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

Comparison of prognostic prediction models for rectal gastrointestinal stromal tumor

BACKGROUND

Rectal gastrointestinal stromal tumors (RGISTs) are biologically characterized tumors that are relatively rare. Thus, few studies have reported a specific prognostic system for this subset of tumors but integrated it into parallel systems, such as small intestine. Our aim is to develop a new predictive staging system nomogram (named FD-ZS system) for RGISTs.

RESULTS

Tumor size and mitotic rate were independent risk factors for tumor recurrence in RGISTs according to univariate and multivariate survival analyses. A prognostic predictive nomogram was developed, and a cut-off value of 65 points was calculated by X-tile to discriminate risk based on tumor size and mitotic rate. The C-indices for the FD-ZS, FD-Hou, NIH, and WHO systems were 0.706, 0.693, 0.687, and 0.680, respectively.

CONCLUSION

In the present study, a concise two-tier grading system (FD-ZS) for prognostic prediction of RGISTs that is simpler to several reported systems was developed, and a cut-off value was established to help RGIST patients determine whether to undergo adjuvant imatinib treatment.

METHODS

A nomogram was employed, and its predictive accuracy and discriminative ability were determined by concordance index (C-index) and calibration curve analyses. The nomogram was then compared with three stratification systems used for GISTs (FD-Hou, NIH, and WHO).

Gastrointestinal Stromal Tumors: A Single Institution Experience of 176 Surgical Patients

Large single-institution series of patients undergoing resection for gastrointestinal stromal tumors (GIST) are lacking. Clinicopathologic characteristics and postoperative outcomes were retrospectively collected and analyzed from patients undergoing resection for GIST from 2002 to 2011. One hundred seventy-six patients were identified; 156 underwent resection of primary nonmetastatic disease. KIT mutations were identified in 131 patients (84.0%). Of the 156 patients with primary disease, the most common site was the stomach (75.6%). Tumors were categorized as very low (24.4%), low (35.9%), intermediate (12.2%), high (24.4%), or unknown (3.2%) risk. Symptomatic patients more often had high risk (35.6 vs 9.8%; P < 0.0001) and larger tumors (7.3 vs 3.0 cm; P < 0.0001). Forty-seven patients (30.1%) underwent laparoscopic resection (LR). Compared with open surgery, LR was performed for smaller tumors (3.8 vs 6.2 cm; P = 0.002). Positive margin rates were similar (4.3% LR vs 10.2% open; P = 0.346). Median follow-up for the 156 patients with primary tumors was 32.9 months; mean overall survival was 120.9 months (median not reached). Of the 20 patients with metastatic GIST (excluded from above analysis), five patients (25.0%) died of disease with a median follow-up of 15.9 months. Most patients with resectable primary GIST have a favorable prognosis. The presence of symptoms directly related to GIST may be associated with a poor prognosis and is likely related to increased tumor size. Laparoscopic resection is well tolerated and does not appear to compromise outcomes in well-selected patients. Highly selected patients with metastatic disease may benefit from resection.

Population-based incidence of gastrointestinal stromal tumors in Puglia

INTRODUCTION

This study presents the incidence of gastrointestinal stromal tumors (GISTs) in an Italian region of over 4 million inhabitants monitored for 10 years and is the largest incidence study of this type of cancer conducted so far in Italy.

METHODS

In order to ensure the registration of all GISTs, including those with nonmalignant behavior, a cancer list was integrated with the cases found through an ad hoc data mining process that covered all the pathologic reports of Puglia. Case distributions by sex, age groups, site, and prognostic groups according to Miettinem and Lasota classification and crude and age-standardized incidence rates were produced.

RESULTS

In the 10-year period 2006 to 2015, 708 cases of GIST were recorded in Puglia. The average crude incidence rate was 1.7 per 100,000 person-years and the age-standardized incidence rate, using 2013 European standard population, was 1.8 per 100,000 person-years (95% confidence interval [CI], 1.6-1.9). Incidence was higher in men than in women: crude incidence rate was 2.0 per 100,000 person-years and age-standardized incidence rate 2.2 per 100,000 person-years (95% CI, 2.0-2.4) in men and 1.5 per 100,000 person-years and 1.4 per 100,000 person-years (95% CI, 1.2-1.6) in women.

DISCUSSION

Our incidence rates are comparable with those of other international studies and they are located in the medium to high end of the range. The comparisons are affected by a different capacity of the cancer registries to intercept and record GISTs with nonmalignant behavior. Distribution of cases for sex, age groups, sites, and prognostic risk groups are consistent with previous results.

Development and Validation of a Deep Learning Model for Non-Small Cell Lung Cancer Survival

IMPORTANCE

There is a lack of studies exploring the performance of a deep learning survival neural network in non-small cell lung cancer (NSCLC).

OBJECTIVES

To compare the performances of DeepSurv, a deep learning survival neural network with a tumor, node, and metastasis staging system in the prediction of survival and test the reliability of individual treatment recommendations provided by the deep learning survival neural network.

DESIGN, SETTING, AND PARTICIPANTS

In this population-based cohort study, a deep learning-based algorithm was developed and validated using consecutive cases of newly diagnosed stages I to IV NSCLC between January 2010 and December 2015 in a Surveillance, Epidemiology, and End Results database. A total of 127 features, including patient characteristics, tumor stage, and treatment strategies, were assessed for analysis. The algorithm was externally validated on an independent test cohort, comprising 1182 patients with stage I to III NSCLC diagnosed between January 2009 and December 2013 in Shanghai Pulmonary Hospital. Analysis began January 2018 and ended June 2019.

MAIN OUTCOMES AND MEASURES

The deep learning survival neural network model was compared with the tumor, node, and metastasis staging system for lung cancer-specific survival. The C statistic was used to assess the performance of models. A user-friendly interface was provided to facilitate the survival predictions and treatment recommendations of the deep learning survival neural network model.

RESULTS

Of 17 322 patients with NSCLC included in the study, 13 361 (77.1%) were white and the median (interquartile range) age was 68 (61-74) years. The majority of tumors were stage I disease (10 273 [59.3%]) and adenocarcinoma (11 985 [69.2%]). The median (interquartile range) follow-up time was 24 (10-43) months. There were 3119 patients who had lung cancer-related death during the follow-up period. The deep learning survival neural network model showed more promising results in the prediction of lung cancer-specific survival than the tumor, node, and metastasis stage on the test data set (C statistic = 0.739 vs 0.706). The population who received the recommended treatments had superior survival rates than those who received treatments not recommended (hazard ratio, 2.99; 95% CI, 2.49-3.59; P < .001), which was verified by propensity score-matched groups. The deep learning survival neural network model visualization was realized by a user-friendly graphic interface.

CONCLUSIONS AND RELEVANCE

The deep learning survival neural network model shows potential benefits in prognostic evaluation and treatment recommendation with respect to lung cancer-specific survival. This novel analytical approach may provide reliable individual survival information and treatment recommendations.

Identification of low-density lipoprotein receptor class A domain containing 4 (LDLRAD4) as a prognostic indicator in primary gastrointestinal stromal tumors

BACKGROUND

There is an urgent clinical need to select the patients with resectable gastrointestinal stromal tumors (GISTs) who can benefit from adjuvant treatment after complete resection based on disease recurrence risk stratification. We hypothesized that integrating biomarkers into available risk assessment tools may improve the precision of GIST prognostic predictions.

METHODS

Candidate genes that may cause GIST progression were identified using the Gene Expression Omnibus dataset GSE20708. Quantitative Real-time was used to confirm the prognostic value of the candidate genes for recurrence-free survival (RFS) in a cohort of 94 patients.

RESULTS

Thirty-seven differentially expressed genes between localized tumors and metastatic primary tumors were found; 14 (37.8%) were upregulated and 23 (62.2%) were downregulated in the latter tumors. Low-density lipoprotein receptor class A domain containing 4 (LDLRAD4) was selected for further prognostic analysis. Although LDLRAD4 mRNA expression was not associated with recurrence risk grades as determined by the revised NIH consensus criteria, multivariate Cox regression analysis showed that LDLRAD4 expression (hazard ratio [HR] = 4.403, 95% confidence interval [CI]: 1.822-10.641, P = 0.001), tumor size (HR = 1.174, 95% CI: 1.027-1.342, P = 0.019) and tumor location (HR = 6.291, 95% CI: 1.128-35.080, P = 0.036) were independent prognostic factors for RFS in patients with resectable GISTs. Moreover, the RFS model constructed by these three factors may effectively predict GIST prognosis within the first 2 postsurgical years.

CONCLUSION

Our study identifies LDLRAD4 as a suitable prognostic marker for GISTs. The integration of biomarkers into risk assessment tools may improve the precision of GIST prognostic predictions.

Prognostic value and nomograms of proximal margin distance in gastric cancer with radical distal gastrectomy

Objective

The proximal margin (PM) distance for distal gastrectomy (DG) of gastric cancer (GC) remains controversial. This study investigated the prognostic value of PM distance for survival outcomes, and aimed to combine clinicopathologic variables associated with survival outcomes after DG with different PM distance for GC into a prediction nomogram.

Methods

Patients who underwent radical DG from June 2004 to June 2014 at Department of General Surgery, Nanfang Hospital, Southern Medical University were included. The first endpoints of the prognostic value of PM distance (assessed in 0.5 cm increments) for disease-free survival (DFS) and overall survival (OS) were assessed. Multivariate analysis by Cox proportional hazards regression was performed using the training set, and the nomogram was constructed, patients were chronologically assigned to the training set for dates from June 1, 2004 to January 30, 2012 (n=493) and to the validation set from February 1, 2012 to June 30, 2014 (n=211).

Results

Among 704 patients with pTNM stage I, pTNM stage II, T1−2, T3−4, N0, differentiated type, tumor size ≤5.0 cm, a PM of (2.1−5.0) cmvs. PM≤2.0 cm showed a statistically significant difference in DFS and OS, while a PM>5.0 cm was not associated with any further improvement in DFS and OSvs. a PM of 2.1−5.0 cm. In patients with pTNM stage III, N1, N2−3, undifferentiated type, tumor size >5.0 cm, the PM distance was not significantly correlated with DFS and OS between patients with a PM of (2.1−5.0) cm and a PM≤2 cm, or between patients with a PM >5.0 cm and a PM of (2.1−5.0) cm, so there were no significant differences across the three PM groups. In the training set, the C-indexes of DFS and OS, were 0.721 and 0.735, respectively, and in the validation set, the C-indexes of DFS and OS, were 0.752 and 0.751, respectively.

Conclusions

It is necessary to obtain not less than 2.0 cm of PM distance in early-stage disease, while PM distance was not associated with long-term survival in later and more aggressive stages of disease because more advanced GC is a systemic disease. Different types of patients should be considered for removal of an individualized PM distance intra-operatively. We developed a universally applicable prediction model for accurately determining the 1-year, 3-year and 5-year DFS and OS of GC patients according to their preoperative clinicopathologic characteristics and PM distance.

Progress in determining response to treatment in gastrointestinal stromal tumor

Introduction: Gastrointestinal stromal tumor (GIST) is the most common malignant mesenchymal tumor of the gastrointestinal system. Multiple advances in the management of GIST from the discovery of KIT/PDGRA and other genetic alterations have led to the development of multiple tyrosine kinase inhibitors. Response assessment in GIST is determined with iRECIST (Response Evaluation Criteria in Solid Tumors), PERCIST (PET response criteria in solid tumors), or Choi criteria. Molecular genotyping of the tissue samples is the recent standard for diagnosis, treatment, and response to treatment.Areas covered: In this study, we provide a brief overview of the history of the GIST, molecular sequencing, available treatment options and clinical trials, radiologic response assessment, and the role of ctDNA in response evaluation.Expert opinion: Future GIST management is related to the development of sensitive assays to detect genetic alterations for initial diagnosis, treatment selection, monitoring the response to treatment, resistant mutations, and predicting survival.

Difference of computed tomographic characteristic findings between gastric and intestinal gastrointestinal stromal tumors

PURPOSE

We aimed to compare the computed tomography (CT) imaging differences between gastric and intestinal gastrointestinal stromal tumors (GISTs).

MATERIALS AND METHODS

Thirty-eight patients with 38 gastric GISTs and 27 with 31 intestinal GISTs were enrolled. Tumors were classified as small (< 5 cm) or large (≥ 5 cm). Qualitative and quantitative CT imaging characteristics on non-contrast and contrast-enhanced CT were evaluated by two radiologists independently and statistically compared.

RESULTS

Early venous return and higher CT number of the draining vein in the arterial phase were more frequent in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). Small-sized intestinal GISTs demonstrated a wash-out pattern, whereas small-sized gastric GISTs showed a plateau pattern. Contrast enhancement was higher in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). CT number was inversely proportional to the diameter of intestinal GISTs in both arterial and venous phases but not to that of gastric GISTs.

CONCLUSION

Strong enhancement with wash-out pattern and early venous return are characteristic findings of small-sized intestinal GISTs. Radiologists should be aware that CT findings of GISTs have a wide spectrum and may differ according to size and site of origin.

Prognostic Factors for Primary Localized Gastrointestinal Stromal Tumors After Radical Resection: Shandong Gastrointestinal Surgery Study Group, Study 1201

BACKGROUND

Most previous risk-prediction models for gastrointestinal stromal tumors (GISTs) were based on Western populations. In the current study, we collected data from 23 hospitals in Shandong Province, China, and used the data to examine prognostic factors in Chinese patients and establish a new recurrence-free survival (RFS) prediction model.

METHODS

Records were analyzed for 5285 GIST patients. Independent prognostic factors were identified using Cox models. Receiver operating characteristic curve analysis was used to compare a novel RFS prediction model with current risk-prediction models.

RESULTS

Overall, 4216 patients met the inclusion criteria and 3363 completed follow-up. One-, 3-, and 5-year RFS was 94.6% (95% confidence interval [CI] 93.8-95.4), 85.9% (95% CI 84.7-87.1), and 78.8% (95% CI 77.0-80.6), respectively. Sex, tumor location, size, mitotic count, and rupture were independent prognostic factors. A new prognostic index (PI) was developed: PI = 0.000 (if female) + 0.270 (if male) + 0.000 (if gastric GIST) + 0.350 (if non-gastric GIST) + 0.000 (if no tumor rupture) + 1.259 (if tumor rupture) + 0.000 (tumor mitotic count < 6 per 50 high-power fields [HPFs]) + 1.442 (tumor mitotic count between 6 and 10 per 50 HPFs) + 2.026 (tumor mitotic count > 10 per 50 HPFs) + 0.096 × tumor size (cm). Model-predicted 1-, 3-, and 5-year RFS was S(12, X) = 0.9926^exp(PI), S(36, X) = 0.9739^exp(PI) and S(60, X) = 0.9471^exp(PI), respectively.

CONCLUSIONS

Sex, tumor location, size, mitotic count, and rupture were independently prognostic for GIST recurrence. Our RFS prediction model is effective for Chinese GIST patients.

Safety of Imatinib Mesylate in a Multicenter Expanded Access Program in Adult Patients with Gastrointestinal Stromal Tumors in the Adjuvant Setting

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors most often caused by activating mutations of the KIT gene. KIT tyrosine kinase inhibitors provide targeted therapy for the underlying genetic mutation, and adjuvant therapy is indicated for patients who are at significant risk of relapse following GIST resection. This is a report of the safety of imatinib in patients with GIST in the adjuvant setting in an expanded access program.

METHODS

In this multicenter, open-label, single-arm trial, safety was assessed based on the frequency of adverse events (AEs).

RESULTS

Three hundred patients were treated and analyzed; 40 patients discontinued treatment. Median overall exposure during the program was 181 days (range 9-420); most patients (260/300 treated) completed the study. Six patients had disease recurrence, 4 of whom discontinued. In line with previously published reports, the most frequent AEs were nausea, diarrhea, and periorbital edema. The AEs were mild to moderate in most cases (76%).

CONCLUSIONS

These findings are in agreement with the known safety profile of imatinib and confirm the safety of imatinib at 400 mg/day in the adjuvant setting. The incidence of severe AEs was low.

A Novel PRKAR1B-BRAF Fusion in Gastrointestinal Stromal Tumor Guides Adjuvant Treatment Decision-Making During Pregnancy

Gastrointestinal stromal tumors (GISTs) are rare in pregnancy, with only 11 reported cases. Adjuvant imatinib therapy, which targets the most common driver mutations in GIST (KIT and PDGFRA), is recommended for patients with high-risk GIST, but it has known teratogenicity in the first trimester. A 34-year-old G3P2 woman underwent exploratory laparotomy at 16 weeks' gestation for a presumed adnexal mass. Surgical findings included normal adnexa and a 14-cm solid small bowel mass. The mass was resected en bloc with a segment of jejunum followed by a primary anastomosis. Histopathology and genomic analyses demonstrated a GIST with high-risk features but lack of KIT/PDGFRA mutations and identified the presence of a previously unreported, pathogenic PRKAR1B-BRAF gene fusion. Given her tumor profile, adjuvant therapy with imatinib was not recommended. GIST is rare in pregnancy, but can masquerade as an adnexal mass in women of childbearing age. Because neoadjuvant/adjuvant imatinib has risks of teratogenicity, tumor molecular profiling is critical as we identified a previously unreported gene fusion of PRKAR1B with BRAF that is predicted to be imatinib-resistant. In this case, testing provided the rationale for not offering adjuvant imatinib to avoid unnecessary toxicity to the patient and fetus.

Multi-institutional Development and External Validation of a Nomogram to Predict Recurrence After Curative Resection of Pancreatic Neuroendocrine Tumors

OBJECTIVE

To develop a nomogram estimating the probability of recurrence free at 5 years after resection for localized grade 1 (G1)/ grade 2 (G2) pancreatic neuroendocrine tumors (PanNETs).

BACKGROUND

Among patients undergoing resection of PanNETs, approximately 17% experience recurrence. It is not established which patients are at risk, with no consensus on optimal follow-up.

METHOD

A multi-institutional database of patients with G1/G2 PanNETs treated at 2 institutions was used to develop a nomogram estimating the rate of freedom from recurrence at 5 years after curative resection. A second cohort of patients from 3 additional institutions was used to validate the nomogram. Prognostic factors were assessed by univariate analysis using Cox regression model. The nomogram was internally validated using bootstrap resampling method and on the external cohort. Performance was assessed by concordance index (c-index) and a calibration curve.

RESULTS

The nomogram was constructed using a cohort of 632 patients. Overall, 68% of PanNETs were G1, the median follow-up was 51 months, and we observed 74 recurrences. Variables included in the nomogram were the number of positive nodes, tumor diameter, Ki-67, and vascular/perineural invasion. The model bias-corrected c-index from the internal validation was 0.85, which was higher than European Neuroendocrine Tumors Society/American Joint Committee on Cancer 8th staging scheme (c-index 0.76, P = <0.001). On the external cohort of 328 patients, the nomogram c-index was 0.84 (95% confidence interval 0.79-0.88).

CONCLUSION

Our externally validated nomogram predicts the probability of recurrence-free survival at 5 years after PanNETs curative resection, with improved accuracy over current staging systems. Estimating individual recurrence risk will guide the development of personalized surveillance programs after surgery.

Is Peritoneal Tumor Penetration of Prognostic Importance in Gastrointestinal Stromal Tumors?

BACKGROUND

Peritoneal tumor penetration (PP) strongly affects prognosis in gastrointestinal carcinomas. In gastrointestinal stromal tumor (GIST), its significance in the absence of tumor rupture has not been subjected to detailed analysis.

METHODS

Patients undergoing complete resection for non-metastatic GIST from 2000 to 2017 were identified in the regional sarcoma database at Oslo University Hospital. Patients with extraperitoneal tumors (esophagus, rectum) or ruptured tumors were excluded from the study. Rupture was defined according to the Oslo criteria, and PP was assessed via routine histopathologic examination by sarcoma pathologists.

RESULTS

The study enrolled 341 patients. The median follow-up period was 51 months (range 0-175) months. In 82 (24%) of the 341 patients, PP was recorded. There were 32 recurrences, 9 in patients with PP and 23 in patients without PP. Despite statistically significant associations between PP and established risk factors (size, mitotic index, non-gastric location), the 5-year recurrence-free survival rate did not differ between the patients with PP (86%) and those without PP (90%) (hazard ratio 1.25; 95% confidence interval 0.58-2.70; P = 0.577). Adjuvant imatinib was administered to 53 of 97 patients in the high-risk category. The recurrence rates did not differ between the PP-positive and PP-negative patients in either group.

CONCLUSIONS

In GIST, PP without tumor rupture appears not to influence prognosis. This lack of prognostic significance may reflect unexplored differences between epithelial and mesenchymal malignancies.

Case report of rhabdomyosarcomatous transformation of a primary gastrointestinal stromal tumor (GIST)

Background

Gastrointestinal stromal tumor (GIST) is the most common primary mesenchymal neoplasm of the gastrointestinal tract. Mutations of KIT and platelet-derived growth factor receptor alpha have been well characterized in GISTs. Patients with KIT mutations are generally sensitive to treatment with tyrosine kinase inhibitors. However, some patients with GIST, while initially sensitive to TKIs, gain resistance in later stages of treatment. Heterologous rhabdomyomsarcomatous dedifferentiation of advanced GISTs after long-term imatinib mesylate (IM) therapy has been reported. In these cases, the underlying molecular mechanism of tumor progression and transformation is unclear.

Case presentation

We report one such patient with rhabdomyosarcomatous dedifferentiation of a GIST without metastatic disease after brief 3-month therapy with IM. The tumor was composed of two distinct phenotypes, a CD117 negative region with rhabdomyosarcomatous differentiation directly adjacent to a CD117 positive classic GIST region. Molecular analysis identified the activating KIT exon 11 mutation in both regions, indicating a common origin for both phenotypes. Additionally, the dedifferentiated component contained two synonymous variants in platelet-derived growth factor receptor alpha and KIT. The increased number of synonymous variants in the rhabdomyosarcomatous region may reflect increased genetic instability of this tumor that may have resulted in the loss of CD117 expression in the dedifferentiated component.

Conclusion

This study adds to the growing consensus that rhabdomyosarcomatous GIST progresses from a common GIST primary tumor. The role of IM in this progression is uncertain; however short duration of IM treatment in this study supports the hypothesis that rhabdomyosarcomatous GIST progression is not a consequence of IM therapy. Furthermore, we provide additional information supporting the observation that CD117 negative rhabdomyosarcomatous transformation maintains the activating KIT variant without KIT expression.

Optimal thresholds of risk parameters for gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal neoplasms of the gastrointestinal tract with highly variable potential for relapse. Tumor size and mitotic index (MI) are major risk factors that predict the outcome of GIST patients. Recent risk stratification schemes include some or all of the empirical size thresholds of 2 cm, 5 cm, and 10 cm and MI thresholds of 5 per 50 high-power fields (hpf) and 10 per 50 hpf. However, data that verify these numbers are sparse.

METHODS

By exhaustive regression tree analysis, maximally selected rank statistics and survival difference analysis with bootstrap sampling on a naive GIST population of 161 patients with a mean follow-up of 44 months, current stratification schemes using tumor size and MI were analyzed herein.

RESULTS

/Conclusions: Thresholds that optimally stratify the risk of recurrence are observed at tumor sizes of 4-5 cm and 10-11 cm and at mitotic indices of about 5 per 50 hpf and 10 per 50 hpf, respectively. While these data validate the canonical thresholds for size and MI used in risk stratification of GIST, transition regions as well as differences in the implementation of these thresholds between the different classification schemes proposed in the recent years should be considered when classifying GIST.

Prognostic nomogram for overall survival in upper aerodigestive tract extranodal natural killer/T-cell lymphoma, nasal type, stages IE and IIE: A SEER-based study

The present study aimed to develop a widely accepted prognostic nomogram for stage IE and IIE extranodal natural killer/T-cell lymphoma (ENKTCL) of the upper aerodigestive tract by using the Surveillance, Epidemiology, and End Results program database. A total of 396 patients with ENKTCL were included in the present study and were divided into training (n=280) and validation (n=116) cohorts. The Kaplan-Meier method and Cox regression model were used to evaluate the prognostic value of multiple clinical parameters on overall survival. The C-index and calibration curves were both used to determine the predictive and discriminatory capacities of the nomogram. In the training cohort, multivariate analysis demonstrated that age, primary site, radiation therapy and stage were independent prognostic factors. Nomograms with a C-index of 0.717 in the training cohort and a C-index of 0.737 in the validation cohort were developed. The calibration curves reported excellent consistency between predicted and real survival in patients with ENKTCL. In addition, a subgroup analysis of 264 patients who were receiving chemotherapy revealed that based on chemotherapy, supplementation with radiation therapy was significantly beneficial to patients survival. In conclusion, the present study demonstrated that this prognostic model may serve as a novel tool for improving prediction of survival outcomes and may therefore be used in clinical applications.

Imaging surveillance of gastrointestinal stromal tumour: current recommendation by National Comprehensive Cancer Network and European Society of Medical Oncology-European Reference Network for rare adult solid cancers

Imaging plays an active role in the surveillance of gastrointestinal stromal tumours (GISTs). Risk stratification schemes, based on size, mitotic count, and anatomical site of origin of the GIST, help in planning preoperative and postoperative imaging strategies especially in determining the frequency and duration of surveillance; however, there is no clear consensus on the optimal imaging strategies in patients with GISTs who are completely cured by surgery and patients who are at risk of recurrence. In addition, current surveillance protocols depend on the resectability of the primary tumour and presence of metastatic disease. The objective of this article is to provide a comprehensive review of the role of the different imaging methods for surveillance of GISTs, focusing on the guidelines recommended by National Comprehensive Cancer Network and European Society of Medical Oncology - European Network for Rare adult solid Cancers, and to propose practical guidelines for surveillance of GISTs for various risk categories.

Tailored management of primary gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common human sarcoma and can form along the entire gastrointestinal tract. Over the last 20 years, considerable advances have been made in our understanding of the biology of GISTs. The advent of tyrosine kinase inhibitors has provided effective medical therapy for the first time. In fact, given that GIST typically is driven by either a KIT or PDGFRA gene mutation, it has become a paradigm of targeted molecular therapy. In addition, diagnostic and surgical techniques have been refined. Here, the critical aspects of primary GISTs and how they are now managed with an integrated approach are summarized. Treatment plans are developed based on specific pathologic and molecular features of the tumor. The authors outline the general principles of therapy and highlight some of the nuances. Particular focus is given to diagnosis, surgical considerations, and the use of preoperative and postoperative tyrosine kinase inhibitors.

Overexpression of CD55 correlates with tumor progression and poor prognosis in gastric stromal tumors

Backgrounds: Accumulating evidences have demonstrated that CD55 can protect cells from complement-mediated attack, and is involved in tumor dedifferentiation, migration, invasiveness, and metastasis. However, the role of CD55 in gastrointestinal stromal tumors (GISTs) has not been investigated. Aims: Our study aimed to analyze the expression of CD55 in gastric GISTs and its correlations with clinicopathologic characteristics and prognosis. Materials and methods: A total of 118 gastric GIST patients were included in our study. CD55 expression in GIST tissue samples was evaluated using immunohistochemistry. Cumulative survival was conducted using the Kaplan-Meier method. Cox regression analyses were performed to identify factors associated with progression-free survival (PFS) for patients with gastric GISTs. Results: Of 118 gastric GISTs patients included in our study, 44 (37.3%) were positive for CD55 expression. Positive CD55 expression in gastric GISTs was closely associated with tumor size (13.52±7.35 vs 5.07±1.90 cm, respectively; P<0.001), Ki 67 labeling index (P=0.001), mitotic counts (P=0.005), NIH risk classification (P<0.001), PLR (P<0.001), and metastasis at initial diagnosis (P=0.002). Kaplan-Meier analyses revealed that tumor size (P<0.001), mitotic counts (P<0.001), Ki 67 labeling index (P<0.001), PLR (P<0.001), metastasis at initial diagnosis (P=0.031), and CD55 expression (P<0.001) were statistically significant risk factors affecting PFS of patients with gastric GISTs. Cox multivariate survival analysis showed that mitotic counts, Ki 67 labeling index, and CD55 expression were independent predictors of PFS for gastric GISTs. Conclusion: CD55 may be a potential prognostic marker in gastric GISTs patients.

The prognostic value of gastrointestinal bleeding in gastrointestinal stromal tumor: A propensity score matching analysis

Background and objectives

Whether gastrointestinal (GI) bleeding indicates gastrointestinal stromal tumor (GIST) rupture and impacts prognosis is unclear. We examined the prognostic value of GI bleeding in GIST.

Methods

Primary GIST patients with (GB group) or without (NGB group) initial symptoms of GI bleeding were retrospectively studied. Propensity score matching (PSM) was conducted to reduce confounders.

Results

Eight hundred patients were enrolled. Male gender [odds ratio (OR) = 1.517, P = 0.011], tumors in the small intestine (OR = 2.539, P < 0.001), and tumor size 5‐10 cm (OR = 2.298, P = 0.004) increased the odds of GI bleeding; age >60 years decreased the odds (OR = 0.683, P = 0.031). After PSM, 444 patients were included (222 in each group). Relapse‐free survival (RFS) (P = 0.001) and overall survival (OS) (P = 0.002) were both superior in the GB group. In subgroup analysis, the GB group achieved a superior RFS (P = 0.005) and OS (P = 0.007) in patients with small intestine GIST, but not stomach or colorectal GIST.

Conclusions

GIST patients with age <60, male gender, tumors located in the small intestine, and tumors 5‐10 cm in size had a higher risk of GI bleeding. GIST patients with GI bleeding had a superior RFS and OS. This difference was statistically significant only in small intestine GIST.

Predictive ability of prognostic nutritional index in surgically resected gastrointestinal stromal tumors: a propensity score matching analysis

Prognostic nutritional index was found to be correlated with prognosis in GISTs before and after propensity score matching and its incorporation improved the prognostic stratification of NIH risk criteria.

New frontiers in the medical management of gastrointestinal stromal tumours

The tyrosine kinase inhibitor (TKI) imatinib has radically changed the natural history of KIT-driven gastrointestinal stromal tumours (GISTs). Approved second-line and third-line medical therapies are represented by the TKIs sunitinib and regorafenib, respectively. While imatinib remains the cardinal drug for patients with GISTs, novel therapies are being developed and clinically tested to overcome the mechanisms of resistance after treatments with the approved TKI, or to treat subsets of GISTs driven by rarer molecular events. Here, we review the therapy of GISTs, with a particular focus on the newest drugs in advanced phases of clinical testing that might soon change the current therapeutic algorithm.

Gastrointestinal Stromal Tumors of the Stomach and Esophagus

Gastrointestinal stromal tumors (GISTs) arise anywhere along the gastrointestinal tract, most commonly as a result of c-kit or PDGFRA proto-oncogene mutations. Surgical resection is an important component of treatment. However, molecular profiling of GISTs has provided many insights into adjuvant and neoadjuvant therapy options. Imatinib, the most frequently studied medical therapy, has been shown in numerous studies to provide benefit to patients in both the neoadjuvant and adjuvant setting. Interval imaging is an important component of the treatment of GISTs and national surveillance recommendations should be followed.

Differential immune profiles distinguish the mutational subtypes of gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common human sarcoma, frequently characterized by an oncogenic mutation in the KIT or platelet-derived growth factor receptor alpha (PDGFRA) genes. We performed RNA sequencing of 75 human GIST tumors from 75 patients, comprising the largest cohort of GISTs sequenced to date, in order to discover differences in the immune infiltrates of KIT and PDGFRA-mutant GIST. Through bioinformatics, immunohistochemistry, and flow cytometry, we found that PDGFRA-mutant GISTs harbored more immune cells with increased cytolytic activity when compared to KIT-mutant GISTs. PDGFRA-mutant GISTs expressed many chemokines, such as CXCL14, at a significantly higher level when compared to KIT-mutant GISTs and exhibited more diverse driver-derived neoepitope:HLA binding, both of which may contribute to PDGFRA-mutant GIST immunogenicity. Through machine learning, we generated gene expression-based immune profiles capable of differentiating KIT and PDGFRA-mutant GISTs, and also identified additional immune features of high PD-1 and PD-L1 expressing tumors across all GIST mutational subtypes, which may provide insight into immunotherapeutic opportunities and limitations in GIST.

The assessment of different risk classification systems for gastrointestinal stromal tumors (GISTs): the analytic results from the SEER database

BACKGROUND

Although various risk classification systems for GISTs have been proposed, the optimum one remains uncertain. In the present study, we compared the prognostic stratification of different risk classification systems for GIST patients.

METHODS

We reviewed those patients who were pathologically diagnosed with GISTs in the SEER database between 2009 and 2014. All patients were classified into different risk groups according to the NIH criteria, AFIP criteria and AJCC staging system, respectively. The prognostic differences between different risk groups were compared and clinicopathologic features were analyzed.

RESULTS

The prognosis of small intestinal GISTs was not significantly different from that of gastric GISTs. For gastric GIST patients, there was no significant prognostic difference between very low risk and low risk group according to the NIH and AFIP criteria. However, the prognostic stratification for two groups could be improved by the AJCC staging system. For small intestinal GIST patients, the prognostic difference between low risk and intermediate risk group was not stratified properly by the NIH and AFIP criteria. However, the prognostic difference between two groups could reach statistical significance according to the AJCC staging system. Unlike gastric GISTs, tumor size was not identified as an independent factor influencing the prognosis of small intestinal GISTs.

CONCLUSIONS

The AJCC staging system could provide a better prognostic stratification for GIST patients compared with the NIH and AFIP criteria, regardless of gastric or small intestinal tumor. However, primary tumor location and tumor size may be reconsidered and revised in the risk classification system.

Prognostic value of tumor necrosis in gastrointestinal stromal tumor: A meta-analysis

BACKGROUND AND AIMS

There is currently no consensus regarding the influence of tumor necrosis on the prognosis of gastrointestinal stromal tumors (GISTs). Therefore, we conducted a meta-analysis to determine the prognostic role of tumor necrosis in patients with GIST.

METHODS

PubMed, Embase, and Web of Science electronic databases were searched from their inception to March 2018. Studies reporting data on the relationship between tumor necrosis and GIST prognosis were eligible. The measure of the effect of interest was the odds ratios (ORs) with 95% confidence intervals (CIs). This study has been registered in the Prospero (number CRD42018096036).

RESULTS

In total, 18 studies including 2320 patients were identified. The total odds of tumor necrosis were associated with a poor GIST prognosis (OR = 5.54, 95% CI = 4.39-6.99). Subgroup analysis of different observed outcomes indicated that tumor necrosis was associated with a decreased disease-free survival (OR = 7.08, 95% CI = 4.78-10.49), recurrence-free survival (OR = 3.96, 95% CI = 2.48-6.32), and overall survival (OR = 4.29, 95% CI = 2.02-9.13). In addition, any tumor site, tumor size, follow-up time, ethnicity, different outcomes of GIST, and different degrees of positive staining of immunohistochemical markers subgroups showed a significantly increased risk of a poor prognosis.

CONCLUSIONS

Tumor necrosis may likely predict a poorer prognosis for GIST. However, further well-designed prospective studies with large sample size are required in the future.

Prognostic impact of preoperative neutrophil-lymphocyte ratio for surgically resected gastrointestinal stromal tumors

Neutrophil-lymphocyte ratio (NLR) was shown to be prognostic value in various malignancies. There are limited data about predictive or prognostic role of NLR during gastrointestinal stromal tumors (GISTs) patients. This study evaluated the prognostic significance of preoperative NLR in patients with GIST.We retrospectively enrolled 72 primary GIST patients who received initial curative surgical resection with or without adjuvant imatinib therapy. The preoperative NLR in the peripheral blood was calculated. Univariate and multivariate Cox proportional hazard regression models were used to identify potential predictors of tumor outcomes.The NLR cut-off value of 4.18 was selected. Multivariate analysis revealed that high NLR was associated with a unfavorable prognosis of GISTs (P < .05). Tumor size, tumor location, and age were significantly correlated with the NLR (P < .05).High NLR was an unfavorable prognostic factor of overall survival in GISTs and may be a useful preoperative biomarker of the prognosis of GISTs.

Establishment and Verification of Prognostic Nomograms for Patients with Gastrointestinal Stromal Tumors: A SEER-Based Study

With gastrointestinal tract as the origin, gastrointestinal stromal tumor (GIST) is recognized as the very widespread mesenchymal tumor. A precise prognostic model of survival is required to guide the treatment options of patients with GIST. This study was designed to map the overall survival (OS) and cancer-specific survival (CSS) of GIST patients. According to the Surveillance, Epidemiology, and End Results (SEER) program database, we acquired the data of 6,713 patients with GIST who were diagnosed between 2004 and 2014. We randomly separated the patients into training (n = 4,699) and validation (n = 2,014) groups. To assess the prognostic impact of multiple clinical parameters, the Kaplan-Meier approach and the Cox proportional hazards regression model were adopted, where essential prognostic variables were combined to create nomograms. The consistency index and curve of calibration had been adopted to assess nomogram discrimination ability and prediction accuracy. A multifactor analysis of the training cohort showed that age, gender, size of tumor, location, and primary surgery were remarkably related to survival, and these variables were applied to create nomograms. The nomogram demonstrated excellent accuracy in estimating 2-, 3-, and 5-year OS and CSS, with a C-index of 0.740 (95% confidence interval [CI], 0.723-0.757) for OS and 0.743 (95% CI, 0.718-0.768) for CSS. In the validation cohort, the nomogram-predicted C-index was 0.741 for OS (95%CI, 0.717-0.765) and 0.746 (95%CI, 0.713-0.779) for CSS. All calibration curves showed good consistency between predicted and actual survival. A new nomogram was created and verified to predict the OS and CSS of patients with GIST. These new prognostic models can help enhance the accuracy of survival outcome predictions, thus facilitating to provide constructive therapeutic suggestions.

Performance of risk stratification systems for gastrointestinal stromal tumors: A multicenter study

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor type in the gastrointestinal system. Presently, various classification systems to prognosticate GISTs have been proposed.

AIM

To evaluate the application value of four different risk stratification systems for GISTs.

METHODS

Patients who were diagnosed with GISTs and underwent surgical resection at four hospitals from 1998 to 2015 were identified from a database. Risk of recurrence was stratified by the modified National Institute of Health (NIH) criteria, the Armed Forces Institute of Pathology (AFIP) criteria, the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram, and the contour maps. Receiver operating characteristic (ROC) curves were established to compare the four abovementioned risk stratification systems based on the area under the curve (AUC).

RESULTS

A total of 1303 patients were included in the study. The mean age of the patients was 55.77 ± 13.70 yr; 52.3% of the patients were male. The mean follow-up period was 64.91 ± 35.79 mo. Approximately 67.0% the tumors were located in the stomach, and 59.5% were smaller than 5 cm; 67.3% of the patients had a mitotic count ≤ 5/50 high-power fields (HPFs). Thirty-four tumors ruptured before and during surgery. Univariate analysis demonstrated that tumor size > 5 cm (P < 0.05), mitotic count > 5/50 HPFs (P < 0.05), non-gastric location (P < 0.05), and tumor rupture (P < 0.05) were significantly associated with increased recurrence rates. According to the ROC curve, the AFIP criteria showed the largest AUC (0.754).

CONCLUSION

According to our data, the AFIP criteria were associated with a larger AUC than the NIH modified criteria, the MSKCC nomogram, and the contour maps, which might indicate that the AFIP criteria have better accuracy to support therapeutic decision-making for patients with GISTs.

Defining Tumor Rupture in Gastrointestinal Stromal Tumor

Tumor rupture is an important risk factor predictive of recurrence after macroscopically complete resection of gastrointestinal stromal tumors (GISTs), and an indication for defined interval or even lifelong adjuvant therapy with imatinib according to guidelines. However, there is no consensus or universally accepted definition of the term ‘tumor rupture’, and, consequently, its incidence varies greatly across reported series. Without predefined criteria, the clinical significance of rupture has also been difficult to assess on multivariate analysis of retrospective data. We reviewed the relevant literature and international guidelines, and, based on the Oslo criteria, proposed the following six definitions for ‘tumor rupture’: (1) tumor fracture or spillage; (2) blood-stained ascites; (3) gastrointestinal perforation at the tumor site; (4) microscopic infiltration of an adjacent organ; (5) intralesional dissection or piecemeal resection; or (6) incisional biopsy. Not all minor defects of tumor integrity should not be classified as rupture, i.e. mucosal defects or spillage contained within the gastrointestinal lumen, microscopic tumor penetration of the peritoneum or iatrogenic damage only to the peritoneal lining, uncomplicated transperitoneal needle biopsy, and R1 resection. This broad definition identifies GIST patients at particularly high risk of recurrence in population-based cohorts; however, its applicability in other sarcomas has not been investigated. As the proposed definition of tumor rupture in GIST has limited evidence based on the small number of patients with rupture in each retrospective study, we recommend validating the proposed definition of tumor rupture in GIST in prospective studies and considering it in clinical practice.

A radiomics nomogram based on multiparametric MRI might stratify glioblastoma patients according to survival

OBJECTIVES

To construct a radiomics nomogram for the individualized estimation of the survival stratification in glioblastoma (GBM) patients using the multiregional information extracted from multiparametric MRI, which could facilitate the clinical decision-making for GBM patients.

MATERIALS AND METHODS

A total of 105 eligible GBM patients (57 in the long-term and 48 in the short-term survival groups, separated by an overall survival of 12 months) were selected from the Cancer Genome Atlas. These patients were divided into a training set (n = 70) and a validation set (n = 35). Radiomics features (n = 4000) were extracted from multiple regions of the GBM using multiparametric MRI. Then, a radiomics signature was constructed using least absolute shrinkage and selection operator regression for each patient in the training set. Combined with clinical risk factors, a radiomics nomogram was constructed based on a multivariate logistic regression model. The performance of this radiomics nomogram was assessed by calibration, discrimination, and clinical usefulness.

RESULTS

The radiomics signature consisted of 25 selected features and performed better than clinical risk factors (i.e., age, Karnofsky performance status, and treatment strategy) in survival stratification. When the radiomics signature and clinical risk factors were combined, the radiomics nomogram exhibited promising discrimination in the training (C-index, 0.971) and validation (C-index, 0.974) sets. The favorable calibration and decision curve analysis indicated the clinical usefulness of the radiomics nomogram.

CONCLUSIONS

The presented radiomics nomogram, as a non-invasive prediction tool, could exhibit a favorable predictive accuracy and provide individualized probabilities of survival stratification for GBM patients.

KEY POINTS

• Non-invasive survival stratification of GBM patients can be obtained with a radiomics nomogram. • The proposed nomogram constructed by radiomics signature selected from 4000 radiomics features, combined with independent clinical risk factors such as age, Karnofsky performance status, and treatment strategy. • The proposed radiomics nomogram exhibited good calibration and discrimination for survival stratification of GBM patients in both training (C-index, 0.971) and validation (C-index, 0.974) sets.

PRE-OPERATIVE GASTRIC GIST DOWNSIZING: THE IMPORTANCE OF NEOADJUVANT THERAPY

Introduction:

Gastric gastrointestinal tumors (GIST) are a rare and usually asymptomatic neoplasm that can present as abdominal mass in more advanced scenarios. Since surgical resection is the main aspect of the treatment, locally advanced tumors require multivisceral resection and, therefore, higher postoperative morbidity and mortality.

Objective:

To perform a review the literature on the topic, with emphasis on the neoadjuvant therapy.

Methods:

Literature review on the Medline database using the following descriptors: gastrointestinal stromal tumors, neoadjuvant therapy, imatinib mesylate and molecular targeted therapy.

Results:

Surgical resection remains the cornerstone for the treatment of GISTs; however, tyrosine kinase inhibitors have improved survival as an adjuvant therapy. More recently, neoadjuvant therapy have been described in the treatment of locally advanced tumors in order to avoid multivisceral resection.

Conclusion:

Despite surgical resection remains as the most important aspect of the treatment of GISTs, adjuvant and neoadjuvant therapy with tyrosine kinase inhibitors have shown to both improve survival and resectability, respectively.

A Rare Case of Gastrointestinal Stromal Tumor with a Liver Metastasis Infiltrating the Inferior Vena Cava and Extending to the Right Atrium with an Early Recurrence after Surgical Extraction

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract. The major cause of GIST is the presence of an abnormal form of tyrosine protein kinase (KIT) protein also known as CD117, which causes uncontrollable growth of the gastrointestinal cells. Most studies report incidences between 10 and 15 cases of GISTs per million. Metastases to the liver and peritoneum are the most frequent. We report a case of advanced GIST with a liver metastasis infiltrating the inferior vena cava (IVC) and extending to the right atrium in the form of a large, floating, isolated intracardiac liver metastasis with diastolic prolapsing through the tricuspid valve. This is a very rare manifestation. One week after heart surgery and removal of a 5 × 6 cm tumor mass from the right atrium and the IVC, echocardiography depicted an early recurrence.

Development and validation of a nomogram to individually predict survival of young patients with nonmetastatic gastric cancer: A retrospective cohort study

BACKGROUND/AIMS

Evidence regarding gastric cancer (GC) patients <40 years old is limited. The aim of the study was to identify risk factors affecting overall survival (OS) of young patients with nonmetastatic GC and to establish a nomogram for prognostic prediction using data from the Surveillance, Epidemiology and End Results (SEER) database. Furthermore, this study sought to externally validate this nomogram in an independent patient cohort.

PATIENTS AND METHODS

In this retrospective cohort study, the records of patients aged <40 years with nonmetastatic GC (n = 559), from the SEER database, between 2006 and 2015, were examined. The nomogram was established based on the Cox proportional hazards regression model using the SEER dataset. Patients with nonmetastatic GC (n = 201) in our department between 2009 and 2015 were selected as an external validation set. Discrimination and calibration were performed in both cohorts.

RESULTS

The multivariate Cox model identified race, tumor subsites, tumor size, depth of invasion, lymph node metastasis, number of examined lymph nodes, and surgery as independent covariates associated with OS. The nomogram exhibited superior discriminative power than the eighth tumor, node, metastasis (TNM) staging system in both the training set [Harrell's concordance index (C index): 0.762 vs. 0.635,P < 0.001] and validation set (C index: 0.805 vs. 0.712,P= 0.176). Calibration of the nomogram was good in both cohorts.

CONCLUSIONS

We developed a nomogram predicting 3- and 5-year OS rates in young patients with nonmetastatic GC. Both the training set and validation set showed good discrimination and calibration, suggesting good clinical applicability.

Relationship between diagnostic imaging features and prognostic outcomes in gastrointestinal stromal tumors (GIST)

Gastrointestinal stromal tumors (GISTs), the most frequent mesenchymal neoplasms of the gastrointestinal tract, are a relatively recently described entity. GISTs can occur across any age but are more common in patients older than 50 years. GISTs most commonly are in the stomach (60-70%), followed by the small intestine (20%-30%); they also rarely occur in the abdominal cavity, such as in the mesentery, the omentum and the retroperitoneum. Contrast-enhanced multi-detector computed tomography (MDCT) is the most largely used imaging modality for the localization, characterization and staging of GISTs. All patterns of enhancement on contrast-enhanced MDCT can be seen with GISTs, including hypoenhancing, isoenhancing, and hyperenhancing neoplasms. A lot of prognostication systems have been proposed for the risk stratification of GISTs. This review outlines the relationship between different diagnostic imaging features and prognostic outcomes in GISTs.

Neoadjuvant and adjuvant therapy for gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are rare and mesenchymal in origin with a yearly incidence of 10-15 cases per million people. If it is technically resectable, surgical resection is the mainstay of therapy regardless of tumor location,. Although complete (R0) resection can be achieved in up to 85% of patients with primary disease, approximately 50% of patients experience recurrence or metastases within 5 years of primary resection. Moreover, prior to 2000, the prognosis of patients with advanced, inoperable GIST was poor because the molecular mechanism had not sufficiently been elucidated, thus effective therapy was lacking. The tyrosine kinase inhibitor imatinib, which selectively inhibits tyrosine kinase KIT, has shown substantial clinical benefit for patients with GIST. In clinical trials, imatinib treatment resulted in response rates of 40%-55% and longer progression-free survival for patients with a KIT-positive unresectable or metastatic GIST. Furthermore, recent clinical trials have shown that giving imatinib after curative resection for high-risk cases prolonged recurrence-free survival and overall survival in an adjuvant setting. Several clinical trials of imatinib treatment in a neoadjuvant setting are ongoing; however, in clinical settings, there are problems to resolve, such as optimal agents, duration of administration, and postoperative management. In this review, we discuss the application of surgical options, combined with adjuvant/neoadjuvant or perioperative imatinib treatment and their potential impact on survival for patients with primary, recurrent, or metastatic GIST.

Developed and validated a prognostic nomogram for recurrence-free survival after complete surgical resection of local primary gastrointestinal stromal tumors based on deep learning

This study aimed to develop and validate a prognostic nomogram for recurrence-free survival (RFS) after surgery in the absence of adjuvant therapy to guide the selection for adjuvant imatinib therapy based on Residual Neural Network (ResNet). The ResNet model was developed based on contrast-enhanced computed tomography (CE-CT) in a training cohort consisted of 80 patients pathologically diagnosed gastrointestinal sromal tumors (GISTs) and validated in internal and external validation cohort respectively. Independent clinicopathologic factors were integrated with the ResNet model to construct the individualized nomogram. The performance of the nomogram was evaluated in regard to discrimination, calibration, and clinical usefulness. The ResNet model was significantly associated with RFS. Integrable predictors in the individualized ResNet nomogram included the tumor site, size, and mitotic count. Compared with modified NIH, AFIP, and clinicopathologic nomogram, both ResNet nomogram and ResNet model showed a better discrimination capability with AUCs of 0·947(95%CI, 0·910-0·984) for 3-year-RFS, 0·918(0·852-0·984) for 5-year-RFS, and AUCs of 0·912 (0·851-0·973) for 3-year-RFS, 0·887(0·816-0·960) for 5-year-RFS, respectively. Calibration curve shows the good calibration of the nomogram in terms of the agreement between the estimated and the observed 3- and 5- year outcomes. Decision curve analysis showed that the ResNet nomogram had a higher overall net benefit. In conclusion, we presented a deep learning-based prognostic nomogram to predict RFS after resection of localized primary GISTs with excellent performance and could be a potential tool to select patients for adjuvant imatinib therapy.

A new nomogram for recurrence-free survival prediction of gastrointestinal stromal tumors: Comparison with current risk classification methods

BACKGROUND

This study aimed to build a new risk stratification nomogram for gastrointestinal stromal tumors (GISTs) focused on a popular factor Ki-67 to enable individualized and precise predictions of the most suitable candidates for imatinib therapy.

METHODS

We retrospectively collected clinicopathologic data of the patients diagnosed with GISTs from January 1998 to December 2015 at Southern Medical University Nanfang Hospital as the experiment group. And patients with GISTs at the Sun Yat-sen University Cancer Center from January 2007 to December 2012 were included as the validation group. The nomogram was built using Kaplan-Meier method and the Cox proportional hazards regression model. The receiver operating characteristic (ROC) curves were established to compare the discriminative ability of the new nomogram with other risk stratification systems, including the modified National Institute of Health (modified NIH) criteria, Armed Forces Institute of Pathology (AFIP) criteria, Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram, and contour maps.

RESULTS

In univariate analysis, the tumor size, site, mitotic count, tumor rupture and Ki-67 labeling index were significant factors (all P < 0.05) and included in the Cox model to build our nomogram. According to the ROC curve, our new nomogram showed the largest AUC value (0.778) compared with that of the other classification methods (contour maps, AUC = 0.743; AFIP, AUC = 0.719; MSKCC, AUC = 0.712; and modified NIH, AUC = 0.719).

CONCLUSION

Our new nomogram exhibits an excellent performance and might become a potential risk stratification to support therapeutic decision-making for GISTs.

Efficacy and Tolerability of 5-Year Adjuvant Imatinib Treatment for Patients With Resected Intermediate- or High-Risk Primary Gastrointestinal Stromal Tumor: The PERSIST-5 Clinical Trial

Importance

Three years of adjuvant imatinib mesylate therapy is associated with reduced recurrence rates and improved overall survival in patients with high-risk primary gastrointestinal stromal tumor (GIST) compared with patients who receive 1 year of treatment. The impact of a longer duration of therapy is unknown.

Objective

To determine whether adjuvant treatment for primary GIST with imatinib for 5 years is tolerable and efficacious.

Design, Setting, and Participants

This prospective, single-arm, phase 2 clinical trial (Postresection Evaluation of Recurrence-free Survival for Gastrointestinal Stromal Tumors With 5 Years of Adjuvant Imatinib [PERSIST-5]) included adult patients with primary GIST (expressing KIT) at 21 US institutions who underwent a macroscopically complete resection and were at intermediate or high risk of recurrence, defined as primary GIST at any site measuring 2 cm or larger with 5 or more mitoses per 50 high-power field or nongastric primary GIST measuring 5 cm or larger. Data were collected from August 5, 2009, through December 20, 2016.

Interventions

Imatinib, 400 mg once daily, orally for 5 years or until discontinuation of therapy because of progression or intolerance.

Main Outcomes and Measures

The primary end point was recurrence-free survival (RFS). The secondary end point was overall survival.

Results

Of the 91 patients enrolled, 48 (53%) were men with a median age of 60 years (range, 30-90 years). Median tumor size was 6.5 cm (range, 2.3-30.0 cm). Median treatment duration was 55.1 months (range, 0.5-60.6 months); 46 patients (51%) completed 5 years of imatinib therapy. Estimated 5-year RFS was 90% (95% CI, 80%-95%), and overall survival was 95% (95% CI, 86%-99%). Recurrence was noted in 7 patients: 1 had disease recur while receiving imatinib (PDGFRA D842V mutation) and died; 6 had disease recur after discontinuation of imatinib therapy. Two additional deaths were unrelated to treatment or tumor progression. Forty-five patients (49%) stopped treatment early because of patient choice (10 [21%]), adverse events (15 [16%]), or other (11 [12%]). All 91 patients experienced at least 1 adverse event, and 17 (19%) experienced grade 3 or 4 adverse events.

Conclusions and Relevance

In this first adjuvant trial, to our knowledge, of patients with resected primary GIST who received 5 years of imatinib therapy, no patient with imatinib-sensitive mutations had disease recur during therapy. For patients in whom disease recurred, recurrence was within 2 years of discontinuation of imatinib therapy. Approximately half of the patients discontinued treatment early, most commonly because of patient choice, thus emphasizing the importance of close clinical monitoring to continue imatinib treatment for patients at appropriate risk.

Trial Registration

ClinicalTrials.gov identifier: NCT00867113.

Standard Approach to Gastrointestinal Stromal Tumors - Differences between China and Europe

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. With the considerable research and application of molecular-targeted therapy for GISTs in the last two decades, GISTs have become a model of multidisciplinary oncological treatment. Although Western clinical guidelines are available for GISTs, such as those by the European Society of Medical Oncology (ESMO), the clinical situations in China are different from those in European countries. There are distinct differences between the clinical practice, diagnostic methods, surgical approach, and availability of new targeted agents in China and those in Europe. This review summarizes the Chinese GIST consensus guidelines compared to the European ones, which may provide an optimal approach to the diagnosis and management of GIST patients.

Comparing the long-term outcomes among patients with stomach and small intestine gastrointestinal stromal tumors: An analysis of the National Cancer Database

BACKGROUND AND OBJECTIVES

Gastrointestinal stromal tumors (GIST) are the most common sarcoma arising from the gastrointestinal tract. Data regrading long-term prognosis based on tumor location (stomach vs small intestine) are mixed, so we aimed to analyze their outcomes using a large national oncology database.

METHODS

The National Cancer Database was queried for cases of stomach and small intestine GIST between the years 2004 and 2014. Survival analysis was performed using the Kaplan-Meier method, and factors related to survival were compared using the Cox proportional hazards model.

RESULTS

Of 18 900 total patients, those with small intestine GIST had larger median tumor size (6.2 cm; interquartile range [IQR], 3.8 to 10.0 vs stomach: 5.0 cm; IQR, 3.0 to 9.0; P < 0.001) and a higher incidence of tumors with ≥5 mitoses/50 HPF (29.3% vs stomach: 24.2%; P < 0.001). Unadjusted median overall survival (OS) was longer for patients with stomach GIST (10.3 years) as compared to small intestine GIST (9.4 years) (P = 0.01). After controlling for patient and tumor-related factors, however, OS did not differ between stomach and small intestine GIST (hazard ratio, 1.19; 95% confidence interval, 0.88 to 1.61; P = 0.26).

CONCLUSIONS

Patients with small intestine GIST more commonly have larger, high mitotic rate tumors, but despite these worse prognostic features, tumor location did not independently impact OS.

A cohort study of prognostic factors associated with recurrence or metastasis of gastrointestinal stromal tumor (GIST) of stomach

Background

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. The major risk factors of recurrence and metastasis are mitotic index and tumor size. This study investigates the risk of recurrence and metastasis in solely gastric GIST. The primary outcome is to evaluate risk of recurrence and metastasis. The secondary outcome is to analyse survival rates of patients who have recurrence and metastasis after curative resection.

Method

A cohort of patients who underwent curative resection of gastric GIST between January 2006 to December 2016 was reviewed. The diagnosis was confirmed with positive CD34, DOG1 or KIT (CD117) immunohistochemistry. Risk factors of recurrence and metastasis were analyzed.

Results

Sixty-eight patients who received curative resection and diagnosed as gastric GIST were included in this study. Twenty (29.41%) had recurrence or metastasis. The median follow up time was 31.95 months. The mostcommon type of surgery was partial gastric resection. There were statistically-significant differences between mitotic index 6 HPF or 6 HPF in tumor size 0-5 cm, 5-10 cm and 10 cm and the risk of recurrence or metastasis (p-value 0.036). In tumors sized 6-10 cm, patients with mitotic index 6 HPF had longer survival than patients with mitotic index 6 HPF (p-value 0.0147).

Conclusion

The factor that determines the outcome of recurrence or metastasis in solely gastric GIST is high mitotic index count. Patients who have abdominal pain may be suspected as advanced disease. The type of operation and tumor size are not associated with recurrence or metastasis.

•

The factor that determines the outcome of recurrence or metastasis in gastric GIST is high mitotic index count more than 6.

•

Patients who have abdominal pain may be suspected as advanced disease.

•

The tumor size are not associated with recurrence or metastasis.

•

The overall survival did not depend on the tumor size, in contrast, the overall survival depends on the mitotic index.

Molecular biomarkers for prognosis of gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. However, the development of molecular markers, especially circulating biomarkers, remains largely undone for the prognosis of GIST. We discussed the clinical-pathological characteristics of GIST and identified potential biomarkers for guidance of therapy and prognosis of GIST. Around 90% of GISTs contain mutations in KIT or PDGFRA and the remaining 10% of GISTs are wild-type. Recent studies have indicated that various DNAs and miRNAs could serve as potential biomarkers for prognosis of GIST, including KIT, PDGFRA, other DNAs (such as BRAF, SDH, SETD2 and ROR2), and microRNAs (miRNAs). The pressing need and challenges in the development of circulating prognostic biomarkers for GIST are also discussed. Although challenges remain, DNAs and miRNAs are promising circulating biomarkers for surveillance and prognosis of GIST. Advances in clarification of aberrant molecular alterations may open new avenues for exploration of reliable and robust biomarkers to improve the management of GIST.

Secreted protein acidic and rich in cysteine-like 1 suppresses metastasis in gastric stromal tumors

Background

Malignant growth and metastasis of gastrointestinal stromal tumors (GIST) occur in some patients even during the course of treatment, but their mechanisms remains poorly understand at the molecular level so far.

Methods

Profiles of protein expression in gastric GIST tissues were explored using protein microarray analysis, down-regulation of SPARCL1 (secreted protein acidic and rich in cysteine-like protein 1) was validated by RT-qPCR, western blot and immunohistochemistry. The effect of specific shRNA-induced SPARCL1 downregulation on the biological traits of GIST 882 cell was investigated. We then employed a mouse xenograft model to investigate whether the low-expression of SPARCL1 impact the metastasis ability of GIST cells in vivo.

Results

SPARCL1 was significantly downregulated in the gastric GIST with high-grade malignance as compared with low-grade malignance, its expression was closely correlated with tumor size, mitotic index, distant metastasis at the time of initial diagnosis and tumor progression of GIST (P < 0.05). Moreover, results of the Cox analysis showed that expression of SPARCL1 is an independent prognostic predictors for gastric GIST (P = 0.008; HR 0.157, 95% CI 0.040~ 0.612). Downregulation of SPARCL1 promoted cell migration and invasion, but did not affect proliferation, cell cycle and apoptosis of GIST 882 cells. In mouse xenograft model, GIST cells with the decreased expression of SPARCL1 presented an enhanced ability of liver metastasis (P < 0.05).

Conclusions

Taken together, our present study demonstrated that SPARCL1 have a certain degree of malignancy-suppressing potential through inhibiting the metastasis of gastric GIST.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0833-8) contains supplementary material, which is available to authorized users.

Postoperative imatinib in patients with intermediate risk gastrointestinal stromal tumor

Aim: To determine whether imatinib adjuvant treatment improved recurrence-free survival (RFS) in gastrointestinal stromal tumor (GIST) with intermediate risk. Materials & methods: Patients who had undergone complete tumor resection with intermediate risk were enrolled. Results: A total of 99 patients received imatinib adjuvant therapy and 93 patients only received observation. The RFS in patients who received adjuvant therapy was superior to RFS in control group (p = 0.004). GIST with location of intestine or rectum and GIST with exon 11 deletion mutation had longer RFS. Conclusion: Adjuvant imatinib improves RFS of GIST with intermediate risk of recurrence, particularly in GIST with intestinal and rectal location or c-kit gene exon 11 deletion mutation.

Clinicopathological Features and Prognosis of Primary GISTs with Tumor Rupture in the Real World

Background

Patients with ruptured gastrointestinal stromal tumor (GIST) are recommended for imatinib adjuvant therapy; however, their clinicopathological features and prognosis in the era of imatinib are unknown.

Patients and Methods

The study cohort included 665 patients with histologically proven primary GISTs who underwent R0 or R1 surgery between 2003 and 2007; the validation cohort included 182 patients between 2000 and 2014. The definitions of tumor rupture in the study included perforation at tumor site, tumor fracture, piecemeal resection including open biopsy, and macroscopic injuries to the pseudocapsule.

Results

Tumor rupture occurred in 21 (3.2%) of 665 and 5 (2.9%) of 182 patients in the study and validation cohort, respectively. Ruptured GISTs were more symptomatic, were larger in size, and had higher mitotic count than nonruptured GISTs but were not associated with tumor location or laparoscopic surgery. GISTs with intraoperative rupture had clinicopathological features and prognostic outcomes similar to those with preoperative rupture. Recurrence rates were higher and median recurrence-free survival (RFS) and overall survival (OS) were shorter with ruptured than nonruptured GIST. Tumor rupture was one of the independent prognostic factors for RFS, but not OS, according to multivariate analysis.

Conclusions

Ruptured GISTs were symptomatic larger tumors with high mitotic activity, frequent relapse, and shorter RFS. Tumor rupture was an independent prognostic factor for RFS, but not for OS, in the era of imatinib.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6505-7) contains supplementary material, which is available to authorized users.

Nomograms predicting survival of patients with unresectable or metastatic gastric cancer who receive combination cytotoxic chemotherapy as first-line treatment

BACKGROUND

Some clinicopathological variables are known to influence the survival of patients with advanced gastric cancer. A comprehensive model based on these factors is needed for prediction of an individual's survival and appropriate patient counseling.

METHODS

A nomogram for predicting 1-year survival in patients with advanced gastric cancer in the palliative chemotherapy setting was developed using clinicopathological data from 949 patients with unresectable or metastatic gastric cancer who had received first-line doublet cytotoxic chemotherapy from 2001 to 2006 at the National Cancer Center, Korea (Baseline Nomogram). For 836 patients whose initial response to chemotherapy is known, another nomogram (ChemoResponse-based Nomogram) was constructed using the response to chemotherapy as additional variable. Nomogram performance in terms of discrimination and calibration ability was evaluated using the C statistic and Hosmer-Lemeshow-type χ ² statistics.

RESULTS

Two different nomograms were developed and subjected to internal validation. The baseline nomogram incorporated 13 baseline clinicopathological variables, whereas the chemoresponse-based nomogram was composed of 11 variables including initial response to chemotherapy. Internal validation revealed good performance of the two nomograms in discrimination: C statistics = 0.656 (95% confidence interval, 0.628-0.673) for the baseline and 0.718 (95% confidence interval, 0.694-0.741) for the chemoresponse-based nomogram, which showed significantly better discrimination performance than the baseline nomogram (Z statistics = 3.74, p < 0.01).

CONCLUSION

This study suggests that individual 1-year survival probability of patients receiving first-line doublet cytotoxic chemotherapy for advanced gastric cancer can be reliably predicted by a nomogram-based method incorporating clinicopathological variables and initial response to chemotherapy.

Nationwide trends in the incidence and outcome of patients with gastrointestinal stromal tumour in the imatinib era

Background

The incidence, treatment and outcome of patients with newly diagnosed gastrointestinal stromal tumour (GIST) were studied in an era known for advances in diagnosis and treatment.

Methods

Nationwide population‐based data were retrieved from the Netherlands Cancer Registry. All patients with GIST diagnosed between 2001 and 2012 were included. Primary treatment, defined as any treatment within the first 6–9 months after diagnosis, was studied. Age‐standardized incidence was calculated according to the European standard population. Changes in incidence were evaluated by calculating the estimated annual percentage change (EAPC). Relative survival was used for survival calculations with follow‐up available to January 2017.

Results

A total of 1749 patients (54·0 per cent male and median age 66 years) were diagnosed with a GIST. The incidence of non‐metastatic GIST increased from 3·1 per million person‐years in 2001 to 7·0 per million person‐years in 2012; the EAPC was 7·1 (95 per cent c.i. 4·1 to 10·2) per cent (P < 0·001). The incidence of primary metastatic GIST was 1·3 per million person‐years, in both 2001 and 2012. The 5‐year relative survival rate increased from 71·0 per cent in 2001–2004 to 81·4 per cent in 2009–2012. Women had a better outcome than men. Overall, patients with primary metastatic GIST had a 5‐year relative survival rate of 48·2 (95 per cent c.i. 42·0 to 54·2) per cent compared with 88·8 (86·0 to 91·4) per cent in those with non‐metastatic GIST.

Conclusion

This population‐based nationwide study found an incidence of GIST in the Netherlands of approximately 8 per million person‐years. One in five patients presented with metastatic disease, but relative survival improved significantly over time for all patients with GIST in the imatinib era.

Surgery improves survival