Introduction
The incidence of second malignancies is on the rise, constituting approximately one in six of all new cancer cases. These malignancies fall into three primary categories based on their predominant etiological factors: treatment-related, syndromic, and those resulting from shared exposures.
Radiation-Induced Malignancies: Insights and Case Studies
Researchers found that high doses of radiation caused soft-tissue sarcomas in some patients. This article sheds light on radiation-induced malignancies, with illustrative cases including thyroid, rectal cancer, and sarcoma. Notably, these second malignancies are typically identified within the previous radiation field, with varying time intervals ranging from 8 to 21 years following the initial tumor diagnosis.
Radiation-Induced Sarcomas in Childhood Cancer Survivors
Radiation-induced sarcoma (RIS) is a late and potentially severe consequence of radiation therapy, often associated with a challenging prognosis. As advances in childhood cancer treatment continue to yield improved patient outcomes, the incidence of RIS may become more prevalent. This study seeks to examine the experiences of RIS in survivors of pediatric cancer.
Key Findings
Among the 12 cases of RIS identified, the median age at initial diagnosis was 3.5 years, with a latency period from radiation therapy to RIS diagnosis averaging 24.5 years. Initial diagnoses encompassed a range of pediatric cancers, including neuroblastoma, rhabdomyosarcoma, Ewing sarcoma, Wilms tumor, retinoblastoma, and Hodgkin’s Lymphoma. Histological analysis of RIS cases revealed predominantly osteosarcoma and soft tissue sarcomas.
Comparative analysis of treatment protocols at the time of diagnosis versus current guidelines (2022) indicated that a significant proportion of patients (58%) would have still required radiation therapy. The therapeutic approach for RIS encompassed chemotherapy (27%), radiation (90%), and surgery (63%).
With a median follow-up period of 4.7 years from RIS diagnosis, 66% of patients remained alive, while 33% succumbed to progressive RIS.
Conclusion
Radiation-induced second malignancies represent a critical concern in oncology, demanding careful patient selection and refined radiation techniques in radiotherapy. Diligent surveillance and early detection are pivotal in ensuring successful treatment outcomes.
Moreover, RIS in childhood cancer survivors underscores the need for specialized multi-disciplinary collaboration to mitigate not only RIS but also other potential late effects of radiotherapy. Radiation continues to be a crucial component in the management of primary tumors, underscoring the importance of a comprehensive and integrated approach to cancer care.
Citations
- Mahmood S, Vu K, Tai P, Joseph K, Koul R, Dubey A, Yu E. Radiation-induced second malignancies. Anticancer Res. 2015 Apr;35(4):2431-4. PMID: 25862910.
- Dutra MP, Rodrigues CM, Peretz-Soroka H, Ribeiro M, Shultz D, Hodgson D, Tsang DS, Gupta AA. Radiation-induced sarcomas following childhood cancer – A Canadian Sarcoma Research and Clinical Collaboration Study (CanSaRCC). Cancer Rep (Hoboken). 2023 Jun;6(6):e1834. doi: 10.1002/cnr2.1834. Epub 2023 May 13. PMID: 37178052; PMCID: PMC10242652.
- Hamilton SN, Tyldesley S, Li D, Olson R, McBride M. Second malignancies after adjuvant radiation therapy for early stage breast cancer: is there increased risk with addition of regional radiation to local radiation? Int J Radiat Oncol Biol Phys. 2015 Apr 1;91(5):977-85. doi: 10.1016/j.ijrobp.2014.12.051. PMID: 25832690.
