Role of RT-PCR and FISH in diagnosis and monitoring of acute promyelocytic leukemia

BACKGROUND

Patients with a presence of Promyelocytic Leukemia-Retinoic Acid Receptor Alpha (PML-RARA) genes rearrangement predict a favorable response to all-trans retinoic acid (ATRA), and a significant improvement in survival. Therefore, establishing the presence of PML-RARA rearrangement is important for optimal patient management.

AIM

The objective of this study is to compare and assess the role of fluorescent in situ hybridization (FISH) and reverse transcriptase polymerase chain reaction (RT-PCR) in the diagnosis and long-term monitoring of Acute Promyelocytic Leukemia (APL).

MATERIALS AND METHODS

We compared 145 samples received at different interval of times to analyze the sensitivity of RT-PCR and FISH.

RESULTS

The failure rate for RT-PCR was 4% at baseline, 13% at induction, and 0% at the end of consolidation. And for FISH it was 8% at baseline, 38% at induction, and 66% at the end of consolidation. The predictive values of relapse in the patients who were positive and negative by RT-PCR, at the end of induction, were 60% and 3%, respectively, and at end of consolidation it was 67% and 4%, respectively. On the other hand the predictive values of relapse in patients who were positive and negative by FISH at end of induction were 57% and 6%, respectively; while at end of consolidation it was 14% who were negative by FISH.

CONCLUSION

Both RT-PCR and FISH are important for the diagnosis of APL cases, as both techniques complement each other in the absence or failure of any one of them. However, RT-PCR is more sensitive than FISH for the detection of minimal residual disease in the long-term monitoring of these patients. The present study shows that the predictive value of relapse is more associated with minimal residual disease (MRD) results by RT-PCR than that by FISH.

Prognostic factors and outcome in Askin-Rosai tumor: a review of 104 patients

PURPOSE

To evaluate the prognostic factors and treatment outcome of patients with Askin-Rosai tumor of the chest wall treated at a single institution.

METHODS AND MATERIALS

Treatment comprised multiagent chemotherapy and local therapy, which was either in the form of surgery alone, radical external-beam radiotherapy (EBRT) alone, or a combination of surgery and EBRT. Thirty-two patients (40%) were treated with all three modalities, 21 (27%) received chemotherapy and radical EBRT, and 19 (24%) underwent chemotherapy followed by surgery only.

RESULTS

One hundred four consecutive patients aged 3-60 years were treated at the Tata Memorial Hospital from January 1995 to October 2003. Most (70%) were male (male/female ratio, 2.3:1). Asymptomatic swelling (43%) was the most common presenting symptom, and 25% of patients presented with distant metastasis. After a median follow-up of 28 months, local control, disease-free survival, and overall survival rates were 67%, 36%, and 45%, respectively. Median time to relapse was 25 months, and the median survival was 76 months. Multivariate analysis revealed age ≥18 years, poor response to induction chemotherapy, and presence of pleural effusion as indicators of inferior survival. Fifty-six percent of patients with metastatic disease at presentation died within 1 month of diagnosis, with 6-month and 5-year actuarial survival of 14% and 4%, respectively.

CONCLUSION

Primary tumor size, pleural effusion, response to chemotherapy, and optimal radiotherapy were important prognostic factors influencing outcome. The combination of neoadjuvant chemotherapy, surgery, and radiotherapy resulted in optimal outcome.

Leiomyosarcoma of the maxilla as second malignancy in retinoblastoma

Patients with hereditary retinoblastoma are at increased risk of second primary tumor, the commonest tumor being osteosarcoma. Leiomyosarcoma developing as second primary neoplasm in retinoblastoma patients is unusual and most have occurred in the field of previous radiotherapy. Although with aggressive therapy better survival can be achieved, the overall prognosis of patients developing these second neoplasms is poor. In this report we present a case of leiomyosarcoma of the maxilla as a second neoplasm in a patient with bilateral retinoblastoma which has developed outside the radiation field.

RUNX1 aberrations in ETV6/RUNX1-positive and ETV6/RUNX1-negative patients: its hemato-pathological and prognostic significance in a large cohort (619 cases) of ALL

A large-cohort study (619) of acute lymphoblastic leukemia (ALL) revealed an ETV6/RUNX1 (previously known as TEL/AML1) incidence of 18% in pediatric B-cell precussor ALL, indicating no geographical heterogeinity. Association of CD34-negative phenotype, peak incidence in the 3- to 7-year age group, and a comparatively low frequency of ETV6 homologue loss in ETV6/RUNX1-positive cases were distinct findings in this series. Additional genetic changes, such as ETV6 loss, extra RUNX1, ETV6/RUNX1 duplication, and MLL aberrations in the ETV6/RUNX1-positive group, supported the hypothesis of the ETV6/RUNX1 leukemogenic model that these secondary changes are necessary for leukemogenesis rather than progression of disease. This study disclosed RUNX1 alterations in the ETV6/RUNX1-negative group of BCP-ALL that encourages the investigation of RUNX1 at a large scale with longer follow-up, which will focus on the prognostic importance and the underlying biology of disease.

Uptake characteristics of fluorodeoxyglucose (FDG) in deep fibromatosis and abdominal desmoids: potential clinical role of FDG-PET in the management

In this preliminary report, we explore the uptake pattern of fluorodeoxyglucose (FDG) in fibromatosis and hypothesize the potential clinical role of FDG-positron emission tomography (PET) in the management of this benign but locally aggressive heterogeneous group of soft-tissue tumours. Five patients were studied (two men and three women, age range 23-35 years), among whom were three cases of deep musculoskeletal fibromatosis, one of abdominal fibromatosis (abdominal desmoid) associated with familial adenomatous polyposis (Gardner's syndrome) and one case of both deep musculoskeletal fibromatosis and abdominal desmoid. The FDG uptake in the lesions was heterogeneous in four cases and relatively homogeneous in one case. The uptake ranged from low to moderate grade with areas or foci of relatively avid FDG uptake. The maximum standardized uptake value (SUV(max)) observed was up to 4.7; the avidity probably related to the biological aggressiveness and tendency for recurrence, characteristic of fibromatosis. A dual-point FDG-PET carried out over four active foci in two cases registered an increase in SUV ranging from 6.93% to 25.85% (mean 19.28%). Treatment monitoring with chemotherapy was carried out in two cases: the reduction in FDG uptake was consistent with the histological evidence of fibrosis and reduction in mitosis. Hence, a baseline FDG-PET can serve a valuable role in monitoring the effect of systemic pharmacotherapy in patients with recurrent progressive disease after unsuccessful local-regional treatment. The findings in this report can be extrapolated and have implications for studying the utility of FDG-PET in defining aggressiveness, guiding biopsy and defining excision site in a large tumour and in monitoring therapy in fibromatosis.

p53 gene gets altered by various mechanisms: studies in childhood sarcomas and retinoblastoma

BACKGROUND

Somatic and constitutional mutation screening of p53 in childhood sarcomas and retinoblastoma was investigated by a multitechnical approach to evaluate its role in the development/progression by somatic mutation events and/or genetic predisposition.

MATERIAL/METHODS

The studies were carried out on a cohort of 100 sarcoma cases, i.e. Ewing's sarcoma (n=44), osteosarcoma (n=36), and rhabdomyosarcoma (n= 20), and on 50 retinoblastoma (Rb) cases.

RESULTS

Constitutional allelic deletion was found by FISH in 4% of sarcoma cases. Overall, 20% of sarcoma tumors showed p53 rearrangement by PCR/SSCP and Southern blot. Allelic deletion of p53 was detected in 78% of sarcoma and 55% of Rb tumors. p53 protein expression was detected by immunohistochemistry in 20% of sarcoma tumors.

CONCLUSIONS

This study for the first time provided evidence of p53 alteration through allelic deletion that are common primary somatic mutation events which occur irrespective of grade and stage and are hence probably associated with an early phase of tumorigenesis and/or tumor progression. The studies also explored the occurrence of de novo constitutional deletion of p53 in sporadic childhood sarcomas. This study in retinoblastoma provided evidence for the synergistic role of RB1 and p53, probably essential for the full-blown development of malignancy.

Results of chemotherapy (CT) based protocol for treatment of retinoblastoma (RB)

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Background: One the main reasons for delayed presentation of children with RB in India is non acceptance of enucleation. CT is being increasingly utilized as primary treatment of RB to reduce the tumor volume and thus avoid enucleation and/or external beam radiation (EBRT) in early stage disease and reduce the risk of relapse in advanced stage disease. Methods: This retrospective (from 1996 to 2001) study involved 62 Patients (pts) (30 were bilateral) who received CT consisting of monthly cycles of carboplatin, etoposide, vincristine and cyclophosphomide. Pts with stage I disease, were started on CT alone, whereas most of the other pts were also started on concurrent EBRT (50Gy). Where indicated, pts also received local therapy, usually cryotherapy & EBRT. Eyes which did not show response or had stable disease, were advised enucleation. Results: Majority of pts had Reese-Ellsworth groups IV-V (74.1%). 17 pts had Stg I, 22 Stg II, 17 Stg III & 6 Stg IV disease (St Jude’s). All pts received CT (median 12 cycles). Out of 92 eyes only 79 were evaluable (13 were already enucleated).The response rate was 73.2% (51.8% CR or near CR); 12.9% had progressive disease. 47 Pts (74%) received RT. Only 23 pts received focal treatment (Cryotherapy 15, laser 3, combination 5). Vision was present in 38 eyes (48.1%) at presentation. 26 eyes (68.4%) were finally saved with useful vision. 20 pts had recurrence. 18 have died (17 died of disease, 1 treatment related sepsis). In those following up in the clinic, survival is 77% for stage I; 78.5% for stage II; 41.6% for stage III. All stage IV pts have died except 1 with nodal disease. Conclusions: CT has a role in the management of RB, however unless it is coupled with good focal therapy the results are poor as shown here. Also longer follow-ups are required because of late recurrences. This data highlights that in developing countries the social reasons complicate patient treatment & compliance. Further efforts are needed to spread awareness of this disease so that patients are diagnosed and treated in earlier stages so as to improve the outcomes.

No significant financial relationships to disclose.

Treatment of acute lymphoblastic leukaemia in countries with limited resources; lessons from use of a single protocol in India over a twenty year peroid

In the 1970s, survival rates after treatment for acute lymphoblastic leukaemia (ALL) in children and young adults (less than 25 years) in India were poor, even in specialised cancer centres. The introduction of a standard treatment protocol (MCP841) and improvements in supportive care in three major cancer centres in India led to an increase in the event-free survival rate (EFS) from less than 20% to 45-60% at 4 years. Results of treatment with protocol MCP841 between 1984 and 1990 have been published and are briefly reviewed here. In addition, previously unpublished data from 1048 patients treated between 1990 and 1997 are reported. Significant differences in both patient populations and treatment outcome were noted among the centres. In one centre, a sufficiently large number of patients were treated each year to perform an analysis of patient characteristics and outcome over time. Although steady improvement in outcome was observed, differences in the patient populations in the time periods examined were also noted. Remarkably, prognostic factors common to all three centres could not be defined. Total white blood cell count (WBC) was the only statistically significant risk factor identified in multivariate analyses in two of the centres. Age is strongly associated with outcome in Western series, but was not a risk factor for EFS in any of the centres. Comparison of patient characteristics with published series from Western nations indicated that patients from all three Indian centres had more extensive disease at presentation, as measured by WBC, lymphadenopathy and organomegaly. The proportions of ALLs with precursor T-cell immunophenotypes, particularly in Chennai, were also increased, even when differences in the age distribution were taken into consideration (in <18-year olds, the range was 21.1-42.7%), and in molecular analyses performed on leukaemic cells from over 250 patients less than 21-years-old with precursor B-cell ALL, a lower frequency of TEL-AML1-positive ALL cases than reported in Western series was observed. The worse outcome of treatment in Indian patients compared with recent Western series was probably due to the higher rate of toxic deaths in the Indian patients, and possibly also due to their more extensive disease - which is, at least partly, a consequence of delay in diagnosis. Differences in the spectrum of molecular subtypes may also have played a role. The higher toxic death rates observed are likely to have arisen from a combination of more extensive disease at diagnosis, co-morbidities (e.g., intercurrent infections), differences in the level of hygiene achievable in the average home, poor access to acute care, and more limited supportive care facilities in Indian hospitals. Toxic death was not associated with WBC at presentation, and hence would tend to obscure the importance of this, and, potentially, other risk factors, as prognostic indicators. Since the prevalence of individual risk factors varies in different populations and over time, their relative importance would also be expected to vary in different centres and in different time periods. This was, in fact, observed. These findings have important implications for the treatment of ALL in countries of low socioeconomic status; it cannot be assumed that risk factors defined in Western populations are equally appropriate for patient assignment to risk-adapted therapy groups in less affluent countries. They also demonstrate that heterogeneity in patient populations and resources can result in significant differences in outcome, even when the same treatment protocol is used. This is often overlooked when comparing published patient series.

Identification of various MLL gene aberrations that lead to MLL gene mutation in patients with acute lymphoblastic leukemia (ALL) and infants with acute leukemia

Studies were done to investigate MLL gene aberrations using Conventional Cytogenetics, Southern blotting as well as FISH using a panel of probes on 218 cases which included 206 cases of pediatric/young adult ALL and 12 cases of infantile acute leukemias from Tata Memorial Hospital, India. The incidence of MLL gene rearrangements in acute lymphoblastic leukemia (ALL) was 9.4% which included infants as well as pediatric/young adults. In infantile group which included ALL as well as AML cases, MLL gene rearrangement was very common (75% frequency). Application of metaphase-FISH helped unravel MLL rearrangements not only as a result of translocations but also inversions, insertions, partial deletion, duplications, partial duplication-->self-fusion. Besides age, MLL gene rearrangements showed significant association with hyperleukocytosis, peripheral blood blast percentage and early Pre-B phenotype. Clinical outcome of patients with MLL gene rearrangements revealed unfavorable prognosis.