Daniel L. Van Dyke

DIPSS Plus: A Refined Dynamic International Prognostic Scoring System for Primary Myelofibrosis That Incorporates Prognostic Information From Karyotype, Platelet Count, and Transfusion Status

PURPOSE The Dynamic International Prognostic Scoring System (DIPSS) for primary myelofibrosis (PMF) uses five risk factors to predict survival: age older than 65 years, hemoglobin lower than 10 g/dL, leukocytes higher than 25 × 10(9)/L, circulating blasts ≥ 1%, and constitutional symptoms. The main objective of this study was to refine DIPSS by incorporating prognostic information from karyotype, platelet count, and transfusion status. PATIENTS AND METHODS Mayo Clinic databases for PMF were used to identify patients with available bone marrow histologic and cytogenetic information. RESULTS Seven hundred ninety-three consecutive patients were selected and divided into two groups based on whether or not their referral occurred within (n = 428; training set) or after (n = 365; test set) 1 year of diagnosis. Multivariable analysis identified DIPSS, unfavorable karyotype, platelets lower than 100 × 10(9)/L, and transfusion need as independent predictors of inferior survival. Hazard ratio (HR)-weighted adverse points were assigned to these variables to develop a composite prognostic model using the training set. The model was subsequently validated in the test set, and its application to all 793 patients resulted in median survivals of 185, 78, 35, and 16 months for low, intermediate-1 (HR, 2.2; 95% CI, 1.4 to 3.6), intermediate-2 (HR, 4.9; 95% CI, 3.2 to 7.7), and high-risk groups (HR, 10.7; 95% CI, 6.8 to 16.9), respectively (P < .001). Leukemia-free survival was predicted by the presence of thrombocytopenia or unfavorable karyotype (10-year risk of 31% v 12%; HR, 3.3; 95% CI, 1.9 to 5.6). CONCLUSION DIPSS plus effectively combines prognostic information from DIPSS, karyotype, platelet count, and transfusion status to predict overall survival in PMF. In addition, unfavorable karyotype or thrombocytopenia predicts inferior leukemia-free survival.

Evidence for a Turner Syndrome Locus or Loci at Xp11.2-p22.1

Turner syndrome is the complex human phenotype associated with complete or partial monosomy X. Principle features of Turner syndrome include short stature, ovarian failure, and a variety of other anatomic and physiological abnormalities, such as webbed neck, lymphedema, cardiovascular and renal anomalies, hypertension, and autoimmune thyroid disease. We studied 28 apparently nonmosaic subjects with partial deletions of Xp, in order to map loci responsible for various components of the Turner syndrome phenotype. Subjects were carefully evaluated for the presence or absence of Turner syndrome features, and their deletions were mapped by FISH with a panel of Xp markers. Using a statistical method to examine genotype/phenotype correlations, we mapped one or more Turner syndrome traits to a critical region in Xp11.2-p22.1. These traits included short stature, ovarian failure, high-arched palate, and autoimmune thyroid disease. The results are useful for genetic counseling of individuals with partial monosomy X. Study of additional subjects should refine the localization of Turner syndrome loci and provide a rational basis for exploration of candidate genes.

RARE TRISOMY MOSAICISM DIAGNOSED IN AMNIOCYTES, INVOLVING AN AUTOSOME OTHER THAN CHROMOSOMES 13, 18, 20, AND 21: KARYOTYPE/PHENOTYPE CORRELATIONS

In order to determine the significance of trisomy mosaicism of an autosome other than chromosomes 13, 18, 20, and 21, 151 such cases diagnosed prenatally through amniocentesis were reviewed. These rare trisomy mosaicism cases include 54 from 17 cytogenetic laboratories, 34 from a previous North American mosaicism survey, and 63 from published reports. All were cases of true mosaicism with information available on pregnancy outcome, and with no evidence of biased ascertainment. There were 11 cases of 46/47,+2; 2 of 46/47,+3; 2 of 46/47,+4; 5 of 46/47,+5; 3 of 46/47,+6; 8 of 46/47,+7; 14 of 46/47,+8; 25 of 46/47,+9; 2 of 46/47,+11; 23 of 46/47,+12; 5 of 46/47,+14; 11 of 46/47,+15; 21 of 46/47,+16; 7 of 46/47,+17; 1 of 46/47,+19; and 11 of 46/47,+22. As to the risk of an abnormal outcome, the data showed a very high risk (>60 per cent) for 46/47,+2, 46/47,+16, and 46/47,+22; a high risk (40–59 per cent) for 46/47,+5, 46/47,+9, 46/47,+14, and 46/47,+15; a moderately high risk (20–39 per cent) for 46/47,+12; a moderate risk (up to 19 per cent) for 46/47,+7 and 46/47,+8; a low risk for 46/47,+17; and an undetermined risk, due to lack of cases, for the remaining autosomal trisomy mosaics. Most cases were evaluated at birth or at termination, so subtle abnormalities may have escaped detection and developmental retardation was not evaluated at all. Comparison of the phenotypes of prenatally diagnosed abnormal cases and postnatally diagnosed cases with the same diagnosis showed considerable concordance. Since the majority of anomalies noted are prenatally detectable with ultrasound, an ultrasound examination should be performed in all prenatally diagnosed cases. In cytogenetic confirmation studies, the data showed much higher confirmation rates in cases with abnormal outcomes than in cases with normal outcomes [81 per cent vs. 55 per cent for fibroblasts (from skin, fetal tissue, and/or cord); 88 per cent vs. 46 per cent for placental cells; 22 per cent vs. 10 per cent for blood cells]. The confirmation rate reached 85 per cent when both fibroblasts and placental tissues were studied in the same case (with trisomic cells found in one or the other, or both). Therefore, one must emphasize that both fibroblasts and placental tissues should be studied. Except for 46/47,+8 and 46/47,+9, PUBS is of limited value for prenatal diagnosis of rare trisomy mosaicism. DNA studies for UPD are suggested for certain chromosomes with established imprinting effects, such as chromosomes 7, 11, 14, and 15, and perhaps for chromosomes 2 and 16, where imprinting effects are likely.

Clinical significance of Y chromosome loss in hematologic disease.

We have studied 215 male patients (aged 45–97 years) whose sole cytogenetic abnormality was clonal loss of the Y chromosome in metaphase cells from unstimulated cultures. The patients comprised a control group with no evidence of hematologic disease and four disease case groups: 1) myelodysplastic syndrome (MDS), refractory anemia, refractory anemia with excess blasts (RAEB), RAEB in transformation, and chronic myelomonocytic leukemia; 2) acute myelogenous leukemia; 3) myeloproliferative disorder (MPD), chronic granulocytic leukemia, and polycythemia vera; and 4) B‐cell lymphoma/leukemia. The frequency of cells with Y loss increased with age and was significantly greater in cases than in controls, but it was not correlated with survival or with prior therapy. The frequency of cases with a ‐Y clone was 6.3% of male karyotypes and represented 16.4% of all abnormal male cytogenetic reports. Much of the difference between cases and controls appears to be accounted for by a greater frequency of cases with > 75% Y loss. A value of 81% chromosome Y loss maximized the combined sensitivity (28%) and specificity (100%) for predicting disease status, but a 75% cutoff provided the best estimate of disease risk. Even in older males, if > 75% of metaphase cells are 45,X,‐Y, they probably represent a disease‐associated clonal population, and it is possible that the critical genetic change is not visible through the microscope. This observation is true for MDS, MPD, B‐cell disease, and especially acute myelogenous leukemia. The prognostic association of Y chromosome loss for survival appears to be neutral or favorable. Genes Chromosomes Cancer 27:11–16, 2000.

De novo deletion 17p13.1 chronic lymphocytic leukemia shows significant clinical heterogeneity: the M. D. Anderson and Mayo Clinic experience

To determine the clinical fate of patients with de novo deletion 17p13.1 (17p-) chronic lymphocytic leukemia (CLL), we retrospectively studied the outcome of 99 treatment-naive 17p- CLL patients from the M. D. Anderson Cancer Center (n = 64) and the Mayo Clinic (n = 35). Among 67 asymptomatic patients followed for progression, 53% developed CLL requiring treatment over 3 years. Patients who had not progressed by 18 months subsequently had stable disease, with 3 of 19 patients progressing after follow-up of up to 70 months. Risk factors for progressive disease were Rai stage of 1 or higher and unmutated immunoglobulin variable region heavy chain (IgVH). The overall survival rate was 65% at 3 years. Rai stage 1 or higher, unmutated IgVH, and 17p- in 25% or more of nuclei were adverse factors for survival. The 3-year survival rates of patients with 1 or fewer, 2, and 3 of these factors were 95%, 74%, and 22%, respectively (P < .001). Response rates to therapy with rituximab (n = 6); purine analogues and rituximab (n = 25); and purine analogues, rituximab, and alemtuzumab (n = 16) combinations were 50%, 72%, and 81%, respectively. Patients with 17p- CLL exhibit clinical heterogeneity, with some patients experiencing an indolent course. Survival can be predicted using clinical and biologic characteristics.

Common clonal origin of synchronous primary head and neck squamous cell carcinomas: Analysis by tumor karyotypes and fluorescence in situ hybridization

Two synchronously arising primary squamous cell carcinomas (SCC) originating from separate sites in the anterior floor of mouth (FOM) and the pyriform sinus (PS) were evaluated by karyotype and fluorescence in situ hybridization (FISH) to determine whether they were of common or independent ancestry. The primary tumors were designated Henry Ford Hospital (HFH)-SCC-8a (FOM) and HFH-SCC-9a (PS), and the respective recurrent tumors after chemotherapy and radiation were designated -8b and -9b. HFH-SCC-8a and -8b were cultured and had closely related hypotetraploid karyotypes of monoclonal origin. Karyotypes could not be obtained from the second primary tumor HFH-SCC-9a or its recurrence -9b. However, we used karyotypes from HFH-SCC-8a and -8b as a guide to select FISH probes for the histological evaluation of genetic markers in tumor sections. Fluorescence in situ hybridization on metaphase chromosomes from the cell cultures was useful in modifying the tumor karyotypes. Fluorescence in situ hybridization identified a chromosome Y rearrangement that was not obvious from the HFH-SCC-8a and -8b karyotypes, and this Y rearrangement served as a unique clonal marker. Using two probes for the Y chromosome we showed that all four tumors shared the same Y rearrangement with loss of Yq (DYZ1) and retention of Ycen (DYZ3). Furthermore, FISH showed that all four tumors had the same aneuploidy patterns for chromosomes X, Y, 7, 9, 15, 16, and 17. From karyotypic and FISH analysis disomy for X and 9 centromere regions and the rearranged Y were all predicted and observed in the tumor tissue sections. Tetrasomy and trisomy for 7, 15, 16, and 17 were predicted from the karyotypes and this also was observed using FISH in all four tumors. These FISH aneuploidy patterns and the presence of a clonal Y marker in all four tumor samples indicate that the synchronous primaries and their recurrences were of monoclonal origin.

Methylprednisolone-rituximab is an effective salvage therapy for patients with relapsed chronic lymphocytic leukemia including those with unfavorable cytogenetic features

Chronic lymphocytic leukemia (CLL) patients with aggressive molecular characteristics such as deletion of 17p13.1 do not respond to conventional treatments and have a shorter survival. Studies suggest that high-dose methylprednisolone (HDMP) has activity in such patients and combining HDMP with rituximab may enhance efficacy. We identified 37 patients with CLL treated with the HDMP-rituximab who had follow-up at Mayo Clinic. Nine of 27 (33%) had deletion of 17p13.1 and six of 27 (22%) had deletion of 11q22.3. After a median of one cycle of HDMP-rituximab, 29 (78%) patients had an objective response according to the National Cancer Institute CLL Working Group Criteria including five of nine patients with deletion of 17p13.1. Eight (22%) patients had a complete clinical response. Although well tolerated, 11 (29%) patients developed infectious complications before completing one month of therapy. Three-year survival was 41% (95% CI: 26 – 66%). HDMP-rituximab is an active regimen in patients with relapsed, refractory, and cytogenetically high-risk CLL. Further evaluation of this regimen in controlled trials appears warranted.

Incidence and significance of chromosome mosaicism involving an autosomal structural abnormality diagnosed prenatally through amniocentesis: A collaborative study

Among 179 663 prenatal diagnosis cases collected from ten institutions and two publications, 555 (0·3 per cent) were diagnosed as having chromosome mosaicism. Of these, 57 (10·3 per cent) were mosaic for an autosomal structural abnormality, 28 (5 per cent) for a sex chromosome structural abnormality, and 85 (15·3 per cent) were mosaic for a marker chromosome. Ninety‐five cases of prenatally diagnosed mosaicism with a structural abnormality in an autosome and a normal cell line, and with a known phenotypic outcome, were collected for karyotype–phenotype correlations through our collaboration (40 cases), a prior survey (26 cases), and published reports (29 cases). They included 13 balanced reciprocal translocations, one unbalanced reciprocal translocation, four balanced Robertsonian translocations, four unbalanced Robertsonian translocations, four inversions, 17 deletions, three ring chromosomes, 19 i(20q), seven +i(12p), six other isochromosomes, and 17 partial trisomies resulting from a duplication or other rearrangement. All cases mosaic for a balanced structural rearrangement resulted in a normal phenotype. All cases of 46/46,i(20q) resulted in normal liveborns. Five of seven cases with 46/47,+i(12p) had an abnormal phenotype compatible with Killian–Pallister syndrome. The overall risk for an abnormal outcome for a mosaic case with an unbalanced structural abnormality, excluding 46/46,i(20q) and 46/47,+i(12p), is 40·4 per cent. In the same category, the study also suggested a correlation between the percentage of abnormal cells and an abnormal phenotype. For mosaicism involving a terminal deletion, the possibility of a familial fragile site should be considered.

Preclinical validation of fluorescence in situ hybridization assays for clinical practice

Purpose: Validation of fluorescence in situ hybridization assays is required before using them in clinical practice. Yet, there are few published examples that describe the validation process, leading to inconsistent and sometimes inadequate validation practices. The purpose of this article is to describe a broadly applicable preclinical validation process.Methods: Validation is performed using four consecutive experiments. The Familiarization experiment tests probe performance on metaphase cells to measure analytic sensitivity and specificity for normal blood specimens. The Pilot Study tests a variety of normal and abnormal specimens, using the intended tissue type, to set a preliminary normal cutoff and establish the analytic sensitivity. The Clinical Evaluation experiment tests these parameters in a series of normal and abnormal specimens to simulate clinical practice, establish the normal cutoff and abnormal reference ranges, and finalize the standard operating procedure. The Precision experiment measures the reproducibility of the new assay over 10 consecutive working days. To illustrate documentation and analysis of data with this process, the results for a new assay to detect fusion of IGH and BCL3 associated with t(14;19)(q32;q13.3) in lymphoproliferative disorders are provided in this report.Results: These four experiments determine the analytic sensitivity and specificity, normal values, precision, and reportable reference ranges for validation of the new test.Conclusion: This report describes a method for preclinical validation of fluorescence in situ hybridization studies of metaphase cells and interphase nuclei using commercial or home brew probes.

Conventional cytogenetics in myelofibrosis: literature review and discussion.

The clinical phenotype of myelofibrosis (MF) is recognized either de novo (primary) or in the setting of polycythemia vera (post‐PV) or essential thrombocythemia (post‐ET). Approximately one‐third of patients with primary MF (PMF) present with cytogenetic abnormalities; the most frequent are del(20q), del(13q), trisomy 8 and 9, and abnormalities of chromosome 1 including duplication 1q. Other less frequent lesions include −7/del(7q), del(5q), del(12p), +21 and der(6)t(1;6)(q21;p21.3). In general, cytogenetic abnormalities are qualitatively similar among PMF, post‐ET MF and post‐PV MF although their individual frequencies may differ. Based on prognostic effect, cytogenetic findings in MF are classified as either ‘favorable’ or ‘unfavorable’. The former include normal karyotype or isolated del(20q) or del(13q) and the latter all other abnormalities. Unfavorable cytogenetic profile in both PMF and post‐PV/ET MF confers an independent adverse effect on survival; it is also associated with higher JAK2V617F mutational frequency. In addition to their prognostic value, cytogenetic studies in MF ensure diagnostic exclusion of other myeloid neoplasms that are sometimes associated with bone marrow fibrosis (e.g. BCR‐ABL1‐positive or PDGFRB‐rearranged) and also assist in specific treatment selection (e.g. lenalidomide therapy is active in MF associated with del(5q).