Growth Factor And Its Role In The Treatment Of Patients With Soft Tissue Extremity Sarcoma Receiving Chemotherapy Managed At An Academic Center: A Retrospective Study.

e23573 Background: Surgery still remains the mainstay of treatment with curative intent for high grade extremity soft tissue non rhabdomyosarcoma sarcomas (HG ESTS). Adjuvant/neoadjuvant Chemotherapy (CT) is still debatable, but most experts agree about its role in HG-ESTS in combination with radiation (R). Interdigitated CT+R is an attractive method of delivering these modalities of treatment in short time prior to surgery, however safety of using growth factor (GF) while administering CT+R in HG ESTS is largely unknown. We conducted a retrospective study of the toxicities associated with GF administration in this setting at a single institution. Methods: Electronic medical records at one institution were reviewed to identify patients having a diagnosis of extremity STS between October 2017- January 2020. Demographics, details of tumor characteristics, and treatment details were noted. Details of Interdigitated (ID)CRT were noted; the intended CT regimen was doxorubicin/ifosphamide/mesna (MAI) at 100% of the intended dosing. Data regarding the toxicities associated with GF administration were also evaluated in these patients; specifically, the development of febrile neutropenia, thrombocytopenia and pulmonary toxicity were evaluated. Patients who presented with metastatic disease were excluded from this analysis. Results: 22 patients were identified. Median age was 63 years. Of these, 9 patients (40%) were smokers. At diagnosis, 6 patients (27%) had metastatic disease. The most common site of primary disease was the thigh (50%). The most common histology was undifferentiated pleomorphic sarcoma (59%). CT monotherapy was administered in 3 patients. RT was administered in 14 patients, out of whom interdigitated CRT was administered in 10 patients. 60% of patients who initiated were able to receive 3 cycles of ID-CRT prior to Surgery. GF was administered in 14 patients who received regimens including CT. Of patients receiving ID-CRT who received GF, 60% completed ID-CRT without delays. No delays occurred due to thrombocytopenia. Febrile neutropenia occured in 22% of patients who received GF. Only 1 patient who received GF suffered prolonged thrombocytopenia. No patients who received GF were noted to have pulmonary toxicity. Conclusions: For adults with HG ESTS, GF administration with ID-CRT does not appear to cause any additional delay in treatment due to prolonged thrombocytopenia or lung toxicity. Inclusion of GF administration in further prospective trials of ID-CRT appears feasible.