1494P - Imatinib mesylate in desmoplastic small round cell tumour

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Anti-Cancer Agents & Biologic Therapy
Soft Tissue Sarcomas
Presenter Alexia Bertuzzi
Authors A. Bertuzzi1, G. Bisogno2, M. Carli2, A. Ferrari3, A. Comandone4, M. Gasco5, R. De Sanctis6, C. Gnocchi7, A. Santoro8
  • 1Medical Oncology And Hematology, Humanitas Cancer Center, IRCCS, IT-20089 - Rozzano/IT
  • 2Pediatric Medical Oncology And Hematology, Clinica di Onco-Ematologia Pediatrica, Padova/IT
  • 3Pediatric Oncology Unit, Fondazione IRCCS - Istituto Nazionale dei Tumori, IT-20133 - Milano/IT
  • 4Ospedale Gradenigo, IT-10153 - Torino/IT
  • 5Medical Oncology, Humanitas Cancer Center, IRCCS, IT-20089 - Rozzano/IT
  • 6Dipartimento Di Medicina Sperimentale, Humanitas Cancer Center, IRCCS, IT-20089 - Rozzano/IT
  • 7Novartis Farma, Novartis, Origgio/IT
  • 8Humanitas Cancer Center, IRCCS, IT-20089 - Rozzano/IT

Abstract

Introduction

Desmoplastic small round cell tumor (DSRCT) is a very rare and aggressive mesenchymal neoplasia with an extremely poor prognosis. The typical translocation t(11;22) determines the overexpression of PDGF-Rα and �, responsible of clinical stromal fibrosis reaction constantly detected in abdominal lesions. We investigated the role of imatinib, as tyrosine kinase inhibitor of PDGF-R, in DSRCT.

Patients and methods

From August 2005 to June 2009 we enrolled patients (pts) with histologically proven diagnosis of DSRCT, refractory to conventional treatment. Inclusion criteria comprised immunohistochemical positivity of imatinib targets (PDGF-Rα and �). Treatment consisted of imatinib 400 mg p.o. daily. Primary endpoint of the study was objective response rate. Secondary endpoint was safety and tolerability assessment.

Results

Of the 13 enrolled patients, 8 pts were evaluable for response (4 screening failure and 1 never treated). Median age was 20 years (range, 9-32). M/F ratio was 7/1. ECOG PS was 0 in 6 pts. Median time from diagnosis was 24.5 months (range, 6-148). 75% of pts had metastatic disease. The primary site was abdominal-pelvic for all pts. PDGFRα and � were expressed with an heterogeneous intensity pattern. Objective responses at first radiological evaluation at 3 months were: stable disease in one pt (12.5%) and progressive disease in 7 (87.5%) pts. Treatment-related adverse events were G1-2 nausea/vomiting, fatigue and periorbital oedema.

Conclusions

In our limited case series, imatinib showed no efficacy in the treatment of DSRCT pts unresponsive to conventional therapy, despite molecular-based selection of pts. Probably to identify responder pts, it is necessary a more complex evaluation comprehensive of both levels of expression and activation of PDGFRα and �. Furthermore, enrolled pts were affected by advanced refractory disease, probably less responsive to target therapies. It would be hopeful a global effort to define a new combined approach based on the association of conventional chemotherapy and biological drugs.

Disclosure

C. Gnocchi: Novartis Patient Advocacy Manager.

All other authors have declared no conflicts of interest.