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To standardize the results obtained in PML/RAR alpha RT-PCR detection by laboratories of hospitals involved in the Spanish Program for Treatment of Hematological Malignancies (PETHEMA) LPA-96, designed for the treatment of acute promyelocytic leukemia (APL), cDNA samples obtained by reverse transcription of RNA from bone marrow samples of patients with APL were sent to participating laboratories. During the first year of this external quality assessment trial nine samples were tested by a maximum of 12 laboratories. The control gene was satisfactorily amplified in 90% of the samples (62 of 69 samples), supporting the adequacy of the cDNA to be used as control sample. There was an 83% concordance between laboratories for PML/RAR alpha detection with similar results for the type of PML/RR alpha rearrangements. However, 17% disagreement still remained, attributable to low sensitivity or inadequacy of methods followed. The results stressed the need for implementation of an external quality assessment scheme to ensure the standardization of the results. [ABSTRACT FROM AUTHOR]

Conventional G-banding cytogenetics (CC) detects chromosome 17 (chr17) abnormalities in 2% of patients with de novo myelodysplastic syndromes (MDS). We used CC and fluorescence in situ hybridization (FISH) (LSI p53/17p13.1) to assess deletion of 17p in 531 patients with de novo MDS from the Spanish Group of Hematological Cytogenetics. FISH detected - 17 or 17p abnormalities in 13 cases (2.6%) in whom no 17p abnormalities were revealed by CC: 0.9% of patients with a normal karyotype, 0% in non-informative cytogenetics, 50% of patients with a chr17 abnormality without loss of 17p and 4.7% of cases with an abnormal karyotype not involving chr17. Our results suggest that applying FISH of 17p13 to identify the number of copies of the TP53 gene could be beneficial in patients with a complex karyotype. We recommend using FISH of 17p13 in young patients with a normal karyotype or non-informative cytogenetics, and always in isolated del(17p).

Integrative genomic and gene-expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene-expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated 20 homozygous deletions at 7 chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them were frequently silenced by epigenetic mechanisms. Notably, the pattern of genetic and epigenetic inactivation differed among B-NHL subtypes. Thus, the P53-inducible PIG7/LITAF was silenced by homozygous deletion in primary mediastinal B-cell lymphoma and by promoter hypermethylation in germinal center lymphoma, the proapoptotic BIM gene presented homozygous deletion in mantle cell lymphoma and promoter hypermethylation in Burkitt lymphoma, the proapoptotic BH3-only NOXA was mutated and preferentially silenced in diffuse large B-cell lymphoma, and INK4c/P18 was silenced by biallelic mutation in mantle-cell lymphoma. Our microarray strategy has identified novel candidate tumor suppressor genes inactivated by genetic and epigenetic mechanisms that substantially vary among the B-NHL subtypes.

Among 20 cases of typical splenic marginal zone lymphoma (SMZL), two cases had blastic transformation. The genetic mechanisms underlying the morphologic transformation were investigated by comparing genetic changes in initial and blastic phases. A complex karyotype including trisomy of 3q and genomic gain of 17q22-q24 was seen in both cases at diagnosis. However, the extra copy of 3q was lost during the transformation process in both tumors. Additionally, the Karpas 1718 cell line, which was derived from a patient with transformed SMZL and carried a trisomy of 3q, also evidenced the spontaneous loss of the extra 3q during the culturing process. Other acquired abnormalities observed exclusively in the transformation phase included amplification and/or translocation of bands 7p22-q22 and 19p13. These findings suggest that the loss of + 3q and the acquisition of other genomic imbalances may represent unique markers for the transformation process of SMZL. We hypothesize that the trisomy of 3q may correlate with the indolent nature of SMZL, and that the loss of this acquired abnormality leads to or accompanies the development of blastic tumors.

Patients with mantle cell lymphoma (MCL) may present with either nodal or leukemic disease. The molecular determinants underlying this different biologic behavior are not known. This study compared the pattern of genetic abnormalities in patients with nodal and leukemic phases of MCL using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) for specific gene loci. Although both leukemic and nodal MCL showed similar genomic patterns of losses (involving 6q, 11q22-q23, 13q14, and 17p13) and gains (affecting 3q and 8q), genomic loss of chromosome 8p occurred more frequently in patients with leukemic disease (79% versus 11%, P <.001). Subsequent CGH analysis confirmed the genomic loss of 8p21-p23 in 6 of 8 MCL cell lines. Interestingly, MYC gene amplification was restricted to cases with 8p deletion. These data indicate the presence of a novel tumor suppressor gene locus on 8p, whose deletion may be associated with leukemic dissemination and poor prognosis in patients with MCL.

Introduction: Mantle cell leukemia (MCLeu) has been considered as a leukemic form of mantle cell lymphoma (MCL). However, the presence of certain features rarely observed in MCL, such as transformation to prolymphocytic leukemia (PLL) or indolent clinical course, suggests that MCLeu may represent a distinct disorder., Methods: Seven cases of MCLeu with t(11;14)(q13;q32) and BCL1-IGH gene rearrangement were ascertained among 140 newly diagnosed chronic B-cell lymphoproliferative disorders with leukemic expression. Comparative genomic hybridization, FISH for specific gene loci, and immunological studies were preformed in them., Results: In comparison with CLL, MCLeu cases had low immunological scores < or =2 with respect to B-CLL (P<0.0001). Expression of CD38 was absent in 43% of MCLeu and in 44% of B-CLL. Comparative genomic hybridization analysis identified genomic imbalances in 86% of MCLeu with a similar pattern than in MCL: gains of 3q, 8q involving MYC gene and 15q, and losses of 6q, 9p, 13q and 17p affecting P53 gene. Differently from MCL and CLL, genomic loss of 8p was frequently detected in MCLeu (83%). Although clinical presentation of MCLeu was indistinguishable from CLL, all patients but one had disease progression within three years. According to the immunologic and genomic profiles, two distinct subgroups of MCLeu were defined: one related to PLL, showing CD38-, deletion of P53, and MYC amplification and another which corresponds to a leukemic form of classical MCL, presenting with CD38+ and normal P53 and MYC status., Conclusion: MCLeu and MCL are closely related disorders, as they show similar genomic and molecular patterns. However, the deletion of the short arm of chromosome 8 may represent a specific marker for MCLeu. Two distinct subgroups of MCLeu may also be distinguished according to the immunologic and genomic cell profiles.

We have analyzed retrospectively 439 women with recurrent breast cancer, followed at a single institution, in order to define potential prognostic factors for survival at the time of first recurrence. Median age at the time of first recurrence was 58 and the median disease free interval (DFI) from initial diagnoses to recurrence was 33 months. Thirteen percent of the patients did not receive any adjuvant therapy while 87% received different combinations of chemotherapy, radiotherapy and hormone therapy as adjuvant treatment. With a median follow-up of 44 months from the time of recurrence the median survival (MSR) was 24 months (SE 1.24) and five-year overall survival was 18% (SE 2.02). On the univariate analysis, pathological tumor size (pT) at diagnosis (p < 0.0006), axillary lymph node status at diagnosis (p < 0.00001), negative estrogen receptor (ER) status (p < 0.0001), negative progesterone receptor (PgR) status (p < 0.0001), adjuvant chemotherapy (p < 0.001), disease free interval (p < 0.00001), location of recurrence (p < 0.0002) and number of metastatic sites (> or = 3: p < 0.0003), were significantly associated with shorter survival from first relapse. On the multivariate analysis, only the site of recurrence, axillary lymph node status at diagnosis, ER status and DFI remained independently associated with decreased MSR after first relapse.