Per-Gunnar Nilsson

Pooled analysis of clinical and cytogenetic features in treatment-related and de novo adult acute myeloid leukemia and myelodysplastic syndromes based on a consecutive series of 761 patients analyzed 1976–1993 and on 5098 unselected cases reported in the literature 1974–2001

To ascertain the frequency of treatment-related acute myeloid leukemias and myelodysplastic syndromes (t-AML/t-MDS) in an unselected series, we have identified all adult cases analyzed in our department from 1976 to 1993. Further aims were to compare karyotypic features of t-AML/t-MDS with de novo AML/MDS, in our material as well as in 5098 unselected, cyto- genetically abnormal, published cases, and to analyze associations between type of prior therapy and karyotype. Among our 372 AML and 389 MDS, 47 (13%) were t-AML and 62 (16%) were t-MDS. Clonal abnormalities were significantly more common in t-AML and t-MDS than in de novo disease (68% vs 50%, P < 0.05 and 84% vs 45%, P < 0.001, respectively). Among the available 4230 AML and 1629 MDS (the present series and published cases), 14% were t-AML and 15% were t-MDS. In t-AML/t-MDS, the number of anomalies and the ploidy levels differed significantly from de novo cases, with complex and hypodiploid karyotypes being more common in t-AML/t-MDS. In t-AML, unbalanced changes in general, t(1;3), der(1;7), 3p−, −5, 5q−, −7, 7q−, t(9;11), t(11;19), t(11q23), der(12p), −17, der(17p), −18, and −21 were significantly more frequent than in de novo AML. In t-MDS, −5, −7, 7q−, 13q−, der(17p), and −18 were significantly more common. Type of prior treatment correlated significantly with number of anomalies in t-AML and with ploidy levels in t-AML/t-MDS. The frequencies of several aberrations varied with type of therapy, eg, 5q− was more frequent in radiotherapy-associated t-MDS, monosomy 7 was more common in t-AML and t-MDS after treatment with alkylators, and t(11q23) in t-AML was associated with topoisomerase II inhibitors. Abnormalities significantly more common in de novo disease were +8 as a sole anomaly, balanced changes in general, t(8;21), t(9;22), t(15;17), inv(16), and t(21q22) in AML, and −Y, 5q−, and 20q− as sole anomalies and +8 in MDS. The results emphasize the strong association between previous genotoxic exposure and karyotypic features.

Chromosome pattern, occupation, and clinical features in patients with acute nonlymphocytic leukemia

Chromosome banding pattern of bone marrow cells, cell morphology according to the FAB classification, and clinical finding were compared in two groups of adult patients with acute nonlymphocytic leukemia (ANLL): 52 patients occupationally exposed to chemical solvents, insecticides, or petrol products, and 110 patients with no history of occupational exposure to potential mutagenic/carcinogenic agents. Striking differences were found between the two groups: (1) Clonal chromosomal aberrations were present in 75% of exposed patients compared with only 32% in the nonexposed group. (2) Of the patients exposed to solvents and insecticides 92% had abnormal chromosomes, whereas only 29% of patients exposed to petrol products showed abnormalities; in the total material 10/13 exposed patients with normal chromosomes were exposed to petrol products. (3) The relationship between chromosomal abnormality and exposure was evident in both females and males. However, only 29% of women with an abnormal karyotype were exposed, whereas 70% of males with an abnormal karyotype were exposed. (4) The incidence of certain characteristic karyotypic abnormalities, i.e., -5/5q-, 7/7q-, +8, +21, t(8;21), and t(9;22), were decidedly more common in exposed than in nonexposed patients. At least one of these changes were present in 92% of exposed patients with aberrations, whereas in the nonexposed group the incidence was only 60%. (5) The monocytic varieties of ANLL (M4 + M5) were more common in the nonexposed patients, whereas erythroleukemia (M6) was more common in the exposed group. The predominance of abnormal karyotypes in the exposed compared to the nonexposed patients was similar in leukemia types M1 + M2 and in M4 + M5. (6) There was no difference in survival time between the two groups and the same correlation was obvious in both exposed and nonexposed patients: patients who had only abnormal metaphases had poorer prognosis than those with normal bone marrow metaphases only (6 vs 1.5 months). This correlation was obvious in patients classified as acute myeloid leukemia (AML) as well as in the monocytic varieties of ANLL.

A single-center population-based consecutive series of 1500 cytogenetically investigated adult hematological malignancies: karyotypic features in relation to morphology, age and gender.

Abstract:  During the 18‐yr period 1976–93, a population‐based series of 1586 adults with suspected or confirmed hematological malignancies were successfully cytogenetically investigated at a single center. Eighty‐six cases were excluded due to unretrievable medical records or if analyzed only in remission or at relapse. The remaining 1500 medical records were reviewed regarding morphology and clinical parameters in order to investigate possible associations between karyotypic pattern (normal, 1, 2 or complex anomalies; specific abnormalities) and gender, age and morphological subgroups. The impact of time‐period, i.e. 1976–87 vs. 1988–93, and referring center on cytogenetic findings was also studied. A total of 372 acute myeloid leukemias (AML), 389 myelodysplastic syndromes (MDS), 64 acute lymphoblastic leukemias (ALL) and 262 chronic myeloid leukemias (CML) were identified, altogether 1087 cases. Patients with other (n = 261) or no hematological malignancies (n = 152) were excluded from the present analysis. Cytogenetic abnormalities were detected in 52% AML, 51% MDS, 68% ALL and 97% CML, frequencies that did not differ significantly between the 2 time periods or referring centers. No significant age‐ or gender‐related differences in karyotypic patterns were discerned in AML, MDS, ALL or CML, whereas the karyotypic patterns varied among the FAB groups in both AML (p = 0.001) and MDS (p< 0.001). The specific abnormalities t(8;21), t(15;17) and inv(16) were more common (p<0.001) in younger AML patients and 5q‐ was more frequent in females with MDS (p< 0.001). These findings indicate, in contrast to previous series, that neoplasia‐associated karyotypic aberrations are not more common among older patients or in males.

Are occupational, hobby, or lifestyle exposures associated with Philadelphia chromosome positive chronic myeloid leukaemia?

OBJECTIVES To investigate a broad range of occupational, hobby, and lifestyle exposures, suggested as risk factors for Philadelphia chromosome positive (Ph+) chronic myeloid leukaemia (CML). METHODS A case-control study, comprising 255 Ph+CML patients from southern Sweden and matched controls, was conducted. Individual data on work tasks, hobbies, and lifestyle exposures were obtained by telephone interviews. Occupational hygienists assessed occupational and hobby exposures for each subject individually. Also, occupational titles were obtained from national registries, and group level exposure—that is, the exposure proportion for each occupational title—was assessed with a job exposure matrix. The effects of 11 exposures using individual data and two exposures using group data (organic solvents and animal dust) were estimated. RESULTS For the individual data on organic solvents, an effect was found for moderate or high intensity of exposure (odds ratio (OR) 3.4, 95% confidence interval (95% CI) 1.1 to 11) and for long duration (15–20 years) of exposure (OR 2.1, 95% CI 1.1 to 4.0). By contrast, the group data showed no association (OR 0.69, 95% CI 0.27 to 1.8; moderate or high intensity versus no exposure). For extremely low frequency electromagnetic fields (EMFs), only individual data were available. An association with long occupational exposure to EMFs was found (OR 2.3, 95% CI 1.2 to 4.5). However, no effect of EMF intensity was indicated. No significant effects of benzene, gasoline or diesel, or tobacco smoking were found. OR estimates below unity were suggested for personal use of hair dye and for agricultural exposures. CONCLUSIONS Associations between exposure to organic solvents and EMFs, and Ph+CML were indicated but were not entirely consistent.

Paired multiplex reverse-transcriptase polymerase chain reaction (PMRT-PCR) analysis as a rapid and accurate diagnostic tool for the detection of MLL fusion genes in hematologic malignancies

The MLL gene in chromosome band 11q23 is frequently rearranged in acute lymphoblastic and acute myeloid leukemias. To date, more than 50 different chromosomal regions are known to participate in translocations involving 11q23, many of which affect MLL. The pathogenetically important outcome of these rearrangements is most likely the creation of a fusion gene consisting of the 5′ part of the MLL gene and the 3′ end of the partner gene. Although abnormalities of the MLL gene as such are generally associated with poor survival, recent data suggest that the prognostic impact varies among the different fusion genes generated. Hence, detection of the specific chimeric gene produced is important for proper prognostication and clinical decision making. We have developed a paired multiplex reverse-transcriptase polymerase chain reaction analysis to facilitate a rapid and accurate detection of the most frequent MLL fusion genes in adult and childhood acute leukemias. To increase the specificity, two sets of primers were designed for each fusion gene, and these paired primer sets were run in parallel in two separate multiplex one-step PCR reactions. Using the described protocol, we were able to amplify successfully, in one single assay, the six clinically relevant fusion genes generated by the t(4;11)(q21;q23) [MLL/AF4], t(6;11)(q27;q23) [MLL/AF6], t(9;11)(p21–22;q23) [MLL/AF9], t(10;11)(p11–13;q23) [MLL/AF10], t(11;19)(q23;p13.1) [MLL/ELL], and t(11;19)(q23; p13.3) [MLL/ENL] in cell lines, as well as in patient material.

Cytogenetic polyclonality in hematologic malignancies

The present study was undertaken to ascertain the frequency of cytogenetic polyclonality in various hematologic malignancies and to investigate whether morphologic subgroup, age, gender, or previous genotoxic exposure influences the incidence. Among 2,243 cytogenetically investigated hematologic malignancies, 10 acute myeloid leukemias (AML), 5 myelodysplastic syndromes (MDS), 2 acute lymphoblastic leukemias (ALL), 1 acute undifferentiated leukemia (AUL), 1 atypical Philadelphia chromosome‐negative (Ph‐) chronic myeloid leukemia (CML), 1 chronic myeloproliferative disorder (CMD), and 1 chronic lymphoproliferative disorder (CLD) with karyotypically unrelated clones were identified, constituting 2.6% of AML, 1.6% of MDS, 0.8% of ALL, 13% of AUL, 9.1% of Ph‐ CML, 1.5% of CMD, and 2.8% of CLD with chromosomal abnormalities. In contrast to the cytogenetic features, the X‐inactivation pattern was monoclonal in the two informative female patients that could be investigated. Among 17,733 karyotypically aberrant published cases surveyed, significant frequency differences (P < 0.001) were discerned: 1.7% of 6,526 AML, 3.4% of 2,391 MDS, 0.4% of 1,920 Ph+ CML, 2.9% of 856 CMD, 0.9% of 4,226 ALL, and 5.8% of 1,814 CLD displayed unrelated clones. The incidence of cytogenetic polyclonality did not differ significantly among the MDS, CMD, or ALL subgroups, between males and females, between children (<16 years) and adults, or between B‐ and T‐cell ALL, whereas the frequencies varied among the AML FAB types (P < 0.05), among the different CLD entities (P < 0.001), and between B‐ and T‐cell CLD (P < 0.001). Furthermore, the incidence was higher in therapy‐related AML and MDS than in de novo AML and MDS (P < 0.001 and P < 0.01, respectively). Genes Chromosomes Cancer 24:222–229, 1999.

The prognostic impact of karyotypic subgroups in myelodysplastic syndromes is strongly modified by sex

The prognostic impact of karyotypic patterns in a consecutive series of 389 adult myelodysplastic syndromes (MDS) was investigated. Time period did not significantly influence the survival times. In the analyses, the MDS cases were subdivided into the cytogenetic subgroups used in the International Prognostic Scoring System, i.e. favourable [–Y, del(5q) or del(20q) as single aberrations or normal karyotype, n = 241], poor [−7, del(7q), der(1;7) or complex karyotypes, i.e. ≥ three abnormalities, n = 89] and intermediate (other aberrations, n = 59). The survival times correlated well with the prognostic subgroups, confirming that the cytogenetic classification was valid. Expressed as hazard ratios (HRs), with the favourable subgroup as the reference, the intermediate and poor subgroup HRs increased to 1·5 (95% confidence interval, 1·1–2·1) and 3·2 (2·4–4·1) respectively. Sex, age, morphological subtype and smoking habits significantly modified this prognostic impact. Shorter survival was detected for men in the favourable and the intermediate subgroups, but not in the poor prognosis subgroup. Using women in the favourable subgroup as the reference and adjusting for age, the HR for men was 1·6 (1·2–2·1) in the favourable subgroup. Adjusting for smoking habits as well decreased the HR to 1·4 (1·1–2·0) and, when also excluding cases with del(5q) as the sole anomaly, no significant difference could be discerned [HR 1·2 (0·9–1·6], suggesting that the better outcome for women in the favourable subgroup was mainly as a result of the ‘5q‐syndrome’ and to smoking habits. In the intermediate subgroup, the corresponding HRs were 3·0 (1·5–6·0) when adjusted for age and 2·7 (1·3–5·5) when also adjusted for smoking habits. Different survival times between men and women have never previously been reported for this MDS group. Although it remains to be elucidated whether environmental and/or constitutional factors cause the observed sex‐related difference, these observations have obvious clinical ramifications, not least in designing and evaluating therapy protocols.

Multicolor COBRA-FISH analysis of chronic myeloid leukemia reveals novel cryptic balanced translocations during disease progression.

During the initial indolent chronic phase of chronic myeloid leukemia (CML), the t(9;22)(q34;q11), resulting in the Philadelphia chromosome (Ph), is usually the sole cytogenetic anomaly, but as the disease progresses into the accelerated phase (AP), and eventually into aggressive blast crisis (BC), secondary aberrations, mainly unbalanced changes such as +8, i(17q), and +Ph, are frequent. To date, molecular genetic studies of CML BC have mainly focused on alterations of well‐known tumor‐suppressor genes (e.g., TP53, CDKN2A, and RB1) and oncogenes (e.g., RAS and MYC), whereas limited knowledge is available about the molecular genetic correlates of the unbalanced chromosomal abnormalities. Balanced secondary changes are rare in CML AP/BC, but it is not known whether cryptic chromosomal translocations, generating fusion genes, may be responsible for disease progression in a subgroup of CML. To address this issue, we used multicolor combined binary ratio fluorescence in situ hybridization (FISH), which allows the simultaneous visualization of all 24 chromosomes in different colors, verified by locus‐specific FISH in a series of 33 CML cases. Two cryptic balanced translocations, t(7;17)(q32–34;q23) and t(7;17)(p15;q23), were found in two of the five cases showing the t(9;22) as the only cytogenetic change. Using several BAC clones, the breakpoints at 17q23 in both cases were mapped within a 350‐kb region. In the case with the 7p15 breakpoint, a BAC clone containing the HOXA gene cluster displayed a split signal, suggesting a possible creation of a fusion gene involving a member of the HOXA family. Furthermore, one case with a partially cryptic t(9;11)(p21–22;q23) and an MLL rearrangement as well as a previously unreported t(3;10)(p22;p12–13) were identified. Altogether, a refined karyotypic description was achieved in 12 (36%) of the 33 investigated cases, illustrating the value of using multicolor FISH for identifying pathogenetically important aberrations in CML AP/BC.

Mixed micelles of ionic and nonionic surfactants: Quasielastic light scattering and nmr self—diffusion studies of C12E5-SDS micelles

Abstract Mixed micelles of C12H25(OCH2CH2)5OH(C12E5) and C12H25OSO3Na(SDS) have been studied by quasielastic light scattering and NMR self-diffusion. Over wide composition ranges, the light-scattering correlation function is distinctly bimodal with widely spaced decay times. The slow mode diffusion coefficients (10−11–10−12m2sec−1) are close to the self-diffusion coefficients obtained by the NMR method and are referred to the translational motion of the micelles. The fast mode (2–3 × 10−10 m2 sec−1) is interpreted as a collective mode involving strong electrostatic interactions. Micelle size varies strongly when the SDS content is varied and this is discussed in terms of electrostatic head group repulsions and steric packing restrictions.

Autologous and allogeneic stem cell transplantation in adult ALL: the Swedish Adult ALL Group experience

Summary:Adult patients with acute lymphoblastic leukaemia (ALL) have been treated according to national protocols in Sweden since 1986. Stem cell transplantation (SCT) has been recommended in first remission for patients with risk factors for relapse, and for standard risk patients only after relapse. In this retrospective study, the results of autologous and allogeneic SCT in these populations were evaluated. In total, 187 patients with a median age of 34 years (17–66 years) underwent SCT. The 5-year disease-free survival (DFS), for all patients, was 26% (Confidence intervals (CI) 20–32%). The 5-year DFS was higher for patients transplanted in first remission 32% (CI 24–40%) compared to 14% (CI 5–23%; P<0.0001) in patients transplanted beyond first remission. No significant differences in DFS (P=0.06) were determined between autologous, related donor and unrelated donor SCT in the whole cohort. A lower relapse rate was counterbalanced by higher treatment-related mortality in patients undergoing allogeneic SCT. In Philadelphia-positive ALL, allogeneic SCT was superior to autologous SCT, with a 5-year DFS of 30% (CI 12–47%) vs 0% (P=0.04). Limited chronic graft-versus-host-disease (GVHD) was associated with an improved DFS of 53% (CI 38–69%) compared to no chronic GVHD of 22% (CI 10–36%; P=0.0008), indicating a clinically important graft-versus-leukaemia effect.