SIL-TAL1 fusion gene negative impact in T-cell acute lymphoblastic leukemia outcome.

SIL-TAL1 fusion gene and the ectopic expression of HOX11L2 are common molecular abnormalities in T-cell acute lymphoblastic leukemia (T-ALL). To verify their influence on outcome, we analyzed a Brazilian pediatric T-ALL series of cases. One hundred and ninety two children, age ranged 0-21 years old, were consecutively diagnosed and treated. Reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to identify the molecular alterations. Kaplan-Meyer method was applied to estimate overall survival. The most frequent maturation stage was T-IV (40.1%), and 30.7% of cases were CD10(+). SIL-TAL1(+) and HOX11L2(+) accounted for 26.7% and 10.3% of the cases, respectively. The overall survival (OS) was 74% in 80-month follow-up. HOX11L2(+) was not predictive factor for outcome. Considering patients younger than nine years-old, those with SIL-TAL1(+) presented a poorer outcome (p = 0.02). The results of this study suggest that in the Brazilian population only the presence of SIL-TAL1 can predict outcome in a restricted group of patients.

PML-RARalpha fusion gene transcripts and biological features in acute promyelocytic leukemia patients.

Acute promyelocytic leukemia (APL) is characterized by the presence of rearrangements involving the retinoic acid receptor alpha (RARalpha) gene and a variable incidence in different populations. The hybrid gene PML-RARalpha, present in 98% of cases, encodes a fusion protein essential to the pathogenesis of the disease. Depending of the PML's gene breakpoint in chromosome 15, the transcript subtypes bcr1, bcr2 and bcr3 may be formed. The correlation between these transcript subtypes and clinical parameters is still controversial. The objective of this study was to determine the frequencies of the PML-RARalpha transcripts and subtypes in a series of 32 APL patients from Northeast Brazil and to evaluate the association of these subtypes to different parameters. The method used was RT-PCR. The frequency of our APL cases is approximately 28% of the acute leukemias. The results showed the presence of PML-RARalpha isoform in all patients and a higher frequency of the bcr1/2 subtype. No significant statistical association was found between molecular subtypes and age, sex, French-American-British (FAB) classification, leukocyte and platelet count, hemoglobin level or coagulation tests. In conclusion, these data suggest similar molecular and biological features for our APL patients at diagnosis in comparison with those reported in current scientific literature.

Treatment of acute promyelocytic leukemia: a single institution experience.

The results of the treatment of 14 patients with promyelocytic leukemia (PML) treated with all trans-retinoic acid (ATRA), combined chemotherapy (CT) and prophylactic prednisone are reported; the median age was 30 years (range 7 - 49). A complete remission (CR) was obtained in 13 / 14 patients (93%). All patients were given ATRA fully as outpatients; the CR was achieved after the administration of ATRA in five patients, whereas in the remaining eight, CT was required to achieve it. There were no instances of the ATRA syndrome. One patient relapsed with a PML/RAR-a negative PML 575 days after achieving the CR, failed to respond again to ATRA and died. The median overall (OS) and disease free survival (DFS) has not been reached, being above 4,000 days, whereas the 12-month DFS was 93%, the three and five years DFS being 85%. The treatment employed differs from others in: Oral prednisone is used prophylactically, ATRA is given on an outpatient basis and adriamycin is used instead of other anthracyclines. The results are similar to those obtained in other centers worldwide and it is possible that the prophylactic administration of prednisone precluded the development of the full-blown ATRA syndrome in this group of patients.

Treatment of acute promyelocytic leukemia: A single institution experience / Tratamiento de la leucemia promielocítica aguda: Experiencia de una sola institución

The results of the treatment of 14 patients with promyelocytic leukemia (PML) treated with all trans-retinoic acid (ATRA), combined chemotherapy (CT) and prophylactic prednisone are reported; the median age was 30 years (range 7 - 49). A complete remission (CR) was obtained in 13 / 14 patients (93%). All patients were given ATRA fully as outpatients; the CR was achieved after the administration of ATRA in five patients, whereas in the remaining eight, CT was required to achieve it. There were no instances of the ATRA syndrome. One patient relapsed with a PML/RAR-a negative PML 575 days after achieving the CR, failed to respond again to ATRA and died. The median overall (OS) and disease free survival (DFS) has not been reached, being above 4,000 days, whereas the 12-month DFS was 93%, the three and five years DFS being 85%. The treatment employed differs from others in: Oral prednisone is used prophylactically, ATRA is given on an outpatient basis and adriamycin is used instead of other anthracyclines. The results are similar to those obtained in other centers worldwide and it is possible that the prophylactic administration of prednisone precluded the development of the full-blown ATRA syndrome in this group of patients.

Se informan los resultados del tratamiento en una sola institución de 14 pacientes con leucemia aguda promielocítica (LAPM) en quienes se empleó la combinación de ácido holotrans-retinoico (ATRA) quimioterapia combinada y prednisona profiláctica. La mediana de edad fue de 30 años (rango 7-49). Se obtuvo remisión completa (hematológica y molecular) (RC) en 13 pacientes (93%); a todos los pacientes se les administró el ATRA de manera ambulatoria. La RC se obtuvo con el ATRA en cinco pacientes; en los demás la RC se obtuvo después de habérseles administrado la quimioterapia con citarabina/adriamicina. No hubo ningún caso de síndrome de ATRA. Un paciente recayó con una LAPM PML/ RAR-a negativa, 575 días después de haber logrado la RC y falleció. Otro paciente recayó 20 meses después de haber logrado la RC y fue rescatado con el mismo esquema de tratamiento; permanece en segunda remisión molecular por más de seis años. La mediana de supervivencia (SV), tanto global como libre de recaídas de todo el grupo, no se ha alcanzado y es mayor de 4,000 días, en tanto que la SV a 12 meses fue de 93% y a tres y cinco años de 85%. El esquema de tratamiento usado difiere de otros en que se usa prednisona oral, se administra el ATRA de manera ambulatoria y se usa adriamicina y no otras antracidinas; los resultados son similares a los obtenidos con otros esquemas parecidos en otros sitios del mundo; es posible que el uso profiláctico de prednisona haya eliminado la ocurrencia del síndrome de ATRA.

Analysis of ETV6/RUNX1 fusions for evaluating the late effects of cancer therapy in ALL (acute lymphoblastic leukemia) cured patients.

Acute Lymphoblastic Leukemia (ALL) is the most common malignancy in childhood. The improvements of therapies have increased the number of long-term survivors. However, an increased incidence of secondary neoplasias has been observed in this cohort. Our purpose was to evaluate the late effects of cancer therapy in cured patients previously treated for ALL, considering previous reports on the occurrence of gene fusions as putative markers of chromosomal instability. Twelve ALL patients (aged 5 to 16 years) and twelve healthy subjects (aged 18 to 22 years) were studied for the presence of ETV6/RUNX1 (TEL/AML1) translocations, which were detected by FISH (fluorescence in situ hybridization). The blood samples were collected months or years after completion of the therapy, and the frequencies of gene fusions in lymphocytes were compared with those obtained retrospectively for bone marrow samples at the time of diagnosis, and also for the control group. It was demonstrated that ETV6/RUNX1 gene fusion was a frequent event (0.59-1.84/100 cells) in peripheral blood lymphocytes from normal individuals and the ALL patients who underwent chemotherapy showed significantly (P = 0.0043) increased frequencies (0.62-3.96/100 cells) of the rearrangement when compared with the control groups (patients at diagnosis and healthy subjects). However, a significant difference was not found between the groups of patients at diagnosis and healthy subjects, when the two patients who were positive for the rearrangement were excluded. Therefore, increased frequencies of ETV6/RUNX1 fusions in ALL cured patients indicate the influence of previous exposure to anti-cancer drugs, and they may represent an important genetic marker for estimating the risk of relapse, or development of secondary neoplasias.