Guidelines for time-to-event end point definitions in sarcomas and gastrointestinal stromal tumors (GIST) trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†

Predictive Value of a New Muscle Parameter in Patients with Resectable Gastric Cancer: A Pooled Analysis of Three Prospective Trials

BACKGROUND

Sarcopenia is closely associated with gastric cancer (GC) prognosis. However, its exact definition remains controversial.

METHODS

This study included computed tomography images and clinical data of patients from three prospective studies. The skeletal muscle index (SMI) and skeletal muscle radiation attenuation (SMRA) were analyzed, and a new muscle parameter, skeletal muscle gauge (SMG), was obtained by multiplying the two parameters. The values of the three indices for predicting the prognosis of patients with GC were compared.

RESULTS

The study included 717 patients. The findings showed median values of 42 cm2/m2 (range, 36.8-48.2 cm2/m2) for SMI, 45 HU (range, 41-49 HU) for SMRA, and 1842 (range, 1454-2260) for SMG. Postoperatively, 111 patients (15.5%) experienced complications. The 3-year overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) were 74.3%, 68.2%, and 70%, respectively. Univariate logistic analysis showed that postoperative complications were associated with SMI (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.92-0.96), SMRA (OR, 0.87; 95% CI 0.84-0.90), and SMG (OR 0.99; 95% CI 0.98-0.99). After a two-step multivariate analysis, only SMG (OR 0.98, 95% CI 0.97-0.99) was an independent protective factor of postoperative complications. Multivariate analysis showed that SMG also was an independent protective factor of OS, DFS, and RFS. The patients were divided into low-SMG (L-SMG) group and high-SMG (H-SMG) groups. Chemotherapy benefit analysis of the patients with stage II low SMG showed that the OS, DFS, and RFS of the chemotherapy group were significantly better than those of the non-chemotherapy group (p < 0.05).

CONCLUSION

The prospective large sample data showed that the new muscle parameter, SMG, can effectively predict the short-term outcome and long-term prognosis of patients with resectable gastric cancer. As a new muscle parameter index, SMG is worthy of further study.

Handling missing covariates in observational studies: an illustration with the assessment of prognostic factors of survival outcomes in soft-tissue or visceral sarcomas in irradiated fields (SIF)

Background

Missing covariates are common in observational research and can lead to bias and loss of statistical power. Limited data regarding prognostic factors of survival outcomes of sarcomas in irradiated fields (SIF) are available. Because of the long lag time between irradiation of first cancer and scarcity of SIF, missing data are a critical issue when analyzing long-term outcomes. We assessed prognostic factors of overall (OS), progression-free (PFS), and metastatic-progression-free (MPFS) survivals in SIF using three methods to account for missing covariates.

Methods

We relied on the NETSARC French Sarcoma Group database, Cox (OS/PFS), and competitive hazards (MPFS) survival models. Covariates investigated were age, sex, histological subtype, tumor size, depth and grade, metastasis, surgery, surgical resection, surgeon's expertise, imaging, and neo-adjuvant treatment. We first applied multiple imputation (MI): observed data were used to estimate the missing covariate. With the missing-data modality approach, a category missing was created for qualitative variables. With the complete-case (CC) approach, analysis was restricted to patients without missing covariates.

Results

CC subjects (N = 167; 33%) presented more often with soft-tissue sarcoma (versus visceral sarcoma) and grade I-II tumors as compared to the 504 eligible cases. With MI (N = 504), factors associated with the worst outcome included metastasis (p = 0.04) and R1/R2 resection (p < 0.001) for OS; higher grade/non-gradable tumors (p = 0.002) and R1/R2 resection (p < 0.001) for PFS; and metastasis (p = 0.01) for M-PFS. The 'missing-data modality' approach (N = 504) led to different associations, including significance reached due to variables with the modality 'missing'. The CC analysis led to different results and reduced precision.

Conclusion

The CC population was not representative of the eligible population, introducing bias, in addition to worst precision. The 'missing-data modality method' results in biased estimates in non-randomized studies, as outcomes may be related to variables with missing values. Appropriate statistical methods for missing covariates, for example, MI, should therefore be considered.

Assessing patient-reported outcomes (PROs) and patient-related outcomes in randomized cancer clinical trials for older adults: Results of DATECAN-ELDERLY initiative

As older adults with cancer are underrepresented in randomized clinical trials (RCT), there is limited evidence on which to rely for treatment decisions for this population. Commonly used RCT endpoints for the assessment of treatment efficacy are more often tumor-centered (e.g., progression-free survival). These endpoints may not be as relevant for the older patients who present more often with comorbidities, non-cancer-related deaths, and treatment toxicity. Moreover, their expectation and preferences are likely to differ from younger adults. The DATECAN-ELDERLY initiative combines a broad expertise, in geriatric oncology and clinical research, with interest in cancer RCT that include older patients with cancer. In order to guide researchers and clinicians coordinating cancer RCT involving older patients with cancer, the experts reviewed the literature on relevant domains to assess using patient-reported outcomes (PRO) and patient-related outcomes, as well as available tools related to these domains. Domains considered relevant by the panel of experts when assessing treatment efficacy in RCT for older patients with cancer included functional autonomy, cognition, depression and nutrition. These were based on published guidelines from international societies and from regulatory authorities as well as minimum datasets recommended to collect in RCT including older adults with cancer. In addition, health-related quality of life, patients' symptoms, and satisfaction were also considered by the panel. With regards to tools for the assessment of these domains, we highlighted that each tool has its own strengths and limitations, and very few had been validated in older adults with cancer. Further studies are thus needed to validate these tools in this specific population and define the minimum clinically important difference to use when developing RCTs in this population. The selection of the most relevant tool should thus be guided by the RCT research question, together with the specific properties of the tool.

Progression-free survival, disease-free survival and other composite end points in oncology: improved reporting is needed

Composite outcome measures such as progression-free survival and disease-free survival are increasingly used as surrogate end points in oncology research, frequently serving as the primary end point of pivotal trials that form the basis for FDA and EMA approvals. Such outcome measures combine two or more distinct events (for example, tumour (re)growth, new lesions and/or death) into a single, time-to-event end point. The use of a composite end point can increase the statistical power of a clinical trial and decrease the follow-up period required to demonstrate efficacy, thus lowering costs; however, these end points have a number of limitations. Composite outcomes are often vaguely defined, with definitions that vary greatly between studies, complicating comparisons of results across trials. Altering the makeup of events included in a composite outcome can alter study conclusions, including whether treatment effects are statistically significant. Moreover, the events included in a composite outcome often vary in clinical significance, reflect distinct biological pathways and/or are affected differently by treatment. Therefore, knowing the precise breakdown of the component events is essential to accurately interpret trial results and gauge the true benefit of an intervention. In oncology clinical trials, however, such information is rarely provided. In this Perspective, we emphasize this deficiency through a review of 50 studies with progression-free survival as an outcome published in five top oncology journals, discuss the advantages and challenges of using composite end points, and highlight the need for transparent reporting of the component events.

Consensus Guidelines for the Definition of Time-to-Event End Points in Image-guided Tumor Ablation: Results of the SIO and DATECAN Initiative

There is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue.

Conditional copula models for correlated survival endpoints: Individual patient data meta-analysis of randomized controlled trials

Correlations among survival endpoints are important for exploring surrogate endpoints of the true endpoint. With a valid surrogate endpoint tightly correlated with the true endpoint, the efficacy of a new drug/treatment can be measurable on it. However, the existing methods for measuring correlation between two endpoints impose an invalid assumption: correlation structure is constant across different treatment arms. In this article, we reconsider the definition of Kendall's concordance measure (tau) in the context of individual patient data meta-analyses of randomized controlled trials. According to our new definition of Kendall's tau, its value depends on the treatment arms. We then suggest extending the existing copula (and frailty) models so that their Kendall's tau can vary across treatment arms. Our newly proposed model, a joint frailty-conditional copula model, is the implementation of the new definition of Kendall's tau in meta-analyses. In order to facilitate our approach, we develop an original R function condCox.reg(.) and make it available in the R package joint.Cox (https://CRAN.R-project.org/package=joint.Cox). We apply the proposed method to a gastric cancer dataset (3288 patients in 14 randomized trials from the GASTRIC group). This data analysis concludes that Kendall's tau has different values between the surgical treatment arm and the adjuvant chemotherapy arm (p-value<0.001), whereas disease-free survival remains a valid surrogate at individual level for overall survival in these trials.

MRI Volumetrics and Image Texture Analysis in Assessing Systemic Treatment Response in Extra-Abdominal Desmoid Fibromatosis

Purpose To determine whether MRI volumetric and image texture analysis correlates with treatment-induced biologic changes in desmoid fibromatosis (DF) earlier than conventional response criteria. Materials and Methods This retrospective study included 27 patients with histologically proven extra-abdominal DF who were managed with active surveillance or systemic therapy (from 2004 to 2016). MRI volumetric and image texture parameters were derived from manual tumor segmentations, and tumor signal intensity was normalized to muscle. Results were compared with objective response rates based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, World Health Organization (WHO) lesion response, volumetrics, and MRI-modified Choi criteria. Correlation coefficients (r) between image texture features and maximum tumor diameters were obtained by using a meta-analysis approach. Results The 27 included patients (mean age, 39 years; 74% women) were followed for an average of 4 years, comprising 207 distinct time-point assessments. The mean baseline tumor maximum diameter was 7.9 cm (range, 3.4-15.2 cm). Partial response (PR) rates as best response were 37%, 44%, 70%, and 81% by RECIST, WHO, volumetrics, and MRI-modified Choi criteria, respectively. Among the 10 tumors showing RECIST PR, a preceding MRI-modified Choi PR was observed in 70% (seven of 10), on average 1.3 years earlier. Multiple image texture parameters showed associations with objective measurements of tumor diameter including mean tumor-to-muscle signal ratio (r = 0.51; P = .004), median tumor-to-muscle signal ratio (r = 0.52; P = .003), energy (r = 0.48; P < .001), run entropy (r = 0.32, P = .04), and gray-level nonuniformity (r = 0.54; P ≤ .001). Conclusion Volumetric signal and image texture assessment allows more comprehensive analysis of DF biologic change and may permit early prediction of DF behavior and therapeutic response. Keywords: MR Imaging, Soft Tissues/Skin, Neoplasms-Primary © RSNA, 2021.

Systematic review of phase-I/II trials enrolling refractory and recurrent Ewing sarcoma: Actual knowledge and future directions to optimize the research

BACKGROUND

Optimal Phase-II design to evaluate new therapies in refractory/relapsed Ewing sarcomas (ES) remains imperfectly defined.

OBJECTIVES

Recurrent/refractory ES phase-I/II trials analysis to improve trials design.

METHODS

Comprehensive review of therapeutic trials registered on five databases (who.int/trialsearch, clinicaltrials.gov, clinicaltrialsregister.eu, e-cancer.fr, and umin.ac.jp) and/or published in PubMed/ASCO/ESMO websites, between 2005 and 2018, using the criterion: (Ewing sarcoma OR bone sarcoma OR sarcoma) AND (Phase-I or Phase-II).

RESULTS

The 146 trials identified (77 phase-I/II, 67 phase-II, and 2 phase-II/III) tested targeted (34%), chemo- (23%), immune therapies (19%), or combined therapies (24%). Twenty-three trials were ES specific and 48 had a specific ES stratum. Usually multicentric (88%), few trials were international (30%). Inclusion criteria cover the recurrent ES age range for only 12% of trials and allowed only accrual of measurable diseases (RECIST criteria). Single-arm design was the most frequent (88%) testing mainly single drugs (61%), only 5% were randomized. Primary efficacy outcome was response rate (RR=CR+PR; Complete+Partial response) (n = 116/146; 79%), rarely progression-free or overall survival (16% PFS and 3% OS). H0 and H1 hypotheses were variable (3%-25% and 20%-50%, respectively). The 62 published trials enrolled 827 ES patients. RR was poor (10%; 15 CR=1.7%, 68 PR=8.3%). Stable disease was the best response for 186 patients (25%). Median PFS/OS was of 1.9 (range 1.3-14.7) and 7.6 months (5-30), respectively. Eleven (18%) published trials were considered positive, with median RR/PFS/OS of 15% (7%-30%), 4.5 (1.3-10), and 16.6 months (6.9-30), respectively.

CONCLUSION

This review supports the need to develop the international randomized phase-II trials across all age ranges with PFS as primary endpoint.

CXCR3 from chemokine receptor family correlates with immune infiltration and predicts poor survival in osteosarcoma

Background: Chemokine receptors have a crucial role in regulating tumor mediating immunity and are also implicated in the prognosis of some cancers. Here, the association between CXC chemokine receptors (CXCR2–5) and prognosis in osteosarcoma was studied.

Methods: Differences between CXCR2, CXCR3, CXCR4, and CXCR5 expression and overall survival (OS) and event-free survival (EFS) were compared using Kaplan–Meier analyses. The associations of CXCR3 expression with clinical features and the prognosis were also analyzed. The signaling pathways modulated by CXCR3 were investigated. The correlations between CXCR3 and immune infiltrates were investigated.

Results: The expression of CXCR2, CXCR4, and CXCR5 was not associated with the prognosis, but CXCR3 low expression was correlated with worse OS and EFS of osteosarcoma, especially for female, patients aged less than 15.1 years, or patients without metastasis. Low CXCR3 expression was related to tumor site and histologic response (P<0.05), but not associated with other clinical characteristics. Multivariate Cox analysis revealed that CXCR3 remained independently associated with the prognosis, especially for OS (hazard ratio (HR) = 3.26, 95% CI = 1.15–9.24, P=0.026). The cell adhesion, apoptosis, metabolism, KRAS, P53, NOTCH, reactive oxygen species (ROS), PI3K/Akt/mTOR, vascular endothelial growth factor (VEGF), inflammation, and immune-related pathways such as IL-6/JAK/STAT3, TNF-α via NF-κB, Toll/NOD-like receptor, and complement were modulated by CXCR3. CXCR3 expression showed an especially positive correlation with immune infiltration of T cells CD8, macrophages M1, plasma cells, and NK cells activated.

Conclusions: CXCR3 may be an independent risk factor for the prognosis and is most likely to benefit from immunotherapy in osteosarcoma.

Impact of Non-Steroidal Anti-Inflammatory Drugs on Recurrence and Survival after Melanoma Surgery: A Cohort Study

The aim of the study was to investigate if there was an association between intraoperative NSAID use and recurrence or survival. A cohort of patients who underwent sentinel lymph node biopsy for the treatment of cutaneous melanoma was retrospectively recruited. After applying inclusion and exclusion criteria, 516 were included (NSAIDs = 307). The 10-year melanoma-specific survival was 63.2%. Log-rank test showed no statistically significant differences in time to treatment failure, melanoma-specific survival, disease-free survival, and overall survival between the study groups. The current study did not support the use of intraoperative NSAIDs in preventing death or recurrence in patients with melanoma.

Value of peri-operative chemotherapy in patients with CINSARC high-risk localized grade 1 or 2 soft tissue sarcoma: study protocol of the target selection phase III CHIC-STS trial

BACKGROUND

The value of chemotherapy in soft tissue sarcoma (STS) remains controversial. Several expert teams consider that chemotherapy provides a survival advantage and should be proposed in high-risk (HR) patients. However, the lack of accuracy in identifying HR patients with conventional risk factors (large, deep, FNCLCC grade 3, extremity STS) is an issue that cannot be neglected. For example, while the FNCLCC grading system is a powerful tool, it has several limitations. CINSARC, a 67-gene signature, has proved to be an additional independent factor for predicting metastatic spread and outperforms histological grade. Regardless of FNCLCC grade, CINSARC stratifies patients into two separate prognostic groups: one with an excellent prognosis (low-risk (LR) CINSARC) and the other with a worse outcome (HR-CINSARC) in terms of metastatic relapse. Here we evaluate the role of chemotherapy in grade 1-2 STS patients with HR-CINSARC and assess the prognostic value of CINSARC in patients treated with standard of care.

METHODS

CHIC is a parallel, randomized, open-label, multicenter study evaluating the effect on metastasis-free survival of adding perioperative chemotherapy to standard of care in patients with grade ½ STS sarcoma defined as HR by CINSARC. In this target selection design, 600 patients will be screened with CINSARC to randomize 250 HR-CINSARC patients between standard of care and standard of care plus chemotherapy (4 cycles of 3 weeks of intravenous chemotherapy with doxorubicin in combination with dacarbazine or ifosfamide according to histologic subtype). LR-CINSARC patients will be treated by standard of care according to the investigator. The primary endpoint is metastasis-free survival. Secondary endpoints include overall survival, disease-free survival and safety. Furthermore, the prognostic value of CINSARC will be evaluated by comparing LR-CINSARC patients to HR-CINSARC patients randomized in standard of care.

DISCUSSION

CHIC is a prospective randomized phase III trial designed to comprehensively evaluate the benefit of chemotherapy in HR-CINSARC patients and to prospectively validate the prognostic value of CINSARC in grade ½ STS sarcoma patients.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04307277 Date of registration: 13 March 2020.

Blood eosinophilic relative count is prognostic for breast cancer and associated with the presence of tumor at diagnosis and at time of relapse

Background

Cancer outcome is associated with circulating immune cells, including eosinophils. Here we analyze the relative eosinophil count (REC) in different breast cancer subtypes.

Methods

Stage I–III breast cancer patients were included in the study and classified as REC-high vs low (cutoff 1.5%) or relative lymphocyte count (RLC)-high vs low (cutoff 17.5%). The co-primary endpoints were the breast cancer-specific survival (BCSS) or the time to treatment failure (TTF) in the REC groups.

Results

Overall 930 patients were included in the study. We observed a benefit for REC-high vs REC-low in TTF (HR 0.610, 95% CI 0.458–0.812), and in BCSS (HR 0.632, 95% CI 0.433–0.923). Similarly, we observed a better TTF (HR 0.421, 95% CI 0.262–0.677) and BCSS (HR 0.350, 95% CI 0.200–0.614) in RLC-high vs low. A lower relapse rate was observed in the REC-high vs REC-low group (17.1% vs 24.7%, p = 0.005), not confirmed in the multivariate analysis. A lower median REC at baseline and at relapse was observed compared to REC after surgery and during cancer-free follow-up (p < .0001).

Conclusions

REC could be a new promising, affordable and accessible predictive and prognostic biomarker in all breast cancer subtypes.

Clinical outcomes of head and neck adenoid cystic carcinoma patients treated with pencil beam-scanning proton therapy

OBJECTIVE

The aim of this study was to evaluate the outcome of patients with head and neck adenoid cystic carcinoma (ACC) treated using pencil beam scanning proton therapy (PBS PT) at our institution.

MATERIALS AND METHODS

Thirty-five patients who underwent treatment with PBS PT for ACC between 2001 and 2017 were included. Local control (LC), distant control (DC), progression-free survival (PFS), overall survival (OS) and their prognostic factors were evaluated. Adverse effects were prospectively assessed.

RESULTS

The median patient follow-up was 30 months. Prior to PT, 26 patients (74.3%) underwent surgery with R0/R1/R2 outcome in 5, 13 and 8 cases, respectively. Nine patients (25.7%) presented with inoperable disease. The 2-year LC, DC, PFS and OS was 92.2%, 77.8%, 74.3% and 88.8%, respectively. LC was influenced by patient age (p = 0.002) with a significant difference between local and distant failure (median 61.3 vs. 42.3 years, p = 0.005). Tumor T stage was a significant risk factor for PFS (p = 0.045) and tumor prognostic group affected OS (p = 0.049). No significant survival advantage for operable vs. inoperable disease could be identified. The acute and late grade 3 toxicity rates were 14.3% and 6.1%, respectively. No acute or late grade 4/5 toxicities were observed.

CONCLUSIONS

PBS PT is an effective and safe treatment for patients with head & neck ACC in both definitive and adjuvant setting. Distant metastases are the main pattern of failure. Age, tumor stage and clinical stage had a significant negative impact on LC, OS and PFS.

Postoperative Radiation Therapy in Patients with Extracranial Chondrosarcoma: A Joint Study of the French Sarcoma Group and Rare Cancer Network

PURPOSE

Postoperative radiation therapy (poRT) of intracranial/skull base chondrosarcomas (CHSs) is standard treatment. However, consensus is lacking for poRT in extracranial CHS (eCHS) owing to their easier resectability and intrinsic radioresistance. We assessed the practice and efficacy of poRT in eCHS.

METHODS AND MATERIALS

This multicentric retrospective study of the French Sarcoma Group/Rare Cancer Network included patients with eCHS who were operated on between 1985 and 2015. Inverse propensity score weighting (IPTW) was used to minimize poRT allocation biases.

RESULTS

Of 182 patients, 60.4% had bone and 39.6% had soft-tissue eCHS. eCHS were of conventional (31.9%), myxoid (28.6%; 41 extraskeletal, 11 skeletal), mesenchymal (9.9%), or other subtypes. En-bloc surgery with complete resection was performed in 52.6% and poRT in 36.8% of patients (median dose, 54 Gy). Irradiated patients had unfavorable initial characteristics, with higher grade and incomplete resection. Median follow-up time was 61 months. Five-year incidence of local relapse was 10% with poRT versus 21.6% without (P = .050). Using the IPTW method, poRT reduced the local relapse risk (hazard ratio, 0.27; 95% confidence interval, 0.14-0.52; P < .001). Five-year disease-free survival (DFS) was 71.8% with poRT and 64.2% without (P = .680). Using the IPTW method, poRT improved DFS (hazard ratio, 0.51; 95% confidence interval, 0.30-0.85; P = .010). The benefit of poRT on local relapse and DFS was confirmed after exclusion of the extraskeletal subtype. There was no difference in overall survival. Prognostic factors of poorer DFS in multivariate analysis were deeper location, higher grade, incomplete resection, and no poRT.

CONCLUSIONS

poRT should be offered in patients with eCHS and high-grade or incomplete resection, regardless of the histologic subtype.

Guidelines for time-to-event end-point definitions in adjuvant randomised trials for patients with localised colon cancer: Results of the DATECAN initiative

BACKGROUND

The variability of definitions for time-to-event (TTE) end-points impacts the conclusions of randomised clinical trials (RCTs). The Definition for the Assessment of Time-to-event Endpoints in CANcer (DATECAN) initiative aims to provide consensus definitions for TTE end-points used in RCTs. Here, we formulate guidelines for adjuvant colon cancer RCTs.

METHODS

We performed a literature review to identify TTE end-points and events included in their definition in RCT publications. Then, a consensus was reached among a panel of international experts, using a formal modified Delphi method, with 2 rounds of questionnaires and an in-person meeting.

RESULTS

Twenty-four experts scored 72 events involved in 6 TTE end-points. Consensus was reached for 24%, 57% and 100% events after the first round, second round and in-person meeting. For RCTs not using overall survival as their primary end-point, the experts recommend using disease-free survival (DFS) rather than recurrence-free survival (RFS) or time to recurrence (TTR) as the primary end-point. The consensus definition of DFS includes all causes of death, second primary colorectal cancers (CRCs), anastomotic relapse and metastatic relapse as an event, but not second primary non-CRCs. Events included in the RFS definition are the same as for DFS with the exception of second primary CRCs. The consensus definition of TTR includes anastomotic or metastatic relapse, death with evidence of recurrence and death from CC cause.

CONCLUSION

Standardised definitions of TTE end-points ensure the reproducibility of the end-points between RCTs and facilitate cross-trial comparisons. These definitions should be integrated in standard practice for the design, reporting and interpretation of adjuvant CC RCTs.

Para-aortic lymph node surgical staging in locally-advanced cervical cancer: comparison between robotic versus conventional laparoscopy

OBJECTIVE

With the expansion of the use of minimally invasive surgical techniques within the field of gynecological oncology, a robot assisted procedure seems to be an attractive technique for para-aortic lymph node sampling. The aim of this study was to compare robotic versus conventional laparoscopic para-aortic lymphadenectomy in patients with locally advanced cervical cancer.

METHODS

In this monocentric retrospective study, we included patients with locally-advanced cervical cancer (International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB2-IVA or IB1 with suspicious pelvic lymph nodes), who underwent a para-aortic lymphadenectomy up to the inferior mesenteric artery between December 1994 and December 2016 (robotic technique starting from December 2012).

RESULTS

A total of 217 patients were included in the study (robotic, n=55 vs laparoscopic, n=162). When comparing conventional laparoscopic versus robotic para-aortic lymphadenectomy, the median age was 48 versus 49 years and the median body mass index was 24.4 vs 24.7 kg/m², respectively. In the robotic or laparoscopic group, 85% and 83% were squamous carcinomas, respectively. Patients who underwent a robotic procedure had a higher American Society of Anesthesiologists (ASA) score (ASA2: 62% vs 56%, ASA3: 20% vs 2%, p<0.001), more prior major abdominal surgery (18% vs 6%, p=0.016), less estimated blood loss (median, 25 mL vs 62.5 mL, p<0.001), more para-aortic lymph nodes removed (11 vs 6, p<0.001), shorter postoperative stay (1.8 vs 2.3 days, p=0.002), and a higher, but non-significant, rate of metastatic para-aortic lymph nodes (13% vs 5%, p=0.065) compared with the laparoscopic procedure, respectively. There was no difference in complication rates between the two approaches. The most frequent complications were grade I and grade II according to the Clavien Dindo classification. No difference was observed in progression-free survival between robotic and laparoscopic para-aortic lymphadenectomy after 2 years (both groups 66%) (p=0.472). Also, 2 year overall survival was similar between the groups (77% vs 81% for robotic vs conventional laparoscopy group, respectively) (p=0.749).

CONCLUSION

Robotic para-aortic lymphadenectomy in patients with locally-advanced cervical cancer resulted in better perioperative outcomes and similar survival outcomes when compared with a conventional laparoscopic approach.

Durable therapeutic gain despite competing mortality in long-term follow-up of a randomized hyperfractionated radiotherapy trial for locally advanced head and neck cancer

Purpose/objectives

To examine the therapeutic ratio and mortality profile over time in a radiotherapy randomized trial in stage III-IV larynx/pharynx cancer with long-term follow-up.

Materials/methods

From 1988 to 1995, 331 cases were randomized to either hyperfractionated (HF) (58 Gy/40 fractions, twice daily) or conventional (CF) (51 Gy/20 fractions, once daily) radiotherapy. Overall survival (OS), locoregional (LRC), distant control (DC), ≥Grade 3 late toxicity (LT), and relative mortality risk profile over time were compared between both arms.

Results

Median follow-up was 13.6 years. HF had a 10% improved OS at 5-years (40% vs 30%, p = 0.04), but the benefit diminished to 3% at 10-years (21% vs 18%). A trend towards higher LRC with HF remained (5-year: 49% vs 40%; 10-year: 49% vs 39%, p = 0.05). DC rates were unchanged (5-year: 87% vs 85%; 10-year: 87 vs 84%, p = 0.56). LT rates were similar (HF vs CF: 5-year: 9% vs 12%; 10-year: 11% vs 14%, p = 0.27). Multivariable analysis confirmed that HF reduced mortality risk by 31% [HR 0.69 (0.55-0.88), p < 0.01] and locoregional failure risk by 35% [HR 0.65 (0.48-0.89), p < 0.01]. Index cancer mortality (5-year: 46% vs 51%; 10-year: 49% vs 55%) was lower in the HF arm. Competing mortality (mostly smoking-related) was also numerically lower with HF at 5-years (14% vs 19%) but became similar at 10-years (30% vs 28%).

Conclusions

This trial confirms that HF with augmented total dose has a durable 10% effect size on LRC with comparable LT. OS benefit is evident at 5-years (10%) but relative mortality risk profile changes in longer follow-up.

Quality of surgery and surgical reporting for patients with primary gastrointestinal stromal tumours participating in the EORTC STBSG 62024 adjuvant imatinib study

BACKGROUND

EORTC (European Organisation of Research and Treatment of Cancer) 62024 is a phase III randomised trial evaluating adjuvant imatinib in patients with gastrointestinal stromal tumours (GISTs) and no evidence of residual disease after surgery in 908 patients from 11 countries participated. As surgical treatment aspects (tumour rupture and incomplete resection) contribute to the risk of recurrence, the data of primary surgery were reviewed.

METHODS

The surgical record, local pathology report and a surgical questionnaire on details of the operation had to be completed when patients entered the study. Surgeons from 5 countries, covering 8 languages, reviewed the full set of data being available from 793 patients (87.3%).

RESULTS

A known GIST was the reason for surgery in only 58% of the cases, and 12% of the patients were treated as an emergency. The R0-resection rate was 87%. The extent of resection was local excision in 17%, segmental resection in 59%, full-organ resection in 11% and multivisceral resection in 11%, with lymphadenectomy performed in 24% of the patients. Shelling out of the tumour was performed in 9.7%, and the proportion of tumours removed in parts was higher in the endoscopy/laparoscopy group. The incidence of tumour rupture (representing M1) was 9%. The consistency between preoperative and intraoperative findings was 82%. The postoperative complication rate was 7.3%.

CONCLUSION

The standardisation of surgery in this study was inferior. Given the review data, 18% of the patients should not have participated in the trial. Quality of surgery and improperly reported intraoperative details might influence the trial results. A detailed surgical questionnaire filled out by the surgeon is mandatory before entering the patient in an adjuvant trial in GIST.

Trebananib or placebo plus carboplatin and paclitaxel as first-line treatment for advanced ovarian cancer (TRINOVA-3/ENGOT-ov2/GOG-3001): a randomised, double-blind, phase 3 trial

BACKGROUND

Angiopoietin 1 and 2 regulate angiogenesis and vascular remodelling by interacting with the tyrosine kinase receptor Tie2, and inhibition of angiogenesis has shown promise in the treatment of ovarian cancer. We aimed to assess whether trebananib, a peptibody that inhibits binding of angiopoietin 1 and 2 to Tie2, improved progression-free survival when added to carboplatin and paclitaxel as first-line therapy in advanced epithelial ovarian, primary fallopian tube, or peritoneal cancer in a phase 3 clinical trial.

METHODS

TRINOVA-3, a multicentre, multinational, phase 3, double-blind study, was done at 206 investigational sites (hospitals and cancer centres) in 14 countries. Eligible patients were aged 18 years or older with biopsy-confirmed International Federation of Gynecology and Obstetrics (FIGO) stage III to IV epithelial ovarian, primary peritoneal, or fallopian tube cancers, and an ECOG performance status of 0 or 1. Eligible patients were randomly assigned (2:1) using a permuted block method (block size of six patients) to receive six cycles of paclitaxel (175 mg/m²) and carboplatin (area under the serum concentration-time curve 5 or 6) every 3 weeks, plus weekly intravenous trebananib 15 mg/kg or placebo. Maintenance therapy with trebananib or placebo continued for up to 18 additional months. The primary endpoint was progression-free survival, as assessed by the investigators, in the intention-to-treat population. Safety analyses included patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT01493505, and is complete.

FINDINGS

Between Jan 30, 2012, and Feb 25, 2014, 1164 patients were screened and 1015 eligible patients were randomly allocated to treatment (678 to trebananib and 337 to placebo). After a median follow-up of 27·4 months (IQR 17·7-34·2), 626 patients had progression-free survival events (405 [60%] of 678 in the trebananib group and 221 [66%] of 337 in the placebo group). Median progression-free survival did not differ between the trebananib group (15·9 months [15·0-17·6]) and the placebo group (15·0 months [12·6-16·1]) groups (hazard ratio 0·93 [95% CI 0·79-1·09]; p=0·36). 512 (76%) of 675 patients in the trebananib group and 237 (71%) of 336 in the placebo group had grade 3 or worse treatment-emergent adverse events; of which the most common events were neutropenia (trebananib 238 [35%] vs placebo 126 [38%]) anaemia (76 [11%] vs 40 [12%]), and leucopenia (81 [12%] vs 35 [10%]). 269 (40%) patients in the trebananib group and 104 (31%) in the placebo group had serious adverse events. Two fatal adverse events in the trebananib group were considered related to trebananib, paclitaxel, and carboplatin (lung infection and neutropenic colitis); two were considered to be related to paclitaxel and carboplatin (general physical health deterioration and platelet count decreased). No treatment-related fatal adverse events occurred in the placebo group.

INTERPRETATION

Trebananib plus carboplatin and paclitaxel did not improve progression-free survival as first-line treatment for advanced ovarian cancer. The combination of trebananib plus carboplatin and paclitaxel did not produce new safety signals. These results show that trebananib in combination with carboplatin and paclitaxel is minimally effective in this patient population.

FUNDING

Amgen.

Prognostic value of ALDH1 and Nestin in advanced cancer: a systematic meta-analysis with trial sequential analysis

Background

Novel prognostic markers and therapeutic targets for advanced cancer are urgently needed. This report with trial sequential analysis (TSA) was first conducted to provide robust estimates of the correlation between aldehyde dehydrogenase 1 (ALDH1) and Nestin and clinical outcomes of advanced cancer patients.

Methods

Hazard ratios (HRs) with 95% confidence intervals (CIs) were summarized for overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), relapse/recurrence-free survival (RFS), and metastasis-free survival (MFS) from multivariable analysis. TSA was performed to control for random errors.

Results

A total of 20 studies with 2050 patients (ALDH1: 15 studies with 1557 patients and Nestin: 5 studies with 493 patients) were identified. ALDH1 (HR = 2.28, p < 0.001) and Nestin (HR = 2.39, p < 0.001) were associated with a worse OS, as confirmed by TSA. Nestin positivity was linked to a poor PFS (HR = 2.08, p < 0.001), but ALDH1 was not linked to DFS, RFS, MFS, or PFS, and TSA showed that more studies were needed. Subgroup analysis by tumor type indicated that ALDH1 positivity may be associated with shorter OS in breast, head and neck cancers, but there was no association with colorectal cancer. Subgroup analysis by study source showed that ALDH1 positivity was correlated with a worse OS for Japanese (HR = 1.94, p = 0.002) and European patients (HR = 4.15, p < 0.001), but there was no association for Chinese patients. Subgroup analysis by survival rate showed that ALDH1 positivity correlated with poor OS at ⩾ 5 years (HR = 2.33, p < 0.001) or 10 years (HR = 1.76, p = 0.038).

Conclusions

ALDH1 may be more valuable as an effective therapeutic target than Nestin for improving the long-term survival rate of advanced cancer. Additional prospective clinical trials are needed across different cancer types.

A Systematic Review and Recommendation for Reporting of Surrogate Endpoint Evaluation Using Meta-analyses

Background

Meta-analysis of randomized controlled trials (RCTs) has been widely conducted for the evaluation of surrogate endpoints in oncology, but little attention has been given to the adequacy of reporting and interpretation. This review evaluated the reporting quality of published meta-analyses on surrogacy evaluation and developed recommendations for future reporting.

Methods

We searched PubMed through August 2017 to identify studies that evaluated surrogate endpoints using the meta-analyses of RCTs in oncology. Both individual patient data (IPD) and aggregate data (AD) meta-analyses were included for the review.

Results

Eighty meta-analyses were identified: 22 used IPD and 58 used AD from multiple RCTs. We observed variability and reporting deficiencies in both IPD and AD meta-analyses, especially on reporting of trial selection, endpoint definition, study and patient characteristics for included RCTs, and important statistical methods and results. Based on these findings, we proposed a checklist and recommendations to improve completeness, consistency, and transparency of reports of meta-analytic surrogacy evaluation. We highlighted key aspects of the design and analysis of surrogate endpoints and presented explanations and rationale why these items should be clearly reported in surrogacy evaluation.

Conclusions

Our reporting of surrogate endpoint evaluation using meta-analyses (ReSEEM) guidelines and recommendations will improve the quality in reporting and facilitate the interpretation and reproducibility of meta-analytic surrogacy evaluation. Also, they should help promote greater methodological consistency and could also serve as an evaluation tool in the peer review process for assessing surrogacy research.

Efficacy and safety of regorafenib in adult patients with metastatic osteosarcoma: a non-comparative, randomised, double-blind, placebo-controlled, phase 2 study

BACKGROUND

Regorafenib has proven activity in patients with pretreated gastrointestinal stromal tumours and colorectal and hepatocellular carcinoma. We designed REGOBONE to assess the efficacy and safety of regorafenib for patients with progressive metastatic osteosarcoma and other bone sarcomas. This trial comprised four parallel independent cohorts: osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma. In this Article, we report the results of the osteosarcoma cohort.

METHODS

In this non-comparative, double-blind, placebo-controlled, phase 2 trial, patients aged 10 years or older with histologically confirmed osteosarcoma whose disease had progressed after treatment with one to two previous lines of chemotherapy for metastatic disease and an Eastern Cooperative Oncology Group performance status of 0 or 1 were enrolled. Patients were randomly assigned (2:1) to receive either oral regorafenib (160 mg/day, for 21 of 28 days) or matching placebo. Patients in both groups also received best supportive care. Randomisation was done using a web-based system and was stratified (permuted block) by age at inclusion (<18 vs ≥18 years old). Investigators and patients were masked to treatment allocation. Patients in the placebo group, after centrally confirmed progressive disease, could cross over to receive regorafenib. The primary endpoint was the proportion of patients without disease progression at 8 weeks. Analyses were done by modified intention to treat (ie, patients without any major entry criteria violation who initiated masked study drug treatment were included). All participants who received at least one dose of study drug were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT02389244, and the results presented here are the final analysis of the osteosarcoma cohort (others cohorts are ongoing).

FINDINGS

Between Oct 10, 2014, and April 4, 2017, 43 adult patients were enrolled from 13 French comprehensive cancer centres. All patients received at least one dose of assigned treatment and were evaluable for safety; five patients were excluded for major protocol violations (two in the placebo group and three in the regorafenib group), leaving 38 patients who were evaluable for efficacy (12 in the placebo group and 26 in the regorafenib group). 17 of 26 patients (65%; one-sided 95% CI 47%) in the regorafenib group were non-progressive at 8 weeks compared with no patients in the placebo group. Ten patients in the placebo group crossed over to receive open-label regorafenib after centrally confirmed disease progression. 13 treatment-related serious adverse events occurred in seven (24%) of 29 patients in the regorafenib group versus none of 14 patients in the placebo group. The most common grade 3 or worse treatment-related adverse events during the double-blind period of treatment included hypertension (in seven [24%] of 29 patients in the regorafenib group vs none in the placebo group), hand-foot skin reaction (three [10%] vs none), fatigue (three [10%] vs one [3%]), hypophosphataemia (three [10%] vs none), and chest pain (three [10%] vs none). No treatment-related deaths occurred.

INTERPRETATION

Regorafenib demonstrated clinically meaningful antitumour activity in adult patients with recurrent, progressive, metastatic osteosarcoma after failure of conventional chemotherapy, with a positive effect on delaying disease progression. Regorafenib should be further evaluated in the setting of advanced disease as well as potentially earlier in the disease course for patients at high risk of relapse. Regorafenib might have an important therapeutic role as an agent complementary to standard cytotoxic chemotherapy in the therapeutic armamentarium against osteosarcoma.

FUNDING

Bayer HealthCare.

Retrospective evaluation of toceranib phosphate (Palladia®) use in the treatment of gastrointestinal stromal tumors of dogs

Background

Gastrointestinal stromal tumors (GISTs) are uncommon intestinal neoplasms in the dog. Literature regarding adjunctive therapy for GISTs in dogs is sparse. High‐risk GISTs in humans respond to tyrosine kinase inhibition in the adjuvant setting.

Objectives

To review cases of toceranib phosphate use in dogs with GISTs and provide initial assessment of possible biological activity. A secondary aim was to evaluate patient and tumor characteristics for possible prognostic value.

Animals

Twenty‐seven dogs with confirmed GISTs based on histopathology and immunohistochemistry treated with toceranib.

Methods

Retrospective study in which cases of toceranib use in dogs with GIST were solicited using the American College of Veterinary Internal Medicine Oncology and Small Animal Internal Medicine listservs.

Results

Five of 7 dogs with gross disease experienced clinical benefit (71%; 3 complete responses, 1 partial response, 1 stable disease). These included 2 dogs with durable responses after toceranib discontinuation. Median progression‐free interval (PFI) in dogs with gross disease was 110 weeks (range, 36‐155 weeks). Median PFI in dogs with microscopic disease was 67 weeks (range, 9‐257 weeks). Metastasis at diagnosis (P = 0.04) and high mitotic index (P < 0.001) were associated with shorter PFI in toceranib‐treated dogs.

Conclusions and Clinical Importance

Biological activity of toceranib is evident in dogs with gross disease. Metastasis of GIST at diagnosis, as well as high tumor mitotic index, was associated with shorter PFI in toceranib‐treated dogs. Larger studies are needed to define postsurgical risk and refine the use of toceranib in dogs with gross and microscopic GIST.

Surrogate endpoints in advanced sarcoma trials: a meta-analysis

Background

Alternative endpoints to overall survival (OS) are frequently used to assess treatment efficacy in randomized controlled trials (RCT). Their properties in terms of surrogate outcomes for OS need to be assessed. We evaluated the surrogate properties of progression-free survival (PFS), time-to-progression (TTP) and time-to-treatment failure (TTF) in advanced soft tissue sarcomas (STS).

Results

A total of 21 trials originally met the selection criteria and 14 RCTs (N = 2846) were included in the analysis. Individual-level associations were moderate (highest for 12-month PFS: Spearman’s rho = 0.66; 95% CI [0.63; 0.68]). Trial-level associations were ranked as low for the three endpoints as per the IQWiG criterion.

Materials and Methods

We performed a meta-analysis using individual-patient data (IPD). Phase II/III RCTs evaluating therapies for adults with advanced STS were eligible. We estimated the individual- and the trial-level associations between then candidate surrogates and OS. Statistical methods included weighted linear regression and the two-stage model introduced by Buyse and Burzykowski. The strength of the trial-level association was ranked according to the German Institute for Quality and Efficiency in Health Care (IQWiG) guidelines.

Conclusions

Our results do not support strong surrogate properties of PFS, TTP and TTF for OS in advanced STS.

Gastrointestinal stromal tumours of stomach: Robot-assisted excision with the da Vinci Surgical System regardless of size and location site

Aims:

The role of minimally invasive surgery of gastrointestinal stromal tumours (GISTs) of the stomach remains uncertain especially for large and/or difficult located tumours. We are hereby presenting a single-centre series of robot-assisted resections using the da Vinci Surgical System (Si or Xi).

Subjects and Methods:

Data of patients undergoing robot-assisted treatment of gastric GIST were retrieved from the prospectively collected institutional database and a retrospective analysis was performed. Patients were stratified according to size and location of the tumour. Difficult cases (DCs) were considered for size if tumour was >50 mm and/or for location if the tumour was Type II, III or IV sec. Privette/Al-Thani classification.

Results:

Between May 2010 and February 2017, 12 consecutive patients underwent robot-assisted treatment of GIST at our institution. DCs were 10/12 cases (83.3%), of which 6/10 (50%) for location, 2/10 (25%) for size and 2/10 (25%) for both. The da Vinci Si was used in 8 patients, of which 6 (75%) were DC, and the da Vinci Xi in 4, all of which (100%) were DC. In all patients, excision was by wedge resection. All lesions had microscopically negative resection margins. There was no conversion to open surgery, no tumour ruptures or spillage and no intraoperative complications.

Conclusion:

Our experience suggests a positive role of the robot da Vinci in getting gastric GIST removal with a conservative approach, regardless of size and location site. Comparative studies with a greater number of patients are necessary for a more robust assessment.

Presentation and outcome of frequent and rare sarcoma histologic subtypes: A study of 10,262 patients with localized visceral/soft tissue sarcoma managed in reference centers

BACKGROUND

The objective of this study was to describe characteristics at diagnosis and outcomes of adults with soft tissue sarcoma.

METHODS

The authors conducted a retrospective multicenter study of 12,262 patients who were treated between January 1980 and 31 December 2013 in French Sarcoma Group centers and enrolled in the "Conticabase." Diagnoses were systematically reviewed by expert pathologists, and entities were classified according to the 2013 World Health Organization classification. Diagnostic characteristics, treatments, and outcomes are described for the entire cohort, for the subgroup of patients with translocation-related sarcomas, and for 9 different histologic subtypes.

RESULTS

The results stressed the magnitude of heterogeneity among adult sarcomas. For example, compared with other sarcomas, translocation-related sarcomas (2143 tumors; 20.8%) were associated with a younger age at presentation (40.6 vs 60.0 years; P < .0001), a low rate of predisposing conditions (0.01% vs 22.3%; P < .0001), a higher rate of lymph node involvement (4.7% vs 1.3%; P < .0001), and a higher rate of synchronous metastasis (11.9% vs 6.7%; P < .001); and complete (R0) resection (41.6% vs 31.9%; P < .0001), receipt of (neo)adjuvant radiation therapy (62.6% vs 42.2%; P < .0001), and receipt of (neo)adjuvant chemotherapy (36.6% vs 22.3%; P < .0001) were significantly more frequent. Overall, translocation-related sarcomas were associated with a lower rate of local relapse (18.1% vs 26.0%; P < .0001) but a higher rate of metastatic relapse (42.0% vs 30.7%; P < .0001).

CONCLUSIONS

Collaborative efforts are urgently needed to better assess the natural history and management options for every histologic subtype of sarcoma. Cancer 2018;124:1179-87. © 2017 American Cancer Society.

Evolution of Randomized Trials in Advanced/Metastatic Soft Tissue Sarcoma: End Point Selection, Surrogacy, and Quality of Reporting

PURPOSE

Randomized controlled trials (RCTs) in soft tissue sarcoma (STS) have used varying end points. The surrogacy of intermediate end points, such as progression-free survival (PFS), response rate (RR), and 3-month and 6-month PFS (3moPFS and 6moPFS) with overall survival (OS), remains unknown. The quality of efficacy and toxicity reporting in these studies is also uncertain.

METHODS

A systematic review of systemic therapy RCTs in STS was performed. Surrogacy between intermediate end points and OS was explored using weighted linear regression for the hazard ratio for OS with the hazard ratio for PFS or the odds ratio for RR, 3moPFS, and 6moPFS. The quality of reporting for efficacy and toxicity was also evaluated.

RESULTS

Fifty-two RCTs published between 1974 and 2014, comprising 9,762 patients, met the inclusion criteria. There were significant correlations between PFS and OS (R = 0.61) and between RR and OS (R = 0.51). Conversely, there were nonsignificant correlations between 3moPFS and 6moPFS with OS. A reduction in the use of RR as the primary end point was observed over time, favoring time-based events (P for trend = .02). In 14% of RCTs, the primary end point was not met, but the study was reported as being positive. Toxicity was comprehensively reported in 47% of RCTs, whereas 14% inadequately reported toxicity.

CONCLUSION

In advanced STS, PFS and RR seem to be appropriate surrogates for OS. There is poor correlation between OS and both 3moPFS and 6moPFS. As such, caution is urged with the use of these as primary end points in randomized STS trials. The quality of toxicity reporting and interpretation of results is suboptimal.

Robot-assisted resection of gastrointestinal stromal tumors (GIST): a single center case series and literature review

BACKGROUND

Robotic techniques are claimed to be an alternative to laparoscopic and open approaches for gastrointestinal stromal tumors (GIST) treatment. Our aim is to present our single center experience and a literature review.

MATERIALS AND METHODS

From June 2012 to August 2014, six patients with preoperative diagnosis of GIST were treated by robotic surgery at Sanchinarro University Hospital.

RESULTS

Two GIST tumors were localized in the second part of the duodenum, one in the first portion, two in the gastricantrum and another in the angular notch. Surgical procedures performed were two subtotal gastrectomies, one gastric wedge resection and three duodenal enucleations. None of the interventions needed conversion to open surgery. Mean operative time was 245 min (150-540). Mean hospital stay was 10.5 days (6-24). All lesions had microscopically negative resection margins. Mean follow-up was 24 months (8-33) with a disease-free survival rate of 100%.

CONCLUSIONS

A robotic approach for GIST tumors is a safe and feasible procedure with a well-accepted oncological surgical result. Copyright © 2015 John Wiley & Sons, Ltd.