Childhood cancer survival in Finland (1953-2010): a nation-wide population-based study.

Population based survival studies are critical in monitoring changes in anticancer therapy, evaluating effectiveness of new treatments as well as identifying possibilities for further improvement. The previous report on cancer survival in Finland covered patients diagnosed in 1953-1995. Data on survival in the European and Nordic pediatric populations have been published with follow-up ending in 2002. We describe population-based survival of childhood cancer patients (n = 8270, age 0-14 years) in Finland overall and by disease category with follow-up extending from 1953 to 2010 and focusing on the modern treatment era. Data were collected from the Finnish Cancer Registry. Age-standardised observed survival proportions (rates) were calculated using the actuarial (or life-table) method. Trends in observed survival rates were studied over six diagnostic periods: 1953-1960, 1961-1970, 1971-1980, 1981-1990, 1991-2000 and 2001-2010. The overall 5-year survival reached 82.1% (95% CI 80.0-84.2) in the most recent period. In most diagnostic categories, the biggest leap in survival was seen between 1961-1970 and 1981-1990, after which slight improvements occurred between 1981-1990 and 1991-2000, with no significant increase thereafter. In analyses by diagnostic group, positive trends in survival over the last three decades were seen for leukemia (p = 0.000), non-Hodgkin's lymphoma (p = 0.002) and CNS tumours (p = 0.02). Although survival of childhood cancer patients overall has significantly improved from 1953 to 2000, improvement thereafter has been marginal. Future treatment efforts should be directed at bone tumours, soft-tissue sarcoma, neuroblastoma and malignant brain tumours as well as high-risk leukemia.

Surgical treatment of neuroblastoma: twenty-three years of experience at a single institution.

PURPOSE: Neuroblastoma (NB) is treated with surgery, chemotherapy and radiotherapy. We assessed the effects of surgical resection on the outcome over a 23-year period at our institution. METHODS: 85 children were included with a median age at diagnosis of 2.0 (range 0.1-15) years. We assessed the correlation of the complete surgical resection (CR) rate, metastases, NMYC amplification (NMYCA) and chemotherapeutic response with the 5-year overall survival (OS). RESULTS: The INSS stage of NB was 1 in 11 (13 %) patients, 2 in 10 (11 %), 3 in 13 (17 %), 4 in 46 (53 %) and 4S in five patients (6 %). Fifty-two (61 %) patients had high-risk NB and 22 (26 %) had NMYCA. The resection was complete in 72 (85 %) patients, incomplete (ICR) in seven (8 %) and six (7 %) patients did not undergo surgery. Fifty-five patients were administered neoadjuvant and 61 were administered adjuvant chemotherapy (high-dose, n = 50). The OS (5 year) was 68 %: stage 1 (100 %), 2 (90 %), 3 (77 %), 4 (52 %), 4S (80 %) and high-risk NB (52 %). The OS in high-risk NB patients was correlated with a good chemotherapeutic response of the primary tumour, with a RR for mortality = 0.3 (95 % CI 0.1-0.7; p = 0.01), but not with the CR, which had an RR = 0.9 (95 % CI 0.3-2.4; p = 0.84). CONCLUSIONS: The OS in high-risk NB patients was related to a good histological chemotherapeutic response, but not with complete excision of the primary tumour.

Integrated analysis of gene copy number, copy neutral LOH, and microRNA profiles in adult acute lymphoblastic leukemia.

We adopted an integrated analysis of gene copy number alterations (CNAs), copy number neutral loss of heterozygosity (CNN LOH), and microRNA (miRNA) profiling in 21 adult acute lymphoblastic leukemia (ALL) patients. This study revealed the most frequent CNAs to be at chromosomes 9p, 7, and 17 and recurrent CNN LOH at 5p, 9p, and Xq. As for the most differentially expressed miRNAs, they included 8 upregulated and 14 downregulated miRNAs, of which miR-148a at 7p15.2, miR-22 at 17p13.3, miR-223 at Xq12, as well as miR-101-2 at 9p24.1 exhibited recurrent CNAs or CNN LOH. miR-101-2 was recurrently downregulated, and although the related CNN LOH was detected only in BCR-ABL1 negative cases (2/14), deletions of miR-101-2 were observed solely in BCR-ABL1 positive cases (4/7). Finally, BCR-ABL1 positive cases, in contrast to negative ones, were characterized by slightly, but still significantly, higher expression levels of miR-29b.

Clinical and biological markers of premature aging after autologous SCT in childhood cancer.

The aim of this study was to analyze the prevalence of frailty and physical health limitations among long-term survivors of high-risk neuroblastoma (HR NBL) and to investigate whether frail health is associated with variables of cardiovascular function, markers of inflammation and telomere length. A national study cohort of 19 (median age 22, range 16-30 years) long-term (>10 years) HR NBL survivors was studied and the findings were compared with 20 age- and sex-matched controls. Frailty was defined as ⩾3 of the following conditions: low muscle mass, low energy expenditure, slow running and weakness. The prevalence of frailty was significantly higher among the HR NBL survivors 9/19 (47%) than among the controls (0%). Thirteen (68%) of the survivors reported significant physical health limitations in vigorous activities, as opposed to none of the controls. The HR NBL survivors had significantly shorter telomere length and higher serum levels of high sensitivity C-reactive protein than did the controls. Frail health and poor physical functioning are prevalent among HR NBL survivors and suggest premature aging. Survivors with gonadal damage, very low fat mass percentage, low glycosylated hemoglobin A1c and increased common carotid artery intima-media thickness may be more prone to early aging after high dose therapy.

No disadvantage in outcome of using matched unrelated donors as compared with matched sibling donors for bone marrow transplantation in children with acute lymphoblastic leukemia in second remission.

PURPOSE: We evaluated the outcome of children with acute lymphoblastic leukemia (ALL) in second remission (2CR), comparing bone marrow transplantation (BMT) using either matched sibling donors or unrelated donors (URDs). PATIENTS AND METHODS: A total of 65 patients, aged 2 months to 20 years at BMT, with ALL in 2CR underwent allogeneic BMT at seven Nordic centers during 1990 to 1997. Of the first relapses, 85% were in bone marrow; 46% occurred on therapy, and 54%, off therapy. The preparative regimens were cyclophosphamide plus total-body irradiation +/- antithymocyte/antilymphocyte globulin, busulfan plus cyclophosphamide +/- antithymocyte/antilymphocyte globulin, or cytarabine plus total-body irradiation. Of the allografts, 37 were from HLA-matched siblings and 28 were from URDs. RESULTS: In the sibling versus URD graft recipient groups, the posttransplantation 5-year event-free survival was 39% versus 54% (P =.4), the estimated posttransplantation relapse rate was 76% versus 40% (P = not significant [NS]), and the toxic death rate was 19% versus 11% (P = NS). The incidence of significant (grade 2 to 4) acute graft-versus-host disease (GVHD) was 38% versus 64% (P <.05) and was 14% versus 32% (P <.10) for severe (grade 3 to 4) acute GVHD; the incidence of chronic GVHD was 26% versus 57% (P <.05) and was 13% versus 22% (P = NS) for extensive chronic GVHD in the sibling and URD groups. CONCLUSION: BMT with matched URD allografts offers at least equal survival for children with ALL in 2CR, as compared with allografts from matched sibling donors. URD allografts were not associated with a higher toxic mortality rate, although both acute and chronic GVHD were more frequent with URD. Indications for using matched URD allografts in ALL 2CR can be considered the same as for using matched sibling donors.

Circulating dendritic cell subset levels after allogeneic stem cell transplantation in children correlate with time post transplant and severity of acute graft-versus-host disease.

We examined the recovery of circulating monocytoid (Lin- CD11+ HLA-DR+) and plasmacytoid (Lin- CD123+ HLA-DR+) precursor (pre) dendritic cell (DC) subsets after allogeneic stem cell transplantation (SCT) in 39 children, using age-matched healthy children as controls. The frequencies of DCs in peripheral blood samples were determined by flow cytometry. The initial recovery of DC occurred simultaneously with myeloid engraftment. However, with time, DC subset values declined, being very low 40-50 days after SCT. Low monocytoid and plasmacytoid DC values were associated significantly with the development of severe acute graft-versus-host disease (aGVHD) (P=0.042 and 0.017, respectively). Plasmacytoid DC values were lower than in the age-matched controls for the entire follow-up period (range 102-2569 days), although, with time, values approached normal levels. Normal monocytoid DC numbers were observed within 300-400 days post SCT. The severity of chronic GVHD did not correlate with quantitative recovery of DC. We conclude that in pediatric SCT, initial recovery of DC production is concurrent with that of myelopoiesis, yet with time, DC subset values decline and low counts are associated with severe aGVHD. Monocytoid DC numbers approach normal levels within a year of SCT, but plasmacytoid DC counts recover very slowly.

Improving outcome through two decades in childhood ALL in the Nordic countries: the impact of high-dose methotrexate in the reduction of CNS irradiation. Nordic Society of Pediatric Haematology and Oncology (NOPHO).

In this population-based material from the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), 2860 children below 15 years of age were diagnosed with acute lymphoblastic leukemia (ALL) from July 1981 to June 1998. The annual incidence was 3.9/100,000 children and was stable throughout the study period. The development from regional or national protocols to common Nordic treatment protocols for all risk groups was completed in 1992 through a successive intensification with multidrug chemotherapy, including pulses of methotrexate in high doses and avoidance of cranial irradiation in most children. The overall event-free survival (EFS) at 5 years has increased from 56.5 +/- 1.7% in the early 1980s to 77.6 +/- 1.4% during the 1990s. The main improvements were seen in children with non-high risk leukemia. In high-risk patients, progress has been moderate, especially in children with high WBC (> or =100 x 10(9)/l) at diagnosis. During the last time period (January 1992-June 1998), only 10% of the patients have received cranial irradiation in first remission, while 90% of the patients have received pulses of high dose methotrexate (5-8 g/m2) isolated or combined with high-dose cytosine arabinoside (total dose 12 g/m2) plus multiple intrathecal injections of methotrexate as CNS-targeted treatment, not translating into increased cumulative incidence of CNS relapse.

Comparative genomic hybridization in childhood acute lymphoblastic leukemia.

DNA copy number changes were studied by comparative genomic hybridization (CGH) on bone marrow samples obtained from 72 patients with childhood acute lymphoblastic leukemia (ALL) at diagnosis. The patients had been admitted to the Helsinki University Central Hospital (Finland) between 1982 and 1997. CGH showed DNA copy number changes in 45 patients (62.5%) with a mean of 4.6 aberrations per patient (range, 1 to 22). The results of CGH and chromosome banding analysis were generally concordant, but CGH facilitated specific karyotyping in 34 cases. DNA copy number gains were more frequent than losses (gains:losses, 6:1). Gains of DNA sequences affected almost exclusively whole chromosomes and were most commonly observed in chromosomes 21 (25%), 18 (22.2%), X (19.4%), 10 (19.4%) and 17 (19.4%). The most common partial gain was 1q31-q32 (8.3%). The most common gains of chromosomes 21, 18, X, 10, 17, 14, 4, 6 and 8 appeared concurrently. High-level amplifications of small chromosome regions were sporadic, detected only in two patients (2.8%). Chromosome 21 was involved in both cases. The most common losses were 9p22-pter (12.5%) and 12p13-pter (11.1%). No statistically significant association between the CGH findings and the diagnostic white blood cell count was observed.

Expression of myeloid-specific genes in childhood acute lymphoblastic leukemia - a cDNA array study.

Several specific cytogenetic changes are known to be associated with childhood acute lymphoblastic leukemia (ALL), and many of them are important prognostic factors for the disease. Little is known, however, about the changes in gene expression in ALL. Recently, the development of cDNA array technology has enabled the study of expression of hundreds to thousands of genes in a single experiment. We used the cDNA array method to study the gene expression profiles of 17 children with precursor-B ALL. Normal B cells from adenoids were used as reference material. We discuss the 25 genes that were most over-expressed compared to the reference. These included four genes that are normally expressed only in the myeloid lineages of the hematopoietic cells: RNASE2, GCSFR, PRTN3 and CLC. We also detected over-expression of S100A12, expressed in nerve cells but also in myeloid cells. In addition to the myeloid-specific genes, other over-expressed genes included AML1, LCP2 and FGF6. In conclusion, our study revealed novel information about gene expression in childhood ALL. The data obtained may contribute to further studies of the pathogenesis and prognosis of childhood ALL.

Adverse health events and late mortality after pediatric allogeneic hematopoietic SCT-two decades of longitudinal follow-up.

Treatment-related late toxicities after pediatric allogeneic hematopoietic SCT (allo-HSCT) are increasingly important as long-term survival has become an expected outcome for many transplanted children and adolescents. In a retrospective cohort study, we assessed long-term health outcomes in 204 allo-HSCT survivors transplanted in childhood or adolescence (<20 years) between 1978 through 2000 after a median follow-up time of 12 (range 4-28) years. Data on conditioning regimen, adverse health events (AE) and growth and hormonal substitutions (hormone replacement therapies (HRTs)) were obtained from medical records. AEs were graded retrospectively according to Common Terminology Criteria for Adverse Events v3.0. Late deaths (⩾48 months after allo-HSCT) were evaluated separately. Multivariate analysis demonstrated that chronic GVHD (P<0.000) and longer follow-up time (P<0.05) correlated with AEs, whereas CY-based conditioning was inversely correlated (P<0.002). TBI and longer follow-up duration predicted more severe AEs (P<0.001 and P<0.001, respectively). HRTs were more frequent after TBI. Diabetes type II, dyslipidemia and hypertension were detected in 9, 7 and 7% of the survivors, respectively. Late deaths (n=22) were most frequently due to pulmonary failure (n=7), followed by secondary malignancy (n=5). The occurrence of AEs after pediatric allo-HSCT is high and likely to increase during extended follow-up, particularly in patients who have received TBI.

Hematopoietic stem cell transplantation in infantile neuronal ceroid lipofuscinosis.

OBJECTIVE: To study the effect of allogeneic hematopoietic stem cell transplantation (SCT) on the clinical course of infantile neuronal ceroid lipofuscinosis (INCL), a lysosomal storage disease. BACKGROUND: INCL is a progressive encephalopathy with severe neuronal loss, especially in the cerebral and cerebellar cortex and retina. Autofluorescent lipopigments constitute the typical storage material in INCL. The disease is caused by recessive mutations in the palmitoyl protein thioesterase 1 (PPT1) gene. PPT1 is a depalmitoylating enzyme, which is transported to lysosomes through the mannose-6-phosphate receptor-mediated pathway, and participates in the lysosomal degradation of fatty acylated proteins. METHODS: Three patients with INCL received transplants and were followed up after SCT at the Hospital for Children and Adolescents at the University of Helsinki. The first patient rejected the first graft at the age of 7 months and had mild symptoms of INCL at the second transplantation at 11 months. The two other patients were asymptomatic when they received their transplants at the age of 4 months. RESULTS: PPT1 enzyme activity was normalized in peripheral leukocytes, but remained low in the CSF and resulted only in a mild and transient amelioration of the classic INCL. All patients who received transplants developed INCL by the age of 2 or 3 years. CONCLUSIONS: More experimental animal and cell culture studies are needed to determine the in vivo function of PPT1. SCT currently cannot be recommended as therapy for INCL.

Successful liver transplantation after induction chemotherapy in children with inoperable, multifocal primary hepatic malignancy.

BACKGROUND: The prognosis for primary epithelial liver tumor in children in whom radical surgery cannot be performed after chemotherapy is poor. Orthotopic liver transplantation has resulted in mortality up to 50%, largely as a result of problems in determining the criteria for transplantation. METHODS: We report results on liver transplantation for primary epithelial liver malignancy in five children (mean age at transplantation: 6.0 years). Only patients with inoperable residual tumor in the liver after four cycles of multidrug chemotherapy, but without extrahepatic infiltration or metastases, were considered eligible for transplantation. RESULTS: Mean follow-up was 4.6 years. Patient and graft survival was 100%, with no signs of residual or de novo malignancy. CONCLUSION: In children with inoperable primary liver malignancy with no extrahepatic tumor growth, orthotopic liver transplantation has an excellent outcome.

Increase in height during the first year after bone marrow transplantation reflecting nutritional status of children.

We studied the influence of pre-transplant nutritional status on height velocity during the first post-transplant year. Thirty-seven children aged 1.4-12.4 years, 19 males and 18 females, underwent bone marrow transplantation (24 allogeneic, 13 autologous) with fractionated total body irradiation included in the preparative regimen of 25. The underlying diagnoses were leukemia (n = 16), malignant solid tumor (n = 11), and non-malignant hematologic or metabolic disease (n = 10). The serum concentrations of albumin, pre-albumin and transferrin were measured. Anthropometric measurements included weight, mid-arm circumference (MAC) and triceps skinfold thickness, expressed as percentages of the age- and sex-specific standards. The skeletal muscle protein reserve was estimated as muscle index (MI) by ultrasonographic imaging of the femoral quadriceps muscle. Height velocity was expressed as a standard deviation score (SDS) of the age- and sex-specific mean. The mean relative height velocity SDS was -1.6 (95% CI -2.2- -1.0). Height velocity correlated significantly with pre-transplant MI (r = 0.54, P = 0.004), concentration of serum transferrin (r = 0.33, P = 0.05) and MAC (r =0.45, P = 0.04). Our data suggest that pre-transplant nutritional status has an impact on growth in height during the post-transplant period.

Short-term toxicity in pediatric marrow transplantation using related and unrelated donors.

The use of volunteer, unrelated donors has substantially increased the number of potential donors for pediatric marrow transplantation during the past few years. We describe our single institution experience of short-term toxicity after pediatric marrow transplantation using sibling or unrelated donors. Fully matched (A, B and DR loci) donors were employed in 94% of the cases in both groups. Conditioning of similar intensity and uniform supportive care were employed in the two groups. Both primary non-engraftment and secondary graft failure were more common among recipients of unmanipulated URD grafts. Clinically significant (grades III-IV) acute GVHD and toxic mortality during the immediate post-transplant period were also higher in this group of patients. Pediatric marrow transplantation using volunteer, unrelated donors appears to be associated with an increased incidence of procedure-related toxic complications.

Maximal preservation of renal function in patients with bilateral Wilms' tumor: therapeutic strategy of late kidney-sparing surgery and replacement of radiotherapy by high-dose melphalan and stem cell rescue.

In children with bilateral Wilms' tumor, the therapy should aim at maximal preservation of renal parenchyma and function. Local radiotherapy may give rise to second malignant neoplasms and may impair renal function. We present a therapeutic strategy without any irradiation. Three children were diagnosed with bilateral Wilms' tumor at ages from 6 months to 5 years. Each patient had a massive tumor with local stage III on one side; one had pulmonary metastases. The therapeutic strategy was first to obtain tissue for histology by percutaneous needle biopsy, to administer pre-operative chemotherapy until desired tumor shrinkage, and then to perform kidney-sparing resective surgery. After a period of conventional chemotherapy, the patients were consolidated with high-dose (HD) melphalan and ABMT. Renal parenchyma spared post-surgery (right/left) was 0%/70%, 60%/40% and 40%/60% of the original kidney volumes. The toxicity of the ABMT procedure was mild, the patients engrafted promptly, and were discharged on days +14 to +27. All patients survive disease-free, 3 years 4 months to 4 years 5 months post-transplant. Our program resulted in good preservation of renal parenchyma and normal function, and we consider the risk of this ABMT program smaller than the late consequences of local radiotherapy for children with bilateral Wilms' tumor. The therapeutic strategy described merits further evaluation.

Invasive fungal infections in pediatric bone marrow transplant recipients: single center experience of 10 years.

Invasive fungal infections (IFI) with substantial mortality constitute an increasing problem among BMT patients. From 1986 to 1996 148 children underwent BMT, and are included in a retrospective analysis of the incidence, risk factors and outcome of IFI. By histopathology or culture-proven IFI (Candida, 10; Aspergillus, 8) was documented in 12/73 (16%) allogeneic and in 6/75 (8%) autologous BMT patients. Of these 18 patients, 15 subsequently died, and in 12 (66%) IFI was regarded as the main cause of death. In addition to the patients with documented IFI, 48 had suspected and 82 no fungal infection. Invasive candidal infections were more frequent in patients with semiquantitatively estimated abundant candidal colonization as compared with those with no colonization (18% vs 3%, P = 0.015). In the allogeneic group, 50% of those with severe (grades III-IV) aGVHD had IFI as opposed to 8% of those with no or mild aGVHD (P < 0.001). Regarding cGVHD, 57% of those with extensive cGVHD vs 5% of those with absent or limited cGVHD had IFI (P < 0.001). The dose of steroids was associated with IFI: 77% of those who received high-dose steroids (methylprednisolone 0.25-1 g/day for 5 days) vs 5% of those with conventional-dose (prednisone 2 mg/kg/day) had IFI (P < 0.001). Particularly for BMT patients at risk, new, quicker and better diagnostic tests and more effective anti-fungal agents, both for prophylaxis and treatment, are needed.

Imminent allograft rejection prevented by donor lymphocyte transfusions: report of two pediatric cases.

Gradual allograft rejection after initial good engraftment may occur with simultaneous autologous reconstitution particularly in patients receiving nonmyeloablative conditioning. Careful post-transplant follow-up of the chimerism status can reveal these cases early on, when the immunological balance may still be shifted to the donor cells. We describe two children with nonmalignant diseases, in whom imminent rejection of their sibling allografts was prevented with donor lymphocyte transfusions (DLT). DLT dosing and timing need to be individually guided by monitoring of the chimerism status.

Very low-dose methotrexate in the treatment of GVHD in children.

Acute GVHD is an important clinical problem frequently encountered in relation to stem cell transplantation. In its initial treatment glucocorticoids remain the established drug of choice. In the face of the side-effects related to therapy with glucocorticoids other, possibly less toxic, options for the initial treatment of acute GVHD might be of use. We report the successful treatment of progressive cutaneous acute GVHD up to grade II in five pediatric recipients of unrelated marrow grafts.

Impaired androgen production in female adolescents and young adults after total body irradiation prior to BMT in childhood.

Pubertal development and androgen production were evaluated 1-10 years after bone marrow transplantation (BMT) in 15 females aged 14-23 (mean 17) years. Before BMT, these patients had received combination chemotherapy for hematologic malignancy, and all had had a transplant program including total body irradiation (TBI). Of the nine patients who were pre-menarcheal at BMT, two had subsequently experienced spontaneous menarche at 11.5 and 13.3 years of age. Six were post-menarcheal, but became amenorrheic after BMT. Menstruation subsequently started spontaneously in one of them 6 years after BMT. At the time of the study, three patients were early to mid-pubertal and 12 late pubertal or post-pubertal. Twelve patients were receiving sex steroid substitution therapy. Serum concentrations of testosterone, androstenedione, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) were determined. Androgen levels of late pubertal and post-pubertal transplanted patients were compared with 19 post-menarcheal patients aged 14-21 (mean 17) years who had been treated for hematologic malignancy with conventional chemotherapy. Testosterone levels of 52 healthy post-menarcheal females aged 14-29 (mean 19) years were measured as controls. Androgen levels of the BMT patients were lower than those of the conventionally treated patients. Differences in testosterone, androstenedione and DHEA levels were significant. Three spontaneously menstruating BMT patients had normal androgen levels. Testosterone levels of the conventionally treated patients and healthy controls were similar. Subnormal androgen production might be one factor behind the problems in pubertal development and sex life experienced by females after BMT. The use of these hormone levels for follow-up purposes and the potential value of androgen replacement therapy in females after TBI merit further study.

Subnormal androgen levels in young female bone marrow transplant recipients with ovarian dysfunction, chronic GVHD and receiving glucocorticoid therapy.

Ovarian function and sex hormone production with special focus on androgens (testosterone, androstenedione, dehydroepiandrosterone and its sulfate, DHEAS) was followed up during 1.5-20 (mean 9) years after bone marrow transplantation (BMT) in 24 female subjects aged 16-33 (mean 21) years at the last follow-up. All patients had received TBI and high-dose chemotherapy as the preparative regimen. A total of 24 female patients with conventionally treated pediatric hematologic malignancies served as controls. Four of 24 transplanted patients had spontaneous menstruation several years post transplantation, but in only one of them were serum FSH levels normal. Androgen levels of the BMT patients were lower than those of the conventionally treated patients. Subnormal testosterone levels were observed in 43% of BMT patients and subnormal DHEAS levels in 34% of BMT patients, the latter being a constant finding during glucocorticoid therapy for chronic GVHD (cGVHD). These results indicate that ovarian damage is a common late effect in patients transplanted at a young age, still having a seemingly normal pubertal development. Ovarian damage and cGVHD with glucocorticoid therapy are strongly associated with subnormal androgen levels. The clinical consequences of these changes and possible benefits of putative androgen replacement therapy remain to be elucidated.