Non-linear dynamics of human locomotion: effects of rhythmic auditory cueing on local dynamic stability

It has been observed that times series of gait parameters [stride length (SL), stride time (ST), and stride speed (SS)], exhibit long-term persistence and fractal-like properties. Synchronizing steps with rhythmic auditory stimuli modifies the persistent fluctuation pattern to anti-persistence. Another non-linear method estimates the degree of resilience of gait control to small perturbations, i.e., the local dynamic stability (LDS). The method makes use of the maximal Lyapunov exponent, which estimates how fast a non-linear system embedded in a reconstructed state space (attractor) diverges after an infinitesimal perturbation. We propose to use an instrumented treadmill to simultaneously measure basic gait parameters (time series of SL, ST, and SS from which the statistical persistence among consecutive strides can be assessed), and the trajectory of the center of pressure (from which the LDS can be estimated). In 20 healthy participants, the response to rhythmic auditory cueing (RAC) of LDS and of statistical persistence [assessed with detrended fluctuation analysis (DFA)] was compared. By analyzing the divergence curves, we observed that long-term LDS (computed as the reverse of the average logarithmic rate of divergence between the 4th and the 10th strides downstream from nearest neighbors in the reconstructed attractor) was strongly enhanced (relative change +73%). That is likely the indication of a more dampened dynamics. The change in short-term LDS (divergence over one step) was smaller (+3%). DFA results (scaling exponents) confirmed an anti-persistent pattern in ST, SL, and SS. Long-term LDS (but not short-term LDS) and scaling exponents exhibited a significant correlation between them (r = 0.7). Both phenomena probably result from the more conscious/voluntary gait control that is required by RAC. We suggest that LDS and statistical persistence should be used to evaluate the efficiency of cueing therapy in patients with neurological gait disorders.

Local dynamic stability as a responsive index for the evaluation of rehabilitation effect on fall risk in patients with multiple sclerosis: a longitudinal study

BACKGROUND

Gait and balance problems are common in patients with multiple sclerosis, leading to high risk for falls. Local Dynamic Stability (LDS), a non-linear gait stability index, has been advocated as an early indicator of risk for falls. With this longitudinal study over three weeks, we aimed to assess the responsiveness of Local Dynamic Stability to a rehabilitation program and to compare it to other measures.

METHODS

Eighteen patients (mean 54 years, median EDSS score: 5) participated. They were admitted to inpatient rehabilitation and received a three weeks individually tailored program. They performed a 3-minute walking test at the beginning and at the end of the stay, as well as pain, wellbeing, fatigue, and balance assessment. The Local Dynamic Stability was computed from the acceleration signals measured with a 3D-accelerometer.

RESULTS

At the end of the rehabilitation process, patients reported reduced pain (Effect Size: -0.7), fatigue (ES:-0.6), and increased wellbeing (ES: 1.1). A small positive effect on static balance was observed (ES: 0.3). LDS was improved (ES: 0.6), and the effect was higher than walking speed improvement (ES: 0.4).

CONCLUSIONS

The Local Dynamic Stability seemed responsive to assess rehabilitation effects in patients with multiple sclerosis. It could constitute a valuable gait quality index, which could evaluate potential effects of rehabilitation on fall risk.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN69803702.

Incidence and predictive factors of late relapse in patients with soft tissue sarcomas: Implications for prolonged follow-up

10574

Background: There is no consensus on how to follow soft-tissue sarcoma (STS) patients after their initial management. In particular, the incidence of late relapse which would justify prolonged surveillance is unknown. Methods: Follow-up data were reviewed from 719 patients with localized STS, included in the French Sarcoma Group database from January 1990 to June 2005, and who achieved complete remission maintained for at least five years after their initial management. The outcomes of interest were the cumulative probabilities of late (> 5 years) local and metastatic relapse with death as a competing event. Estimations and 95% confidence intervals (CIs) were computed with the cumulative incidence function. Patients who did not experience the event of interest or death over the course of the study were censored at their last follow-up. Results: 67 (9.3%) and 42 (5.8%) patients had late local and metastatic relapse respectively. On univariate analysis, internal trunk location, liposarcoma histological subtype, tumor size > 10 cm, R1 margins, no adjuvant radiotherapy were significantly associated with increased risk of late local relapse. On multivariate analysis, internal trunk location (HR= 3.9, 95% CI 2.2-6.7, p<0.001) and tumor size > 10 cm (HR= 2.1, 95% CI 1.1-4, p=0.03) were the two factors independently associated with local relapse. On univariate analysis, leiomyosarcoma histological subtype, and grade > 1 were significantly associated with increased risk of late metastatic relapse. On multivariate analysis, grade > 1 (HR= 4.7, 95% CI 1.1-21, p=0.04) was the sole factor independently associated with the risk of late metastatic relapse. Conclusions: Late relapse of STS (> 5 years after initial management) is relatively uncommon. However, its existence and our results emphasize the critical role of long-term follow-up to detect late local recurrence in patients with retroperitoneal or very large STS and late metastatic recurrence in patients with high grade disease.

Impact of adjuvant treatments on local and metastatic relapse of soft-tissue sarcoma patients in the setting of competing risks

10575

Background: Competing risk is the risk of an event that interferes with the probability of experiencing the disease-specific outcome of interest. Indeed, the occurrence of a competing risk (for instance death by local relapse or another cause) may preclude the onset of the event of interest (for instance metastatic relapse) or at least modify its probability. Competing risk is ignored by Kaplan Meier method and standard Cox survival model. Methods: 3369 adult patients with localized STS were included prospectively in the French Sarcoma Group (GSF) database from January 1990 to December 2009. The outcomes of interest were the cumulative probabilities of local (LR) and of metastatic (MR) relapse with death as a competing event. Estimations and 95% confidence intervals (CIs) were computed with the cumulative incidence function. Results: Median follow-up was 4.5 years. 1-year and 5-year cumulative incidence of LR were 6.4% (95% CI 5.6-7.3) and 25.9% (95% CI 24.2-27.6), respectively. Age, histological subtype, anatomic site and grade were independently associated with the cumulative probability of LR. After adjustment to these prognostic factors, adjuvant radiotherapy was associated with a significant impact on LR (HR=0.5 95% CI 0.4; 0.6, p <0.001). The magnitude of this effect was similar whatever the grade or the anatomic site. Because of the competing effect of death, adjuvant chemotherapy had no significant impact on the cumulative probability of LR. 1-year and 5-year cumulative incidence of MR were 7.4% (95% CI 6.5-8.3) and 26.9% (95% CI 25.2-28.7), respectively. Tumor depth, histological subtype, tumor size and grade were independently associated with the cumulative incidence of MR. After adjustment to these prognostic factors, adjuvant chemotherapy was associated with a significant impact on MR (HR=0.5 95% CI 0.4-0.7, p < 0.001) in grade 3 but not in grade 2 patients (HR=1.3 95% CI 0.9-1.9, p= 0.1). Conclusions: Adjuvant radiotherapy was associated with improved LR outcome even in patients with high risk of competing death from metastatic disease or other causes. Adjuvant chemotherapy was associated with improved MR outcome in patients with grade 3 but not grade 2 disease.

Prognostic significance of radiologic and histologic response to neoadjuvant chemotherapy in localized synovial sarcoma

10578

Background: The role of neoadjuvant and adjuvant chemotherapy in localized synovial sarcoma (SS) is still controversial. Histologic response to neoadjuvant chemotherapy is an independent prognostic variable in bone sarcomas. Data regarding the prognostic value of response to noeadjuvant chemotherapy in STS are limited. Methods: 68 patients with localized STS, treated with neoadjuvant anthracycline/ifosfamide-based chemotherapy and assessable for response to chemotherapy were included prospectively in the French Sarcoma Group (GSF) database from 1985 to 2011. All the cases were reviewed by the pathology subcommittee of the GSF. Radiological response to chemotherapy was assessed according to RECIST criteria. Good response was defined as partial response or stable disease according to RECIST and ≤10% recognizable tumor cells in the surgical specimen. Poor response was defined as stable or progressive disease according to RECIST and ≥ 50% recognizable tumors cells in the surgical specimen. All the other cases were defined as intermediate response. Results: Median age was 38 years. Median tumor size was 8 cm (range 2-20). 56% of tumors were located in the limbs and 52% were grade 3. Response to chemotherapy was considered as good in 9 cases (13%), intermediate in 20 cases (29.5%) and poor in 39 cases (57.5%). Median metastasis-free (MFS) and overall (OS) survivals were 45 (95% CI 11-79) and 84 months (95%CI 88-120), respectively. On univariate analysis, grade, tumor size and response to chemotherapy were significantly associated with metastasis-free survival (MFS). Radiological response according to RECIST has no prognostic value. On multivariate analysis, grade was the sole variable independently associated with MFS (HR=3.4, 95% CI 1.5-7.5, p=0.003). On univariate analysis, grade, and response to chemotherapy were significantly associated with overall survival (OS). On multivariate analysis, grade was the sole factor independently associated with OS (HR=2.5, 95% CI 1.2-5.7, p=0.03). Conclusions: Response to neoadjuvant chemotherapy may not have prognostic value in patients with SS. Grade represents the most significant predictive factor of outcome in this setting.

Immune infiltrates are prognostic factors in localized gastrointestinal stromal tumors

Cancer immunosurveillance relies on effector/memory tumor-infiltrating CD8(+) T cells with a T-helper cell 1 (TH1) profile. Evidence for a natural killer (NK) cell-based control of human malignancies is still largely missing. The KIT tyrosine kinase inhibitor imatinib mesylate markedly prolongs the survival of patients with gastrointestinal stromal tumors (GIST) by direct effects on tumor cells as well as by indirect immunostimulatory effects on T and NK cells. Here, we investigated the prognostic value of tumor-infiltrating lymphocytes (TIL) expressing CD3, Foxp3, or NKp46 (NCR1) in a cohort of patients with localized GIST. We found that CD3(+) TIL were highly activated in GIST and were especially enriched in areas of the tumor that conserve class I MHC expression despite imatinib mesylate treatment. High densities of CD3(+) TIL predicted progression-free survival (PFS) in multivariate analyses. Moreover, GIST were infiltrated by a homogeneous subset of cytokine-secreting CD56(bright) (NCAM1) NK cells that accumulated in tumor foci after imatinib mesylate treatment. The density of the NK infiltrate independently predicted PFS and added prognostic information to the Miettinen score, as well as to the KIT mutational status. NK and T lymphocytes preferentially distributed to distinct areas of tumor sections and probably contributed independently to GIST immunosurveillance. These findings encourage the prospective validation of immune biomarkers for optimal risk stratification of patients with GIST.

Transgelin is a novel marker of smooth muscle differentiation that improves diagnostic accuracy of leiomyosarcomas: a comparative immunohistochemical reappraisal of myogenic markers in 900 soft tissue tumors

Immunohistochemical use of myogenic markers serves to define smooth or skeletal muscle differentiation in soft tissue tumors. Establishing smooth muscle differentiation in malignant lesions can be challenging in some cases. We immunohistochemically examined 900 soft tissue tumors selected from the French Sarcoma Group's archived tissue collection, which contains a large number of leiomyosarcomas. The four most widely used smooth muscle diagnostic markers were evaluated (smooth muscle actin, desmin, h-caldesmon and calponin), and compared with a novel marker, transgelin. The diagnostic performance of each marker was statistically assessed in terms of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (A), in leiomyosarcomas versus all other sarcomas including gastrointestinal stromal tumors (GIST), and second in leiomyosarcomas versus specific tumor types. In leiomyosarcomas versus all other sarcomas including GIST, transgelin emerged as the best diagnostic marker (Se: 83%, Sp: 82%, PPV: 67%, NPV: 92%, A: 83%), compared with smooth muscle actin (Se: 75%, Sp: 83, PPV: 66%, NPV: 89%, A: 81%), desmin (Se: 45%, Sp: 88%, PPV: 62%, NPV: 79%, A: 75%), h-caldesmon (Se: 50%, Sp: 90%, PPV: 67%, NPV: 81%, A: 78%) and calponin (Se: 76%, Sp: 70, PPV: 52%, NPV: 87%, A: 71%). In leiomyosarcomas compared with other specific tumor types such as undifferentiated pleomorphic sarcoma and myxofibrosarcoma, the accuracy for transgelin varied from 80 to 87% whereas it was lower for all other markers (between 51 and 80%). These results indicate that transgelin could be used in practice as an additional marker useful for decision making, especially in those tumors with incomplete immunophenotypes.

Do orthopaedic shoes improve local dynamic stability of gait? An observational study in patients with chronic foot and ankle injuries

Background

Complex foot and ankle fractures, such as calcaneum fractures or Lisfranc dislocations, are often associated with a poor outcome, especially in terms of gait capacity. Indeed, degenerative changes often lead to chronic pain and chronic functional limitations. Prescription footwear represents an important therapeutic tool during the rehabilitation process. Local Dynamic Stability (LDS) is the ability of locomotor system to maintain continuous walking by accommodating small perturbations that occur naturally during walking. Because it reflects the degree of control over the gait, LDS has been advocated as a relevant indicator for evaluating different conditions and pathologies. The aim of this study was to analyze changes in LDS induced by orthopaedic shoes in patients with persistent foot and ankle injuries. We hypothesised that footwear adaptation might help patients to improve gait control, which could lead to higher LDS:

Methods

Twenty-five middle-aged inpatients (5 females, 20 males) participated in the study. They were treated for chronic post-traumatic disabilities following ankle and/or foot fractures in a Swiss rehabilitation clinic. During their stay, included inpatients received orthopaedic shoes with custom-made orthoses (insoles). They performed two 30s walking trials with standard shoes and two 30s trials with orthopaedic shoes. A triaxial motion sensor recorded 3D accelerations at the lower back level. LDS was assessed by computing divergence exponents in the acceleration signals (maximal Lyapunov exponents). Pain was evaluated with Visual Analogue Scale (VAS). LDS and pain differences between the trials with standard shoes and the trials with orthopaedic shoes were assessed.

Results

Orthopaedic shoes significantly improved LDS in the three axes (medio-lateral: 10% relative change, paired t-test p < 0.001; vertical: 9%, p = 0.03; antero-posterior: 7%, p = 0.04). A significant decrease in pain level (VAS score -29%) was observed.

Conclusions

Footwear adaptation led to pain relief and to improved foot & ankle proprioception. It is likely that that enhancement allows patients to better control foot placement. As a result, higher dynamic stability has been observed. LDS seems therefore a valuable index that could be used in early evaluation of footwear outcome in clinical settings.

Chromosome Instability Accounts for Reverse Metastatic Outcomes of Pediatric and Adult Synovial Sarcomas

Purpose

Synovial sarcoma (SS) occurs in both children and adults, although metastatic events are much more common in adults. Whereas the importance of the t(X;18) translocation in SS oncogenesis is well established, the genetic basis of SS metastasis is still poorly understood. We recently reported expression (CINSARC; Complexity Index in Sarcoma) and Genomic Index prognostic signatures related to chromosome integrity in sarcomas and GI stromal tumors. Here we investigate whether these signatures can also predict outcomes in SS.

Patients and Methods

One hundred patients who had primary untreated SS tumors were selected for expression and genomic profiling in a training/validation approach.

Results

CINSARC and Genomic Index have strong independent and validated prognostic values (P < .001). By comparing expression profiles of tumors with or without metastasis, 14 genes that are common to the CINSARC signature were identified, and the two top-ranked genes, KIF14 and CDCA2, were validated as prognostic markers in an independent cohort. Comparing genomic profiles of adult versus pediatric SS, we show that metastasis is associated with genome complexity in both situations and that the adult genome is more frequently rearranged. Accordingly, pediatric patients with an even genomic profile do not develop metastasis.

Conclusion

Metastasis development in SS is strongly associated with chromosome complexity, and CINSARC and Genomic Index are validated independent prognostic factors. The differences in metastasis frequency between adults and children are associated with genome instability, which is much more frequent in adults. Genomic Index is potentially the best overall biomarker and clearly the most clinically relevant, considering that genome profiling from formalin-fixed samples is already used in pathology.

Should adjuvant radiotherapy be administered in addition to front-line aggressive surgery (FAS) in patients with primary retroperitoneal sarcoma?

BACKGROUND

As most patients with retroperitoneal sarcomas (RPS) die of local recurrence, front-line aggressive surgery (FAS) has been developed, and it seems to achieve better local control. The aim of this study was to evaluate conformal postoperative radiotherapy (PORT) in patients who had enlarged surgery.

PATIENTS AND METHODS

Between 1994 and 2008, 110 patients with primary RPS mainly operated by FAS were analysed. Sixty-two patients underwent surgery and no PORT (group S), and 48 received surgery and PORT (group S + R). The median age was 52. Most patients had 3D conformal PORT (81%) with a median dose of 50 Gy.

RESULTS

Comparing results at 5 years in the S and the S + R group, the cumulative rate of local failure was, respectively, 36% and 22% (NS); relapse-free survival was 47% and 60% (P = 0.02), and overall survival was, respectively, 77% and 71% (NS).

CONCLUSION

Even if patients with adjuvant PORT were at higher risk of recurrence, there was a trend for radiotherapy (RT) to decrease the local relapse rate and improve recurrence-free survival. This study confirms that adjuvant conformal RT should be evaluated in a randomized trial, the control arm being FAS. Adjuvant RT in the preoperative setting is being evaluated in an EORTC trial.

Step-to-step variability in treadmill walking: influence of rhythmic auditory cueing

While walking, human beings continuously adjust step length (SpL), step time (SpT), step speed (SpS = SpL/SpT) and step width (SpW) by integrating both feedforward and feedback mechanisms. These motor control processes result in correlations of gait parameters between consecutive strides (statistical persistence). Constraining gait with a speed cue (treadmill) and/or a rhythmic auditory cue (metronome), modifies the statistical persistence to anti-persistence. The objective was to analyze whether the combined effect of treadmill and rhythmic auditory cueing (RAC) modified not only statistical persistence, but also fluctuation magnitude (standard deviation, SD), and stationarity of SpL, SpT, SpS and SpW. Twenty healthy subjects performed 6 × 5 min. walking tests at various imposed speeds on a treadmill instrumented with foot-pressure sensors. Freely-chosen walking cadences were assessed during the first three trials, and then imposed accordingly in the last trials with a metronome. Fluctuation magnitude (SD) of SpT, SpL, SpS and SpW was assessed, as well as NonStationarity Index (NSI), which estimates the dispersion of local means in the times series (SD of 20 local means over 10 steps). No effect of RAC on fluctuation magnitude (SD) was observed. SpW was not modified by RAC, what is likely the evidence that lateral foot placement is separately regulated. Stationarity (NSI) was modified by RAC in the same manner as persistent pattern: Treadmill induced low NSI in the time series of SpS, and high NSI in SpT and SpL. On the contrary, SpT, SpL and SpS exhibited low NSI under RAC condition. We used relatively short sample of consecutive strides (100) as compared to the usual number of strides required to analyze fluctuation dynamics (200 to 1000 strides). Therefore, the responsiveness of stationarity measure (NSI) to cued walking opens the perspective to perform short walking tests that would be adapted to patients with a reduced gait perimeter.

Association of chromosome complexity with age and metastasis in synovial sarcomas: Validation of expression and genomic prognostic signatures

9536

Background: Synovial sarcoma (SS) is one of the rare sarcomas that occurs in adolescents as well as in adults. Nevertheless, metastasis occurs with a lowest frequency in the former, 10 vs 50% respectively. In almost all cases, a characteristic translocation t(X;18)(p11.2;q11.2) exists and the importance of this translocation in SS oncogenesis is well established, but the genetic basis of SS metastasis is still poorly understood. We recently published expression (CINSARC) and genomic (GI) signatures related to chromosome integrity control that predict outcome in undifferentiated sarcomas and GIST and ask whether these signatures could also predict outcome in SS. Methods: To asses this issue we selected in the European sarcoma database CONTICABASE 92 primary untreated SS for expression and genomic profiling. Results: As demonstrated by metastasis-free survival, CINSARC and GI have strong and independent prognostic values (p = 1.6 x 10-5 and p = 4 x 10-6, respectively). Comparing expression profiles of tumors with or without metastasis in a training series of 58 SS, a 52-genes signature was identified and validated in an independent series of 34 SS. Fourteen of these genes are common with CINSARC and these 52 genes are involved the same pathways than CINSARC, mitosis checkpoints and chromosome integrity. Comparing genomic profiles of adult versus pediatric SS we show that in both situations metastasis is associated to genome complexity and that the adult genome is highly more frequently rearranged. In line with this, the pediatric good-prognosis patients, according to GI, do not develop metastasis. Conclusions: Results clearly indicate that SS metastasis development is strongly associated with chromosome complexity and that CINSARC and GI are powerful prognostic factors. Data also mean that the metastasis frequency difference between adult and children likely is associated to the genome instability which is highly more frequent in adults. Finally, among these tree signatures, GI is potentially the best overall and clearly the most clinically relevant considering that CGH from FFPE samples is already used in the daily practice of pathology.

Localized angiosarcomas (AS): Identification of prognostic factors (PF) and analysis of treatment impact—Series from the French Sarcoma Group (GSF/GETO)

10018

Background: AS represents less than 2% of all adult soft tissue sarcoma. PF and role of respective (neo)-adjuvant treatments in management of localized AS remain badly established. Methods: We have conducted a retrospective multicentre study (June 1980-October 2009) of 107 patients with localized AS. All cases have been centrally reviewed by pathologist expert. Univariate and multivariate analysis were conducted to identify independent PF. Overall survival (OS) and Local Recurrence Free Survival (LRFS) were estimated using the Kaplan-Meier method. Impact of treatments had been explored with Cox Model after adjustment to the PF. Results: The sex ratio was 18/89 (0.2). Median age was 71 years. 22% (24/107) and 62% (67/107) of patients developed AS in preexisting lymphoedema and in irradiated field, respectively. 71 cases (66%) were superficial. The most frequent primary locations were: limbs (35, 33%), chest wall (32, 29%) and breast (22, 20%). Grade was 1 in 21/103 (20%), 2 in 35/103 (34%) and 3 in 47/103 cases (46%). Treatments consisted in surgery, adjuvant radiotherapy and (neo)-adjuvant chemotherapy in, respectively, 95, 27 and 27 cases. R0 margin was obtained in 49 cases. The median OS and LRFS were, respectively, 38.8 months and 27 months. In multivariate analysis, the following PF influenced the OS: lymphedema (HR=2.02 [1.15-3.55]) and size>5 cm (HR=1.48 [1.01-2.45]). After adjustment to these PF, R0 margins was the sole treatment parameter improving the OS (HR=0.19 [0.05-0.73]). In multivariate analysis, the following PF influence the LRFS: Age>70 (HR=1.68 [1.02-2.76]) and pre-existing lymphedema (HR=2.07 [1.15-3.75]). After adjustment to these prognostic factors, R0 margins (HR=0.48 [0.38-0.69]) and adjuvant radiotherapy (HR=0.29 [0.10-0.83]) improved the LRFS. Conclusions: Pre-existing lymphedema, tumour size and age>70 are the major PF in patients with localized AS. The achievement of R0 margins is of major importance for improving the outcome whatever the endpoint (OS, LRFS) Adjuvant radiotherapy decreased the local recurrence. (Neo)-adjuvant chemotherapy does not influence survivals.

High-dose ifosfamide (HDI) in metastatic synovial sarcoma: The Institut Gustave Roussy experience

10044

Background: Synovial sarcoma (SS) is one of the most chemo-sensitive histological subtypes of sarcoma but with a dismal prognosis. In metastatic setting, Anthracyclin/ifosfamide-containing chemotherapy (CT) regimen is the gold standard of treatment in front-line therapy. Patients (pts) with resistant diseases are candidates to investigational drugs or higher dose ifosfamide regimen in selected pts. Methods: Pts treated in our institution, with histological confirmation of advanced SS, adequate organ function and in good condition (PS≤2) were included in this retrospective analysis. Pts who progressed after 1–2 chemotherapy lines received High-dose ifosfamide (HDI) in the form of 4 g/m2 daily (over 24 hours CI) for 3 days for a total dose of 12 g/m2; cycles were given with growth factor support and were repeated every 3 weeks. The primary endpoints were PFS and overall response rate (ORR); the secondary endpoints OS and toxicity profile. AE were assessed by NCI-CTC v. 3.0. Results: 34 pts (21 males) with a median age of 39 years (range 19-66) received this HDI regimen. PS was 0-1 in 90%. 95% of pts received prior doxorubicin, ifosfamide or both, 7 patients had 2 prior lines. Grade III monophasic pattern was seen in 21 patients, grade II in 13. 171 cycles were delivered, median number of cycles was 4 (2-10). The objective responses were CR 0; PR 15; SD 14; PD 2; and NE 3, resulting in an ORR of 44%. The clinical benefit rate was 85%. Median PFS: 11.6 months (95% CI: 9-14). Eleven pts were amenable to a subsequent resection of residual disease. Common adverse events included grade III/IV neutropenia: 47%, febrile neutropenia: 12%, thrombocytopenia: 12%, cystitis: 3%, neurologic: 3%. There was no treatment related death. Conclusions: HDI demonstrated clinically meaningful efficacy with manageable toxicity in pts who failed previous standard Ifosfamide dose. Ifosfamide remains the most active agents in SS and high dose regimen have to be considered in pts previously treated with ifosfamide.

From PTEN loss of expression to RICTOR role in smooth muscle differentiation: complex involvement of the mTOR pathway in leiomyosarcomas and pleomorphic sarcomas

Over the past decade, comprehensive genomic studies demonstrated that leiomyosarcomas and most of the tumors previously labeled as 'malignant fibrous histiocytomas' share complex karyotypes and genomic profiles, and can be referred to as 'sarcomas with complex genomics'. We recently reported a series of 160 sarcomas with complex genomics such as leiomyosarcomas, myxofibrosarcomas, pleomorphic liposarcomas/rhabdomyosarcomas and undifferentiated pleomorphic sarcomas. These tumors present with a frequent loss of chromosome 10 region encompassing the tumor suppressor gene PTEN. In the present study, we assessed PTEN genomic level and protein expression in this large series of sarcomas with complex genomics, as well as activation of downstream pathways. PTEN partial genomic loss was observed in only 46% of tumors, especially in well-differentiated leiomyosarcomas, whereas up to 68% of these tumors demonstrate a loss of protein expression on western blot analysis. Specific discrepancies in PTEN immunohistochemical results suggested bias in this latter technique. PTEN mutations were rare, with only 4 point mutations in the 65 samples studied. Subsequent activation of AKT and mTOR pathways was only observed in 2 out of 3 of PTEN-deleted tumors. On the other hand, RICTOR, a major component of the mTOR complex 2, was significantly overexpressed in well-differentiated leiomyosarcomas. These results, confirmed on tissue micro-array immunohistochemical analysis of 459 sarcomas, could suggest a link between RICTOR overexpression and leiomyosarcomas oncogenesis. As therapeutics directed against the mTOR pathway are assessed in sarcomas, RICTOR overexpression in sarcomas and its links to therapeutic response need to be assessed.