Detection of bcr-abl fusion in chronic myelogeneous leukemia by in situ hybridization.

Chronic myelogeneous leukemia (CML) is genetically characterized by fusion of the bcr and abl genes on chromosomes 22 and 9, respectively. In most cases, the fusion involves a reciprocal translocation t(9;22)(q34;q11), which produces the cytogenetically distinctive Philadelphia chromosome (Ph1). Fusion can be detected by Southern (DNA) analysis or by in vitro amplification of the messenger RNA from the fusion gene with polymerase chain reaction (PCR). These techniques are sensitive but cannot be applied to single cells. Two-color fluorescence in situ hybridization (FISH) was used with probes from portions of the bcr and abl genes to detect the bcr-abl fusion in individual blood and bone marrow cells from six patients. The fusion event was detected in all samples analyzed, of which three were cytogenetically Ph1-negative. One of the Ph1-negative samples was also PCR-negative. This approach is fast and sensitive, and provides potential for determining the frequency of the abnormality in different cell lineages.

Dosimetric analysis of the effects of the bladder volume on organs at risk (OAR) in high-dose-rate intracavitary brachytherapy in carcinoma cervix - an institutional study.

PURPOSE: The purpose of this study was to establish a dosimetric correlation between the bladder volume and its effects on the dose received by the organs at risk (OARs) (urinary bladder, rectum, and sigmoid) during computed tomography (CT)-guided high-dose-rate (HDR) brachytherapy in carcinoma cervix, and to determine an optimum bladder volume to limit the dose to OARs. MATERIAL AND METHODS: Seventy-five intracavitary applications in patients of carcinoma cervix (stage IIB, IIIA, IIIB, IVA) treated with external beam radiotherapy with concurrent chemotherapy followed by CT-based HDR intracavitary brachytherapy (tandem and ovoid type) at our institute between July 2014 to January 2016 were studied. The bladder volume at the time of imaging was noted and was correlated with the radiation dose received by bladder, rectum, and sigmoid colon. RESULTS: Dose volume histogram (DVH) parameters of the bladder increases by elevating the volume of the bladder. Rectum dose does not follow a continuous increasing trend. It increases up to a bladder volume of 110 cc and then starts decreasing. The highest rectal dose observed was in the bladder volume, range 70-110 cc. The minimum doses were recorded when the bladder volume was > 170 cc. Sigmoid colon DVH parameters follow a similar trend as that of the rectum. CONCLUSIONS: A relationship exists between the volume of the OARs and the dose received by them. A bladder volume of about 70 cm3 or less proved better for achieving the prescribed dose limits of bladder, rectum, and sigmoid. The correlations between the bladder volume and the doses received by the OARs were not significant.

Treatment of localized primary non-Hodgkin's lymphoma of bone in children: a Pediatric Oncology Group study.

PURPOSE: The treatment of primary lymphoma of bone (PLB) in children has traditionally included radiotherapy to the primary site; more recently, it has included systemic chemotherapy. Because of concern about the untoward effects of treatment in a disease that is curable, we attempted to determine whether radiotherapy can be safely excluded from treatment. PATIENTS AND METHODS: The results of three consecutive Pediatric Oncology Group (POG) studies were examined to determine the impact on outcome of radiotherapy as adjunctive treatment in children and adolescents receiving chemotherapy for early-stage primary lymphoma of bone. RESULTS: From 1983 to 1997, 31 patients with localized PLB were entered onto POG studies of early-stage non-Hodgkin's lymphoma (NHL). Between 1983 and 1986, seven patients were treated with 8 months of chemotherapy with irradiation (XRT) of the primary site. After 1986, patients were treated without XRT; four received 8 months of chemotherapy, and 20 received 9 weeks of chemotherapy. Primary sites were the femur (nine), tibia (eight), mandible (five), mastoid (one), maxilla (one), zygomatic arch (one), rib (one), clavicle (one), scapula (one), ulna (one), talus (one), and calcaneous (one). Histologic classification revealed 21 cases of large cell lymphoma, five cases of lymphoblastic lymphoma, two cases of small, noncleaved-cell lymphoma, and three cases of NHL that could not be classified further. One patient relapsed at a distant site 22 months after completion of therapy. There have been no deaths. CONCLUSION: Localized PLB is curable in most children and adolescents with a 9-week chemotherapy regimen of modest intensity, and radiotherapy is an unnecessary adjunct.

Wilms' tumour. Optimal treatment strategies.

Wilms' tumour (WT) is the most common renal tumour in children. Much progress has been made in the management of patients with this malignancy over the last 3 decades. The improved outcome has mainly resulted from the availability of cooperative national and international trials involving the National Wilms' Tumour Study Group (NWTS) and the International Society of Paediatric Oncology (SIOP). These groups have focused on optimising postoperative (NWTS) and preoperative (SIOP) therapy, respectively. The early studies by the NWTS (1 and 2) identified the following separate subgroups of patients (based on age and stage) that benefited either from the addition of irradiation to postoperative chemotherapy or from combination chemotherapy as opposed to single agents, and those patients who did not benefit from prolonged chemotherapy administration. Additionally, these studies identified histologic features associated with a poor outcome. The more recent studies by NWTS (3 and 4) concentrated on reducing treatment for low risk patients to avoid long term sequelae while intensifying therapy for patients with high risk features, such as those with unfavourable histology and/or metastatic disease. The early SIOP trials (1, 2 and 5) concluded that patients treated with preoperative therapy (chemotherapy alone or combined with irradiation) experienced fewer intraoperative tumour ruptures compared with patients who had immediate surgery. However, preoperative chemotherapy preserved tumour histology at surgical exploration better than preoperative irradiation. The more recent SIOP trials (6, 9 and 93-01) have compared the use of different preoperative treatment regimens as well as the intensity and duration of postoperative therapy based on prognostic features (stage and histology). These studies have also identified groups benefiting from the addition of irradiation and/or the use of a third chemotherapeutic agent. Bilateral WT occurs in a small percentage of patients and treatment strategies, although efficacious, are limited by the need to maximise residual renal parenchyma. Recurrent WT occurs in 10 to 15% of cases and although a proportion of patients are curable, the overall outcome is poor with 3-year survival being in the range of 30%. There are several ongoing studies utilising new drug combinations (carboplatin, cyclophosphamide and etoposide) attempting to improve the outcome for these patients. Overall, the majority of patients with WT will be cured and become long term survivors. Cooperative group studies continue to address the issue of minimising long term morbidity for low risk patients while maximising outcome for high risk patients.

Modified cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone therapy for posttransplantation lymphoproliferative disease in pediatric patients undergoing solid organ transplantation.

PURPOSE: The authors report the use of a cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (CHOP)-based chemotherapy regimen in treating six children with posttransplantation lymphoproliferative disorder (PTLD) that developed after solid organ transplantation. MATERIALS AND METHODS: The chemotherapy regimen consisted of a 29-day induction with CHOP and then as many as 15 cycles of maintenance therapy using methotrexate and cytarabine alternating with vincristine, adriamycin, mercaptopurine, and prednisone. RESULTS: All patients attained remission. One patient died of sepsis while in remission. Four of the five remaining patients have been followed-up in remission for as long as 8 years without losing the graft. One of the patients experienced relapse after completing therapy and subsequently died with disease. CONCLUSIONS: The authors conclude that pediatric patients with PTLD after solid organ transplantation that fails conservative management can be treated successfully with CHOP-based chemotherapy.

Consistent involvement of the bcr gene by 9;22 breakpoints in pediatric acute leukemias.

To investigate the relationship of bcr-abl fusion mRNAs with childhood acute lymphoblastic leukemias (ALL), we examined 27 pediatric Philadelphia chromosome (Ph1)-positive acute leukemias using a reverse polymerase chain reaction (PCR) procedure. In cells from 24 leukemias, single bcr-abl PCR products were detected that corresponded to breakpoints in the minor breakpoint cluster region (mbcr in intron 1 of the bcr gene) associated with production of the P190 fusion protein. Cells from the three remaining leukemias contained breakpoints in the major breakpoint cluster region (Mbcr) as shown by PCR and Southern blot analyses. These three leukemias also contained low levels of the mbcr PCR product that may have resulted from alternative splicing of the bcr-abl precursor RNA. A screen of 35 additional leukemias from patients who failed therapy before day 180 (induction failures or early relapses) found one case with unsuccessful cytogenetics to express Mbcr-abl RNA. All four children with Mbcr breakpoints had white blood cell levels in excess of 250,000 at presentation (compared with 2 of 24 with mbcr breakpoints) and two had hematologic and clinical features suggestive of chronic myelogenous leukemias (CML) in lymphoid blast crisis. Our results indicate that in Ph1-positive pediatric leukemias, all 9;22 breakpoints occur in one of the two known breakpoint cluster regions in the bcr gene on chromosome 22. The reverse PCR reliably detected all patients with cytogenetic t(9;22) and is capable of detecting additional Ph1-positive leukemias that are missed by standard cytogenetics. Furthermore, the Mbcr-type breakpoint, associated with production of p210, can be seen in childhood leukemias presenting either as clinical ALL or as apparent lymphoid blast crisis of CML, suggesting that t(9;22) breakpoint locations do not exclusively determine the biologic and clinical features of pediatric Ph1-positive ALL.

Nongestational choriocarcinoma in the postpartum period: a case report.

PURPOSE: To determine the tissue of origin (gestational versus nongestational) of an extensive metastatic choriocarcinoma in an 18-year-old woman to determine prognosis and treatment. METHODS: DNA microsatellite polymorphisms after polymerase chain reaction (PCR) amplification of the tumor tissue and blood from the patient, husband, and daughter were used to determine the tissue of origin. RESULTS: Molecular analyses revealed that the tumor shared the genetic features of only the patient. She responded well to multiagent chemotherapy. CONCLUSIONS: Molecular analysis is a useful tool to determine whether a choriocarcinoma occurring in a female patient of child-bearing age is gestational or nongestational when clinical findings are not clearly indicative of the primary.