Abstract 4526
Background
Imatinib mesylate is approved in unresectable tumors and has been also proposed in the neoadjuvant setting in order to reduce tumor size and post-operative relapses for difficult to resect DFSP. The aim of this study was to evaluate the long-term results of neoadjuvant imatinib and other TKI used in DFSP.
Methods
The files of all patients with the following criteria seen from 2007 to 2017 in our center were collected in this retrospective study: a/histologically proven primary or recurrent DFSP with COL1A1-PDGFB translocation b/ difficult to treat but surgically manageable as assessed in pluridisciplinary tumor board, c/received first-line neoadjuvant TKI (imatinib, pazopanib). The primary endpoint was long-term progression-free survival (PFS).
Results
27 patients (median 42 years, range: 18-63) were included, of whom 9 (33%) had fibrosarcomatous transformation on pre-TKI biopsy. 10 patients had primary tumors and 17 presented recurrences. Median tumor size was 6 cm (range 3-30). 24 patients received imatinib (median dose= 600mg/day), 3 received pazopanib (median dose= 600mg/day) for a median of 7 months. The best MRI response to ITK treatment before surgery according to RECIST1.1 consisted of complete/partial response (33%) or stability (48%). DFSP was surgically removed in 24 patients (89%) after a median of 7 months and 2 surgeries. Two patients (7%) did not receive surgery because of metastasis progression. One other patient declined surgery. 23 of 24 patients surgically treated were disease-free after 50 months of median follow-up (range 10-133). One patient developed distant metastasis 37 months after the complete surgical resection. The median PFS was 44 months (range 10-133).The histological response localization was mainly patchy (n = 10) or diffuse (n = 7). The median percentage of therapeutic response surface was 65%.Treatment-related adverse events occurred in 23 patients (85%). 4 patients had grade 3 or higher toxicities (2 grade 3 and 4 neutropenia, 1 grade 3 cholestasis, 1 grade 3 nausea) requiring temporary treatment disruption and dose reductions.
Conclusions
TKI are effective neoadjuvant treatment for locally advanced or inoperable DFSP with long-term PFS and few severe adverse events.
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.
Resources from the same session
3309 - Heat Shock Protein 90 chaperones and Protein Kinase D3 regulates androgen-independent prostate cancer development
Presenter: Attila Varga
Session: Poster Display session 1
Resources:
Abstract
3441 - The SWI/SNF driven reprograming for the AR cistrome is NSD2 dependent
Presenter: Katia Ruggero
Session: Poster Display session 1
Resources:
Abstract
1659 - IGF1R inhibition affects the survival of HT29 cancer cells by alterations of the TLR9- and autophagy signaling
Presenter: Györgyi Műzes
Session: Poster Display session 1
Resources:
Abstract
1379 - Characterization of atypical dMMR (deficient MisMatch Repair) tumors: a study from a large cohort of 4948 cases
Presenter: Marion Jaffrelot
Session: Poster Display session 1
Resources:
Abstract
1657 - Modulation of TLR9-dependent autophagy response via inhibition of c-Met signaling influences the survival of HT29 cancer cells
Presenter: Ferenc Sipos
Session: Poster Display session 1
Resources:
Abstract
3045 - Positive Feedback Activation of Notch Signal by Obesity Enhances Colorectal Tumorigenicity
Presenter: Dake Chu
Session: Poster Display session 1
Resources:
Abstract
2285 - The Pathological and Functional Roles of BRPF1 in Hepatocellular Carcinoma
Presenter: Lai Hung Carol Cheng
Session: Poster Display session 1
Resources:
Abstract
3210 - Protein tyrosine phosphatase non-receptor type 3 (PTPN3) could be a new therapeutic target for pancreatic cancer.
Presenter: Akio Yamasaki
Session: Poster Display session 1
Resources:
Abstract
3920 - A Novel bispecific BCMAxCD3 T cell engaging antibody that treat multiple myeloma (MM) with minimal cytokine serection
Presenter: Zhenyu Li
Session: Poster Display session 1
Resources:
Abstract
2691 - Quantitative spatial profiling of lymphocyte-activation gene 3 (LAG-3)/major histocompatibility complex class II (MHC II) interaction in gastric and urothelial tumors
Presenter: Cyrus Hedvat
Session: Poster Display session 1
Resources:
Abstract