Clinical manifestations and radiological features may contribute to the early diagnosis of radiation-induced sarcoma after breast cancer

•Abnormalities in the radiation field should alert to the development of RIS.•Skin alterations and bone tumors on images may contribute to the early detection.•Biopsy should be performed immediately when Radiation-induced sarcoma is suspected.

AimTo describe the clinical manifestations and radiological features contributing to the early diagnosis of radiation-induced sarcoma (RIS) after radiotherapy for breast cancer.Materials and methodsThis retrospective analysis included four typical cases of RIS diagnosed at Affiliated Hospital of Academy of Military Medical Sciences between 1980 and 2013. Patient and imaging characteristics, treatment modalities, and outcomes were extracted from patients' medical records. Two pathologists reviewed all histological slides.ResultsAll four cases were misdiagnosed and treated for several months as cases of breast cancer relapse. CT using the bone-window setting and three-dimensional reconstructions clearly displayed bone tumours of RIS in three cases. Skin alterations were observed in all cases. At the time of RIS diagnosis, three patients were free of breast cancer. In one patient with bilateral breast cancer and lung metastasis, chemotherapy resulted in complete remission of the metastasis, but RIS progression. No RIS in this series responded to chemotherapy or endocrine therapy.ConclusionsAbnormalities appearing in the radiation field long after RT should alert clinicians to the potential development of RIS. Careful physical examination and follow-up imaging studies are necessary. The presence of skin alterations, bone tumours at CT or radiography, and poor response to anti-cancer drugs may contribute to the early detection of RIS. Biopsy should be performed immediately when RIS is suspected.