Valérie Laurence

Genomic landscape of Ewing sarcoma defines an aggressive subtype with co-association of STAG2 and TP53 mutations

UNLABELLED Ewing sarcoma is a primary bone tumor initiated by EWSR1-ETS gene fusions. To identify secondary genetic lesions that contribute to tumor progression, we performed whole-genome sequencing of 112 Ewing sarcoma samples and matched germline DNA. Overall, Ewing sarcoma tumors had relatively few single-nucleotide variants, indels, structural variants, and copy-number alterations. Apart from whole chromosome arm copy-number changes, the most common somatic mutations were detected in STAG2 (17%), CDKN2A (12%), TP53 (7%), EZH2, BCOR, and ZMYM3 (2.7% each). Strikingly, STAG2 mutations and CDKN2A deletions were mutually exclusive, as confirmed in Ewing sarcoma cell lines. In an expanded cohort of 299 patients with clinical data, we discovered that STAG2 and TP53 mutations are often concurrent and are associated with poor outcome. Finally, we detected subclonal STAG2 mutations in diagnostic tumors and expansion of STAG2-immunonegative cells in relapsed tumors as compared with matched diagnostic samples. SIGNIFICANCE Whole-genome sequencing reveals that the somatic mutation rate in Ewing sarcoma is low. Tumors that harbor STAG2 and TP53 mutations have a particularly dismal prognosis with current treatments and require alternative therapies. Novel drugs that target epigenetic regulators may constitute viable therapeutic strategies in a subset of patients with mutations in chromatin modifiers.

Vascular Endothelial Growth Factor: A Therapeutic Target for Tumors of the Ewing's Sarcoma Family

Purpose: We have reported previously that intratumoral microvessel density (MVD) is a significant prognostic indicator of event-free survival in the Ewings sarcoma family of tumors (ESFT). Here, the angiogenic growth factor expression profile and its relationship with MVD has been investigated in ESFT. Experimental Design and Results: Using ESFT model systems, the potential of these factors as therapeutic targets has been evaluated. A significant correlation (P = 0.02) was observed between vascular endothelial growth factor (VEGF) expression and MVD, consistent with the hypothesis that VEGF regulates the development of microvessels in ESFT. There was no correlation between MVD and any of the other growth factors studied. All six ESFT cell lines studied produced and secreted VEGF; five of six cell lines also secreted placental growth factor, one cell line (A673) at high levels. Tumor conditioned medium induced proliferation of human umbilical vein endothelial cells. Expression of VEGF receptors Flt-1 and Flk-1/KDR was heterogeneous across the cell lines. Both receptor tyrosine kinase inhibitors SU6668 (targets Flk-1/KDR, platelet-derived growth factor receptor-β, and fibroblast growth factor receptor 1) and SU5416 (targets Flk-1/KDR) as well as anti-VEGF agents rhuMAb-VEGF (bevacizumab) and VEGF Trap delayed s.c. growth of ESFT in mice compared with untreated groups: SU6668 (100 mg/kg/d), SU5416 (25 mg/kg/d), rhuMAb-VEGF (10 mg/kg twice weekly), and VEGF Trap (2.5 or 25 mg/kg twice weekly). Conclusions: These data suggest that VEGF is the single most important regulator of angiogenesis in ESFT and may be exploited for therapeutic advantage.

hSNF5/INI1‐deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti‐hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti‐hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non‐tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss‐of‐function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1‐deficient tumours. Consequently, we believe that anti‐hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected. Copyright

Phase I evaluation of seliciclib (R-roscovitine), a novel oral cyclin-dependent kinase inhibitor, in patients with advanced malignancies

AIM Phase I study of seliciclib (CYC202, R-roscovitine), an inhibitor of cyclin-dependent kinases 2, 7 and 9, causing cell cycle changes and apoptosis in cancer cells. PATIENTS AND METHODS This phase I trial aimed at defining the toxicity profile, the maximum tolerated dose (MTD), the recommended phase II dose (RD) and the main pharmacokinetic and pharmacodynamic parameters of oral seliciclib. Three schedules were evaluated: seliciclib given twice daily for 5 consecutive days every 3 weeks (schedule A), for 10 consecutive days followed by 2 weeks off (schedule B) and for 3d every 2 weeks (schedule C). RESULTS Fifty-six patients received a total of 218 cycles of seliciclib. Dose-Limiting Toxicities (DLT) consisting of nausea, vomiting, asthenia and hypokalaemia occurred at 1600 mg bid for schedule A and in schedule C, DLT of hypokalaemia and asthenia occurred at 1800 mg bid. The evaluation of longer treatment duration in schedule B was discontinued because of unacceptable toxicity at lower doses. Other adverse events included transient serum creatinine increases and liver dysfunctions. Pharmacokinetic data showed that exposure to seliciclib and its carboxylate metabolite increased with increasing dose. Soluble cytokeratin 18 fragments allowed monitoring of seliciclib-induced cell death in the blood of patients treated with seliciclib at doses above 800 mg/d. One partial response in a patient with hepatocellular carcinoma and sustained tumour stabilisations were observed. CONCLUSIONS The MTD and RD for seliciclib are 1250 mg bid for 5d every 3 weeks and 1600 mg bid for 3d every 2 weeks, respectively.

Prognostic factors for survival after neoadjuvant chemotherapy in operable breast cancer: the role of clinical response

The aim of this retrospective study was to assess predictive factors for clinical response to preoperative chemotherapy and prognostic factors for survival. From 1981 to 1992, 936 patients with T2-T3, N0-N1 breast cancer who received 2-6 months (median 4) of preoperative chemotherapy were selected from the Institute Curie database. Preoperative treatment was followed by surgery and/or radiotherapy. Median follow-up was 8.5 years (range 7-211 months). The objective response rate before surgery and/or radiotherapy was 58.3%. In stepwise multivariate analysis (Cox model), favourable prognostic factors for survival were the absence of pathological axillary lymph node involvement (Relative Risk (RR) 1.54; P=0.0004), low histological tumour grade (RR=1.54; P=0.0017), clinical response to preoperative chemotherapy (RR=1.45, P=0.0013), positive progesterone receptor (PR) status (RR=1.56; P=0.0001), smaller tumour size (RR=1.37; P=0.005) and lack of clinical lymph node involvement (RR=1.42; P=0.007). The association of clinical tumour response with survival is independent of the baseline characteristics of the tumour. Clinical response could be used as a surrogate marker for evaluation of the efficacy of neoadjuvant chemotherapy before assessment of the pathological response.

Survival of breast cancer patients with meningeal carcinomatosis

BACKGROUND Breast cancer is the leading nonhematologic cause of meningeal carcinomatosis (MC). The aim of this study was to report the outcome of patients diagnosed with breast cancer MC and treated in single institution by a high-dose intrathecal methotrexate (MTX) regimen. METHODS Ninety-one patients were diagnosed with breast cancer MC from 2000 to 2007. Intrathecal treatment was MTX 15 mg/day (days 1-5), hydrocortisone acetate (day 1) and oral folinic acid (days 1-5), repeated every 2 weeks. Patients and tumor characteristics were associated with the early clinical and biological outcome and with the overall survival (OS). RESULTS The median survival was 4.5 months (range 0-53). In multivariate analysis, adverse prognostic factors at diagnosis were performance status >2 [P = 0.006, response rate (RR) = 0.33 (0.15-0.71)], more than three chemotherapy regimens before MC diagnosis [P = 0.03, RR = 0.40 (0.19-0.93)], negative hormone receptor status [P = 0.02, RR = 0.4 (0.19-0.90)] and high Cyfra 21-1 level [P = 0.048, RR = (0.09-0.99)]. Clinical progression after one cycle and biological response after two cycles were independently associated with OS [P < 0.001, RR = 0.09 (0.02-0.37) and P = 0.003, RR = 3.6 (1.5-8.5), respectively]. We propose a prognostic score in order to define three distinct groups of prognosis. CONCLUSIONS MC presents a poor prognosis, but 1-year survival rate was 25%. This score may become a useful tool for treatment decision and clinical trials.

Extra‐renal non‐cerebral rhabdoid tumours

Rhabdoid tumours (RTs) are aggressive malignancies of childhood, mainly occurring in the kidney and brain. We describe a national multi‐centre retrospective analysis of extra‐renal non‐cranial RTs (ERRTs).

Ewing-like sarcomas with BCOR-CCNB3 fusion transcript: A clinical, radiological and pathological retrospective study from the Société Française des Cancers de L'Enfant

This retrospective multicenter study assessed the clinical, radiological and pathological presentation, treatment and outcome of 26 patients with Ewing‐like sarcoma harboring BCOR‐CCNB3 gene fusion transcript. Tumor samples had been collected between 1994 and April 2012.

Cabazitaxel in patients with advanced solid tumours: results of a Phase I and pharmacokinetic study.

BACKGROUND Although the taxanes paclitaxel and docetaxel are among the most active agents for the treatment of a wide range of cancers, tumours often develop resistance to these treatments. Cabazitaxel is a novel taxane active in both preclinical models of chemotherapy-sensitive and -resistant human tumours and patients with advanced prostate cancer that progressed following docetaxel treatment. AIM To establish the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of cabazitaxel. PATIENTS AND METHODS Cabazitaxel was administered every 3 weeks to patients with advanced solid tumours. The design allowed intrapatient dose escalation. The primary objective was to determine the MTD. Secondary objectives were to describe the safety profile, establish an appropriate dose, determine the pharmacokinetic (PK) profile of cabazitaxel, and assess antitumour activity. RESULTS Twenty-one patients were recruited. The MTD was reached at 30 mg/m(2), at which three of five patients experienced haematologic DLTs during the first cycle. DLTs during subsequent cycles were mainly haematologic and reported at 25 and 30 mg/m(2) dosing levels. Nail disorders and severe alopecia were not reported, and neurotoxicity, fluid retention and hypersensitivity were mild and infrequent. Cabazitaxel demonstrated linear PK, a triphasic elimination profile, with a long half-life and high clearance. Of the 19 patients evaluable for response, one unconfirmed partial response and six occurrences of stable disease were reported. CONCLUSIONS The 25mg/m(2) dose of cabazitaxel was recommended for use in future clinical studies. In this study, cabazitaxel had an acceptable tolerability profile and activity in cervical, colorectal, endometrial and lung cancers.

Desmoplastic small round cell tumors with EWS-WT1 fusion transcript in children and young adults†‡

The presence of the EWS‐WT1 gene fusion transcript (GFT) is characteristic of desmoplastic small round cell tumor (DSRCT), a rare and very aggressive disease for which the treatment has not yet been clearly standardized.