1119 - Secondary Osteosarcoma as a Consequence of Treatment of Ewing’s Sarcoma with Radiation and Alkylating Agent in a Pediatric Population

Thursday, February 22, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

SP

Sung-Hoon Park, n/a

Medical Student
McGovern Medical School - Houston, TX
League City, Texas, United States

Co-Author(s)

AG

Alyson Galanga, BS

Medical Student
McGovern Medical School UT Health Houston
Houston, Texas, United States
SH

Stacey Hall, DO

Associate Professor and Medical Director
UT Health - Houston/TIRR Memorial Hermann
Houston, Texas, United States
SJ

Simra Javaid, DO

Assistant Professor
TIRR Memorial Hermann
Houston, Texas, United States
PV

Peter D. Vu, MD

Resident Physician
University of Texas Heath Science Center at Houston, TIRR Memorial Hermann
Houston, Texas, United States
MM

Mara Martinez Santori, MD

Resident Physician
UT Health Houston PM&R Residency
Houston, Texas, United States

Case Diagnosis: A 14-year-old girl who developed osteosarcoma secondary to chemotherapy and radiation treatments for Ewing’s sarcoma.

Case Description: Patient presented in 2017 for intermittent back and sacral pain. Imaging and biopsy revealed localized Ewing sarcoma of the sacrum. She was treated with 15 weeks of neoadjuvant chemotherapy (AEWS1221, Regimen A) and followed up with proton therapy of 55.8 Gray, which was completed in November 2018. Unfortunately, in February 2022, symptoms and imaging were concerning for recurrent Ewing's. Symptoms persisted despite chemotherapy for 9 months. Biopsy showed results concerning for osteosarcoma. She started MAP chemotherapy and was referred for hemipelvectomy and sacrectomy in December 2022. Upon stabilization, she was transferred for inpatient rehabilitation in January 2023.

This patient received chemotherapy with alkylating properties and radiation therapy of 55.8 Gray and developed secondary osteosarcoma within 3-4 years. This is extremely rare in the general population and, to our knowledge, is the first reported case where the patient developed secondary bone cancer while still in their childhood.

Discussions: Secondary malignancy is an unfortunate, rare consequence in some patients treated for Ewing’s sarcoma in their childhood. Among the secondary malignancies, osteosarcoma is the most common. Several retrospective and prospective studies have determined a significant increase in risk, up to 40-fold, of secondary sarcoma when the concentration of radiation therapy is ≥60 Grays. When adjusting for radiation, exposure to alkylating chemotherapy correlated with increased relative risk to secondary bone cancers. Furthermore, the median time from the completed treatment of Ewing’s sarcoma to the diagnosis of the second malignancy was around 7 years.

Conclusions: This case emphasizes the importance of having a continued close monitoring of patients that were treated for Ewing's sarcoma, even throughout their childhood. This especially applies when exposed to alkylating chemotherapy regimen and/or ≥60 Gy radiation.