Intermediate doses of melphalan and dexamethasone are better than vincristine, adriamycin, and dexamethasone (VAD) and polychemotherapy for the treatment of primary plasma cell leukemia.

Primary plasma cell leukemia (PPCL) is a rare form of disease accounting for 1-2 percent of myelomas. Between September 1990 and November 2000, among 540 patients with myeloma studied, 24 fulfilled the criteria of PPCL (4.4 percent). We found high frequencies of female patients (62 percent), Bence Jones proteinuria (79 percent), anemia (88 percent), bleeding (54 percent), confusional syndrome (42 percent), weight loss (71 percent), hepatomegaly (25 percent), splenomegaly (21 percent), leukocytosis (62 percent), and thrombocytopenia (71 percent). High serum levels of creatinine, calcium, lactate dehydrogenase (LDH), and beta(2)-microglobulin were detected in 50 percent, 37 percent, 58 percent, and 71 percent, respectively. Four patients were treated with vincristine, melphalan, cyclophosphamide, prednisone, and adriamycin (VMCPA), 12 with vincristine, adriamycin, and dexamethasone (VAD), and 8 with M-80 (oral melphalan 80 mg/m(2) plus dexamethasone 40 mg/m(2)). There was a trend toward lower values of Karnofsky score (P=0.07) and higher values of LDH (P=0.2) in the VAD group. Other clinical characteristics were comparable among the three groups. Complete plus partial responses were achieved in one and six patients treated with VMCPA and M-80, respectively. All patients treated with VAD failed to respond to treatment. Patients receiving the M-80 regimen experienced higher platelet toxicity (P=0.05), vomiting (P<0.0003), and mucositis. Also, the need for red blood cell transfusions was higher in the M-80 group. Median overall survival was 60 days. Overall survival was better in patients achieving complete or partial response. In conclusion, our study illustrates that intermediate doses of melphalan plus dexamethasone are an effective chemotherapy regimen for this aggressive disease. Response to treatment is the only prognostic factor for survival in these patients.

BCR/ABL p210, p190 and p230 fusion genes in 250 Mexican patients with chronic myeloid leukaemia (CML).

There are two major forms of the BCR/ABL fusion gene, involving ABL exon 2, but including different exons of BCR gene. The transcripts b2a2 or b3a2 code for a p210 protein. Another fusion gene leads to the expression of an e1a2 transcript, which codes for a p190 protein. Another, less common fusion gene is c3a2[e19a2], which encodes a p230 protein. The incidence of one or the other rearrangement in chronic myeloid leukaemia (CML) patients varies in different reported series. This study was designed to determine the frequency of coexpresion of the p210, p190 and p230 transcripts in 250 Mexican patients with CML. We performed nested and multiplex reverse transcriptase polymerase chain reaction (RT-PCR) on bone marrow samples from adult patients and found that all cases were positive for some type of BCR/ABL rearrangement. In 226 (90.4%) patients it was p210, while the remaining 9.6% showed coexpression or one of the transcripts of p190/p210/p230. In 7% of patients with p210 expression there are both isoforms (b3a2/b2a2), presumably the result of alternative splicing. The rate of coexpression of the p190/p210 transcripts was 5%, which is much lower than in other reports. This may be due to the technical factors. These patients had high platelet counts, marked splenomegaly and chromosomal abnormalities in addition to Ph'. Other types of coexpression seen were p210/p230 and p190/p210/p230, in patients with high-risk clinical factors. Our study confirms the occurrence of coexpression of different BCR/ABL transcripts, although the rate (9.6%) was much lower than has been reported in other populations. This may reflect either the sensitivity of the detection techniques used or the possibility of genetic differences between the populations studied. Coexpression may be due to alternative splicing or to phenotypic variation, with clinical courses different from classical CML.

Cytogenetic findings in 303 Mexican patients with de novo acute myeloblastic leukemia.

In this report we show the chromosomal changes seen in a group of 303 Mexican patients with de novo Acute Myeloblastic Leukemia (AML). Two hundred forty-two patients were diagnosed and treated at two hospitals affiliated with the Instituto Mexicano del Seguro Social (IMSS). These are the Centro Medico Nacional Siglo XXI and Centro Medico La Raza Hospitals; the remaining 61 patients were diagnosed and treated at the Hospital General de Mexico (HGM). Clonal abnormalities were detected in 75.6% of the patients; this result agrees with what has been reported in other large series of AML studies. The incidence of changes per hospital was similar in patients from the IMSS hospitals (72-75%), while an increase was seen in patients from the HGM (85.2%). The chromosomal changes seen in this study in order of frequency were: t(15;17)[18.8%], t(9;22)[9.2%], miscellaneous chromosomal changes (mainly rearrangements of chromosomes 1,2,3,12y17)[8.2%], abnormalities of 16q22 [7.3%], t(8;21)[6.3%], -7/del(7q)[5.6%], t(6;9)[5.3%], and abnormalities of 11q23 [4.6%]. We reported an increase in the incidence of certain types of chromosomal changes seen in cases of AML, in comparison with reports from other countries. These differences could be due to methodological variations, although ethnic, socioeconomic and nutritional differences must not be disregarded. We support this finding when comparing distribution of changes in the population of patients seen in the IMSS hospitals with those from the HGM; the main difference lies in the socioeconomic level.