Development and validation of a prognostic nomogram for recurrence-free survival after complete surgical resection of localised primary gastrointestinal stromal tumour: a retrospective analysis

Blood neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios are independent prognostic factors for surgically resected gastrointestinal stromal tumors

BACKGROUND

Recent studies have demonstrated that the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are prognostic for various malignancies; however, there are limited data to date demonstrating their usefulness for gastrointestinal stromal tumors (GISTs). The aim of this study was to determine whether NLR and PLR are prognostic for GIST.

METHODS

Three hundred patients who underwent operative resection for primary localized GIST with preoperative results for neutrophil, platelet, and lymphocyte counts available were retrospectively reviewed. Optimal cutoff values for high NLR (≥ 3.0) and PLR (≥ 275) in predicting recurrence-free survival (RFS) were determined. Prognostic factors of RFS were determined using univariate and multivariate Cox regression analyses for the 266 patients who did not receive adjuvant imatinib.

RESULTS

On univariate analyses, tumor size, mitotic count, location, and both a high NLR and PLR were significant prognostic indicators of decreased RFS (hazard ratio [HR], 2.89 [95% CI; 1.609-5.179 P < .001] and HR, 3.572 [95% CI, 2.094-6.096; P < .001], respectively). On multivariate analyses, tumor size, mitotic count, tumor location, and both high NLR and PLR were independent prognostic factors of RFS in GIST. Both a high NLR and PLR were significant prognostic factors for GISTs within the National Institutes of Health (NIH) and Armed Forces Institute of Pathology (AFIP) high-risk categories. Addition of NLR or PLR to the NIH or AFIP improved the accuracy of these systems.

CONCLUSION

High NLR and PLR were independent prognostic factors of RFS in GIST. NLR and PLR would be useful as a preoperative prognostic tool and its incorporation into current prognostication systems improved their accuracy.

Global epidemiology of gastrointestinal stromal tumours (GIST): A systematic review of population-based cohort studies

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are rare, yet the most common mesenchymal tumour within the digestive tract. Lack of diagnostic criteria and no specific code in the ICD system has prevented epidemiological evaluation except from overt malignant cases in the past. A global estimate of incidence and disease patterns has thus not been available.

METHODS

A systematic literature search of all available population-based studies on GIST published between January 2000 and December 2014 were reviewed. Descriptive epidemiological data are presented.

RESULTS

The search found 29 studies of more than 13,550 patients from 19 countries that reported sufficient data for regional or national population-based statistics. Age at diagnosis ranged from 10 to 100 years, with median age being mid 60s across most studies. Gender distribution was equal across studies. On average, 18% of patients had an incidental diagnosis (range from 5% to 40%). Anatomical location of primary tumour in 9747 GISTs demonstrated gastric location as the most frequent (55.6%) followed by small bowel (31.8%), colorectal (6.0%), other/various location (5.5%) and oesophagus (0.7%). Most studies reported incidence at 10-15 per million per year. Notably, lowest incidence was in China (Shanxi province) with 4.3 per million per year. Highest incidence rates were reported also from China (Hong Kong and Shanghai areas), and in Taiwan and Norway (Northern part), with up to 19-22 per million per year.

CONCLUSIONS

Epidemiology of GIST demonstrates some consistent features across geographical regions. Whether the reported extreme differences in incidence reflect real variation in population risk warrants further investigation.

Adjuvant Imatinib for High-Risk GI Stromal Tumor: Analysis of a Randomized Trial

PURPOSE

Three years of adjuvant imatinib therapy are recommended for patients with GI stromal tumor (GIST) with high-risk features, according to survival findings in the Scandinavian Sarcoma Group XVIII/AIO (Arbeitsgemeinschaft Internistische Onkologie) trial. To investigate whether the survival benefits have persisted, we performed the second planned analysis of the trial.

PATIENTS AND METHODS

Eligible patients had macroscopically completely excised, KIT-positive GIST with a high risk of recurrence, as determined by using the modified National Institutes of Health criteria. After surgery, the patients were randomly assigned to receive imatinib for either 1 or 3 years. The primary objective was recurrence-free survival (RFS), and the secondary objectives included survival.

RESULTS

A total of 400 patients were entered onto this open-label study between February 4, 2004, and September 29, 2008. During a median follow-up of 90 months, 171 recurrences and 69 deaths were detected. Patients assigned to the 3-year group had longer RFS than those assigned to the 1- year group; 5-year RFS was 71.1% versus 52.3%, respectively (hazard ratio [HR], 0.60; 95% CI 0.44 to 0.81; P < .001), and survival was 91.9% versus 85.3% (HR, 0.60; 95% CI, 0.37 to 0.97; P = .036). Patients in the 3-year group survived longer in the subset with centrally confirmed GIST and without macroscopic metastases at study entry (93.4% v 86.8%; HR, 0.53; 95% CI, 0.30 to 0.93; P = .024). Similar numbers of cardiac events and second cancers were recorded in the groups.

CONCLUSION

Three years of adjuvant imatinib therapy results in longer survival than 1 year of imatinib. High 5-year survival rates are achievable in patient populations with high-risk GIST.

Population-based SEER trend analysis of overall and cancer-specific survival in 5138 patients with gastrointestinal stromal tumor

BACKGROUND

The objective of the present population-based analysis was to assess survival patterns in patients with resected and metastatic GIST.

METHODS

Patients with histologically proven GIST were extracted from the Surveillance, Epidemiology and End Results (SEER) database from 1998 through 2011. Survival was determined applying Kaplan-Meier-estimates and multivariable Cox-regression analyses. The impact of size and mitotic count on survival was assessed with a generalized receiver-operating characteristic-analysis.

RESULTS

Overall, 5138 patients were included. Median age was 62 years (range: 18-101 years), 47.3% were female, 68.8% Caucasians. GIST location was in the stomach in 58.7% and small bowel in 31.2%. Lymph node and distant metastases were found in 5.1 and 18.0%, respectively. For non-metastatic GIST, three-year overall survival increased from 68.5% (95 % CI: 58.8-79.8%) in 1998 to 88.6% (95 % CI: 85.3-92.0%) in 2008, cancer-specific survival from 75.3% (95 % CI: 66.1-85.9%) in 1998 to 92.2% (95 % CI: 89.4-95.1%) in 2008. For metastatic GIST, three-year overall survival increased from 15.0% (95 % CI: 5.3-42.6%) in 1998 to 54.7% (95 % CI: 44.4-67.3%) in 2008, cancer-specific survival from 15.0% (95 % CI: 5.3-42.6%) in 1998 to 61.9% (95 % CI: 51.4-74.5%) in 2008 (all PTrend < 0.05).

CONCLUSIONS

This is the first SEER trend analysis assessing outcomes in a large cohort of GIST patients over a 11-year time period. The analysis provides compelling evidence of a statistically significant and clinically relevant increase in overall and cancer-specific survival from 1998 to 2008, both for resected as well as metastatic GIST.

SLITRK3 expression correlation to gastrointestinal stromal tumor risk rating and prognosis

AIM: To assess the influence of SLIT and NTRK-like family member 3 (SLITRK3) on the prognosis of gastrointestinal stromal tumor (GIST) and determine whether SLITRK3 can help improve current risk stratification systems.

METHODS: We hypothesized that SLITRK3 could be used as a prognostic molecular biomarker for GIST. 35 fresh tumor samples and 417 paraffin-embedded specimens from GIST patients were utilized. SLITRK3 mRNA expression in GIST tumor tissue was detected by real-time polymerase chain reaction, and SLITRK3 protein levels were estimated by immunohistochemistry. The correlation of SLITRK3 expression with various tumor clinicopathological characteristics and follow-up data were analyzed.

RESULTS: GIST tumors had high expression of SLITRK3 compared with adjacent normal tissues and the expression level gradually increased with risk grade. SLITRK3 protein expression was closely associated with gastrointestinal bleeding, tumor site, tumor size, mitotic index, and National Institutes of Health (NIH) classification. Survival analysis showed that SLITRK3 expression was closely correlated with overall survival and disease-free survival of GIST patients. Multivariate analysis also identified SLITRK3 expression, mitotic index, and NIH stage as significant risk factors of GIST recurrence.

CONCLUSION: SLITRK3 expression is a highly significant predictor of GIST recurrence and metastasis. Combinations of SLITRK3 and NIH stage have strong predictive and prognostic value, and are feasible markers for clinical practice in gastrointestinal stromal tumor.

Survival after resection of perihilar cholangiocarcinoma-development and external validation of a prognostic nomogram

BACKGROUND

The objective of this study was to derive and validate a prognostic nomogram to predict disease-specific survival (DSS) after a curative intent resection of perihilar cholangiocarcinoma (PHC).

PATIENTS AND METHODS

A nomogram was developed from 173 patients treated at Memorial Sloan Kettering Cancer Center (MSKCC), New York, USA. The nomogram was externally validated in 133 patients treated at the Academic Medical Center (AMC), Amsterdam, The Netherlands. Prognostic accuracy was assessed with concordance estimates and calibration, and compared with the American Joint Committee on Cancer (AJCC) staging system. The nomogram will be available as web-based calculator at mskcc.org/nomograms.

RESULTS

For all 306 patients, the median overall survival (OS) was 40 months and the median DSS 41 months. Median follow-up for patients alive at last follow-up was 48 months. Lymph node involvement, resection margin status, and tumor differentiation were independent prognostic factors in the derivation cohort (MSKCC). A nomogram with these prognostic factors had a concordance index of 0.73 compared with 0.66 for the AJCC staging system. In the validation cohort (AMC), the concordance index was 0.72, compared with 0.60 for the AJCC staging system. Calibration was good in the derivation cohort; in the validation cohort patients had a better median DSS than predicted by the model.

CONCLUSIONS

The proposed nomogram to predict DSS after curative intent resection of PHC had a better prognostic accuracy than the AJCC staging system. Calibration was suboptimal because DSS differed between the two institutions. The nomogram can inform patients and physicians, guide shared decision making for adjuvant therapy, and stratify patients in future randomized, controlled trials.

Nomograms in oncology: more than meets the eye

Nomograms are widely used as prognostic devices in oncology and medicine. With the ability to generate an individual probability of a clinical event by integrating diverse prognostic and determinant variables, nomograms meet our desire for biologically and clinically integrated models and fulfill our drive towards personalised medicine. Rapid computation through user-friendly digital interfaces, together with increased accuracy, and more easily understood prognoses compared with conventional staging, allow for seamless incorporation of nomogram-derived prognosis to aid clinical decision making. This has led to the appearance of many nomograms on the internet and in medical journals, and an increase in nomogram use by patients and physicians alike. However, the statistical foundations of nomogram construction, their precise interpretation, and evidence supporting their use are generally misunderstood. This issue is leading to an under-appreciation of the inherent uncertainties regarding nomogram use. We provide a systematic, practical approach to evaluating and comprehending nomogram-derived prognoses, with particular emphasis on clarifying common misconceptions and highlighting limitations.

Gastrointestinal stromal tumors: treatment patterns of a population-based sample

OBJECTIVES

The National Cancer Institute (NCI) annually confirms therapy with treating physicians on a sample of patients diagnosed with a specific cancer.

METHODS

Using the NCI Patterns of Care data, treatment patterns were examined on a population-based sample of patients diagnosed with gastrointestinal stromal tumors (GIST) in 2008.

RESULTS

A random sample of 323 of 405 GIST patients registered in SEER was selected. Most patients had gastric GISTs, were ≥ 65 years, white, had private insurance, and treated in a hospital with a residency program. Surgery was primarily performed in patients with non-metastatic disease (94%), in which: 26, 12, and 36% were at low, intermediate, and high-risk of recurrence, respectively. Amongst low-risk patients, ∼ 30% received adjuvant therapy. Amongst patients at higher risk, 26-40% did not receive adjuvant therapy. Imatinib was the most common targeted therapy administered. On multivariate analysis, age and risk-group were associated with receipt of adjuvant targeted therapy.

CONCLUSIONS

Our study shows that in 2008, the majority of patients diagnosed with GIST received appropriate surgical and adjuvant therapies. However, a considerable subset may have been overtreated and undertreated. Future studies identifying factors that impact the delivery of adjuvant therapy should be conducted.

Conditional disease-free survival after surgical resection of gastrointestinal stromal tumors: a multi-institutional analysis of 502 patients

IMPORTANCE

Gastrointestinal stromal tumors (GISTs) are the most commonly diagnosed mesenchymal tumors of the gastrointestinal tract. The risk of recurrence following surgical resection of GISTs is typically reported from the date of surgery. However, disease-free survival (DFS) over time is dynamic and changes based on disease-free time already accumulated following surgery.

OBJECTIVES

To assess the comparative performance of established GIST recurrence risk prognostic scoring systems and to characterize conditional DFS following surgical resection of GISTs.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of 502 patients who underwent surgery for a primary, nonmetastatic GIST between January 1, 1998, and December 31, 2012, at 7 major academic cancer centers in the United States and Canada.

MAIN OUTCOMES AND MEASURES

Disease-free survival of the patients was classified according to 5 prognostic scoring systems, including the National Institutes of Health criteria, modified National Institutes of Health criteria, Memorial Sloan Kettering Cancer Center GIST nomogram, and American Joint Committee on Cancer gastric and nongastric categories. The concordance index (also known as the C statistic or the area under the receiver operating curve) of established GIST recurrence risk prognostic scoring systems. Conditional DFS estimates were calculated.

RESULTS

Overall 1-year, 3-year, and 5-year DFS following resection of GISTs was 95%, 83%, and 74%, respectively. All the prognostic scoring systems had fair prognostic ability. For all tumor sites, the American Joint Committee on Cancer gastric category demonstrated the best discrimination (C = 0.79). Using conditional DFS, the probability of remaining disease free for an additional 3 years given that a patient was disease free at 1 year, 3 years, and 5 years was 82%, 89%, and 92%, respectively. Patients with the highest initial recurrence risk demonstrated the greatest increase in conditional survival as time elapsed.

CONCLUSIONS AND RELEVANCE

Conditional DFS improves over time following resection of GISTs. This is valuable information about long-term prognosis to communicate to patients who are disease free after a period following surgery.

Expression profile of microRNAs in gastrointestinal stromal tumors revealed by high throughput quantitative RT-PCR microarray

AIM: To investigate the microRNA (miRNA) expression profile in gastrointestinal stromal tumor (GIST) tissues that could serve as a novel diagnostic biomarker for GIST detection.

METHODS: We performed a quantitative real-time quantitative reverse transcriptase polymerase chain reaction assay to analyze the expression of 1888 miRNAs in a sample set that included 54 GIST tissue samples.

RESULTS: We found that dysregulation of several miRNAs may be related to the malignant potential of GISTs. Six of these miRNAs, hsa-let-7c, miR-218, miR-488#, miR-4683, miR-34c-5p and miR-4773, were selected as the final list of biomarkers to separate the malignant GISTs (M group) from the benign GISTs (B group). In addition, MiR-29b-2#, hsa-let-7c, miR-891b, miR-218, miR-204, miR-204-3p, miR-628-5p, miR-744, miR-29c#, miR-625 and miR-196a were used to distinguish between the borderline (BO group) and M groups. There were 11 common miRNAs selected to separate the benign and borderline (BB) group from the M group, including hsa-let-7c, miR-218, miR-628-5p, miR-204-3p, miR-204, miR-891b, miR-488#, miR-145, miR-891a, miR-34c-5p and miR-196a.

CONCLUSION: The identified miRNAs appear to be novel biomarkers to distinguish malignant from benign GISTs, which may be helpful to understand the mechanisms of GIST oncogenesis and progression, and to further elucidate the characteristics of GIST subtypes.

Gastrointestinal Stromal Tumors (GIST): A Prospective Analysis and an Update on Biomarkers and Current Treatment Concepts

Gastrointestinal stromal tumors (GIST) are the most common sarcomas of the gastrointestinal tract, with transformation typically driven by activating mutations of cKIT and less commonly platelet-derived growth factor receptor alpha (PDGFRA). Successful targeting of tyrosine-protein kinase Kit with imatinib, a tyrosine kinase inhibitor, has had a major impact in the survival of patients with GIST in both the adjuvant and metastatic setting. A recent modification of treatment guidelines for patients with localized, high-risk GIST extended the adjuvant treatment duration from 1 year to 3 years. In this paper, we review the clinical data of patients with GIST treated in the Oncology Outpatient Unit of "Attikon" University Hospital and aim to assess which patients are eligible for prolongation of adjuvant imatinib therapy as currently suggested by treatment recommendations.

Re-appraisal of risk classifications for primary gastrointestinal stromal tumors (GISTs) after complete resection: indications for adjuvant therapy

BACKGROUND

A substantial number of localized gastrointestinal stromal tumor (GIST) patients have recurrences even after complete resection. The risk of recurrence after complete resection should be estimated when considering adjuvant therapy. In this study, we evaluated prognostic factors of GIST recurrence and compared several reported risk-stratification schemes for defining risk of recurrence to guide the use of adjuvant therapy using data from a large Japanese GIST population.

METHODS

We analyzed clinicopathological data collected retrospectively and prospectively from 712 GISTs with complete resection from 1980-2010. We evaluated possible prognostic factors and compared the National Institutes of Health consensus criteria, the Armed Forces Institute of Pathology criteria, Joensuu's modified NIH classification (J-NIHC), the American Joint Committee on Cancer staging system (AJCCS), and the Japanese modified NIH criteria for prediction of tumor recurrence in adjuvant settings.

RESULTS

Univariate analysis suggested that the following factors were prognostic: tumor size, mitotic count, site, clinically malignant features of rupture and/or invasion, and gender. In multivariate analysis, size >5 cm, mitotic count >5/50 HPF, non-gastric location, and the presence of rupture and/or macroscopic invasion were independent adverse prognostic factors. When adjuvant therapy is considered for patients with high-risk GIST, the J-NIHC was the most sensitive classification system, while the AJCCS appeared to be the most accurate for predicting recurrence.

CONCLUSION

Tumor size, mitotic count, tumor site, and clinical features of rupture and/or invasion were important prognostic factors for GIST recurrence. Joensuu's classification appeared to best identify candidates for adjuvant therapy.

Practical aspects of risk assessment in gastrointestinal stromal tumors

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract, which are characterized in the majority of cases by activating mutations in KIT and platelet-derived growth factor receptor alpha (PDGFRA). The introduction of tyrosine kinase inhibitors has revolutionized the management of patients with metastatic GIST. However, complete surgical resection remains the mainstay of management for those with localized disease. Recently, three large trials have confirmed the benefit of adjuvant imatinib therapy in patients who were at high risk of recurrence following complete resection. In this setting, it is critical that oncologists understand the various GIST risk assessment criteria and be able to apply these methods to accurately assess the risk of recurrence and the need for adjuvant imatinib therapy.

PURPOSE

The aim of this review is to outline the risk stratification systems currently available to oncologists who are treating patients with GIST, so they can be optimally applied for clinical decision-making.

Development and external validation of a prognostic nomogram for metastatic uveal melanoma

Background

Approximately 50% of patients with uveal melanoma (UM) will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM) is generally poor and no standard therapy has been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians.

Patients and Methods

Two cohorts of mUM patients, from Veneto Oncology Institute (IOV) (N=152) and Mayo Clinic (MC) (N=102), were analyzed to develop and externally validate, a prognostic nomogram.

Results

The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6), elevated levels of serum LDH (HR 1.6), and a WHO performance status=1 (HR 1.5) or 2–3 (HR 4.6) were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9). The nomogram had a concordance probability of 0.75 (SE .006) in the development dataset (IOV), and 0.80 (SE .009) in the external validation (MC). Nomogram predictions were well calibrated.

Conclusions

The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials.

Prognostic Factors of Patients with Gastric Gastrointestinal Stromal Tumor after Curative Resection: A Retrospective Analysis of 406 Consecutive Cases in a Multicenter Study

BACKGROUND/PURPOSE

Gastric gastrointestinal stromal tumors (GISTs) have a highly variable clinical course, and recurrent disease sometimes develops despite curative surgery. This study was undertaken to investigate the surgical role in treating gastric GISTs and evaluate the clinicopathological features of a large series of patients who underwent curative resection for gastric GISTs to clarify which features were independent prognostic factors.

METHODS

The clinicopathological data of 406 patients with gastric GISTs who underwent curative resection at 4 university hospitals in Daegu, South Korea, from March 1998 to March 2012 were reviewed. All cases were confirmed as gastric GISTs by immunohistochemical staining, in which CD117 or CD34 was positive. Clinical follow-up was performed periodically, and disease-free survival rates were retrospectively investigated using the medical records.

RESULTS

The mean follow-up period was 42.9 months (range: 2-166). There were 11 recurrent patients (2.7%). Due to the small number of recurrences, age, sex and location were controlled using propensity score matching before performing any statistical analysis. Tumor size, mitotic count, NIH classification, and cellularity were judged to be independent prognostic factors for recurrence by univariate analysis. In a multivariate analysis, tumor size and mitotic count were significantly and independently related to recurrence, and tumor size was determined to be the most important prognostic factor for recurrence after curative resection (hazard ratio: 1.204; p < 0.01).

CONCLUSIONS

The results of this multicenter study demonstrate that disease-free survival rates are good. Tumor size was disclosed as the most important factor for recurrence in gastric GIST patients who underwent radical resection.

Cyclin-Dependent Kinase Activity Correlates with the Prognosis of Patients Who Have Gastrointestinal Stromal Tumors

BACKGROUND

The estimation of recurrence risk remains a critical issue in relation to gastrointestinal stromal tumors (GISTs) treated with adjuvant therapy. The accuracy of the commonly used risk stratifications is not always adequate.

METHODS

For this study, data were prospectively collected from 68 patients with GISTs who underwent R0 surgery between 2004 and 2009. The results from this analysis cohort were evaluated using the data obtained from an additional 40 patients in the validation cohort. Cyclin-dependent kinase 1 (CDK1)- and CDK2-specific activities were measured using a non-RI kinase assay system.

RESULTS

The specific activities of CDK1 and CDK2, but not their expression, significantly correlated with recurrence. The specific activities of both CDK1 and CDK2 were independently correlated with mitosis and significantly correlated with recurrence-free survival (RFS). In the multivariate analysis, CDK2-specific activity (P = 0.0006), tumor size (P = 0.0347), and KIT deletion mutations (P = 0.0006) were significantly correlated with RFS in the analysis cohort. In the validation cohort, CDK2-specific activity (P = 0.0368) was identified as an independent prognostic factor for tumor recurrences with tumor location (P = 0.0442).

CONCLUSION

The results suggest that the specific activities of CDK1 and CDK2 may reflect the proliferative activity of GISTs and that CDK2-specific activity is a good prognostic factor predicting recurrence after macroscopic complete resection of GISTs.

Lessons learned from the study of 10,000 patients with soft tissue sarcoma

BACKGROUND AND OBJECTIVE

The management of rare tumors is difficult because of limited information on natural history. Our objective was to describe a long-term comprehensive prospective database with the assumption that with careful attention to patient, predisposing tumor and treatment variables, valuable knowledge could be obtained that could guide management.

METHODS

In July of 1982, we began a prospective database of all adult patients admitted to our institution for a surgical procedure for soft tissue sarcoma. Patients were included if they had primary, locally recurrent or metastatic disease undergoing a surgical procedure.

RESULTS

Over 3 decades, we entered 10,000 patients into our prospective soft tissue sarcoma database. Data were entered on a weekly or biweekly schedule with full participation of a multidisciplinary team and a dedicated sarcoma pathologist. Extensive information is available from this database. In this article, we describe distribution by site, histopathology, sex, size, and grade. We utilize this information along with outcome data for local recurrence, distant recurrence, disease specific, and overall survival. The value of molecular diagnosis is illustrated.

CONCLUSIONS

Continuous prospective long-term databases are important to obtain knowledge particularly for rare tumors. Such data can be a rich resource for the development of prognostic indicators including nomograms and can be analyzed by Bayesian Belief Networks. These long-term data linked to collection of tumor and germ-line tissue at the time of an initial procedure will remain a resource for future decades.

Validation of the MSKCC Gastrointestinal Stromal Tumor Nomogram and Comparison with Other Prognostication Systems: Single-Institution Experience with 289 Patients

PURPOSE

To validate the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram in a single-institution cohort of patients with gastrointestinal stromal tumors (GISTs), and to compare its predictive accuracy against other established risk classification systems, including the National Institutes of Health (NIH), Armed Forces Institute of Pathology (AFIP), and Joensuu criteria.

METHODS

We retrospectively reviewed 289 patients who underwent surgical resection for primary localized GISTs without adjuvant imatinib therapy and compared the actuarial recurrence-free survival (RFS) with the predicted RFS.

RESULTS

Tumors >5 cm in size, with high mitotic index, and which had ruptured were significantly associated with recurrent disease. The 2-year RFS was 77.2 % [95 % confidence interval (CI) 71.6-81.8], and the 5-year RFS was 67.9 % (95 % CI 61.7-73.4). The concordance probability of the nomogram of 2-year RFS was 0.71 (SE 0.02), and 5-year RFS was 0.71 (SE 0.19). The 2-year and 5-year MSKCC nomogram probability calculations and the AFIP criteria gave a better estimation of RFS compared to the NIH (p < 0.001) and Joensuu (p < 0.001) criteria. There was no significant difference between the predictive accuracy of the nomogram compared to the AFIP criteria.

CONCLUSIONS

The MSKCC nomogram slightly underestimated the probability of RFS after surgical resection of GISTs. It was associated with a significantly better predictive accuracy compared to the NIH and Joensuu. This study suggests that there is a wider than expected prognostic divergence between gastric GISTs versus GISTs arising from the small intestine.

PDL1 expression is an independent prognostic factor in localized GIST

Gastrointestinal stromal tumors (GIST) are the most frequently occurring digestive sarcomas. The prognosis of localized GIST is heterogeneous, notably for patients with an Armed Forces Institute of Pathology (AFIP) intermediate or high risk of relapse. Despite imatinib effectiveness, it is crucial to develop therapies able to overcome the resistance mechanisms. The immune system represents an attractive prognostic and therapeutic target. The Programmed cell Death 1 (PD1)/programmed cell death ligand 1 (PDL1) pathway is a key inhibitor of the immune response; recently, anti-PD1 and anti-PDL1 drugs showed very promising results in patients with solid tumors. However, PDL1 expression has never been studied in GIST. Our objective was to analyze PDL1 expression in a large series of clinical samples. We analyzed mRNA expression data of 139 operated imatinib-untreated localized GIST profiled using DNA microarrays and searched for correlations with histoclinical features including postoperative metastatic relapse. PDL1 expression was heterogeneous across tumors and was higher in AFIP low-risk than in high-risk samples, and in samples without than with metastatic relapse. PDL1 expression was associated with immunity-related parameters such as T-cell-specific and CD8⁺ T-cell-specific gene expression signatures and probabilities of activation of interferon α (IFNα), IFNγ, and tumor necrosis factor α (TNFα) pathways, suggesting positive correlation with a cytotoxic T-cell response. In multivariate analysis, the PDL1-low group was associated with a higher metastatic risk independently of the AFIP classification and the KIT mutational status. In conclusion, PDL1 expression refines the prediction of metastatic relapse in localized GIST and might improve our ability to better tailor adjuvant imatinib. In the metastatic setting, PDL1 expression might guide the use of PDL1 inhibitors, alone or associated with tyrosine kinase inhibitors.

A nomogram to predict disease-free survival after surgical resection of GIST

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Adjuvant imatinib therapy has resulted in improved disease-free survival (DFS) following resection of primary GIST. The aim of our study was to create a nomogram to predict DFS following resection of GIST.

METHOD

Using a multi-institutional cohort of patients who underwent surgery for primary GIST at 7 academic hospitals in the USA and Canada between January 1998 and December 2012, a multivariable Cox proportional hazards model predicting DFS was created using backward stepwise selection. A nomogram to predict DFS following surgical resection of GIST was constructed with the variables selected in the multivariable model. We tested nomogram discrimination by calculating the C-statistic and compared the nomogram to four existing GIST prognostic stratification systems.

RESULTS

A total of 365 patients who underwent surgery for primary GIST was included in the study. Using backward stepwise selection, sex, tumor size, tumor site, and mitotic rate were selected for incorporation into the nomogram. The nomogram demonstrated superior discrimination compared to the NIH criteria, modified NIH criteria, and Memorial Sloan-Kettering Nomogram and had similar discrimination to the Miettinen criteria (C-statistic 0.77 vs 0.73, 0.71, 0.71, and 0.78, respectively).

CONCLUSION

Four independent predictors of recurrence following surgery for primary GIST were used to create a nomogram to predict DFS. The nomogram stratified patients into prognostic groups and performed well on internal validation.

Gastrointestinal stromal tumors: who should get imatinib and for how long?

The application of imatinib for the treatment of GIST remains a remarkable illustration of the ability and promise of targeted molecular therapy. It is gradually becoming evident that the benefit of imatinib depends on the complex interplay between mutational variations that govern tumor sensitivity to the drug, and biological variables that drive clinical outcome. Evidence is mounting that only a select fraction of patients in the adjuvant setting may benefit from imatinib. Unfortunately, most patients with metastatic disease develop resistance to imatinib, as occurs in other diseases treated with kinase inhibitors. Thus, although imatinib has demonstrated that kinase inhibitor therapy is an integral component of cancer care, it has also revealed the challenges in treating a dynamic cancer with a static monotherapy. As greater insight is gained into when imatinib does not help, it will uncover the obvious next pathway in cancer treatment, namely individualized, genotype-directed therapy that is modulated according to the genetic and immunologic landscape of the tumor.

Long-term survival after enucleation of a giant esophageal gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms of the gastrointestinal tract. Less than 1% occurs in the esophagus. Surgery is the primary treatment for patients with GISTs. We report a 29-year-old male was admitted after the detection of a posterior mediastinal mass during work-up with routine examination. He did not have any disease-related symptoms. The physical examination was unremarkable. Chest computed tomographic scan, the barium esophagogram and endoscopic esophageal ultrasound showed benign neoplasm. The patient was performed an enucleation surgery through the right posterolateral thoracotomy. The pathology revealed a 13.0 cm × 12.0 cm × 5.0 cm mass. The tumor was CD117 (C-kit), PDGFRA and DOG1 positive. These findings were consistent with a GIST of the esophagus. So the diagnosis of GIST of esophagus was confirmed. The pathological diagnosis of low grade of GIST of esophagus was confirmed. The patient has no evidence of recurrence and is in good clinical conditions up-to date, five years after surgery.

GEIS 2013 guidelines for gastrointestinal sarcomas (GIST)

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal soft tissue sarcoma of the gastrointestinal tract. Correct diagnosis with thorough use of pathologic and molecular tools of GIST mutations has been of the foremost importance. GIST are usually (95 %) KIT positive and harbor frequent KIT or platelet-derived growth factor receptor α-activating mutations. This deep molecular understanding has allowed the correct classification into risk groups with implications regarding prognosis, essential use in the development of targeted therapies and even response prediction to this drugs. Treatment has been evolving and an update to include lessons learned from recent trials in advanced disease as well as controversies in the adjuvant setting that are changing daily practice, is reviewed here. An effort from the Spanish Group for Sarcoma Research with investigators from the group has been undertaken to launch this third version of the GIST guidelines and provide a practical means for the different disciplines that treat this complex disease.

Clinical presentation, management and outcomes of gastrointestinal stromal tumors

INTRODUCTION

The present study investigated the incidence, management and outcome of Gastrointestinal Stromal Tumors (GIST) in Qatar.

METHODS

A retrospective review of all GIST patients admitted between 1995 and 2012 was conducted. Patients' demographics, clinical presentation, tumor characteristics, radiological, pathological and immunohistochemical findings, surgical procedures, recurrence and mortality were recorded.

RESULTS

A total of 48 GIST patients were identified. Stomach (56%) and small intestine (27%) were the most common sites of tumor. The majority of cases (n = 27) had tumor size >5 cm, 31 cases had primary and 15 cases had locally advanced tumor. Patients were stratified as high, intermediate, and low risk (43.8%, 18.8% and 37.5%, respectively). Almost all the cases were surgically managed and 94% were completely resectable. Robotic partial resection was performed in 4 cases and 5 cases underwent laparoscopic resection. Chemotherapy was initiated in half of patients. During follow up (average 37.5 months), 33 patients showed complete recovery, 7 had recurrent or metastatic disease and 2 died due to liver metastasis.

CONCLUSION

The incidence of GIST in Qatar is apparently low. Surgical resection is the preferred choice of treatment; however, robotic and laparoscopic resections are feasible and safe approaches in some cases.

Tyrosine kinase inhibitors in the treatment of unresectable or metastatic gastrointestinal stromal tumors

INTRODUCTION

Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the gastrointestinal tract. Proliferation of GIST is driven by activating mutations in the KIT or PDGFRA genes that found in most sporadic GISTs. Surgery is the main remedial measure for primary GIST, and imatinib is the principal therapeutic of choice for unresectable or metastatic GIST. Imatinib revolutionized treatment for unresectable or metastatic GISTs; however, resistance to imatinib has inevitably developed for most GIST patients.

AREAS COVERED

PubMed was searched to find biological studies of GIST and clinical trials of molecularly targeted agents on unresectable or metastatic GISTs, and the key papers found have been reviewed. In this paper, the standard therapy which includes imatinib, sunitinib and regorafenib for unresectable or metastatic GIST has been reviewed and molecular mechanisms of resistance for tyrosine kinase inhibitors (TKIs) have been postulated and discussed. Treatment measures for resistant GIST and therapeutic choices after the standard therapy have also been described.

EXPERT OPINION

The standard therapy for unresectable or metastatic GISTs is first-line imatinib, second-line sunitinib and third-line regorafenib. After standard therapy, best supportive care or clinical trials is recommended in the guidelines. However, patients may benefit from continuation of TKIs beyond disease progression and from rechallenge of TKIs used previously.

Outcomes in the management of adult soft tissue sarcomas

Adult soft tissue sarcomas (STSs) are heterogeneous neoplasms that account for 11,410 new diagnoses and 4,390 deaths per year. This article summarizes recent NCCN guidelines for diagnosis and management of STSs of the extremities and retroperitoneum, as well as gastrointestinal stromal tumors (GIST). AJCC staging and recently reported NCDB data regarding outcomes are reviewed. Currently accepted STS prognostic variables are presented, as are future directions regarding the utility of molecular prognosticators and nomograms.

Clinical and therapeutic considerations of GIST

Gastrointestinal stromal tumors (GIST) are rare tumors of the digestive tract, with an incidence of about 1.5 per 100,000/year. Clinical features may vary depending on location, size and aggressiveness. The diagnosis is confirmed by immunohistochemistry tests that identify CD 117 or DOG1 (typical receptors/markers for most GISTs) at the level of biopsy specimen. The treatment of localized GIST is based primarily on the surgery, while for metastatic GIST the targeted therapy with tyrosine kinase inhibitors represents the current standard. The neoadjuvant and adjuvant therapy indications guided and depending on genetic analysis included in the diagnostic and treatment algorithm as well as the strategy for cases surveillance are listed in the journal. All these data obtained from the literature have been integrated in a practical experience of 19 cases of GIST, operated in the clinic in the last 10 years for which we have proposed an adapted diagnostic algorithm.

Pfetin as a risk factor of recurrence in gastrointestinal stromal tumors

Background. Despite complete resection of gastrointestinal stromal tumors (GIST), recurrent and/or metastatic disease occurs, often depending on the grade of malignancy. As such, markers are needed that accurately predict patients at high risk for recurrence. Previously our group reported Pfetin as a prognostic biomarker for GIST. In order to create an approach for predicting risk of recurrence, we incorporated Pfetin expression with clinicopathological data to produce a predictive model. Object. Forty-five patients with localized primary GIST were treated with complete gross surgical resection surgically at our institution between 1995 and 2010 were included. The majority of tumors originated in the stomach (38 cases), as well as small intestine (6 cases) and rectum (1 case). Method. (1) We performed retrospective analysis of the connection between Pfetin expression, clinicopathological data, and incidences of recurrence, using bivariate and multivariate analyses. (2) The reactivity of the monoclonal antibody against Pfetin was examined by immunohistochemistry. Pfetin. We have reported Pfetin, identified microarray technology, and compared between statistically different GISTs for good and poor prognoses and for prognostic marker. Results. There were 7 cases of recurrences. (1) By univariate analysis, tumor size, mitoses, exposure to abdominal cavity, and complete tumor removal predicted risk of recurrence. (2) Pfetin-negative cases were significantly related to recurrence (P = 0.002). Conclusions. This analysis demonstrates that lack of Pfetin expression is an additional predictor of recurrence in resected GIST. Further study may determine the role of this variable added to the current predictive model for selection of adjuvant therapy.

Prevalence of gastrointestinal stromal tumour (GIST) in the United Kingdom at different therapeutic lines: an epidemiologic model

BACKGROUND

The prevalence of patients with gastrointestinal stromal tumourgst (GIST) who fail currently available treatments imatinib and sunitinib (third-line treatment-eligible GIST) is unknown, but is expected to be below an ultra-orphan disease threshold of 2/100,000 population used in England and Wales. Our study was designed to estimate the prevalence and absolute number of UK patients with unresectable/metastatic GIST at first-, second- and eventually third-line treatment.

METHODS

Our open population model estimates the probability that the prevalence of UK third-line treatment-eligible GIST patients will remain under the ultra-orphan disease threshold. Model parameters for incidence, proportion of unresectable/metastatic disease and survival estimates for GIST patients were obtained from a targeted literature review and a UK cancer register. The robustness of the results was checked through differing scenarios taking extreme values of the input parameters.

RESULTS

The base-case scenario estimated a prevalence of third-line treatment-eligible GIST of 1/100,000 and a prevalence count of 598 with a 99.9% likelihood of being below the ultra-orphan disease threshold. The extreme scenarios, one-way and probabilistic sensitivity analyses and threshold analysis confirmed the robustness of these results.

CONCLUSIONS

The prevalence of third-line treatment-eligible GIST is very low and highly likely below the ultra-orphan disease threshold.

Considering the role of radiation therapy for gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors arising in the gastrointestinal tract. Over the last decade, the management and prognosis of GISTs has changed dramatically with molecular characterization of the c-kit mutation and the adoption of targeted systemic therapy. Currently, the standard of care for resectable tumors is surgery, followed by adjuvant imatinib for tumors at high risk for recurrence. Inoperable or metastatic tumors are treated primarily with imatinib. Despite excellent initial response rates, resistance to targeted therapy has emerged as a common clinical problem, with relatively few therapeutic solutions. While the treatment of GISTs does not commonly include radiotherapy, radiation therapy could be a valuable contributing modality. Several case reports indicate that radiation can control locally progressive, drug-resistant disease. Further study is necessary to define whether radiation could potentially prevent or delay the onset of drug resistance, or improve outcomes when given in combination with imatinib.

Controversies in the management of gastrointestinal stromal tumors

Major advances in the medical treatment of gastrointestinal tumors (GISTs) have improved survival for both patients with advanced disease and those diagnosed with high-risk primary tumors. The Consensus approaches to best practice management of gastrointestinal stromal tumors, published in this journal in 2008, provided guidance for the management of GIST to both clinicians and regulatory authorities. Since then, clinical trials have demonstrated the benefit of adjuvant imatinib in high-risk patients, and mature data from advanced GIST studies suggest that a small but significant proportion of patients with advanced disease can achieve long-term benefit with ongoing imatinib treatment. Other evolving management strategies include the controversial use of palliative or debulking surgery to improve outcomes in advanced GIST and the development of promising new multikinase inhibitors, such as regorafenib, which has established benefit in the third-line setting. This review provides an update of recent developments in GIST management and discusses new controversies that these advances have generated.

Pathologic and molecular features correlate with long-term outcome after adjuvant therapy of resected primary GI stromal tumor: the ACOSOG Z9001 trial

PURPOSE

The ACOSOG (American College of Surgeons Oncology Group) Z9001 (Alliance) study, a randomized, placebo-controlled trial, demonstrated that 1 year of adjuvant imatinib prolonged recurrence-free survival (RFS) after resection of primary GI stromal tumor (GIST). We sought to determine the pathologic and molecular factors associated with patient outcome.

PATIENTS AND METHODS

There were 328 patients assigned to the placebo arm and 317 to the imatinib arm. Median patient follow-up was 74 months. There were 645 tumor specimens available for mitotic rate or mutation analysis.

RESULTS

RFS remained superior in the imatinib arm (hazard ratio, 0.6; 95% CI, 0.43 to 0.75; Cox model-adjusted P < .001). On multivariable analysis of patients in the placebo arm, large tumor size, small bowel location, and high mitotic rate were associated with lower RFS, whereas tumor genotype was not significantly associated with RFS. Multivariable analysis of patients in the imatinib arm yielded similar findings. When comparing the two arms, imatinib therapy was associated with higher RFS in patients with a KIT exon 11 deletion of any type, but not a KIT exon 11 insertion or point mutation, KIT exon 9 mutation, PDGFRA mutation, or wild-type tumor, although some of these patient groups were small. Adjuvant imatinib did not seem to alter overall survival.

CONCLUSION

Our findings show that tumor size, location, and mitotic rate, but not tumor genotype, are associated with the natural history of GIST. Patients with KIT exon 11 deletions assigned to 1 year of adjuvant imatinib had a longer RFS.

Gastrointestinal stromal tumors: a case report

Advances in the identification of gastrointestinal stromal tumors, its molecular and immunohiostochemical basis, and its management have been a watershed in the treatment of gastrointestinal tumors. This paradigm shift occurred over the last two decades and gastrointestinal stromal tumors have now come to be understood as rare gastrointestinal tract tumors with predictable behavior and outcome, replacing the older terminologies like leiomyoma, schwannoma or leiomyosarcoma. This report presents a case of gastric gastrointestinal stromal tumor operated recently in a 47-year-old female patient and the outcome, as well as literature review of the pathological identification, sites of origin, and factors predicting its behavior, prognosis and treatment.

Long-term and surgical outcomes of laparoscopic surgery for gastric gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Surgical resection with a free margin is the gold standard treatment for these lesions.

OBJECTIVE

The aim of this study was to evaluate the feasibility of performing laparoscopic resection for gastric GIST from the viewpoint of operative and long-term oncological outcomes.

METHODS

Between 2005 and 2011, a total of 78 consecutive patients undergoing laparoscopic resection of gastric GISTs were enrolled in a retrospective single-center study. Patient and tumor characteristics, surgical procedures, risk classification, postoperative complications, mortality, recurrence, and survival time were collected from a database, and the descriptive statistics were estimated.

RESULTS

Patients (N = 78; 32 males and 46 females) with a median age of 63 years (range 31-82) were evaluated. The tumors were located at the cardia (10.3%), upper stomach (59.0%), middle stomach (23.1), and lower stomach (7.7%). The mean size of the tumors was 34.7 ± 12.1 mm. The laparoscopic procedures included wedge resection (92.3%), such as laparoscopy and endoscopy cooperative surgery (51.3%), and gastrectomy (7.7%). All cases exhibited a pathologically negative margin. The mean operative time was 147.5 ± 63.8 min, and the mean estimated amount of blood loss was 17.8 ± 47.9 ml. The mean length of hospitalization was 9.4 ± 12.8 days. The incidence of perioperative complications higher than grade III was 2.6%, including two cases of anastomotic leakage. Regarding risk classification, low, intermediate and high were observed in 61, 6, and 11 cases, respectively. During a mean follow-up period of 45.3 ± 18.5 months, one patient experienced local recurrence in the omentum. Meanwhile, four patients died due to other diseases; all other patients survived.

CONCLUSIONS

Adequate oncologic resection was achieved in all cases. Laparoscopic surgery is a feasible option for gastric GISTs <5 cm.

The GIST of targeted therapy for malignant melanoma

The high response rates to the tyrosine kinase inhibitor imatinib in KIT-mutated gastrointestinal stromal tumors (GIST) has led to a paradigm shift in cancer treatment. In a parallel fashion, the field of melanoma is shifting with the utilization of targeted therapy to treat BRAF-mutated melanoma. We reviewed published literature in PubMed on GIST and melanoma, with a focus on both past and current clinical trials. The data presented centers on imatinib, vemurafenib, and most recently dabrafenib, targeting KIT and BRAF mutations and their outcomes in GIST and melanoma. The BRAF(V600E) melanoma mutation, like the KIT exon 11 mutation in GIST, has the highest response to therapy. High response rates with inhibition of KIT in GIST have not been recapitulated in KIT-mutated melanoma. Median time to resistance to targeted agents occurs in ~7 months with BRAF inhibitors and 2 years for imatinib in GIST. In GIST, the development of secondary mutations leads to resistance; however, there have been no similar gatekeeper mutations found in melanoma. Although surgery remains an important component of the treatment of early GIST and melanoma, surgeons will need to continue to define the thresholds and timing for operation in the setting of metastatic disease with improved targeted therapies. Combination treatment strategies may result in more successful clinical outcomes in the management of melanoma in the future.

Submucosal tunneling endoscopic resection for submucosal tumors of the esophagogastric junction originating from the muscularis propria layer: a feasibility study (with videos)

BACKGROUND

The esophagogastric junction (EGJ) is a difficult location for endoscopic resection due to its narrow lumen and sharp angle. Potential increased risks of perforation and mediastinal infection exist, especially for submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. We previously demonstrated the safety and efficacy of submucosal tunneling endoscopic resection (STER) for upper gastrointestinal SMTs, but the feasibility of STER for the removal of SMTs at the EGJ requires systematic investigation. The aim of the investigation was to evaluate the clinical impact of STER on the removal of SMTs at the EGJ.

METHODS

A prospective study was carried out which included a consecutive cohort of 57 patients who underwent STER for 57 SMTs of the EGJ originating from the MP layer between July 2010 and August 2012 in a single academic medical center. Adverse events, en bloc resection rate, and local recurrence were evaluated.

RESULTS

The average maximum diameter of the lesions was 21.5 mm (range 6-35 mm). The en bloc resection rate was 100 % (57/57). No delayed hemorrhage or severe adverse events occurred in any of the 57 patients following STER. No local recurrence and distant metastasis occurred during 24 months' follow-up. Less subcutaneous emphysema and pneumomediastinum absorption time (p = 0.005) occurred with CO2 versus air insufflations.

CONCLUSIONS

Our study showed that STER was safe and effective, provided accurate histopathologic evaluation, and was curative for SMTs of the deep MP layers at the EGJ. CO2 gas insufflation is recommended.