Hematologic recovery after tandem high-dose chemotherapy and autologous stem cell transplantation in children with high-risk solid tumors

Tandem high-dose chemotherapy followed by autologous stem cell transplantation: An infant with trilateral retinoblastoma

BACKGROUND

Retinoblastoma (RB) is the most common intraocular malignancy in childhood. Advanced RB, associated with exceedingly poor prognosis, requires more intensive multiagent chemotherapy than conventional regimens. Rescue of the bone marrow after intensive chemotherapy is achieved with stem cell transplantation. The sequential courses (tandem transplantation) of high-dose chemotherapy followed by autologous stem cell transplantation allow for even greater dose intensity in consolidation with the potential to use different active chemotherapeutics at each transplant and have proven feasible and successful in treating children with recurrent/refractory solid tumors.

CASE DESCRIPTION

We report an infant with trilateral high-risk RB who received tandem high-dose chemotherapy (HDC) followed by autologous stem cell transplantation after the conventional chemotherapy. A 5-month-old female patient presented with strabismus, and the ophthalmoscopic examination showed intraocular tumoral lesions in both eyes. Magnetic resonance imaging (MRI) concluded the trilateral retinoblastoma diagnosis due to a tumoral mass in the optic chiasm. The follow-up ophthalmologic examinations and the MRI detected stable disease after six cycles of multiagent chemotherapy.

CONCLUSIONS

Rescue with autologous stem cell transplantation after HDC allows for an increase in chemotherapy intensity. Tandem transplantation provides the chance to perform different chemotherapeutics at each transplant and enables an increase in the chemotherapy intensity, thus providing a positive effect on disease-free survival.

Deep-learning-based personalized prediction of absolute neutrophil count recovery and comparison with clinicians for validation

Neutropenia and its complications are major adverse effects of cytotoxic chemotherapy. The time to recovery from neutropenia varies from patient to patient, and cannot be easily predicted even by experts. Therefore, we trained a deep learning model using data from 525 pediatric patients with solid tumors to predict the day when patients recover from severe neutropenia after high-dose chemotherapy. We validated the model with data from 99 patients and compared its performance to those of clinicians. The accuracy of the model at predicting the recovery day, with a 1-day error, was 76%; its performance was better than those of the specialist group (58.59%) and the resident group (32.33%). In addition, 80% of clinicians changed their initial predictions at least once after the model's prediction was conveyed to them. In total, 86 prediction changes (90.53%) improved the recovery day estimate.

Infectious Complications during Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Children with High-Risk or Recurrent Solid Tumors

We retrospectively analyzed infectious complications during tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) in children and adolescents with high-risk or recurrent solid tumors. A total of 324 patients underwent their first HDCT/auto-SCT between October 2004 and September 2014, and 283 of them proceeded to their second HDCT/auto-SCT (a total of 607 HDCT/auto-SCTs). During the early transplant period of 607 HDCT/auto-SCTs (from the beginning of HDCT to day 30 post-transplant), bacteremia, urinary tract infection (UTI), respiratory virus infection, and varicella zoster virus (VZV) reactivation occurred in 7.1%, 2.3%, 13.0%, and 2.5% of HDCT/auto-SCTs, respectively. The early transplant period of the second HDCT/auto-SCT had infectious complications similar to the first HDCT/auto-SCT. During the late transplant period of HDCT/auto-SCT (from day 31 to 1 year post-transplant), bacteremia, UTI, and VZV reactivation occurred in 7.5%, 2.5%, and 3.9% of patients, respectively. Most infectious complications in the late transplant period occurred during the first 6 months post-transplant. There were no invasive fungal infections during the study period. Six patients died from infectious complications (4 from bacterial sepsis and 2 from respiratory virus infection). Our study suggests that infectious complications are similar following second and first HDCT/auto-SCT in children.

Optimal time to start peripheral blood stem cell collection in children with high-risk solid tumors

In order to clarify the optimal timing for peripheral blood stem cell (PBSC) collection, PBSC collection records of 323 children who were scheduled to undergo autologous stem cell transplantation from two study periods differing in the timing of PBSC collection were analyzed. In the early study period (March 1998 to August 2007, n=198), PBSC collection was initiated when the peripheral WBC count exceeded 1,000/µL during recovery from chemotherapy. Findings in this study period indicated that initiation of PBSC collection at a higher WBC count might result in a greater CD34(+) cell yield. Therefore, during the late study period (September 2007 to December 2012, n=125), PBSC collection was initiated when the WBC count exceeded 4,000/µL. Results in the late study period validated our conclusion from the early study period. Collection of a higher number of CD34(+) cells was associated with a faster hematologic recovery after transplant in the late study period. Initiation of PBSC collection at WBC count > 4,000/µL was an independent factor for a greater CD34(+) cell yield. In conclusion, PBSC collection at a higher WBC count is associated with a greater CD34(+) cell yield, and consequently a faster hematologic recovery after transplant.