Integrative Clinical Sequencing in the Management of Refractory or Relapsed Cancer in Youth

IMPORTANCE

Cancer is caused by a diverse array of somatic and germline genomic aberrations. Advances in genomic sequencing technologies have improved the ability to detect these molecular aberrations with greater sensitivity. However, integrating them into clinical management in an individualized manner has proven challenging.

OBJECTIVE

To evaluate the use of integrative clinical sequencing and genetic counseling in the assessment and treatment of children and young adults with cancer.

DESIGN, SETTING, AND PARTICIPANTS

Single-site, observational, consecutive case series (May 2012-October 2014) involving 102 children and young adults (mean age, 10.6 years; median age, 11.5 years, range, 0-22 years) with relapsed, refractory, or rare cancer.

EXPOSURES

Participants underwent integrative clinical exome (tumor and germline DNA) and transcriptome (tumor RNA) sequencing and genetic counseling. Results were discussed by a precision medicine tumor board, which made recommendations to families and their physicians.

MAIN OUTCOMES AND MEASURES

Proportion of patients with potentially actionable findings, results of clinical actions based on integrative clinical sequencing, and estimated proportion of patients or their families at risk of future cancer.

RESULTS

Of the 104 screened patients, 102 enrolled with 91 (89%) having adequate tumor tissue to complete sequencing. Only the 91 patients were included in all calculations, including 28 (31%) with hematological malignancies and 63 (69%) with solid tumors. Forty-two patients (46%) had actionable findings that changed their cancer management: 15 of 28 (54%) with hematological malignancies and 27 of 63 (43%) with solid tumors. Individualized actions were taken in 23 of the 91 (25%) based on actionable integrative clinical sequencing findings, including change in treatment for 14 patients (15%) and genetic counseling for future risk for 9 patients (10%). Nine of 91 (10%) of the personalized clinical interventions resulted in ongoing partial clinical remission of 8 to 16 months or helped sustain complete clinical remission of 6 to 21 months. All 9 patients and families with actionable incidental genetic findings agreed to genetic counseling and screening.

CONCLUSIONS AND RELEVANCE

In this single-center case series involving young patients with relapsed or refractory cancer, incorporation of integrative clinical sequencing data into clinical management was feasible, revealed potentially actionable findings in 46% of patients, and was associated with change in treatment and family genetic counseling for a small proportion of patients. The lack of a control group limited assessing whether better clinical outcomes resulted from this approach than outcomes that would have occurred with standard care.

Allogeneic transplantation with myeloablative FluBu4 conditioning improves survival compared to reduced intensity FluBu2 conditioning for acute myeloid leukemia in remission

The optimal intensity of conditioning for allogeneic hematopoietic stem cell transplantation (HCT) in acute myeloid leukemia (AML) remains undefined. Traditionally, myeloablative conditioning regimens improve disease control, but at the risk of greater nonrelapse mortality. Because fludarabine with myeloablative doses of intravenous busulfan using pharmacokinetic monitoring has excellent tolerability, we reasoned that this regimen would limit relapse without substantially elevating toxicity when compared to reduced intensity conditioning. We retrospectively analyzed 148 consecutive AML patients in remission receiving T cell replete HCT conditioned with fludarabine and intravenous busulfan at doses defined as reduced (6.4 mg/kg; FluBu2, n = 63) or myeloablative (12.8 mg/kg; FluBu4, n = 85). Early and late nonrelapse mortality (NRM) was similar among FluBu4 and FluBu2 recipients, respectively (day + 100: 4 vs 0 %; 5 years: 19 vs 22 %; p = 0.54). NRM did not differ between FluBu4 and FluBu2 in patients >50 years of age (24 vs 22 %, p = 0.75). Relapse was lower in recipients of FluBu4 (5 years: 30 vs 49 %; p = 0.04), especially in patients with poor risk cytogenetics (22 vs 59 %; p = 0.02) and those >50 years of age (28 vs 51 %; p = 0.02). Overall survival favored FluBu4 recipients at 5 years (53 vs 34 %, p = 0.02), a finding confirmed in multivariate analysis (HR: 0.57; 95 % CI: 0.34-0.95; p = 0.03). These data suggest that myeloablative FluBu4 may provide equivalent NRM, reduced relapse, and improved survival compared to FluBu2, emphasizing the importance of busulfan dose in conditioning for AML.

MIBG scans in patients with stage 4 neuroblastoma reveal two metastatic patterns, one is associated with MYCN amplification and in MYCN-amplified tumours correlates with a better prognosis

Purpose

The aim of this study was to find clinically relevant MIBG-avid metastatic patterns in patients with newly diagnosed stage 4 neuroblastoma.

Methods

Diagnostic ¹²³I-MIBG scans from 249 patients (123 from a European and 126 from the COG cohort) were assessed for metastatic spread in 14 body segments and the form of the lesions: “focal” (clear margins distinguishable from adjacent background) or “diffuse” (indistinct margins, dispersed throughout the body segment). The total numbers of diffuse and focal lesions were recorded. Patients were then categorized as having lesions exclusively focal, lesions more focal than diffuse, lesions more diffuse than focal, or lesions exclusively diffuse.

Results

Diffuse lesions affected a median of seven body segments and focal lesions a median of two body segments (P < 0.001, both cohorts). Patients with a focal pattern had a median of 2 affected body segments and those with a diffuse pattern a median of 11 affected body segments (P < 0.001, both cohorts). Thus, two MIBG-avid metastatic patterns emerged: “limited-focal” and “extensive-diffuse”. The median numbers of affected body segments in MYCN-amplified (MNA) tumours were 5 (European cohort) and 4 (COG cohort) compared to 9 and 11, respectively, in single-copy MYCN (MYCNsc) tumours (P < 0.001). Patients with exclusively focal metastases were more likely to have a MNA tumour (60 % and 70 %, respectively) than patients with the other types of metastases (23 % and 28 %, respectively; P < 0.001). In a multivariate Cox regression analysis, focal metastases were associated with a better event-free and overall survival than the other types of metastases in patients with MNA tumours in the COG cohort (P < 0.01).

Conclusion

Two metastatic patterns were found: a “limited and focal” pattern found mainly in patients with MNA neuroblastoma that correlated with prognosis, and an “extensive and diffuse” pattern found mainly in patients with MYCNsc neuroblastoma.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-014-2909-1) contains supplementary material, which is available to authorized users.

Double umbilical cord blood transplantation after novel myeloablative conditioning using a regimen of fludarabine, busulfan, and total lymphoid irradiation

We conducted a pilot study evaluating double umbilical cord blood transplantation (dCBT) after myeloablative conditioning with fludarabine and busulfan 3.2 mg/kg i.v. × 4, followed by total lymphoid irradiation at 400 cGy (FluBu4/TLI) for any indicated hematological disorder for patients without a suitable donor. Twenty patients with predominantly high-risk disease underwent dCBT according to protocol. The regimen was well tolerated, with mucositis as the primary observed toxicity (n = 19). The cumulative incidence of neutrophil engraftment was 89% (95% confidence interval [CI], 64% to 97%), with a median time to recovery of 16 days (range, 12 to 31 days). All evaluable patients with neutrophil engraftment achieved complete donor chimerism by day 40. The cumulative incidence of grades III and IV acute graft-versus-host disease (GVHD) at day 100 was 10% (95% CI, 2% to 27%), and the cumulative incidence of chronic GVHD was 35% (95% CI, 16% to 55%) by the end of the study. At 1 year, the cumulative incidence of treatment-related mortality (TRM) was 35% (95% CI, 16% to 55%). The leading cause of nonrelapse mortality was acute GVHD (n = 4), followed by graft failure (n = 2) and chronic GVHD (n = 1). TRM was significantly associated with a pretransplantation hematopoietic cell transplantation-specific comorbidity index score ≥ 3 (P = .005). At 1 year, disease relapse occurred in 6 patients and overall survival was 40% (95% CI, 19% to 60%). We conclude that FluBu4/TLI is an adequate preparative regiment before dCBT, providing high engraftment rates and relatively early neutrophil recovery. The best survival outcomes were seen in patients without significant comorbidities before transplantation, and outcomes are comparable to previously published dCBT studies.

Extramedullary relapse of acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation: incidence, risk factors and outcomes

Extramedullary relapse after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia is a contributor to post-transplant mortality but risk factors for, and outcomes of, this condition are not well characterized. We analyzed 257 consecutive patients undergoing allogeneic stem cell transplantation for acute myeloid leukemia at our institution to characterize extramedullary relapse, identify predictive variables and assess outcomes. The 5-year cumulative incidence of isolated extramedullary or bone marrow relapse was 9% and 29%, respectively. Extramedullary relapse occurred later than marrow relapse and most frequently involved skin and soft tissue. Factors predictive of extramedullary relapse after transplantation included previous extramedullary disease, French-American-British classification M4/M5 leukemia, high risk cytogenetics, and advanced disease status at the time of transplantation. Children were more likely than adults to develop extramedullary relapse, a finding probably explained by an overrepresentation of extramedullary disease prior to transplantation and M4/M5 leukemia in children. Acute graft-versus-host disease was not protective against relapse. Unlike medullary relapse, chronic graft-versus-host disease was not protective against extramedullary relapse. The survival rate after extramedullary relapse was 30% at 1 year and 12% at 2 years. Extramedullary relapse is a significant contributor to mortality after allogeneic transplantation for acute myeloid leukemia and appears to be resistant to the immunotherapeutic effect of allogeneic grafting. Effective strategies for patients with extramedullary relapse are needed to improve outcomes after transplantation.

Extramedullary relapse of acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation: incidence, risk factors and outcomes

Extramedullary relapse after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia is a contributor to post-transplant mortality but risk factors for, and outcomes of, this condition are not well characterized. We analyzed 257 consecutive patients undergoing allogeneic stem cell transplantation for acute myeloid leukemia at our institution to characterize extramedullary relapse, identify predictive variables and assess outcomes. The 5-year cumulative incidence of isolated extramedullary or bone marrow relapse was 9% and 29%, respectively. Extramedullary relapse occurred later than marrow relapse and most frequently involved skin and soft tissue. Factors predictive of extramedullary relapse after transplantation included previous extramedullary disease, French-American-British classification M4/M5 leukemia, high risk cytogenetics, and advanced disease status at the time of transplantation. Children were more likely than adults to develop extramedullary relapse, a finding probably explained by an overrepresentation of extramedullary disease prior to transplantation and M4/M5 leukemia in children. Acute graft-versus-host disease was not protective against relapse. Unlike medullary relapse, chronic graft-versus-host disease was not protective against extramedullary relapse. The survival rate after extramedullary relapse was 30% at 1 year and 12% at 2 years. Extramedullary relapse is a significant contributor to mortality after allogeneic transplantation for acute myeloid leukemia and appears to be resistant to the immunotherapeutic effect of allogeneic grafting. Effective strategies for patients with extramedullary relapse are needed to improve outcomes after transplantation.

TNF-inhibition with etanercept for graft-versus-host disease prevention in high-risk HCT: lower TNFR1 levels correlate with better outcomes

Graft-versus-host disease (GVHD) causes most non-relapse mortality (NRM) after alternative donor (unrelated and mismatched related) hematopoietic cell transplant (HCT). We previously showed that increases in day +7 TNF-receptor-1 (TNFR1) ratios (posttransplantation day +7/pretransplantation baseline) after myeloablative HCT correlate with outcomes including GVHD, NRM, and survival. Therefore, we conducted a phase II trial at 2 centers, testing whether the addition of the TNF-inhibitor etanercept (25 mg twice weekly from start of conditioning to day +56) to standard GVHD prophylaxis would lower TNFR1 levels, reduce GVHD rates, and improve NRM and survival. Patients underwent myeloablative HCT from a matched unrelated donor (URD; N = 71), 1-antigen mismatched URD (N = 26), or 1-antigen mismatched related donor (N = 3) using either total body irradiation (TBI)-based conditioning (N = 29) or non-TBI-based conditioning (N = 71). Compared to historical controls, the increase in posttransplantation day +7 TNFR1 ratios was not altered in patients who received TBI-based conditioning, but was 40% lower in patients receiving non-TBI-based conditioning. The latter group experienced relatively low rates of severe grade 3 to 4 GVHD (14%), 1-year NRM (16%), and high 1-year survival (69%). These findings suggest that (1) the effectiveness of TNF-inhibition with etanercept may depend on the conditioning regimen, and (2) attenuating the expected rise in TNFR1 levels early posttransplantation correlates with good outcomes.

Thyroid and hepatic function after high-dose 131 I-metaiodobenzylguanidine (131 I-MIBG) therapy for neuroblastoma

BACKGROUND

(131) I-Metaiodobenzylguanidine ((131) I-MIBG) provides targeted radiotherapy for children with neuroblastoma, a malignancy of the sympathetic nervous system. Dissociated radioactive iodide may concentrate in the thyroid, and (131) I-MIBG is concentrated in the liver after (131) I-MIBG therapy. The aim of our study was to analyze the effects of (131) I-MIBG therapy on thyroid and liver function.

PROCEDURE

Pre- and post-therapy thyroid and liver functions were reviewed in a total of 194 neuroblastoma patients treated with (131) I-MIBG therapy. The cumulative incidence over time was estimated for both thyroid and liver toxicities. The relationship to cumulative dose/kg, number of treatments, time from treatment to follow-up, sex, and patient age was examined.

RESULTS

In patients who presented with Grade 0 or 1 thyroid toxicity at baseline, 12  ±  4% experienced onset of or worsening to Grade 2 hypothyroidism and one patient developed Grade 2 hyperthyroidism by 2 years after (131) I-MIBG therapy. At 2 years post-(131) I-MIBG therapy, 76  ±  4% patients experienced onset or worsening of hepatic toxicity to any grade, and 23  ±  5% experienced onset of or worsening to Grade 3 or 4 liver toxicity. Liver toxicity was usually transient asymptomatic transaminase elevation, frequently confounded by disease progression and other therapies.

CONCLUSION

The prophylactic regimen of potassium iodide and potassium perchlorate with (131) I-MIBG therapy resulted in a low rate of significant hypothyroidism. Liver abnormalities following (131) I-MIBG therapy were primarily reversible and did not result in late toxicity. (131) I-MIBG therapy is a promising treatment for children with relapsed neuroblastoma with a relatively low rate of symptomatic thyroid or hepatic dysfunction.

Elafin is a biomarker of graft-versus-host disease of the skin

Graft-versus-host disease (GVHD), the major complication of allogeneic bone marrow transplantation, affects the skin, liver, and gastrointestinal tract. There are no plasma biomarkers specific for any acute GVHD target organ. We used a large-scale quantitative proteomic discovery procedure to identify biomarker candidates of skin GVHD and validated the lead candidate, elafin, with enzyme-linked immunosorbent assay in samples from 492 patients. Elafin was overexpressed in GVHD skin biopsies. Plasma concentrations of elafin were significantly higher at the onset of skin GVHD, correlated with the eventual maximum grade of GVHD, and were associated with a greater risk of death relative to other known risk factors (hazard ratio, 1.78). We conclude that elafin has significant diagnostic and prognostic value as a biomarker of skin GVHD.