Presentado Domingo 6 de Mayo :
Surgery of Residual Disease of Myxoid Liposarcoma Patients Responding to Trabectedin.
Abstract No: 10056
Author(s): R. Sanfilippo, F. Grosso, M. D'Incalci, P. Dileo, S. Pilotti, C. Morosi, M. Fiore, J. C. Tercero, A. Gronchi, P. G. Casali; Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy; ASO Alessandria, Alessandria, Italy; Istituto di Ricerche Farmacologiche, Milan, Italy; Istituto Nazionale dei Tumori, Milano, Italy; PharmaMar, Colmenar Viejo, Madrid, Spain
Abstract:
Background: Our single-institution series, now including 53 metastatic MLS patients (pts) treated with trabectedin (T), was reviewed focusing on the use of surgery of residual disease. Methods: Since September 2002, 53 pts with metastatic pretreated MLS received T. Median age at T start was 48 yrs (range 27-77). T was given as a 24-hr continuous infusion every 21 days, at a dose between 1.0 to 1.5 mg/sqm.
Results: 578 courses were delivered (median = 10/pt). RECIST response rate was 50%, the median TTP was 15 months (90% CI = 9-18) and OS was 48 months. Eighteen pts stopped T on their best response (2 CR, 10 PR, 6 MR/SD): 10 remained in follow-up after a median of 11 courses and 8 underwent surgery of residual disease after a median of 12 courses. The decision whether to do surgery was based on resectability and extent of metastatic disease. Surgery was complete in all cases. Median TTP from treatment start was 30 and 25 months, respectively, in surgically and non-surgically treated pts. TTP was 14 months from treatment end in both groups. At a median follow-up of 29 months from treatment end, 13 pts relapsed (7 and 6 in the two subgroups). Twelve of these pts were rechallenged with T, obtaining 2 CR, 5 PR and 5 SD (median PFS = 14 months).
Conclusions: T provides prolonged tumor control in MLS. Surgery of residual disease in responding pts is an option. However, in this small series it did not seem to provide any major advantage, in the face of a selection bias favouring in principle operated pts. T rechallenge at progression in pts who stopped their treatment on best response was associated with significant further tumor control. Prospective studies to define optimal management of MLS pts responding to T are warranted.