Significance of hematopoietic surface antigen CD34 in neuroblastoma prognosis and the genetic landscape of CD34-expressing neuroblastoma CSCs

High-risk neuroblastoma (HR-NB) is branded with hematogenous metastasis, relapses, and dismal long-term survival. Intensification of consolidation therapy with tandem/triple autologous stem cell (SC) rescue (with bone marrow [BM]/peripheral blood [PB] CD34⁺ selection) after myeloablative chemotherapy has improved long-term survival. However, the benefit is limited by the indication of NB cells in CD34⁺ PBSCs, CD34 expression in NB cells, and the risk of reinfusing NB cancer stem cells (NB CSCs) that could lead to post-transplant relapse. We investigated the association of CD34 surface expression (92 patients) with NB evolution/clinical outcomes. CD34 gene-level status in NB was assessed through RNA-Seq data mining (18 cohorts, n, 3324). Genetic landscape of CD34-expressing NB CSCs (CD133⁺CD34⁺) was compared with CD34^- CSCs (CD133⁺CD34^-). RNA-seq data revealed equivocal association patterns of CD34 expression with patient survival. Our immunohistochemistry data revealed definite, but rare (mean, 0.73%; range 0.00-7.87%; median, 0.20%) CD34 positivity in NB. CD34⁺ significantly associated with MYCN amplification (p, 0.003), advanced disease stage (p, 0.016), and progressive disease (PD, p < 0.0009) after clinical therapy. A general high-is-worse tendency was observed in patients with relapsed disease. High CD34⁺ correlated with poor survival in patients with N-MYC-amplified HR-NB. Gene expression analysis of CD34⁺-NB CSCs identified significant up (4631) and downmodulation (4678) of genes compared with NB CSCs that lack CD34. IPA recognized the modulation of crucial signaling elements (EMT, stemness maintenance, differentiation, inflammation, clonal expansion, drug resistance, metastasis) that orchestrate NB disease evolution in CD34⁺ CSCs compared with CD34^- CSCs. While the function of CD34 in NB evolution requires further in-depth investigation, careful consideration should be exercised for autologous stem cell rescue with CD34⁺ selection in NB patients. Graphical abstract.

Outcomes of Autologous Stem Cell Transplant Consolidation in Primary Central Nervous System Lymphoma: A Mayo Clinic Experience

A paucity of randomized phase III clinical trials in primary central nervous system lymphoma (PCNSL) has resulted in no uniform consensus on the optimal strategy for consolidation and conditioning regimens for autologous stem cell transplant (ASCT). The past 2 decades have witnessed a preference for thiotepa (TT)-based conditioning regimens due to superior central nervous system penetration. We retrospectively evaluated outcomes of patients with PCNSL who underwent ASCT at Mayo Clinic, Rochester over the past 2 decades, and the impact of TT-based conditioning regimens. Fifty-six patients underwent transplant for PCNSL, with 25 and 31 patients receiving BEAM (non-thiotepa) and carmustine (BCNU)/TT-based conditioning, respectively. All patients received high-dose methotrexate-based induction therapy. While the BCNU/TT group had higher risk disease features such as high International Extranodal Lymphoma Study Group prognostic score, elevated cerebrospinal fluid protein, and older patient population, there was no significant difference at 2 years post-transplant in progression-free survival (BEAM 68.0% [46.1% to 82.5%] versus BCNU/TT, 65.5% [45.2% to 79.8%], P = .99) or overall survival (OS) (84.0% [62.8% to 93.7%] in the BEAM group versus 81.6% [61.3% to 91.9%] in the BCNU/TT group, P = .95). Disease response status before transplant significantly affected the outcomes as those in complete remission had an OS at 2 years post-transplant of 94.7% (68.1% to 99.2%) in the BEAM group and 90.5% (67.0% to 97.5%) in the BCNU/TT group compared with those in partial response, 57.1% (17.2% to 83.7%) in BCNU/TT group and 50.0% (11.1% to 80.4%) in the BEAM group, respectively (P < .0001). Our retrospective cohort adds to the currently available literature and identifies the disease status before transplant as a significant factor affecting survival.

High-dose chemotherapy and stem-cell rescue for salvage therapy for relapsed malignant mixed ovarian germ cell tumor: A case report

Background

Malignant ovarian germ cell tumors are rare, and often treatable with surgery and chemotherapy. Few data are available for treatment of platinum-resistant tumors.

Case

A 31 year old gravida 0 with a 20 cm pelvic mass was found to have a malignant ovarian germ cell tumor after she underwent debulking surgery. She initially responded to chemotherapy; however her AFP began to rise before all cycles were completed. She underwent additional debulking surgery that was again suboptimal. She was then referred for salvage therapy with high-dose chemotherapy with stem cell transplant, which was successful and she has had no evidence of disease for over two years.

Conclusion

High-dose chemotherapy with stem cell transplant is a viable salvage therapy for patients with platinum-resistant germ cell tumors.

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Malignant ovarian germ cell tumors are rare.

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These tumors are often treatable with surgery and adjuvant chemotherapy.

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High-dose chemotherapy and stem cell rescue should be considered for platinum-resistant disease.

The influence of clinical and genetic factors on patient outcome in small cell carcinoma of the ovary, hypercalcemic type

OBJECTIVE

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is an aggressive tumor, with long term survival at ~30% in early stage disease. SCCOHT is caused by germline and somatic SMARCA4 mutations, but the effect of the mutation type on patients remains unknown. Furthermore, the rarity of SCCOHT has resulted in varied treatment, with no standardized protocols. We analyzed 293 cases to determine the effect of treatment modalities and SMARCA4 mutations on patient diagnosis and outcome.

METHODS

In 293 SCCOHT patients we collected information on age and stage at diagnosis, treatment modality (surgery, chemotherapy, radiotherapy, and/or high-dose chemotherapy with autologous stem cell rescue (HDC-aSCR)), SMARCA4 mutation origin (germline/somatic), and overall survival. Cox analysis and log-rank tests were performed on 257 cases with available survival data.

RESULTS

The strongest prognostic factors were stage at diagnosis (p=2.72e-15) and treatment modality (p=3.87e-13). For FIGO stages II-IV, 5-year survival was 71% for patients who received HDC-aSCR, compared to 25% in patients who received conventional chemotherapy alone following surgery (p=0.002). Patients aged ≥40 had a worse outcome than younger patients (p=0.04). Twenty-six of 60 tested patients carried a germline SMARCA4 mutation, including all patients diagnosed <15years; carriers presented at a younger age than non-carriers (p=0.02).

CONCLUSIONS

Stage at diagnosis is the most significant prognostic factor in SCCOHT and consolidation with HDC-aSCR may provide the best opportunity for long-term survival. The large fraction of SMARCA4 germline mutations carriers warrants genetic counseling for all patients.