First report of medulloblastoma in a patient with MUTYH-associated polyposis

Case report: Therapy-related myeloid neoplasms in three pediatric cases with medulloblastoma

Introduction

Medulloblastoma is the most common malignant brain tumor in children, often requiring intensive multimodal therapy, including chemotherapy with alkylating agents. However, therapy-related complications, such as therapy-related myeloid neoplasms (t-MNs), can arise, particularly in patients with genetic predisposition syndromes. This case report presents three pediatric cases of medulloblastoma with subsequent development of t-MNs, highlighting the potential role of genetic predisposition and the importance of surveillance for hematological abnormalities in long-term survivors.

Case presentation

We describe three cases of pediatric medulloblastoma who developed t-MNs after receiving chemotherapy, including alkylating agents. Two of the patients had underlying genetic predisposition syndromes (TP53 pathologic variants). The latency period between initial diagnosis of medulloblastoma and the development of secondary cancer varied among the cases, ranging from 17 to 65 months. The three cases eventually succumbed from secondary malignancy, therapy-related complications and progression of primary disease, respectively.

Conclusions

This report highlights the potential association between genetic predisposition syndromes and the development of therapy-related myeloid neoplasms in pediatric medulloblastoma survivors. It underscores the importance of surveillance for hematological abnormalities among such patients.

Treatment With Antitumor Agents Recommended by Cancer Genome Panel for Uterine Leiomyosarcoma

To date, cancer genomic medicine, using cancer gene panel covered by health insurance from June 2019, has been performed for advanced malignant tumors under public medical insurance. In gynecology, the first-line treatment for uterine leiomyosarcomas, which is a mesenchymal uterine tumor, is surgery. In uterine leiomyosarcoma cases, recurrence is observed within 2 years postoperatively; however, to date, clinical trials have not shown efficacy with existing antitumor agents. We noted efficacy in two cases with advanced/recurrent uterine leiomyosarcoma using an antitumor agent selected on the basis of cancer gene panel testing results. Following uterine leiomyosarcoma diagnosis, they underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy as standard surgical treatment. After the surgical treatment, the imaging test revealed recurrent tumors; subsequently, they were treated with doxorubicin alone or doxorubicin combined with Gemzar. However, cancer genome gene panel test was performed because the malignant tumor worsened. Based on the cancer genome gene panel test results, the two cases with advanced uterine leiomyosarcoma were associated with increased tumor mutational burden (TMB) or pathogenic variants (PVs) of AKT serine/threonine kinase 1 (AKT1). Therefore, treatment with pembrolizumab, which is a drug covered by insurance for patients with TMB-high, or treatment with kinase inhibitors for patients with PVs in AKT, was considered. Cancer genomic medicine using cancer gene panel provides a new treatment strategy for intractable malignant tumors. This study aimed to discuss the usefulness of cancer genomic medicine by cancer gene panel testing using the cases of advanced and recurrence uterine leiomyosarcoma and the latest findings.