Chromosomes and causation of human cancer and leukemia. VII. The significance of the Ph1 in conditions other than CML

Philadelphia chromosome positive myelodysplastic syndrome and acute myeloid leukemia—retrospective study and review of literature

We conducted a retrospective study to define the significance of Philadelphia chromosome (Ph) in myelodysplastic syndrome and acute leukemia in the adults at this institution and the literature was reviewed. One hundred forty-eight cases of t(9;22)(q34;q11) were identified for the period September 1993 through August 2001. The presentation of 124 cases (84%) was that of typical CML in chronic phase. Nineteen cases (13%) presented as de novo ALL, two cases (1%) presented as de novo AML and three cases (2%) presented as myelodysplastic syndrome (MDS). The estimated incidences of t(9;22)(q34;q11) in ALL and AML are 21 and 0.6%, respectively. Ph+ AMLs are increasingly being reported with either M-BCR or m-BCR gene rearrangements, similar to those found with Ph+ ALL lending support to the notion that Ph+ AMLs are distinct entities and not merely blastic phases of undiagnosed CML. This is further supported by the existence of Ph+ MDS cases.

Acquisition of a Philadelphia chromosome concomitant with transformation of a refractory anemia into an acute leukemia

The authors present a case of Philadelphia (Ph1) positive acute myeloblastic leukemia (AML) following a refractory anemia with excess of blasts (RAEB) that had been Ph1-negative for 17 months. During the transformation of RAEB into AML, the Ph1 was discovered in 100% of the examined cells. With therapy a partial remission was obtained, during which some 46,XY cells reappeared mixed with Ph1 cells along with a new clone: 47,XY,+11 originating from a Ph1-negative cell. During the terminal blast crisis, the karyotype returned to 46,XY,Ph1. The AML lasted 21 months. The authors discuss: (1) the significance of Ph1-positive AML with a review of the literature; (2) the de novo acquisition of a Ph1 during the course of a blood disorder; and (3) the meaning of a second abnormal clone originating from 46,XY cells.

Ph1-positive acute leukemia

Twenty-five cases of Ph1-positive acute leukemia (AL) are described, 13 presenting an acute lymphocytic leukemia (ALL) and 12 an acute non-lymphocytic leukemia (ANLL). In 12 cases coarse, pink, peroxidase-negative cytoplasmic granules were found in the leukemic cells. These granules have not been described in Ph1-negative AL and their presence appears to be pathognomonic of Ph1-positive acute leukemia. The leukemias of three patients consisted of both lymphoid and myeloid clones while the cells of two patients had lymphoid and myeloid markers simultaneously present in the same cells. Cytogenetic studies were useful for monitoring response and some patients clearly acquired a Ph1-negative status during clinical remission. The disease appears to be more resistant to chemotherapy than Ph1-negative acute leukemia. While similar to chronic myelocytic leukemia (CML) in the Ph1 translocation, Ph1 AL differed from it both in age at presentation and response to therapy.

Philadelphia chromosome-positive adult acute leukemia with monosomy of chromosome number seven: a subgroup with poor response to therapy

Thirty-four adult patients were seen at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston, Texas between 1969 and 1980 with acute leukemia (AL) and a deleted G-group chromosome that was shown by Giemsa banding to be a Philadelphia (Ph1) chromosome t(9;22) in 21 patients. Fourteen had the Ph1 chromosome as the sole abnormality, 12 had the Ph1 chromosome and loss of one chromosome of the C-group (identified by Giemsa banding analysis as number 7 in eight patients), while eight had the Ph1 chromosome and other changes. These three groups were similar in sex, age distribution and hematologic parameters. The median age of 40 was lower than usually seen in AL. The distribution of the morphologic subtypes was similar to that seen at this institution, with 50% being acute myeloblastic, 12% acute myelomonocytic, 20% lymphoblastic and 18% acute undifferentiated. The complete remission rate with chemotherapy was low: 25% in the Ph1 +/- 7, 50% in the Ph1 +/other group and 43% in the Ph1 +/other group. Median survival time was 8 months for the Ph1 +/- 7 group, 5.5 months for the Ph1 +/other group and 9.0 months for the Ph1 +/alone group. These patients with Ph1 + AL had higher white blood cell counts, increased extramedullary disease and poorer responses to therapy than usual for patients with AL. The deletion of chromosome 7 and the acquisition of the Ph1 chromosome identifies a group of patients with characteristics similar to all the patients with Ph1 + AL but a poor response to therapy and short remission duration.

The significance of Ph1 mosaicism: a report of six cases of chronic granulocytic leukaemia and two cases of acute myeloid leukaemia

Six cases of chronic granulocytic leukaemia (CGL) and two cases of acute myeloid leukaemia (AML) with dual populations of karyotypically normal and Philadelphia (Ph1) chromosome-positive cells are described. GTG and QF-banding characterized the Ph1 as resulting from a 9/22 translocation in all eight cases. Four of the patients suffering from CGL presented with 100% Ph1-positive bone marrows, and after receiving intensive chemotherapy, karyotypically normal cells were demonstrated. The other two patients with CGL showed Ph1 mosaicism at presentation. The two patients with AML exhibited Ph1 mosaicism at presentation and throughout the course of the disease. In both of these patients, a marker No. 10 chromosome was found in some of the Ph1-positive cells and in one hyperdiploidy was observed to have developed only in the clone with the additional chromosome anomaly.

Chromosomes and causation of human cancer and leukemia. XXXII. Unusual features of Ph1-positive acute myeloblastic leukemia (AML), including a review of the literature

Five cases of Ph1-positive AML were studied. In all cases a Ph1-chromosome was shown with banding techniques to be due to a translocation between chromosomes No. 9 and No. 22. Cases 1 and 4 were found to have more than one Ph1 with evidence of only on Ph1-translocation accompanying other chromosome abnormalities. Two cases represented an unusual pattern of appearance and disappearance of the Ph1-positive clone during their clinical courses: Case No. 2 was originally Ph1-positive (46,XY,Ph1) but two months before his expiration the Ph1-positive clone was completely replaced by a newly developed Ph1-negative clone with an abnormal chromosome No. 21 (46,XY,21q+), whereas case No. 3, primarily Ph1-negative, developed a Ph1-positive clone among the previously karyotypically normal cells one month before death. The Ph1-positive AML cases presented have been discussed in relation to: 1) the genesis and significance of the Ph1-positive clone, 2) differentiation from the blastic phase of CML and 31 the general experience with Ph1-positive acute non-lymphocytic leukemia (ANLL), the world literature of which have been tabulated.

Lymphoblastic transformation of Ph1-positive chronic myeloid leukaemia: therapeutic implications and relevance to haemopoietic stem cell theory

A proportion of patients with blast crisis of CML have blast cells identical to those found in common non-T, non-B all, and whilst this disease is often referred to as lymphoid blast crisis (LBC), evidence is presented that it may in fact arise from a prelymphoid, pre-myeloid (pluripotential) stem cell. Recently developed membrane and enzyme markers (anti-ALL antiserum, TdT assay) have provided convenient diagnostic tests for the detection of LBC. The clinical and haematological features of LBC are reviewed: patients with LBC show a higher response rate to therapy with vincristine and prednisolone, and their survival may be significantly prolonged. The frequent occurrence of meningeal leukaemia suggests the need for prophylactic CNS therapy in LBC patients achieving remission.

The significance of the Philadelphia chromosome in acute lymphoblastic leukaemia: a report of two cases

Two cases of Philadelphia chromosome (Ph1) positive acute lymphoblastic leukaemia are reported, both of which lost the Philadelphia chromosome during remission. In one patient remission of the acute lymphoblastic leukaemia continued but classical Ph1 positive chronic granulocytic leukaemia developed. In the other patient relapse of the acute lymphoblastic leukaemia occurred associated with the return of the Ph1 chromosome. The evidence suggests that the chromosome aberration occurred in a pluripotential stem cell, which in one case proliferated along both a lymphoid cell line and a myeloid cell line. Both cases responded well to conventional therapy for acute lymphoblastic leukaemia.

Acute myeloid leukaemia with the Philadelphia chromosome

A case report of serial chromosome studies on a 26-year-old male with acute myeloid leukaemia (AML) is presented. The classic Philadelphia chromosome (Ph1) translocation, t (9;22) was found in 77% of the metaphases at diagnosis and in 100% in relapse; during a 3-month remission period the cytogenetic picture was normal or the Ph1 was present in a minor cell population only. The clinical and morphologic features of this case indicated that it was really a case of AML and less likely chronic myeloid leukaemia (CML) presenting in blast crisis. It is suggested that the oncogen producing the 9;22-translocation and CML may also induce AML in rare instances.

Erythroblastic transformation of chronic granulocytic leukemia

Erythroblastic transformation of chronic granulocytic leukemia was found in seven of 67 unselected patients with blast crisis. This morphologic picture of erythroblastic transformation was indistinguishable from that in erythroleukemia or Di Guglielmo's syndrome. The median survival of the patients with erythroblastic transformation was two months, considerably less than the four-month median survival in the entire series of 67 patients. Only two brief partial remissions were obtained with combination chemotherapy. The causes of death were primarily hemorrhage and infection, related to thrombocytopenia and neutropenia. In this regard, the patients with erythroblastic transformation resembled all the patients with blast crisis and patients with acute leukemia in general. The erythroblastic transformation seems to represent a morphologic variant of chronic granulocytic leukemia blast crisis, without apparent prognostic or therapeutic implications.

The Philadelphia chromosome (Ph1) in adults presenting with acute leukaemia: a comparison of Ph1+ and Ph1-patients

To evaluate the frequency and clinical significance of the Philadelphia chromosome (Ph1) in adult acute leukaemia, bone marrow chromosomes were studied in 15 adults with acute lymphocytic leukaemia (ALL) and 55 with acute nonlymphocytic leukaemia (ANLL). Morphology, clinical findings, therapeutic response and survival were compared in patients with and without the Ph1. The Ph1 was found in six newly diagnosed adults presenting with ALL. Adults with Ph1+ ALL differed from those with Ph1-ALL in being older, in having more frequent lymphadenopathy and splenomegaly and in demonstrating higher initial leucocyte counts and more peripheral blasts. Complete remissions were obtained in all nine adults with Ph1-All but in only three of six with Ph1+ ALL. Adults with Ph1-ALL survived significantly longer. Four adults with ANALL were Ph1+. They did not respond to treatment and survived significantly shorter periods than adults with Ph1-ANLL. No clinical or morphologic features indicated which patients with acute leukaemia would have the Ph1. Since the presence of the Ph1 in acute leukaemia has therapeutic and prognostic significance, marrow chromosome studies should be performed in adults presenting with acute leukaemia, especially ALL.

Chronic myelocytic leukaemia presenting in blastic transformation. Two cases primarily diagnosed as acute myelocytic leukaemia

The interval from diagnosis of chronic myelocytic leukaemia (CML) to onset of blastic transformation (BT) can vary from days to several years. This blastic phase of CML is indistinguishable from acute myelocytic leukaemia (AML), both clinically and morphologically. The Ph1 chromosome has occasionally been demonstrated in acute leukaemia and it has been suggested that these cases may represent CML presenting in BT. 2 such patients are reported, in 1 of whom the characteristics after treatment further confirmed the diagnosis of CML. Differentiation between CML presenting in BT and AML has both prognostic and therapeutic value. For this reason it is recommended that cytogenetic screening for the Ph1 chromosome should be included in the initial examination of patients with acute leukaemia.

Philadelphia chromosome in acute leukemia: case report

A case report of serial chromosome studies on a child presumed to have acute lymphoblastic leukemia (ALL) is presented. Hematologic remission was achieved after 3 weeks and maintained until death 63 weeks later. The classic Philadelphia chromosome translocation was found, both at diagnosis and throughout the course of the disease, in a proportion of cells from PHA-stimulated blood cultures. The finding is related to other reports of Philadelphia-positive clones in ALL, as well as those in chronic myeloid leukemia and its acute transformation, and other myeloproliferative disorders. The origin of the Philadelphia chromosome in this case is considered in the light of current stem cell theory, and its relevance to lymphocytic neoplasia is discussed. We believe that the finding of a Ph1-positive clone in a cell line morphologically indistinguishable from normal lymphocytes in a case of acute leukemia is unique.

Blast crisis as an initial or terminal manifestation of chronic myeloid leukemia. A study of 28 patients

The clinical and morphologic features of nine patients who initially presented with blastic leukemia and the Philadelphia chromosome were studied. Corresponding features were evaluated at the time of diagnosis of blast crisis in 19 patients who had a previous history of chronic myeloid leukemia (CML). Although many of the presenting symptoms and signs were similar, infections, lymphadenopathy, tissue infiltration and central nervous system involvement were more common in patients who presented with blastic leukemia. Marked leukocytosis, basophilia and marrow hypercellularity were present in both groups. Although patients in both groups had morphologic patterns that resembled acute leukemia, cytology suggestive of acute lymphocytic leukemia was more frequent in patients who initially presented with blastic leukemia. Megakaryocyte, platelet and erythroid abnormalities were more frequent in patients with a prior history of CML. Although there were clinical and morphologic features in the patients who presented with blastic leukemia which suggested the diagnosis of CML in blast crisis, chromosome studies were necessary to identify some of these patients. In both groups of patients multiple therapeutic regimens were used. Complete remissions were obtained in two patients; both presented with blastic leukemia, had "lymphoblastic" morphology and were treated with chemotherapeutic agents generally used for the treatment of acute lymphocytic leukemia. It appears that morphology of the blast crisis may be important in choosing the treatment regimen.

Ph1-positive megakaryoblastic leukemia

A case of megakaryoblastic leukemia is presented. Megakaryoblastosis and erythrocytic hyperplasia of the bone marrow, thrombocythemia, and hepatosplenomegaly were the essential features; 100% of the marrow-derived metaphases were found to be Ph1-positive. Cytologic and chromosomal findings are compatible with the assumption that all three marrow systems were involved in the leukemic process.