Treatment of high-risk neuroblastoma with intensive chemotherapy, radiotherapy, autologous bone marrow transplantation, and 13-cis-retinoic acid. Children's Cancer Group

Graft-versus-tumor effect in a patient with advanced neuroblastoma who received HLA haplo-identical bone marrow transplantation

A 5-year-old boy received CD34-positive HLA haplo-identical bone marrow transplantation from his father as treatment for refractory advanced neuroblastoma. He had residual disease in the para-aortic lymph nodes and multiple bones after the transplant. However, all of his residual disease had disappeared completely 3 years later. He developed grade I acute graft-versus-host disease (GVHD) but had no symptoms of chronic GVHD or any other complications. This case demonstrates the possibility of a graft-versus-tumor effect against neuroblastoma by HLA-mismatched allogeneic hematopoietic stem cell transplantation.

MYCN enhances P-gp/MDR1 gene expression in the human metastatic neuroblastoma IGR-N-91 model

Despite intensive high-dose chemotherapy and autologous hematopoietic stem cell transplantation, disseminated neuroblastoma (NB) frequently proves to be chemosensitive but not chemocurable, and more often so in NB-presenting MYCN amplification. To assess the direct relationship between the MYCN oncogene and chemoresistance acquisition during NB metastatic dissemination, we have studied MYCN and MDR1 genes using the human IGR-N-91 ectopic xenograft metastatic model. This characterized experimental in vitro model includes human neuroblasts derived from a subcutaneous primary tumor xenograft, disseminated blood cells, myocardium, and bone marrow (BM) metastatic cells. All IGR-N-91-derived neuroblasts harbor a consistent MYCN genomic content but, unlike primary tumor xenograft, BM, and myocardium, human neuroblasts elicit a concomitant increase in MYCN and MDR1 transcripts levels, consistent with chemoresistance phenotype and active P-gp. In contrast, no variation of MRP1 transcript level was associated with the metastatic process in this model. Using an MDR1 promoter-CAT construct, we have shown that the MycN protein activates MDR1 transcription both in exogenous transient MYCN-transfected SK-N-SH cells and in endogenous BM metastatic neuroblasts with an increase in the MYCN transcript level. Band-shift experiments indicate that IGR-N-91 cells enriched with the MycN transcription factor do bind to two E-box motifs localized within the MDR1 promoter. Overall, our data indicate that MYCN overexpression increment contributes to the acquired drug resistance that occurs throughout the NB metastatic process.

Secondary myelodysplastic syndrome and leukemia following 131I-metaiodobenzylguanidine therapy for relapsed neuroblastoma

PURPOSE

To describe three patients with secondary leukemia after treatment with 131I-metaiodobenzylguanidine (MIBG) for neuroblastoma.

METHODS

Of 95 children with refractory neuroblastoma treated with 131I-MIBG at UCSF, 3 have been identified with secondary myelodysplasia/leukemia. The case records and bone marrow results were reviewed, along with a review of the literature.

RESULTS

Three patients developed secondary myelodysplasia/leukemia, at 7, 11, and 12 months following 131I-MIBG therapy. Cytogenetic abnormalities included -7q/-5, -7/+2q37, -11 and +12. Three additional cases were found in literature review of 509 reported patients treated with 131I-MIBG for neuroblastoma.

CONCLUSIONS

Therapy with 131I-MIBG may contribute to the risk of secondary leukemia in patients who have received intensive chemotherapy, thought the risk of this complication is far lower than the risk of disease progression. Further monitoring for this complication is indicated.

Correlation of early metastatic response by 123I-metaiodobenzylguanidine scintigraphy with overall response and event-free survival in stage IV neuroblastoma

PURPOSE

Metaiodobenzylguanidine (MIBG), specifically taken up in cells of sympathetic origin, provides a highly sensitive and specific indicator for the detection of metastases in neuroblastoma. The aim of this study was to correlate early response to therapy by MIBG scan, using a semiquantitative scoring method, with the end induction response and event-free survival (EFS) rate in stage IV neuroblastoma.

PATIENTS AND METHODS

Seventy-five children older than 1 year and with stage IV neuroblastoma had 123I-MIBG scans at diagnosis, after two and four cycles of induction therapy, and before autologous stem-cell transplantation. The scans were read by two independent observers (concordance > 95%) using a semiquantitative method. Absolute and relative (score divided by initial score) MIBG scores were then correlated with overall pretransplantation response, bone marrow response, and EFS.

RESULTS

The pretransplantation response rate was 81%, and the 3-year EFS rate was 32%, similar to a concomitant group of 375 stage IV patients. The median relative MIBG scores after two, four, and six cycles were 0.5, 0.24, and 0.12, respectively. The probability of having a complete response or very good partial response before transplantation was significantly higher if the relative score after two cycles was < or = 0.5, or, if after four cycles, the relative score was < or = 0.24. Patients with a relative score of < or = 0.5 after two cycles or a score of < or = 0.24 after four cycles had an improved EFS rate (P =.053 and.045, respectively).

CONCLUSION

Semiquantitative MIBG score early in therapy provides valuable prognostic information for overall response and EFS, which may be useful in tailoring treatment.

Neuroblastoma mimicking rhabdoid tumor of the kidney

Rhabdoid tumor of the kidney (RTK) has mimicked other renal tumors histologically, but there has been only one previous report of neuroblastoma mimicking RTK. The authors present the case of a 17-month-old boy who presented with a large left renal mass that was diagnosed as RTK. At the completion of therapy he was found to have residual masses. They were biopsied and found to be viable neuroblastoma.

Effect of 20-epi-1alpha,25-dihydroxyvitamin D3 on the proliferation of human neuroblastoma: role of cell cycle regulators and the Myc-Id2 pathway

The antiproliferative effects of 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and its epimer, 20-epi-1alpha,25-dihydroxyvitamin D(3) [20-epi-1,25(OH)(2)D(3)], in six human neuroblastoma (NB) cell lines (SH-SY5Y, NB69, SK-N-AS, IMR5, CHP134, and NGP) were investigated. We determined the ability of 1,25(OH)(2)D(3) and 20-epi-1,25(OH)(2)D(3) to influence cell viability by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell proliferation by bromodeoxyuridine (BrdU) incorporation, and their antineoplastic effect on colony formation in a soft agar assay. A concentration-dependent decrease in cell viability, inhibition of DNA synthesis, and suppression of clonal proliferation was observed with both compounds. 20-epi-1,25(OH)(2)D(3) was more potent in suppressing the proliferation of all six NB cell lines. To understand the mechanisms of action, we examined the effect of 20-epi-1,25(OH)(2)D(3) on the Myc-Id2 cell proliferative network and also on key regulators of the cell cycle. For the first time, we show that 20-epi-1,25(OH)(2)D(3) down-regulated Myc and Id2 expression by western blot analysis. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that 20-epi-1,25(OH)(2)D(3) induced the expression of retinoic acid receptor-beta and p21(Cip1), and down-regulated the expression of cyclin D1 resulting in decreased phosphorylation of retinoblastoma protein (pRB). In sum, we show that 20-epi-1,25(OH)(2)D(3) exerts strong antiproliferative effects by regulating key growth control networks (Myc-Id2-pRB) in NB cells.

Treatment of metastatic retinoblastoma

PURPOSE

The risk for death in patients with retinoblastoma is increased in those who present with metastatic disease, and the role of intensive chemotherapy and autologous hematopoietic stem cell rescue in these patients remains unclear.

DESIGN

Nonrandomized interventional case series.

PARTICIPANTS

Four consecutive patients with metastatic retinoblastoma.

METHODS

We treated four patients with retinoblastoma metastatic to the bone and bone marrow with intensive chemotherapy, consolidation with megatherapy, and autologous hematopoietic stem cell rescue. Chemotherapy included courses of carboplatin and etoposide alternating with cyclophosphamide, etoposide, and either carboplatin or cisplatin. Radiation therapy was delivered to areas of bone metastases.

MAIN OUTCOME MEASURES

Patient survival.

RESULTS

All patients completed and responded to the scheduled therapy; complete response of the bone marrow disease was documented after two courses of chemotherapy in all cases. Two patients are long-term survivors.

CONCLUSIONS

The treatment described has been successful in obtaining disease-free survival in patients with metastatic retinoblastoma.

Expression of trkB in human neuroblastoma in relation to MYCN expression and retinoic acid treatment

Expression of full-length trkB can be found in some highly malignant neuroblastoma tumors with an amplified MYCN gene. This contrasts sympathetic neuroblasts, from which neuroblastomas are thought to arise, which neither express trkB nor are dependent on the p145(trkB) ligands, brain-derived neurotrophic factor (BDNF) or neurotrophin-4/5, for their normal development. In this study we show that trkB was expressed in two out of five neuroblastoma tumors with amplified MYCN, while no trkB expression was observed when the MYCN gene was overexpressed in a non-MYCN-amplified neuroblastoma cell line. This shows that MYCN overexpression per se is not sufficient to induce trkB expression. trkB expression and BDNF responsiveness in neuroblastoma cells can be induced by all-trans-retinoic acid (RA). When SH-SY5Y cells were stimulated with a combination of RA and BDNF, norepinephrine and tyrosine hydroxylase levels were unaltered, showing that the cells did not change toward a more catecholaminergic sympathetic phenotype. However, expression of growth-associated protein 43, indicative of a neuronal phenotype, was elevated. Vesicular acetylcholine transporter, choline acetyl transferase, and neuropeptide tyrosine mRNA levels also increased in RA-BDNF-treated cells, which could suggest that these cells develop into a sympathetic cholinergic phenotype. In addition, treatment with RA-induced expression of the platelet-derived growth factor receptor-alpha. As previously shown for BDNF, platelet-derived growth factor stimulated growth of the RA-treated cells, findings that could have clinical relevance. If these receptors mediate a mitogenic signal in vivo also, this might limit the effect of RA treatment on neuroblastoma patients.

Detection of micrometastasis of neuroblastoma to bone marrow and tumor dissemination to hematopoietic autografts using flow cytometry and reverse transcriptase-polymerase chain reaction

BACKGROUND

The identification of neuroblastoma metastases to bone marrow (BM) is requisite in staging disease for risk-adopted therapy. However, micrometastases were not elucidated fully.

METHODS

Flow cytometry (FCM) with CD45/CD56/CD81 and reverse transcriptase-polymerase chain reactions (RT-PCR) for tyrosine hydroxylase (TH) transcripts were used to evaluate neuroblastoma in bilateral BM aspirates at diagnosis, BM autografts, peripheral blood stem cell (PBSC) collections, and CD34(+) cell products of 27 children.

RESULTS

TH transcripts were amplified in histology-negative (H(-)) BM specimens from seven patients (four patients with Stage 3 disease, two with Stage 4 disease, and one with Stage 4S disease), revealing a prevalence of submicroscopic metastasis. The median number of CD45(-)CD81(+)CD56(+) cells in four H(-) TH(-) BM samples from two patients with Stage 1 and Stage 2 disease, respectively, was comparable to that encountered in 10 normal BM controls (0.003% [range, 0.002-0.004%] vs. 0.004% [0-0.008%], P = 0.724). In six H(-) TH(+) BM specimens from three patients whom were otherwise diagnosed with neuroblastoma Stage 3, 0.031% (0.009-0.06%) CD45(-)CD81(+)CD56(+) cells were detected. Besides, 1.474% (0.088-3.009%) CD45(-)CD81(+)CD56(+) cells were identified in four H(-) TH(+) BM specimens from two patients at Stage 4. TH transcripts were evident in four of five BM autografts and in 22 of 45 (48.9%) PBSC specimens. FCM demonstrated 0.018% and 0.049% CD45(-)CD81(+)CD56(+) cells in two TH(+) BM autografts, respectively. The number of CD45(-)CD81(+)CD56(+) cells was higher in 19 TH(+) PBSC specimens than in 20 TH(-) PBSC specimens (0.026% [0.006-1.128%] vs. 0% [0-0.009%], P < 0.0001). CD34(+) cell selection achieved 2.9 (2.1-3.5) log depletion of CD45(-)CD81(+)CD56(+) cells in four manipulated products, rendering six of seven PBSC autografts TH-free.

CONCLUSIONS

FCM in combination with RT-PCR evaluated neuroblastoma micrometastasis and assessed the purity of hematopoietic autografts for transplant. However, the clinical relevance remains to be elucidated.

Correlation of elevated level of blood midkine with poor prognostic factors of human neuroblastomas

The heparin-binding growth factor midkine (MK) is the product of a retinoic acid-responsive gene, and is implicated in neuronal survival and differentiation, and carcinogenesis. We previously reported that MK mRNA expression is elevated in neuroblastoma specimens at all stages, whereas pleiotrophin, the other member of the MK family, is expressed at high levels in favourable neuroblastomas. As MK is a secretory protein, it can be detected in the blood. Here, we show a significant correlation of the plasma MK level with prognostic factors of neuroblastomas. The plasma MK level was determined in 220 patients with neuroblastomas, and compared with that in children without malignant tumors (n=17, <500 pg ml(-1)). The plasma MK level became significantly elevated with advancing stages (stage 1: 445 pg ml(-1) (median), n=73; stage 2: 589, n=39; stage 3: 864, n=40; stage 4: 1445, n=56; and stage 4S: 2439, n=12). More importantly, a higher MK level was strongly correlated with poor prognostic factors: over 1 year of age (P=0.0299), MYCN amplification (P<0.0001), low TrkA expression (P=0.0005), nonmass screening, sporadic neuroblastomas (P<0.0001), and diploidy/tetraploidy (P=0.0007). Thus, these results demonstrate that the plasma MK level is a good marker for evaluating the progression of neuroblastomas. Moreover, considering the ability of antisense MK oligodeoxyribonucleotide to suppress tumour growth of colorectal carcinoma cells in nude mice, as recently reported, the present study suggests that MK is a possible candidate molecular target for therapy for neuroblastomas.

Impact of radiotherapy for high-risk neuroblastoma: a Children's Cancer Group study

PURPOSE

To assess the effect of local radiation administered to primary disease sites in children with high-risk neuroblastoma.

MATERIALS AND METHODS

A total of 539 eligible patients were entered on protocol CCG-3891, consisting of chemotherapy, primary surgery, and 10 Gy of external beam radiation therapy (EBRT) to gross residual disease, followed by randomized assignment to continuation chemotherapy (CC) or autologous bone marrow transplantation (ABMT). ABMT patients received total body irradiation (TBI).

RESULTS

Estimated event-free survival and overall survival at 5 years were 25% +/- 2% and 35% +/- 2%, respectively. Estimated 5-year locoregional recurrence rates were 51% +/- 5% and 33% +/- 7% for CC and ABMT patients (p = 0.004). For patients who received 10 Gy of EBRT to the primary, the addition of 10 Gy of TBI and ABMT decreased local recurrence compared with CC (22% +/- 12% and 52% +/- 8%, p = 0.022). EBRT did not increase acute toxicity, except for increased total parenteral nutrition administration.

CONCLUSIONS

In combination with EBRT to the primary tumor site, the addition of 10 Gy of TBI as a component of high-dose chemotherapy with ABMT improved local control compared with CC without TBI. Results suggest a dose-response relationship for local EBRT. Short-term toxicity of local EBRT is limited.

The synthetic retinoid RO 13-6307 induces neuroblastoma differentiation in vitro and inhibits neuroblastoma tumour growth in vivo

Retinoids modulate cell proliferation, differentiation and apoptosis in a variety of tumour cells including leukaemia and neuroblastoma, a childhood tumour of the sympathetic nervous system. 13-cis retinoic acid is in clinical use against minimal residual disease in neuroblastoma, where the effect seems to depend on dose, scheduling and tumour mass. Novel retinoids are searched for, to improve potency and lower toxicity. We investigated the effect of the synthetic retinoid Ro 13-6307 on neuroblastoma growth in vitro on SK-N-BE(2) and SH-SY5Y cells. Furthermore, effects on tumour growth and the toxicity profile were investigated in a rat xenograft model. Effects of Ro 13-6307 were compared to 13-cis RA (retinoic acid) in vitro and in vivo. Neuroblastoma cells treated with 1 microM Ro 13-6307 exhibited neuronal differentiation, decreased proliferation and accumulation of cells in G1 phase in at least the same magnitude as 5 microM 13-cis RA. No apoptosis was detected in vitro. Treatment of nude rats with neuroblastoma using Ro 13-6307, 0.12 mg p.o. daily, decreased neuroblastoma growth in vivo, in terms of tumour volume during treatment and tumour weight at sacrifice (p < 0.05). In contrast, Ro 13-6307, 0.08 mg p.o. daily, resulted in no significant reduction in tumour growth. All rats treated with Ro 13-6307 gained less weight than control rats, but they exhibited no other signs of toxicity. The toxicity profile of Ro 13-6307 was similar to what we found with 13-cis RA. Our preclinical results suggest that Ro 13-6307 may be a candidate retinoid for clinical oral therapy of neuroblastoma in children.

Disseminated neuroblastoma in children older than one year at diagnosis: comparable results with three consecutive high-dose protocols adopted by the Italian Co-Operative Group for Neuroblastoma

PURPOSE

To compare the outcomes associated with modifications in three consecutive protocols employed by the Italian Co-Operative Group for Neuroblastoma (ICGNB) in disseminated neuroblastoma.

PATIENTS AND METHODS

Between January 1985 and November 1997, a total of 359 children aged 1 to 15 years with newly diagnosed stage 4 neuroblastoma were enrolled in three consecutive protocols. Compared with ICGNB-85, the ICGNB-89 protocol contained two more chemotherapy cycles, and some drugs were given at greater doses, whereas in the ICGNB-92 protocol, the induction phase included a chelating agent, and individual cycles contained four drugs instead of two.

RESULTS

A total of 330 of 359 evaluable children were included in this analysis; 106 children were treated with ICGNB-85, 65 children were treated with ICGNB-89, and 159 children were treated with ICGNB-92 protocols. Radical resection of primary tumor was carried out in 59.4%, 50.8%, and 57.9% of the patients, respectively. Major tumor response after induction therapy was achieved in 66.7%, 69.2%, and 68.6% of the patients, respectively. A total of 218 of 232 patients received consolidation therapy consisting of conventional chemotherapy in 65 patients and of high-dose chemotherapy in 153 patients. Disease recurrence or progression occurred in 82.1%, 69.2%, and 74.8% of the patients, respectively. Therapy-related deaths occurred in 1.9%, 12.3%, and 6.9% of the patients, respectively. Five-year overall survival (OS) for the three studies was 26%, 23%, and 28%, and event-free survival (EFS) was 19%, 17%, and 17%, respectively.

CONCLUSION

The therapeutic modifications adopted in the ICGNB-89 and ICGNB-92 protocols were not associated with a significant improvement in response rate or in the 5-year OS and EFS as compared with the ICGNB-85 protocol. Attempts at intensifying chemotherapy were associated with greater toxicity.

Quantitation of GD2 synthase mRNA by real-time reverse transcriptase polymerase chain reaction: clinical utility in evaluating adjuvant therapy in neuroblastoma

PURPOSE

Minimal residual disease (MRD) is one of the final hurdles to cancer cure. Because therapy (myeloablation, immunotherapy, or differentiation) for MRD is applied at the time of clinical remission, objective surrogate markers are needed to gauge treatment efficacy.

PATIENTS AND METHODS

Using quantitative reverse transcriptase polymerase chain reaction (RT-PCR) of GD2 synthase (beta1,4-N-acetylgalactosaminyltransferase, EC 2.4.1.92) mRNA, we evaluated MRD response to anti-GD2 monoclonal antibody 3F8 adjuvant therapy, namely, one cycle of radioimmunotherapy using iodine-131 ((131)I)-3F8 plus one cycle of unlabeled 3F8 in 45 stage 4 neuroblastoma patients (newly diagnosed or without prior relapse) on the N7 protocol at Memorial Sloan-Kettering Cancer Center. The prognostic effect of MRD in their bone marrows before and after this phase of adjuvant therapy on progression-free survival (PFS) and overall survival (OS) was also analyzed.

RESULTS

Before 3F8 treatment, 24 of 45 patients were in complete remission (CR), 12 were in very good partial remission (VGPR), and nine were in partial remission (PR), according to criteria from International Neuroblastoma Staging System plus (131)I-3F8 scan; 71% had detectable tumor cells in marrow by real-time RT-PCR. Of the 32 positive patients, 20 became negative after therapy, with a 63% efficacy. When patients were stratified by CR/VGPR versus PR, GD2 synthase positivity was prognostic when detected before 3F8-targeted therapy (PFS, P =.045 and OS, P =.010). Persistent marker positivity was also predictive of PFS (P =.035) and OS (P =.027). Patients who succumbed to the disease had transcript levels four times higher than those who remain alive.

CONCLUSION

GD2 synthase mRNA is a useful surrogate marker for evaluating adjuvant treatment efficacy in neuroblastoma with prognostic potential.

Combined RAR alpha- and RXR-specific ligands overcome N-myc-associated retinoid resistance in neuroblastoma cells

Retinoids induce human neuroblastoma cells to undergo growth inhibition and neuritic differentiation in vitro, through interactions with nuclear retinoid receptor proteins. In this study, we found that three different neuroblastoma cell lines exhibited wide variation in their responsiveness to the growth inhibitory effects of the retinoic acid receptor (RAR) agonist, all-trans-retinoic acid (aRA). Resistance to the growth inhibitory effect of aRA correlated with the presence of N-myc gene amplification and not aRA-induced RAR beta levels. Over-expression of N-myc in a neuroblastoma cell line with no endogenous N-myc expression caused a marked reduction in retinoid-induced growth inhibition. Combination of receptor-specific retinoid agonists for RXR and RAR alpha significantly enhanced the sensitivity of N-myc-amplified neuroblastoma cells to the growth inhibitory effects of aRA. Our results indicate that combination receptor-specific retinoid therapy can overcome N-myc-mediated retinoid resistance and may be a more effective chemo-preventive strategy in the disease.

Dual expression of CD80 and CD86 produces a tumor vaccine superior to single expression of either molecule

A murine model for neuroblastoma, Neuro-2a (N2a), was used to establish a model tumor vaccine. An aggressive subclone of N2a and the less aggressive parental line were transfected with CD80, CD86, or both molecules and stable lines were established. The less aggressive N2a expressing either CD80 or CD86 induced anti-tumor immunity. In contrast, dual expression of CD80 and CD86 was required to initiate a protective anti-tumor immune response against the aggressive subclone. Control of tumor growth was dependent on CD8+ lymphocytes that infiltrated dual-expressing (CD80 and CD86) lesions. These tumor-infiltrating lymphocytes (TIL) exhibited a non-classical mechanism of tumor cell lysis that may require both the up-regulation of cell surface molecules on the tumor and the subsequent lytic activity normally associated with CD8+ TIL. Although Fas was up-regulated by the tumor in the presence of IFN-gamma, N2a and transfected N2a cell lines were not sensitive to Fas-mediated lysis.

N-(4-Hydroxylphenyl)retinamide (fenretinide, 4-HPR), a retinoid compound with antileukemic and proapoptotic activity in acute lymphoblastic leukemia (ALL)

BACKGROUND

Retinoids have been shown to regulate vital cellular processes including cell proliferation, differentiation and apoptosis. N-(4-Hydroxyphenyl)-all-trans-retinamide (fenretinide, 4-HPR) is a synthetic ATRA derivative with chemopreventive and cytotoxic activity against various cancer cell lines including myeloid leukemia. Although several modes of action have been postulated, its mechanism of action in hematologic malignancies remains unclear. Furthermore, only limited information exists as to its activity in lymphoid malignancies.

METHODS AND RESULTS

To test whether 4-HPR has activity in acute lymphoblastic leukemia (ALL), we first analyzed its antiproliferative effect in five ALL (Z-33, Z-138, Z-119, Z-181, and Jurkat) cell lines. We found that 4-HPR inhibited the proliferation of all cell lines in a dose-dependent manner at concentrations ranging from 1 to 10 microM. We further demonstrated by cell cycle analysis that 5 microM of 4-HPR blocked Z-119 cells in S phase thus preventing their progression through the cycle. Next we tested whether 4-HPR activated the caspase pathway and induced apoptotic cell death. We found that 4-HPR induced apoptosis in Z-119 cells through the activation of caspase-3 and subsequent cleavage of its substrate poly(ADP-ribose) polymerase (PARP). We then asked whether 4-HPR could affect fresh ALL progenitor cells. Therefore, we obtained bone marrow and peripheral blood cells from five patients with newly diagnosed ALL and tested the effect of 4-HPR using the ALL blast colony culture assay. To supplement our results, we also performed the ALL blast assay on one ALL cell line (ALL-1). We found that 4-HPR significantly inhibited ALL colony-forming cell proliferation in a dose-dependent manner.

CONCLUSIONS

Our data show that 4-HPR is a potent inhibitor of ALL cell proliferation and that it induces in vitro apoptotic cell death in ALL blasts. Further studies are warranted to establish the in vivo effect of 4-HPR particularly in patients with ALL.

Second malignancies in children with neuroblastoma after combined treatment with 131I-metaiodobenzylguanidine

BACKGROUND

(131)I-metaiodobenzylguanidine ((131)I-MIBG) is selectively taken up by cells of neural crest origin, allowing targeted radiotherapy of tumors such as neuroblastoma (NB) and pheochromocytoma. Radiotherapy may provide additional benefits in the treatment of NB, with moderate side effects such as hematologic and thyroid toxicity. However, with longer follow-up, other complications might occur. We describe our experience with second cancers occurring in children treated with (131)I-MIBG and chemotherapy.

METHODS

The clinical records of 119 consecutive NB cases treated with (131)I-MIBG at a single institution between 1984 and 2001 were reviewed for the occurrence of a second malignant neoplasm (SMN).

RESULTS

Overall, five cases of SMN occurred in the study patients. In particular, two cases of myeloid leukemia, one of angiomatous fibrous histiocytoma, one of malignant schwannoma, and one case of rhabdomyosarcoma were detected. The schwannoma and the rhabdomyosarcoma developed within the residual neuroblastic mass after first-line therapy.

CONCLUSIONS

Should (131)I-MIBG treatment become more broadly employed in the therapeutic strategy for neuroblastoma, the risk of second cancer will have to be taken into consideration. The organization of an international registry of subjects treated with (131)I-MIBG might better define the frequency and features of second malignancies following this radiometabolic approach.

Successive double high-dose chemotherapy with peripheral blood stem cell rescue collected during a single leukapheresis round in patients with high-risk pediatric solid tumors: a pilot study in a single center

In total, 18 of 26 double high-dose chemotherapies (HDCT) in pediatric solid tumors were rescued with peripheral blood stem cells collected during a single leukapheresis round (single-harvest group, SHG). In the remaining eight HDCT, additional leukapheresis were necessary after the first HDCT (HDCT1) to rescue the second HDCT (HDCT2) (double-harvest group, DHG). Stem cell collection after HDCT1 was inefficient and delayed in patients who had received prior chemotherapy before HDCT1. The interval between HDCT1 and HDCT2 was shorter in SHG than in DHG (median 62.5 days vs 178.5 days, P-value=0.002). Hematologic recovery in HDCT2 was delayed compared to HDCT1. However, there was no difference in hematologic recovery between SHG and DHG. A high rate of treatment-related mortality (TRM) was recorded during HDCT2, but there was no evidence that the shorter interval caused a higher rate of TRM (P-value=0.454). The probability of disease-free survival at 2 years after HDCT2 in the SHG and DHG were 66.7 and 25.0%, respectively (P-value=0.031). Therefore, to administer the second HDCT earlier in double HDCT, and thus to improve the survival of patients with high-risk solid tumors, the single-harvest approach is recommended rather than the double-harvest approach.

Neuroblastoma: biological insights into a clinical enigma

Neuroblastoma is a tumour derived from primitive cells of the sympathetic nervous system and is the most common solid tumour in childhood. Interestingly, most infants experience complete regression of their disease with minimal therapy, even with metastatic disease. However, older patients frequently have metastatic disease that grows relentlessly, despite even the most intensive multimodality therapy. Recent advances in understanding the biology and genetics of neuroblastomas have allowed classification into low-, intermediate- and high-risk groups. This allows the most appropriate intensity of therapy to be selected - from observation alone to aggressive, multimodality therapy. Future therapies will focus increasingly on the genes and biological pathways that contribute to malignant transformation or progression.

Noninvasive estimation of tumour viability in a xenograft model of human neuroblastoma with proton magnetic resonance spectroscopy (1H MRS)

The aim of the study was to evaluate proton magnetic resonance spectroscopy ((1)H MRS) for noninvasive biological characterisation of neuroblastoma xenografts in vivo. For designing the experiments, human neuroblastoma xenografts growing subcutaneously in nude rats were analysed in vivo with (1)H MRS and magnetic resonance imaging at 4.7 T. The effects of spontaneous tumour growth and antiangiogenesis treatment, respectively, on spectral characteristics were evaluated. The spectroscopic findings were compared to tumour morphology, proliferation and viable tumour tissue fraction. The results showed that signals from choline (Cho)-containing compounds and mobile lipids (MLs) dominated the spectra. The individual ML/Cho ratios for both treated and untreated tumours were positively correlated with tumour volume (P<0.05). There was an inverse correlation between the ML/Cho ratio and the viable tumour fraction (r=-0.86, P<0.001). Higher ML/Cho ratios concomitant with pronounced histological changes were seen in spectra from tumours treated with the antiangiogenic drug TNP-470, compared to untreated control tumours (P<0.05). In conclusion, the ML/Cho ratio obtained in vivo by (1)H MRS enabled accurate assessment of the viable tumour fraction in a human neuroblastoma xenograft model. (1)H MRS also revealed early metabolic effects of antiangiogenesis treatment. (1)H MRS could prove useful as a tool to monitor experimental therapy in preclinical models of neuroblastoma, and possibly also in children.

Anti-proliferative effects of 20-epi-vitamin-D3 analogue, KH1060 in human neuroblastoma: induction of RAR-beta and p21(Cip1)

We determined the in vitro biological activities of 1 alpha, 25-dihdroxyvitamin D(3) (1,25-D(3)) and its analogue, 20-epi-22-oxa-24a, 26a, 27a-trihomo-1 alpha, 25 (OH)(2) vitamin D(3) (KH1060) in six human neuroblastoma (NB) cell lines (SH-SY5Y, NB69, SK-N-AS, IMR5, CHP-134, NGP). The ability of these compounds to inhibit cell growth and DNA synthesis was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and BrdU incorporation, respectively. The induction of cell death was monitored by caspase-3 activity. Their antineoplastic effect was assessed by clonal proliferation in soft agar. KH1060 was more effective than 1,25 D(3) in inhibiting cell growth and DNA synthesis. The IC-(50) (inhibition of 50% cell viability) indicated that KH1060 was about 10-20-fold more potent than 1,25 D(3). This growth inhibition was also accompanied by induction of caspase-3 activity, indicating that these compounds induce cell death in a caspase-dependent fashion. Moreover, KH1060 exerted potent antineoplastic activity by suppressing the clonal proliferation of the six NB cells. For the first time we demonstrate that KH1060 induces the expression of retinoic acid receptor-beta and p21(Cip1) suggesting that these proteins in part mediate the growth inhibitory effects. Taken together, all the six NB cells were more susceptible to growth inhibition by KH1060 than 1,25-D(3), suggesting its possible use in NB to potentiate the action of retinoids, which are in clinical use for this disease.

Retinoic acid decreases targeting of p27 for degradation via an N-myc-dependent decrease in p27 phosphorylation and an N-myc-independent decrease in Skp2

Poor prognosis neuroblastoma (NB) tumors are marked by amplification and overexpression of N-myc. Retinoic acid (RA) decreases N-myc levels and induces cell cycle arrest in vitro and increases event-free survival in advanced stage NB patients. In this study, we investigated the mechanism(s) by which RA regulates cell cycle and how N-myc affects NB cell cycle progression. Constitutive N-myc overexpression stimulates increases in cyclin E-dependent kinase activity and decreases in p27 resulting in increased DNA synthesis. N-myc regulates p27 levels through an increase in targeting of p27 to the proteasome via cyclin E kinase-dependent phosphorylation of p27 and its ubiquitination. N-myc also stimulates an increase in proteasome activity. In RA-treated cells in which N-myc levels decline as p27 levels increase, degradation of p27 is also decreased. However, RA does not affect the activity of proteasome. The decrease in the degradation of p27 in RA-treated cells is due in part to a decrease in the N-myc stimulated phosphorylation of p27. However, RA also decreases Skp2 levels thus impairing the ability of p27 to be ubiquitinated. Thus, RA induces both N-myc-dependent and -independent mechanisms to minimize the degradation of p27 and arrest NB cell growth.

Peripheral blood stem cell collection in 24 low-weight infants: experience of a single centre

Peripheral blood stem cells (PBSC) harvest may be difficult in young children. Extracorporeal separator line priming by red blood cells is usually required to improve haemodynamic tolerance and efficacy of collection. We present our experience with 24 children weighing less than 15 kg treated between January 1997 and September 1999, in whom we tried to avoid systematic blood priming. The median age and weight at the time of apheresis were 2.4 years and 12 kg, respectively. A total of 48 PBSC were performed. When haemoglobin was less than 12 g/dl, packed red cells were transfused before collection (40% of aphereses). The median cell yield per apheresis was 7.1 (2.2-30.6)x10(6)/kg CD34(+) cells and 16.0 (3.3-44.3)x10(5) CFU-GM/kg. Initial collection failed in three cases. Four children required an additional haematopoietic progenitor mobilization. This procedure allowed PBSC collection without transfusion in 37.5% of children, and was safe (two serious and five mild transient side effects) and effective (median CD34(+) cells collected per child: 7.1 x 10(6)/kg (4.6-30.6) and CFU-GM: 15.1 x 10(5)/kg (4.7-44.3)). Despite their low weight, insertion of a femoral catheter was avoided in 43% of children.

Preferential inactivation of paediatric solid tumour cells by sequential exposure to Merocyanine 540-mediated photodynamic therapy and Edelfosine: implications for the ex vivo purging of autologous haematopoietic stem cell grafts

Paediatric solid tumours exhibit steep dose-response curves to alkylating agents and are therefore considered candidates for high-dose chemotherapy and autologous stem cell support. There is growing evidence that autologous stem cell grafts from patients with solid tumours are frequently contaminated with live tumour cells. The objective of this study was to perform, in a preclinical purging model, an initial assessment of the safety and efficacy of a two-step purging procedure that combined Merocyanine 540-mediated photodynamic therapy (MC540-PDT) with a brief exposure to the alkyl-lysophospholipid, Edelfosine. Human and murine bone marrow cells and Neuro-2a murine neuroblastoma, SK-N-SH human neuroblastoma, SK-ES-1 and U-2 OS human osteosarcoma, G-401 and SK-NEP-1 human Wilms' tumour, and A-204 human rhabdomyosarcoma cells were exposed to a fixed dose of MC540-PDT followed by a brief incubation with graded concentrations of Edelfosine. Survival was subsequently assessed by in vitro clonal assay or, in the case of CD34-positive haematopoietic stem cells, by an immunohistochemical method. Combination purging with MC540-PDT and Edelfosine depleted all tumour cells by >4 log while preserving at least 15% of murine granulocyte/macrophage progenitors (CFU-GM), 34% of human CFU-GM, and 31% of human CD34-positive cells. The data suggest that combination purging with MC540-PDT and Edelfosine may be useful for the ex vivo purging of autologous stem cell grafts from patients with paediatric solid tumours.

High-risk neuroblastoma in Ontario: a report of experience from 1989 to 1995

PURPOSE

We did a population-based study of children with high-risk neuroblastoma to determine their survival and look for factors that had an impact on survival.

METHODS

We carried out a retrospective cohort study of patients diagnosed in Ontario from 1989 to 1995. 162 cases of neuroblastoma were diagnosed in the province with 70 (43%) considered high-risk: all were older than one year of age, with 15 patients classified as International Neuroblastoma Staging System (INSS) stage 3, and 55 INSS stage 4.

RESULTS

Stage 3 patients did significantly better than Stage 4 patients with a 5-year overall survival of 67.7% and 22.7% respectively (P = 0.015). In stage 4 patients achieving at least a partial response to up-front therapy and surviving for at least 9.5 months after diagnosis (the median time to transplant), there was no difference in survival between the 19 transplant patients and the 17 treated with chemotherapy alone (P = 0.75). However, patients transplanted by peripheral stem cell (PSC) collection did significantly better than both the bone marrow transplantation (P = 0.002) and chemotherapy-alone group (P = 0.047). There was a significant difference in up-front chemotherapy and use of radiation in the three groups (P < 0.001 and P = 0.01 respectively), but no difference in the incidence of bone and bone marrow metastases, MYCN amplification or unfavorable histology.

CONCLUSIONS

In this nonrandomized study, we found that stage 4 neuroblastoma patients alive more than 9.5 months after diagnosis, with at least a partial response to initial therapy, did significantly better with PSC transplant compared with bone marrow transplantation or chemotherapy alone.

Malignant abdominal masses in children: quick guide to evaluation and diagnosis

A palpable mass in the abdomen of a child is a serious finding. In this article the authors present their single-institution experience of how these malignancies present and their distribution by age and diagnosis. The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms' tumor, hepatoblastoma, lymphoma, and germ cell tumors. This article provides the busy general pediatrician with some guidelines of how to proceed after discovering a suspiciousmass.

Novel therapeutic approaches in the treatment of children with hepatoblastoma

Hepatoblastoma is the most common liver tumor diagnosed in children. Children with persistently unresectable disease, metastatic disease at presentation, recurrent disease, or slowly declining alpha-fetoprotein levels are at high risk for recurrence, exhibit an extremely poor prognosis, and are in desperate need of novel therapeutic agents and strategies. Four high-risk patients were treated. One patient with a local recurrence was treated with irinotecan followed by orthotopic liver transplant. Three patients were treated with tandem high-dose chemotherapy (HDT) with autologous stem cell rescue (two with primary metastatic disease and one with recurrent disease). All three of the patients treated with HDT had relapse (two of them subsequently received irinotecan); the remaining patient underwent surgical resection of a solitary recurrent pulmonary metastasis. Irinotecan demonstrated significant antitumor effects in all three treated patients and was well tolerated. None of the three patients treated with HDT remained disease-free, although the patient who underwent surgical resection of a solitary recurrent pulmonary metastasis remains disease-free 6 years from diagnosis. Further exploration of the use of irinotecan is warranted in high-risk patients with hepatoblastoma.

New approaches to hematopoietic cell transplantation in oncology

The use of high-dose chemotherapy followed by autologous HCT and the use of allogeneic HCT in children and adolescents with high-risk ALL, AML, and NBL has successfully improved outcomes. For other diseases, however, the role of HCT in treatment remains a subject of further research. The availability of HCT was significantly expanded by developing alternative graft sources that currently include BM, peripheral blood, and UCB from autologous and allogeneic related or unrelated donors. Progress in autologous HCT has been achieved by the identification of more effective and less toxic preparative regimens and by ex vivo purging of stem cell products. In allogeneic HCT, graft-versus-leukemia or graft-versus-tumor effects are being exploited increasingly to lower relapse rates. In addition, immunomodulation to promote tolerance, as well as allogeneic antitumor reactions have been achieved by antibody therapy, cytokine therapy, or cell-based immunotherapy. Future improvements are likely, as evidenced by promising preliminary results in the development of stem cell collection techniques, in vitro stem cell expansion, and purging techniques of stem cell grafts. The development of less intensive or nonmyeloablative preparative regimens may further reduce regimen-related morbidity and mortality Specific immunotherapy may facilitate tolerance induction in mismatched allogeneic HCT and support allogeneic HCT in the setting of donor-host HLA disparity. Ultimately, advances in cytokine therapy, tumor-specific vaccines, and gene therapy may decrease or even eradicate recurrence of the malignant disease after HCT.

Increasing use of reduced intensity conditioning transplants: report of the 2001 EBMT activity survey

Since 1990, the EBMT has annually collected numbers of HSCT by disease indication, donor type and stem cell source. The 2001 survey concentrates on the use of reduced intensity conditioning (RIC) transplants and its dissemination in Europe. In 2001, there were 19576 HSCT for new patients, 6413 with allogeneic HSCT (33%), 13163 with autologous HSCT (67%) and 3256 additional re- or multiple transplants, 868 (667/201) allogeneic and 2658 (537/2121) autologous, collected from 596 centers in 35 European countries. The main indications in 2001 were leukemias (32%; 73% of them allogeneic); lymphomas (53%; 92% of them autologous); solid tumors (11%; 93% of them autologous) and non-malignant disorders (4%; 90% of them allogeneic). Compared to 2000, there was a drop in allogeneic HSCT of over 20% for chronic myeloid leukemia and an increase of 2% in autologous HSCT. A total of 1759 or 27% of allogeneic transplants were reported as RIC HSCT. These have risen in number in 3 years from <1% in 1998. There are wide variations from 0 to 71% RIC HSCT in European countries with no obvious explanation. These data document the current status of blood and marrow transplantation in Europe and indicate a marked change towards RIC HSCT in allogeneic transplantation.

High-dose chemotherapy and autologous peripheral blood stem-cell transfusion after conventional chemotherapy for patients with high-risk Ewing's tumors

Although the overall results of treatment of Ewing's tumors have improved, patients with high-risk factors, including metastatic disease at diagnosis, bulky primary tumors, axial sites, and age >15 years, continue to have poor prognoses. The effects of high-dose chemotherapy and autologous peripheral blood stem-cell transplantation on high-risk Ewing's tumor patients have been reported. In most of these studies, conditioning and high-dose regimens varied among patients. Here we report the feasibility and effects of a high-dose chemotherapy regimen conducted in our institution. Seven patients with high-risk Ewing's tumors were treated by high-dose chemotherapy. The patients received four cycles of remission induction chemotherapy, and then peripheral blood stem cells were mobilized by high-dose etoposide and harvested. Myeloablative chemotherapy consisted of carboplatin, ifosfamide, and etoposide. The patients have 5-year overall and relapse-free survival probabilities of 0.86 and 0.81, respectively. The results were significantly better than those for patients treated with conventional chemotherapy alone. None of the patients had severe side effects. The high-dose regimen and transplantation were feasible and well tolerated. The poor prognoses of high-risk Ewing's tumor patients may be improved by high-dose chemotherapy with peripheral blood stem cell transplantation. However, the real impact of the therapy on the clinical outcome of patients with high-risk Ewing's tumors should be evaluated in a prospective, randomized study.

The LMCE5 unselected cohort of 25 children consecutively diagnosed with untreated stage 4 neuroblastoma over 1 year at diagnosis

The Lyon-Marseille-Curie-Est (LMCE) of France cooperative group has previously reported successive series of unselected stage four children older than 1 year at diagnosis with metastatic neuroblastoma (LMCE 1 and 3). The goal of LMCE 5 study was to increase progression free survival rate as compared to LMCE 1 and 3. Based on improvements reported with post induction chemotherapy, the LMCE 5 used post induction for all children, but omitted total body irradiation and immunomagnetic purging in megatherapy regimen for all children. Twenty-five sequentially diagnosed children received an induction regimen which compared with previous induction included an increased dose of etoposide and cyclophosphamide, delivered similar dose of cisplatinum, and deleted doxorubicin and vincristin. After surgery treatment was stratified based on response and eligible children received etoposide carboplatin (LMCE 5A : n=10)+/-doxorubicin (LMCE 5B-C n=13) followed by megatherapy (melphalan without total body irradiation and unpurged peripheral blood stem cell rescue). The increase in drug doses during induction did not improve remission rate. The progression free survival at 6 years is 8%. It is significantly worse than LMCE 3, and equivalent to LMCE 1 study though toxic death rate has decreased with increasing experience. Failure to improve the response rate during induction and reducing the megatherapy regimen may be the main factors in this disappointing result. Modified strategies for induction, non toxic alternative to total body irradiation, and post megatherapy regimen should be developed.

Intensified chemotherapy increases the survival rates in patients with stage 4 neuroblastoma with MYCN amplification

PURPOSE

Patients with high-risk neuroblastoma who have multiple copies of MYCN fare much worse than do those without MYCN amplification; however, it has not been clarified whether intensified chemotherapy with or without blood stem cell transplantation can alter the extremely poor prognosis of patients with amplified MYCN.

METHODS AND RESULTS

Between 1985 and 1999, 301 patients older than age 12 months with stage 4 neuroblastoma were treated. From January 1985 to February 1991, 80 patients with stage 4 neuroblastoma with and without MYCN amplification uniformly received induction chemotherapy with regimen A(1) (cyclophosphamide 1,200 mg/m(2) and vincristine 1.5 mg/m(2) on day 1, tetra-hydropyranyl [THP]-Adriamycin 40 mg/m(2) on day 3, and cisplatin 90 mg/m(2) on day 5). Among 22 patients with MYCN amplification, nine (40.9%) achieved a complete remission and seven (31.8%) underwent stem cell transplantation. Of 58 patients without MYCN amplification, 43 (74.1%) achieved a complete remission and 14 (24.1%) underwent stem cell transplantation. The 5-year relapse-free survival rates were 23.2% for stage 4 patients with MYCN amplification and 33.3% for those without MYCN amplification (P = 0.029); the 5-year overall survival rates were 32.8% for stage 4 patients with MYCN amplification and 42.8% for those without MYCN amplification (P > 0.05). From March 1991 to June 1998, patients with stage 4 neuroblastoma who had 10 or more copies of MYCN were treated with regimen A(3) (cyclophosphamide 1,200 mg/m(2) per day on days 1 and 2, THP-Adriamycin 40 mg/m(2) on day 3, etoposide 100 mg/m(2) per day on days 1 to 5, and cisplatin 25 mg/m(2) per day on days 1 to 5); those with fewer than 10 copies of MYCN received regimen new A (cyclophosphamide 1,200 mg/m on day 1, THP-Adriamycin 40 mg/m on day 3, etoposide 100 mg/m per day on days 1 to 5, and cisplatin 90 mg/m on day 5), which is similar in intensity to regimen A. Among 88 patients with MYCN amplification, 63 (71.6%) achieved a complete remission and 63 (71.68%) underwent stem cell transplantation. Of 133 patients without MYCN amplification, 93 (69.9%) achieved a complete remission and 71 (53.4%) underwent stem cell transplantation. The 5-year relapse-free survival rates were 36.0% for stage 4 patients with MYCN amplification and 32.2% for those without MYCN amplification (P > 0.05), the 5-year overall survival rates were 34.0% for stage 4 patients with MYCN amplification and 38.9% for those without MYCN amplification (P > 0.05). The difference in relapse-free survival rates was significantly different (P = 0.003) between patients with MYCN-amplified tumor treated before (regimen A(1)) versus after 1991 (regimen A(3)).

CONCLUSIONS

With the use of the more intensive induction regimen A plus blood stem cell transplantation for MYCN-amplified patients, survival curves for those with or without MYCN amplification now appear similar. Higher doses of chemotherapy may ameliorate the effect of MYCN amplification in patients with high-risk neuroblastoma.

Anti-tumor effect of Merocyanine 540-mediated photochemotherapy combined with Edelfosine: potential implications for the ex vivo purging of hematopoietic stem cell grafts from breast cancer patients

High-dose chemotherapy combined with autologous stem cell support has improved response rates in high-risk and metastatic breast cancer, but has failed to improve long-term survival. Breast cancer has a tendency to metastasize to the bone marrow, and live tumor cells are known to circulate in the peripheral blood of breast cancer patients. Sensitive immunohistochemical, culture-based, and reverse transcriptase polymerase chain reaction (RT-PCR)-based methods have shown that about 50% of histologically normal stem cell grafts from breast cancer patients are contaminated with occult tumor cells, which may cause or contribute to tumor recurrences. Merocyanine 540 (MC540)-mediated photodynamic therapy (PDT) inactivates a wide range of leukemia and lymphoma cells and is well tolerated by normal hematopoietic stem and progenitor cells. Unfortunately, most solid tumor cells (including breast cancer cells) are only moderately sensitive or refractory to MC540-PDT. We report here that if MC540-PDT is followed by a 1-h incubation with the alkyl-lysophospholipid, Edelfosine (ET-18-OCH(3)), the depletion of murine and human breast cancer cells is greatly enhanced whereas the recovery of normal hematopoietic stem and progenitor cells is only minimally degraded. When used under conditions that reduce CD34-positive human bone marrow cells only 5.1-fold, and murine and human granulocyte/macrophage progenitors 6.8- and 3-fold, respectively, combination purging with MC540-PDT and Edelfosine depletes murine (Mm5MT) and human (MDA-MB-435S) breast cancer cells >17,000- and >125,000-fold, respectively. These data suggest that combination purging with MC540-PDT and Edelfosine may offer a simple, safe and effective method for the ex vivo purging of autologous stem cell grafts from breast cancer patients.

Dendritic cells for NK/LAK activation: rationale for multicellular immunotherapy in neuroblastoma patients

Natural killer (NK)/lymphokine-activated killer (LAK) cell-based immunotherapy could be beneficial against major histocompatibility complex class I-negative tumor residual disease such as neuroblastoma (NB), provided that interleukin 2 (IL-2) or surrogate nontoxic NK cell stimulatory factors could sustain NK cell activation and survival in vivo. Here we show that human monocyte-derived dendritic cells (MD-DCs) promote potent NK/LAK effector functions and long-term survival, circumventing the need for IL-2. This study demonstrates (1) the feasibility of differentiating granulocyte colony-stimulating factor-mobilized hematopoietic peripheral blood stem cells (PBSCs) into high numbers of functional MD-DCs and NK/LAK cells in a series of 12 children with stage 4 neuroblastoma (NB); (2) potent DC-mediated NK cell activation in autologous settings; (3) the reciprocal capacity of NK/LAK cells to turn immature DCs into maturing cells electively capable of triggering NK cell functions; and (4) the unique capacity of maturing DCs to sustain NK cell survival, superior to that achieved in IL-2. These data show a reciprocal interaction between DCs and NK/LAK cells, leading to the amplification of NK cell effector functions, and support the implementation of DC/NK cell-based immunotherapy for purging the graft and/or controlling minimal residual disease after autologous stem cell transplantation.

Current trends in hematopoietic stem cell transplantation in Europe

Major changes have occurred in the transplantation of hematopoietic stem cells (HSCs) during the last decade. This report reveals the changes, reflects current status, and provides medium-term projections of HSC transplantation (HSCT) development in Europe. Data on 132 963 patients, 44 165 with allogeneic HSC transplant (33%) and 88 798 with an autologous HSC transplant (67%), collected prospectively from 619 centers by the European Group for Blood and Marrow Transplantation (EBMT) in 35 European countries between 1990 (4234 HSCTs) and 2000 (19 136 HSCTs) illustrate utilization of HSCT. HSCT increased in all European countries and for all indications. There were major differences depending on disease indication and donor type. Transplantation rates (numbers of HSCTs per 10 million inhabitants) varied from less than 1 for some rare indications to 37.7 +/- 4.1 for acute myeloid leukemia in allogeneic HSCT or 95.5 +/- 13.5 for non-Hodgkin lymphoma in autologous HSCT. There were indications with a steady, continuing increase and others with initial increase but subsequent decrease. Projections on medium-term development for each disease based on a weighted sensitivity analysis predict an ongoing increase in allogeneic HSCT except for chronic myeloid leukemia. In autologous HSCT they predict an increase for lymphoproliferative disorders, acute myeloid leukemia, myelodysplastic syndromes, and some solid tumors but a decrease for most solid tumors, acute lymphoid leukemia, and chronic myeloid leukemia. Transplantation rates can be predicted with reasonable sensitivity for most disease indications. Despite marked changes in the rapidly developing field of HSCT, this information on current use, trends, and midterm predictions forms a rational basis for patient counseling and health care planning.

Peripheral blood stem cell support reduces the toxicity of intensive chemotherapy for children and adolescents with metastatic sarcomas

BACKGROUND

To increase the dose intensity (DI) of chemotherapy for pediatric patients with metastatic sarcomas, including the Ewing sarcoma family of tumors (ESFT) and rhabdomyosarcoma (RMS), the authors tested the feasibility of an intensive regimen supported by granulocyte-colony stimulating factor (G-CSF) and peripheral blood stem cells (PBSC).

METHODS

Twenty-three children and adolescents with metastatic sarcomas received vincristine, doxorubicin, cyclophosphamide, ifosfamide, sodium mercaptoethanesulfonate (mensa), and etoposide (VACIME) chemotherapy, consisting of 8 courses of vincristine 2 mg/m(2) on Day 0, doxorubicin 37.5 mg/m(2) per day on Days 0-1, cyclophosphamide 360 mg/m(2) per day on Days 0-4, ifosfamide 1800 mg/m(2) per day on Days 0-4, mesna 2400 mg/m(2) per day, and etoposide 100 mg/m(2) per day on Days 0-4. Doxorubicin was omitted in Courses 7 and 8. G-CSF was given after each course of therapy. Courses of therapy were repeated every 21 days or as soon as hematopoietic recovery permitted. PBSC were collected twice: first, after Course 2 (infused after Courses 3 and 4) and, second, after Course 4 (infused after Courses 5 and 6). Surgical resection followed Course 6, and radiotherapy followed Course 8.

RESULTS

PBSC collections were adequate in 91% of all harvests. The mean DI was 82% (standard deviation, 14%) of the intended DI, which was greater than historic data without PBSC support. Seventeen patients (74%) achieved a complete response (CR), 12 patients with chemotherapy alone and 5 more patients after undergoing surgical resection. Fifteen patients developed progressive disease, with a 2-year event free survival (EFS) rate of 39% (95% confidence interval, 19-59%). Hematopoietic toxicity was severe and cumulative, although it was less than that seen previously without PBSC support.

CONCLUSIONS

PBSC-supported multicycle chemotherapy is a feasible method to increase chemotherapy DI for pediatric patients with metastatic sarcomas. Although the CR rate compared favorably with previously reported response rates, the 2-year EFS rate was similar to that achieved with other intensive regimens.

Chronic neuroblastoma

BACKGROUND

An indolent course is associated with neuroblastoma (NB) in adolescents and adults. In the current study, the authors analyzed this phenomenon in a large series of children with metastatic NB.

METHODS

The authors studied 38 patients who were diagnosed with NB in the first decade of life and had metastatic disease 5 years or more from diagnosis.

RESULTS

The median age at diagnosis was 3 years 10 months. MYCN was amplified in 2 of 28 patients tested. Of 30 patients with classic Stage 4 NB, 9 had a late first recurrence of disease (4.3-13 years from diagnosis). Of eight patients who had atypical cases at diagnosis (one isolated mandibular lesion, two Stage 4-N, five non-Stage 4), six had a late first distant recurrence of disease (4 years 11 months-38 years 8 months). Nineteen patients were off therapy continuously for 3 years or more before disease recurred a first or second time. Myeloablative therapy was used to consolidate a first or second response in 27 patients. High-dose conventional therapy helped to achieve a second remission of disease in 9 of 20 patients assessable for response of first recurrence but achieved no major responses of second or third relapse in 10 of 11 patients. The combination of anti-G(D2) immunotherapy and/or cis-retinoic acid, targeted radiotherapy, and multiple cycles of chemotherapy with modest toxicity helped prolong survival. Twelve patients survive at 5 years 6 months+ to 19 years 4 months+ from diagnosis (median, 6 years 10 months+), including four with complete remission of disease; 10 received anti-G(D2) immunotherapy after recurrence. The other 26 patients died of disease (n = 22) or toxicity (n = 4) at 5 years-41 years 5 months from diagnosis (median, 6 years 5 months).

CONCLUSIONS

The concept of indolent or smoldering NB should not be limited to adolescents/adults. The expanding repertoire of anti-NB treatments, including biologic therapies and chemotherapy regimens of modest toxicity, can convert childhood NB into a chronic disease with prolonged survival after recurrence.

Long-term survival of children with neuroblastoma prior to the neuroblastoma screening project in Germany

BACKGROUND

In the last decades, prognosis of children with neuroblastoma has improved only slightly. Traditional estimates of survival reflect the survival experience of children diagnosed many years ago, and may thus not capture more recent progress in prognosis. We applied a new method of survival analysis, denoted period analysis, to provide more up-to-date estimates of long-term prognosis. We selected the cases diagnosed before the German neuroblastoma screening project in 1995, allowing to assess the method by comparing the 1994 projected survival estimates with the observations made today (2000).

PROCEDURE

The data comes from the population based German Childhood Cancer Registry. We included all 1,353 children diagnosed with neuroblastoma below age 15 between 1980 and 1994. We derived 5-, 10-, and 15-year survival estimates using traditional analysis or period analysis as needed. Where possible we compared the period analysis estimates with the later obtained actual estimates. We showed trends in survival for the sample as a whole and for prognostic subgroups.

RESULTS

Survival probabilities increased over time especially in the subgroups with poor prognosis. Short-term survival probabilities improved more than long-term survival probabilities. Evaluation of the period-analysis estimates showed them to provide accurate and timely projections of prognosis of newly diagnosed patients.

CONCLUSIONS

The results suggest major improvements in prognosis of children with neuroblastoma, even prior to the start of the German neuroblastoma screening project, especially in advanced disease. This could have been disclosed with the application of the period analysis method in 1995 even then with considerable accuracy. We recommend a more widespread application of this method especially in population-based cancer registries.

Intensive chemotherapy for children and young adults with metastatic primitive neuroectodermal tumors of the soft tissue

The MMT4 study was designed to explore an intensive chemotherapy regimen (MMT4-89) and the role of high-dose melphalan (MMT4-91) in children with metastatic soft tissue sarcoma, including extraosseous peripheral neuroectodermal tumor (PNET). Thirty-one patients with PNET were treated between 1989 and 1995 (11 according to MMT4-89 and 20 according to MMT4-91). Chemotherapy consisted of four CEVAIE cycles, each including three 3-week courses: CEV (carboplatin 500 mg/m(2), epirubicin 150 mg/m(2), vincristine 1.5 mg/m(2)), IVA ifosfamide 9 g/m(2), actinomycin 1.5 mg/m(2), vincristine 1.5 mg/m(2)), IVE (ifosfamide 9 g/m(2), etoposide 600 mg/m(2), vincristine 1.5 mg/m(2)). In MMT4-91 the fourth CEVAIE was replaced with melphalan 200 mg/m(2) with stem cell rescue. The CEV combination was evaluated as a window study. Surgery followed the second cycle. Radiotherapy was administered to post-surgical residual disease. The response rate was 55% after CEV, rising to 80% after the first CEVAIE. Twenty-five patients achieved complete remission (CR). Overall, the 5-year EFS was 22.6%: 36.4% and 15% for patients treated according to MMT4-89 and MMT4-91, respectively (P = 0.3). Local control was achieved in 77% of irradiated patients vs 45% of non-irradiated. Age >10 years was associated with significantly poorer outcome (P = 0.04). In conclusion, despite the high CR rate, intensive chemotherapy with or without high-dose melphalan appeared to have little impact on the survival of patients with metastatic extraosseus PNET.

Synergistic cytotoxicity of buthionine sulfoximine (BSO) and intensive melphalan (L-PAM) for neuroblastoma cell lines established at relapse after myeloablative therapy

Patients with high-risk neuroblastoma (NB) initially respond to aggressive, alkylator-based therapy only to die from recurrent disease that is refractory to chemotherapy, including alkylating agents. We examined the ability of buthionine sulfoximine (BSO)-mediated glutathione (GSH) depletion to modulate melphalan (L-PAM) resistance in five NB cell lines established after progressive disease following myeloablative therapy (high-dose melphalan, carboplatin, etoposide and total body irradiation) supported by autologous hematopoietic stem cell transplant (AHSCT), and in 15 NB cell lines established at diagnosis or after non-myeloablative therapy (pre-AHSCT). Four of five post-AHSCT NB cell lines and 10 of 15 pre-AHSCT NB cell lines were sensitive to single agent BSO (LC(90) <300 microM BSO), while two of five post-AHSCT lines and one of 15 pre-AHSCT lines showed high-level resistance to L-PAM (LC(90)>30 microM). Fixed ratio analysis demonstrated BSO/L-PAM synergy (combination index <1) for all five post-AHSCT and for all 15 pre-AHSCT cell lines tested. Multi-log cytotoxicity (often exceeding four logs of cell kill) was observed in post-AHSCT L-PAM-resistant cell lines (including p53 non-functional lines) only when clinically achievable concentrations of BSO were combined with myeloablative concentrations of L-PAM. We conclude that most neuroblastoma cell lines, including post-AHSCT NB cell lines that are highly resistant to myeloablative levels of L-PAM and lack p53 function, are sensitive to clinically achievable concentrations of L-PAM and BSO. However, some L-PAM-resistant NB cell lines (especially those lacking p53 function) require dose escalation of L-PAM to myeloablative concentrations in order to demonstrate significant synergistic cytotoxicity. Thus, optimal clinical application of BSO/L-PAM may require AHSCT.

Activation of the phosphatidylinositol 3-kinase/Akt signaling pathway by retinoic acid is required for neural differentiation of SH-SY5Y human neuroblastoma cells

Retinoic acid (RA) induces neural differentiation of SH-SY5Y neuroblastoma cells. We show that the mRNA levels of the differentiation-inhibiting basic helix-loop-helix transcription factors ID1, ID2, and ID3 are down-regulated during RA-induced differentiation of SH-SY5Y cells. The levels of ID proteins decreased in parallel to the observed transcriptional repression. The expression of other basic helix-loop-helix genes changed during RA-induced differentiation: expression of neuroblast-specific ASCL1 (HASH-1) gene was promptly reduced after RA treatment, whereas expression of differentiation-promoting genes NEUROD6 (NEX-1, HATH-2) and NEUROD1 was increased. Treatments with 12-O-tetradecanoylphorbol-13-acetate, another inducer of neuroblastoma cell differentiation, also resulted in coordinated down-regulation of ID gene expression, underscoring the role of ID genes in differentiation. Down-regulation of ID gene expression by RA involves a complex mechanism because full transcriptional repression required newly synthesized proteins and signaling by phosphatidylinositol 3-kinase (PI3K). RA treatment activates the PI3K/Akt signaling pathway, resulting in increased PI3K activity in extracts from RA-treated cells and a rapid increase in phosphorylation of Akt in Ser-473. Inhibition of PI3K by LY294002 impaired RA-induced differentiation, as assessed by morphological and biochemical criteria. We propose that RA, by activating the PI3K/Akt signaling pathway, plays an important role in the regulation of neuronal cell survival.

Retinoids in combination therapies for the treatment of cancer: mechanisms and perspectives

Retinoid derivatives have been of special interest in cancer research because of their antiproliferative and differentiation-inducing activities in premalignant and malignant cells. Some retinoids are clinically effective in cancer therapy and prevention, and all-trans-retinoic acid is being used for the treatment of acute promyelocytic leukemia. Unfortunately, classical retinoids are not effective against most advanced solid tumors and cause undesirable side effects, which have limited the full development of retinoids as chemopreventive and chemotherapeutic drugs. The recent identification of selective retinoid derivatives capable of inducing apoptosis and their combination with other anticancer therapies promises a more effective and less toxic manner to the successful use of retinoids in cancer therapy.

How do parents perceive high-dose chemotherapy and autologous stem cell transplantation for their children

Our objective was to understand the parents' perception of children treated in an ASCT unit. Parents (40) of children and adolescents were interviewed by the department psychiatrist-psychoanalyst, over 9 months. They expressed great distress (22), considerable difficulty in assuming their parental role (with feelings of helplessness and guilt), and had distorted relations with the child whose behavior was unusual and incomprehensible (22). The relation with care providers, who should be 'all-powerful' and harmless, was ambivalent (15). They found it difficult to think or refused to do so, because their 'thoughts are terrifying', and they wanted to forget everything (11). The couple was going through a crisis (9). Temporal landmarks were disturbed (8); ASCT was experienced as a threatening discontinuity in the course of treatment (parents were unable to think of the past, the future, or the present); social landmarks were disturbed (6) with loss of social and professional relations. We concluded that parents may experience intense distress and disorientation. Trained to understand the parents' and their children's thoughts and behavior, the medical team, which includes a psycho-oncologist, can better help them to understand and support the children, to strike a balance between their parental role and other responsibilities, and prevent conflicts.

Cyclooxygenase-2 expression in pediatric sarcomas

Therapies for metastatic pediatric sarcomas have reached maximum tolerated doses, but continue to provide suboptimal cure rates. Additionally, these treatments are associated with numerous short- and long-term side effects. Therefore, the search for newer, less toxic therapeutic agents is warranted. Overexpression of the inducible enzyme, cyclooxygenase-2 (COX-2), has been discovered in a variety of adult solid tumors and numerous studies have shown COX-2 inhibitors to have significant antiproliferative effects. Therefore, we sought to determine the expression of COX-2 in pediatric sarcomas. We evaluated rhabdomyosarcoma (RMS), osteosarcoma (OS), and Ewing sarcoma (EWS) samples for COX-2 expression by immunohistochemical analysis as well as by cDNA microarray analysis. COX-2 expression was detected in 48/58 (82.8%) tumors by immunohistochemistry and in an additional 52/59 (88.1%) tumors tested by microarray gene analysis. There was a trend toward increased COX-2 expression in metastatic rhabdomyosarcoma and osteosarcoma, though it did not reach clinical significance. The degree of COX-2 immunoreactivity did not vary significantly with other clinicopathologic features such as age, gender, or histologic classification. We conclude that the majority of these pediatric sarcoma samples express COX-2 to varying degrees. Therefore, studies testing the efficacy of COX-2 inhibitors in the treatment of pediatric sarcomas are warranted.