Some Lessons Learned from Imatinib Mesylate Clinical Development in Gastrointestinal Stromal Tumors

Mutation Analysis of Nine Chordoma Specimens by Targeted Next-Generation Cancer Panel Sequencing

Background: Chordoma is a rare primary malignant bone tumour. Treatment options are mainly restricted to surgical excision, since chordomas are largely resistant to conventional ionising radiation and chemotherapy. Thus, there is a strong need to gain more thorough insights into the molecular biology and genetics of chordoma to allow for the development of new therapeutic options. We performed an ultra-deep sequencing analysis to find novel mutations in cancer associated genes in chordomas to date unseen with Sanger sequencing.

Material and Methods: Nine chordomas (skull base (n=3), mobile spine (n=4), and sacrum/coccyx (n=2) were screened for mutations in 48 cancer genes using the Hot Spot Cancer Panel (Illumina). All putative mutations were compared against multiple databases (e.g. NCBI, COSMIC, PolyPhen, EGB, SIFT) and published Copy Number Variation (CNV) data for chordoma.

Results: Our results showed mutations with a frequency above 5% in tumorsuppressor- and onco-genes, revealing new possible driver genes for chordomas. We detected three different variants accounting for 11 point mutations in three cancer associated genes (KIT, KDR and TP53). None of the detected mutations was found in all samples investigated. However, all genes affected interact or are connected in pathway analysis. There were no correlations to already reported CNVs in the samples analysed.

Conclusions: We identified mutations in the associated genes KIT, KDR, and TP53. These mutations have been described previously and have been predicted to be tolerated. Further results on a larger series are warranted. The driver mechanisms of chordoma still have to be identified.

Trabectedin in myxoid liposarcomas (MLS): a long-term analysis of a single-institution series

BACKGROUND

Trabectedin has been approved in Europe as second-line therapy for advanced soft tissue sarcomas. A previous analysis showed that myxoid liposarcomas (MLS) are particularly sensitive to the drug. We report on the long-term efficacy of trabectedin in a subgroup of that series.

METHODS

Since September 2002, 32 advanced pretreated MLS patients received trabectedin at our center. Data were reviewed focusing on their long-term outcome.

RESULTS

Trabectedin was given as a 24-h continuous infusion every 21 days. A total of 376 and a median of 12 courses per patient (range 2-26; interquartiles range (IQR) 8-15) were delivered. Response rate per RECIST was 50% [95% confidence interval (CI) 32% to 68%], median progression-free survival (PFS) was 17 months (95% CI 13.5-30.1) and median overall survival is still not reached. In 10 patients, therapy was stopped in the absence of any evident disease, mostly after complete surgery of residual lesions. In these 10 patients, at a median follow-up of 25 months, PFS was 28.1 months (95% CI 25.6-36.4) from treatment start.

DISCUSSION

These data indicate that the high response rate of MLS to trabectedin translates into prolonged PFS. Surgery of residual metastatic disease is already used quite extensively in metastatic MLS. Trabectedin may give further significance to this kind of surgery.

Efficacy of trabectedin (ecteinascidin-743) in advanced pretreated myxoid liposarcomas: a retrospective study

BACKGROUND

Previous studies have suggested that trabectedin (ecteinascidin-743) could have antitumour activity in soft-tissue sarcoma. We aimed to study the usefulness of trabectedin in the treatment of patients with myxoid liposarcomas, a subtype of liposarcoma that is associated with specific chromosomal translocations t(12;16)(q13;p11) or t(12;22)(q13;q12) that result in the formation of DDIT3-FUS or DDIT3-EWSR1 fusion proteins.

METHODS

51 patients with advanced pretreated myxoid liposarcoma who started treatment with trabectedin between April 4, 2001, and Sept 18, 2006 at five institutions in a compassionate-use programme were analysed retrospectively. Centralised radiological and pathological reviews were done for most patients. Trabectedin was given either as a 24-h continuous infusion or as a 3-h infusion, every 21 days, at 1.1-1.5 mg(2). 558 courses of trabectedin were given in total, with a median of ten courses for each patient (range 1-23). The primary endpoints were response rate and progression-free survival, and the secondary endpoint was overall survival.

FINDINGS

According to Response Evaluation Criteria in Solid Tumors (RECIST), after a median follow-up of 14.0 months (IQR 8.7-20.0), two patients had complete responses (CR) and 24 patients had partial responses (PR); the overall response was 51% (95% CI 36-65). Five patients had early progressive disease. In 17 of the 23 patients who achieved PR or CR as defined by RECIST and who had centralised radiological review, tissue-density changes, consisting of a decrease in tumour density on CT scan or a decrease in contrast enhancement on MRI (or both), preceded tumour shrinkage. Median progression-free survival was 14.0 months (13.1-21.0), and progression-free survival at 6 months was 88% (79-95).

INTERPRETATION

Trabectedin was associated with antitumour activity in this series of patients with myxoid liposarcoma. The noted patterns of tumour response were such that tissue density changes occurred before tumour shrinkage in several patients. In some patients, tissue-density changes only were seen. Long-lasting tumour control was noted in responsive patients. The compassionate-use programme is still ongoing. This analysis has resulted in the initiation of two prospective studies to assess the role of trabectedin in the treatment of patients with myxoid liposarcoma in preoperative and metastatic settings. Furthermore, the selective mechanism of action for trabectedin in this translocation-related sarcoma is being studied.