs 56.2 months, P = .021; median 77.9 vs 26.9 months, P = .006, respectively) and shorter progression-free survival (PFS) (median 33.4 vs 15.8 months, P = .002; median 33.4 vs 19.1 months, P = .011, respectively) than those without the genetic abnormalities. In addition, 1p loss was significantly associated with shorter PFS (median 37.9 vs 18.2 months, P = .001). There was no significant difference in PFS or OS in patients with or without t(4;14) or del(17p). On multivariate analysis, del(13q) was an independent prognostic factor for PFS and OS.

Impact of genomic aberrations including chromosome 1 abnormalities on the outcome of patients with relapsed or refractory multiple myeloma treated with lenalidomide and dexamethasone.

Previous literature suggests that cytogenetics may be used for risk-adapted therapy in patients with relapsed/refractory multiple myeloma (MM) treated with lenalidomide and dexamethasone. However, the significance of each abnormality is still unclear, and chromosome 1 abnormalities have yet to be studied in this population. We therefore evaluated genetic risk factors including chromosome 1q gain and 1p loss by cIg-FISH in 143 patients with relapsed/refractory MM treated with lenalidomide and dexamethasone, and correlated the genomic aberrations with patient clinical outcomes. Patients had a median of two (range 1-7) previous therapies in this cohort. A total of 119 out of 143 (83%) patients had an objective response, with median time to progression (TTP) and overall survival (OS) of 11 and 28 months, respectively. Patients with del(1p21) or del(17p) (p53) deletions had a significantly shorter TTP. OS was shorter in patients with 1p21 or 17p deletions, but did not reach statistical significance. Prior bortezomib or thalidomide treatment was associated with shorter TTP and OS. Multivariate analysis identified del(17p), del(1p21), and prior bortezomib or thalidomide therapy as independent risk factors for shorter TTP. Our data suggest that chromosome 17p and 1p21 deletions adversely impact the outcome of lenalidomide and dexamethasone treated patients with relapsed/refractory MM. Improved therapeutic strategies are required for these patients.

CKS1B nuclear expression is inversely correlated with p27Kip1 expression and is predictive of an adverse survival in patients with multiple myeloma.

BACKGROUND: CKS1B is a member of the highly conserved cyclin kinase subunit 1 (CKS1) family that interacts with cyclin-dependent kinases and plays an important role in cell cycle progression. We and others have shown that CKS1B amplification located on chromosome 1q21 is an adverse prognostic factor in multiple myeloma, but its relationship with CKS1B nuclear protein expression, is unclear. The aim of this study was to correlate nuclear CKS1B protein immunoreactivity, 1q21 amplification status, p27(Kip1) expression and survival in patients with newly-diagnosed multiple myeloma. DESIGN AND METHODS: Nuclear expression of CKS1B and p27(Kip1) was evaluated by immunohistochemistry in decalcified, paraffin-embedded bone marrow biopsies from 94 patients with newly diagnosed multiple myeloma. Clonal plasma cells of the bone marrow aspirates from the same cohort were examined for CKS1B gene status by interphase cytoplasmic fluorescence in situ hybridization. RESULTS: Fluorescence in situ hybridization detected the 1q21 amplification in 36 (38%) of the 94 patients and immunohistochemistry showed CKS1B protein expression in 37 (39%). Thirty-two (86%) of the 36 amplified (1q21) cases expressed CKS1B and 31 (84%) of the 37 CKS1B immunore-active cases had amplified 1q21. 1q21 amplification and CKS1B protein expression were strongly correlated (P<0.0001). CKS1B protein expression was inversely correlated with p27(Kip1) immunostaining (P<0.0001) and was associated with a shorter overall survival (median 44.5 versus 89.3 months, P<0.0001). CONCLUSIONS: Immunohistochemistry for CKS1B is a simple, rapid method that appears to predict 1q21 amplification and adverse outcome for risk stratification of patients with multiple myeloma.

Cytoplasmic expression of nucleophosmin accurately predicts mutation in the nucleophosmin gene in patients with acute myeloid leukemia and normal karyotype.

Mutations in the nucleophosmin (NPM1) exon 12 resulting in delocalization of NPM1 into the cytoplasm occur in 50% to 60% of acute myeloid leukemia cases with a normal karyotype (AML-NK). As recent studies suggest such patients have a favorable prognosis and there are discordant reports of the immunohistochemical detection of cytoplasmic NPM1 (NPMc+) for predicting NPM1 gene mutations, we correlated the immunohistochemical detection of NPMc+, NPM1 gene mutations, and prognosis in 57 cases of AML-NK. All 31 NPMc+ cases (54% of total) had NPM1 mutations, but none of the 26 nucleus-restricted (NPMc-) cases (46% of total) had NPM1 mutations (P < .0001). NPM1 mutations were correlated with FLT3-internal tandem duplication (ITD) (P = .0062), absence of CD34 (P = .0001), and absence of CD7 (P = .041). There was a favorable survival outcome in AML-NK cases that were NPM1 mutated and FLT3-ITD nonmutated. Our data confirm that cytoplasmic NPM1 immunoreactivity predicts NPM1 mutations and warrants inclusion in the routine diagnostic and prognostic workup of AML.

Aberrant nuclear p53 expression predicts hemizygous 17p (TP53) deletion in chronic lymphocytic leukemia.

Hemizygous TP53 gene deletion is the most important adverse risk factor in chronic lymphocytic leukemia (CLL), but its relationship with p53 protein expression is unclear. We investigated 110 CLL cases and correlated nuclear p53 protein immunoreactivity with TP53 gene deletion status and other CLL-associated genetic risk factors. Fluorescence in situ hybridization detected hemizygous TP53 deletions in 15 cases (13.6%), whereas immunohistochemical analysis detected nuclear p53 protein expression in 14 (12.7%). All cases expressing nuclear p53 protein had hemizygous TP53 deletions. Hemizygous TP53 gene deletion and p53 protein expression were strongly correlated (P < .001). There was no association between p53 expression and del(13q), del(11q) or trisomy 12 in CLL cases. Our data indicate that nuclear p53 protein expression, detected by a widely available immunohistochemical method, is strongly associated with TP53 deletion and that p53 immunohistochemical analysis may be adopted as a rapid, robust diagnostic tool for risk stratification of CLL.

Prognostic relevance of 6q deletion in Waldenström's macroglobulinemia: a multicenter study.

The deletion of the long arm of chromosome 6 is the most common cytogenetic abnormality in Waldenstrom's macroglobulinemia (WM), but its prognostic significance is unclear. We investigated 77 patients with WM by interphase cytoplasmic immunoglobulin M fluorescence in situ hybridization (cIgM-FISH) and correlated the 6q status with the patients' clinical features and survival. cIg-FISH detected hemizygous 6q deletions in 32 patients (41.6%). The 6q deletions were correlated with higher C-reactive protein levels (P = .02) and CD23 expression (P = .03) but not with other clinical laboratory features of WM. There was no significant difference in time to the initial treatment between deleted and non-deleted groups (median, 5.6 months vs. 2.6 months; P = .46), or overall survivals in patients with and without del (6q) (163 months vs. not reached; P = .83). Our study confirms that the 6q deletion is a frequent event, but it does not appear to affect the clinical outcome of WM.

Aberrant nuclear p53 protein expression detected by immunohistochemistry is associated with hemizygous P53 deletion and poor survival for multiple myeloma.

Hemizygous TP53 deletion is an adverse risk factor in multiple myeloma (MM) but its relationship with p53 protein expression is unclear. We investigated 105 newly diagnosed myeloma patients and correlated nuclear p53 protein immunoreactivity with TP53 deletion status, myeloma-associated genetic risk factors and survival. Fluorescence in situ hybridisation (FISH) detected hemizygous TP53 deletions in 13 (12%) patients while immunohistochemistry detected nuclear p53 protein expression in 12 (11%). Ten (77%) of the 13 del(TP53) cases expressed nuclear p53 protein while 10 (83%) of the 12 nuclear p53 immunoreactive cases had hemizygous TP53 deletions. Hemizygous TP53 deletion and p53 protein expression were strongly correlated (P < 0.001). The overall survival of patients with p53 protein expression was significantly shorter than that of patients without p53 expression (P < 0.001). A multivariate analysis including other myeloma-associated genetic risk factors confirmed p53 expression as an independent risk factor for survival. Our data indicate that nuclear p53 protein expression, detected by a widely available immunohistochemical method, is strongly associated with TP53 deletion and an adverse clinical outcome for MM.

p53 gene deletion detected by fluorescence in situ hybridization is an adverse prognostic factor for patients with multiple myeloma following autologous stem cell transplantation.

We investigated the relevance of p53 deletions to the clinical outcome of patients with multiple myeloma (MM) treated with high-dose chemotherapy and autologous stem cell transplantation. Hemizygous p53 gene deletions were detected by fluorescence in situ hybridization in 10 of 105 (9.5%) patients studied. p53 deletions were associated with higher serum calcium (P = .0062) and creatinine (P = .013) levels, but there were no association with patient age, gender, beta2-microglobulin, C-reactive protein, hemoglobin, albumin or bone lytic lesions, or immunoglobulin isotype. There were no associations of p53 deletions with 13q deletions or translocations t(11;14) or t(4;14). Patients with p53 deletions had significantly shorter progression-free (median, 7.9 versus 25.7 months, P = .0324) and overall survival (median, 14.7 versus 48.1 months, P = .0008) than patients without a p53 deletion. A multivariate analysis confirmed p53 deletion was an independent prognostic factor predicting shortened progression-free (P = .0009) or overall survival (P = .0002) in patients with MM after high-dose chemotherapy and autologous stem cell transplantation.