Primary mediastinal large cell lymphoma in children: a report from the Childrens Cancer Group

The multilobated morphology is still a better prognosis factor of diffuse large B-cell lymphoma in the R-CHOP era

Diffuse large B-cell lymphoma (DLBCL) is the most common type of B-cell lymphoma. Although the multilobated subtype of DLBCL has been observed since the 1970s, little is known about the clinical significance of this unique variant in the era of rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone/prednisolone (R-CHOP) therapy. In this study, the retrospective clinicopathological analysis of 312 patients diagnosed with DLBCL showed that the multilobated DLBCL group comprised 11% of the cases and was predominantly male (p = 0.027), achieved complete remission in the first therapy (p = 0.023), and exhibited germinal center B-cell phenotypes in the Hans algorithm (p = 0.025). The multilobated DLBCL groups had a better prognosis in overall survival (OS) and progression-free survival (PFS) than the non-multilobated DLBCL group (OS, p = 0.006; PFS, p = 0.010). In the multivariate Cox regression analyses for OS, independent prognosis factors were high soluble IL-2 receptor (p = 0.025), high risk of International Prognostic Index, and multilobated morphology (p = 0.031). The most characteristic copy number gains found in more than 50% of the cases were located at 1q, 3p, 10q, 12q, and 14q. Overall, the multilobated morphology in DLBCL exhibits a good outcome in the R-CHOP era.

Primary mediastinal large B-cell lymphoma with sclerosis in pediatric and adolescent patients: treatment and results from three therapeutic studies of the Berlin-Frankfurt-Münster Group

PURPOSE

Primary mediastinal large B-cell lymphoma with sclerosis (PMLBL) is a rare entity of non-Hodgkin's lymphoma (NHL) arising from thymic mature B cells. Optimal treatment strategies remain to be established, especially in pediatric patients.

PATIENTS AND METHODS

This study analyzes clinical characteristics and treatment outcome of 30 pediatric patients with PMLBL, diagnosed in multicenter therapy NHL-Berlin-Frankfurt-Münster Group (BFM) trials. Treatment was stratified by stage and serum lactate dehydrogenase (LDH) and consisted of four to six 5-day courses of chemotherapy using steroids, oxazaphosphorine alkylating agents, methotrexate, cytarabine, etoposide, and doxorubicin. Radiation was not part of the protocol.

RESULTS

From April 1986 to August 1999, 1,650 patients with newly diagnosed NHL were enrolled in the NHL-BFM trials; 30 patients (1.8%) had PMLBL. Median age was 14.3 years (range, 1.4 to 16.7 years); 15 patients were male and 15 patients were female. With a median observation time of 5 years (range, 1 to 12 years), probability of event-free survival (pEFS) at 5 years was 0.70 (SE, 0.08). Two patients erroneously diagnosed as T-cell NHL received non-B-cell therapy and died from progress of disease. Events in 28 patients receiving B-cell therapy included early progress during therapy (n = 1) and relapse (n = 6). Residual mediastinal masses were present in 23 patients after two courses of therapy and in 15 patients after the end of therapy. LDH > or = 500 U/L was associated with increased risk of failure in multivariate analysis.

CONCLUSION

PMLBL mainly is found in adolescents. Dose-intense chemotherapy including high-dose methotrexate yields a pEFS at 5 years of 0.70 (SE, 0.08). LDH is of prognostic value in pediatric patients with PMLBL.

Alteration of chromosome arm 6p is characteristic of primary mediastinal B-cell lymphoma, as identified by genome-wide allelotyping

Five cases of primary mediastinal B-cell lymphoma (PMBL) each have been studied with 375 microsatellite markers from all 22 autosomes. Of the 151 genomic alterations among the 1,875 assays, only five were allelic losses. The remainder of the microsatellite alterations consisted of 114 allelic imbalances and 32 instabilities. Microsatellite alterations were found in all cases on chromosomal arms 6p and 9p. These allelic imbalances most likely are indicative of genetic amplification, a finding agreeing well with those of studies using either comparative genomic hybridization or arbitrarily primed polymerase chain reaction, in which amplification of chromosome arm 9p in PMBL has been found. The allelic imbalances on chromosome arm 6p always included marker D6S276 located at 6p21.3-p22.3, where the MHC class I genes reside. These allelic imbalances may be reflective of alterations in the expression of the MHC gene products, characteristic of PMBL. Allelic anomalies close to the MYB gene locus on 6q were detected in two cases and prompted the analysis of MYB rearrangements in a series of 30 lymphomas. One rearrangement was detected in one of 18 cases of PMBL and in none of 10 diffuse, large B-cell lymphomas and two T-cell lymphomas. Our genome-wide microsatellite analysis provides independent confirmation that PMBL is characterized by infrequent chromosomal losses and by frequent genetic alterations involving chromosomal arm 9p. For the first time, chromosomal arm 6p has been identified as a highly frequent target of genetic alterations in this tumor type. Finally, MYB may also be involved occasionally in PMBL pathogenesis.

Large-cell lymphoma arising in the mediastinum in children and adolescents is associated with an excellent outcome: a Children's Cancer Group report

PURPOSE

Large-cell lymphoma (LCL) arising in the mediastinum (LCL-M) is a heterogeneous group of non-Hodgkin's lymphoma (NHL) that includes B-cell lymphomas as well as T-cell lymphomas, including anaplastic LCL. LCL-M is well recognized in young adults but is less well characterized and infrequent in children and adolescents.

METHODS

A retrospective review of Children's Cancer Group therapeutic studies for nonlymphoblastic lymphomas (CCG-551, CCG-503, CCG-552, and CCG-5911) identified 20 patients with LCL-M, representing 7.2% of all LCLs classified by central pathology review.

RESULTS

The patients ranged in age from 4 to 19 years (median, 12.5 years; mean, 12 years); 55% of the patients were male. Although a variety of chemotherapy regimens were used, response was excellent, with all 20 patients (100%) achieving a complete response. Four patients (20%) experienced relapse locally or in distant sites including brain and kidney. One patient died of sepsis during therapy. For the 20 patients with LCL-M, the product-limit estimated 5-year event-free survival (EFS) and 5-year overall survival (OS) rates are 75% +/- 10% and 85% +/- 8%, respectively. For disseminated LCLs (192 cases), the EFS and OS rates were 50% +/- 4% and 63% +/- 4%, respectively, which differ significantly from the those of the LCL-M cases (EFS, P =.025; OS, P =.034). The 5-year EFS and OS rates for patients with localized LCL (67 cases) were 92 +/- 3% and 97 +/- 2%, respectively.

CONCLUSION

LCL-M is a heterogeneous group of NHLs that makes up approximately 7.2% of LCL in children and adolescents. Response to therapy and OS in this young age group seems excellent and superior to that of disseminated LCLs but inferior to that of other localized LCL. Future studies of LCL-M will evaluate short intense chemotherapy administered without radiation therapy.

Primary mediastinal malignancies in children: report of 22 patients and comparison to 197 adults

PURPOSE

Examine a contemporary series of patients with primary pediatric malignant mediastinal tumors and determine epidemiology, histology, treatment, and survival. Patients and Methods. All malignancies diagnosed between January 1, 1973 and December 31, 1995 were analyzed.

RESULTS

Twenty-two patients, age 18 years or less, with pediatric primary mediastinal malignancies were identified from a database of 110,284 patients with primary malignancies. During the same period, 197 adult patients with primary mediastinal malignancies were identified. Fifty-nine percent of the pediatric patients were male. Median age was 11 years. Lymphoma was present in 55%, neurogenic malignancies in 23%, malignant germ cell tumors in 18%, and sarcoma in 5%. Neurogenic tumors presented in infants and lymphomas and germ cell tumors presented in teens (p = 0.005). In treated children, surgery was used more often in neurogenic tumors and germ cell tumors than in lymphomas (p = 0.002). Five-year survival was 74% for lymphomas, 67% for neurogenic tumors, 25% for germ cell tumors, and 61% overall (p = 0.23). Compared to adults, children had more neurogenic tumors (p < 0.001) and fewer thymomas (p = 0.0499). There were no significant differences in staging or survival between children and adults.

CONCLUSIONS

Pediatric mediastinal malignancies occurred with a frequency of 1/5,013 patients with malignant tumors. Lymphoma, neurogenic tumors, and germ cell tumors predominated. Compared to adults, children had more neurogenic tumors and fewer thymomas. Within the pediatric group, differences were found in age of presentation between histologic groups. These differences between adults and children, and between infants and teens, should be considered when evaluating a patient suspected of having mediastinal malignancy.

Work-up and diagnosis of pediatric non-Hodgkin's lymphomas

Non-Hodgkin's lymphomas (NHL) in children and adolescents represent about 10% of childhood cancers. Although the types of NHL commonly seen in this population are relatively limited to lymphoblastic lymphomas, Burkitt's and Burkitt-like lymphomas, and large cell lymphomas, correct diagnosis and classification are essential for optimal therapy. Careful handling of pathologic specimens, along with collection of proper materials for ancillary studies such as immunophenotyping, cytogenetics, or molecular studies, will aid the pathologist in reaching a correct diagnosis. Specific morphologic, immunophenotypic, and genetic features of the commonly seen types of pediatric NHL are described.

Large cell non-Hodgkin lymphoma of childhood: Analysis of 78 consecutive patients enrolled in 2 consecutive protocols at the Memorial Sloan-Kettering Cancer Center

BACKGROUND

The authors report a study of pediatric patients with advanced diffuse large cell lymphoma (DLCL) who were treated with 2 consecutive regimens, LSA2-L2 and LSA4, over a 25-year-period at the Memorial Sloan-Kettering Cancer Center. They also describe a comparative analysis of two subgroups retrospectively identified as having CD30 positive (+) anaplastic large cell lymphoma (ALCL) and CD30 negative (-) DLCL. To the authors' knowledge, this study represents the longest follow-up on the largest series of uniformly treated pediatric DLCL patients reported to date.

METHODS

A total of 78 consecutive patients were treated for Stage III/IV DLCL. Immunophenotypic data were obtained retrospectively for 52 patients using a panel of monoclonal antibodies against CD30, CD15, CD45, CD45Ro, CD43, epithelial membrane antigen, CD5, BCL-2, cyclin-D, and p53.

RESULTS

A disease free survival rate of 72% in patients with advanced stage DLCL using the LSA2-L2 and LSA4 regimens. Of the 78 treated patients, 56 are alive and without evidence of disease with a median follow-up of 120 months (range, 24-312 months). The recurrence rate was significantly higher in the CD30+ ALCL subgroup (33%) than in the CD30- DLCL group (0.04%). Of 52 patients for whom immunophenotypic data were available, 28 had disease of B-cell lineage, 24 had disease of T-cell/null phenotype, 19 were CD30+ (36. 5%), 18 had disease of T-cell phenotype, and 1 had disease of B-cell lineage.

CONCLUSIONS

The CD30- DLCL cases mostly were of B-cell lineage, had a small risk of treatment failure, and did not develop a recurrence off therapy. A distinct clinical pattern was identified for the CD30+ ALCL group; although these tumors were of T-cell lineage and had a significantly higher rate of late recurrences (median follow-up of 24 months) they all were salvageable. Based on the findings of the current study, the authors propose that T-cell CD30+ ALCL be addressed in the future according to equal dose intensity regimens in induction therapy, as is done for B-cell lymphomas; prolonged periods of maintenance chemotherapy, as is done for T-cell lymphoblastic lymphomas; and no central nervous system prophylaxis beyond the induction period unless other recognized risk factors are present.