Abstract 84P
Background
Radiation-induced sarcomas (RIS) are rare and aggressive diseases that can occur after radiotherapy (RT) with limited evidence in literature.
Methods
We performed a real-life analysis of patients (pts) with RIS followed at “Regina Elena” National Cancer Institute in Rome, an EURACAN referral centre for sarcomas.
Results
Twenty-three pts with diagnosis of RIS were analysed between March 2007 and June 2022: 18 women (78%) and 5 men (22%). Median age at diagnosis was 65 (range 47 – 85). RIS included 6 bone sarcomas (BS, 26%) and 17 soft tissue sarcomas (STS, 74%): 10 angiosarcomas (44%), 4 undifferentiated pleomorphic sarcomas (17%), 1 malignant peripheral nerve sheath tumor (4%), 1 myxofibrosarcoma (4%), 1 spindle cell sarcoma (4%). Median time between RT and diagnosis of RIS was 14.3 years (yrs, range 4.4 – 61.4). Primary radio-treated tumors or bening conditions were: breast (14 pts, 61%), prostate (3 pts, 13%), non-Hodgkin’s lymphoma (2 pts, 9%), head and neck (1 pt, 4%), cervix (1, pt4%), paraganglioma (1 pt, 4%), shoulder burn (1pt, 4%). Twelve pts (52%) had resectable disease and underwent upfront surgery followed by adjuvant RT (1 pt) or chemotherapy (CT, 2 pts). Nine pts (39%) had locally advanced disease: 6 (26%) received neoadjuvant CT, 1 pt (4%) electrochemotherapy, 1 pt (4%) concomitant RT-CT, 1 pt proton therapy. Overall, 17 patients (74%) underwent surgery (1 pt excluded for rapid progression of disease). Two pts (8%) had metastatic disease at diagnosis. For metastatic and progressive disease, 9 pts received a first-line treatment: 2 BS pts received combination regimens (cisplatinum-adriamycin or gemcitabine-docetaxel), 7 STS pts monochemotherapy (paclitaxel or doxorubicin or cyclophosphamide). Five pts received a second-line CT: 1 BS pt cabozantinib, 4 STS pts doxorubicin or gemcitabine. Three STS pts received a third-line therapy (pazopanib or gemcitabine). 13 pts (57%) had a relapse of disease at a median time of 11 months (range 4 – 168 months). 2-yrs OS after RIS was 52%. mOS was 2 yrs (range 4 - 189 months).
Conclusions
RIS can occur many yrs later RT, thus an extended follow-up after RT is necessary. The rarity of these diseases highlights the importance to refer pts to sarcoma high-volume centres.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.