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

Establishing nomograms for predicting disease-free survival and overall survival in patients with breast cancer

BACKGROUND

Prognostic factors-based nomograms have been utilised to detect the likelihood of the specific cancer events. We have focused on the roles of aldehyde dehydrogenase 1 (ALDH1) and p-AKT in predicting the prognosis of BC patients. This study was designed to establish nomograms based on the integration of aldehyde dehydrogenase 1 (ALDH1) and p-AKT in predicting the disease-free survival (DFS) and overall survival (OS) of breast cancer (BC) patients.

METHODS

Demographic and clinical data were obtained from BC patients admitted to our hospital between September 2015 and August 2016. Univariate and multivariate Cox regression analyses were utilised to analyse the risk factors of recurrence and mortality. The nomograms for predicting the DFS and OS were established using the screened risk factors. Stratified analysis was performed with the cut-off value of exp (pi) of 4.0-fold in DFS and OS, respectively.

RESULTS

Multivariate Cox regression analysis indicated that ALDH, p-AKT and pathological stage III were independent risk factors for the recurrence among BC patients. ALDH1, p-AKT, pathological stage III and ER-/PR-/HER2- were independent risk factors for the mortality among BC patients. The established nomograms based on these factors were effective for predicting the DFS and OS with good agreement to the calibration curve and acceptable area under the receiver operating characteristic (ROC) curve. Finally, stratified analyses showed patients with a low pi showed significant decrease in the DFS and OS compared with those of high risk.

CONCLUSION

We established nomograms for predicting the DFS and OS of BC patients based on ALDH1, p-AKT and pathological stages. The ER-/PR-/HER2- may be utilised to predict the OS rather than DFS in the BC patients.

Interpretable artificial intelligence to optimise use of imatinib after resection in patients with localised gastrointestinal stromal tumours: an observational cohort study

BACKGROUND

Current guidelines recommend use of adjuvant imatinib therapy for many patients with gastrointestinal stromal tumours (GISTs); however, its optimal treatment duration is unknown and some patient groups do not benefit from the therapy. We aimed to apply state-of-the-art, interpretable artificial intelligence (ie, predictions or prescription logic that can be easily understood) methods on real-world data to establish which groups of patients with GISTs should receive adjuvant imatinib, its optimal treatment duration, and the benefits conferred by this therapy.

METHODS

In this observational cohort study, we considered for inclusion all patients who underwent resection of primary, non-metastatic GISTs at the Memorial Sloan Kettering Cancer Center (MSKCC; New York, NY, USA) between Oct 1, 1982, and Dec 31, 2017, and who were classified as intermediate or high risk according to the Armed Forces Institute of Pathology Miettinen criteria and had complete follow-up data with no missing entries. A counterfactual random forest model, which used predictors of recurrence (mitotic count, tumour size, and tumour site) and imatinib duration to infer the probability of recurrence at 7 years for a given patient under each duration of imatinib treatment, was trained in the MSKCC cohort. Optimal policy trees (OPTs), a state-of-the-art interpretable AI-based method, were used to read the counterfactual random forest model by training a decision tree with the counterfactual predictions. The OPT recommendations were externally validated in two cohorts of patients from Poland (the Polish Clinical GIST Registry), who underwent GIST resection between Dec 1, 1981, and Dec 31, 2011, and from Spain (the Spanish Group for Research in Sarcomas), who underwent resection between Oct 1, 1987, and Jan 30, 2011.

FINDINGS

Among 1007 patients who underwent GIST surgery in MSKCC, 117 were included in the internal cohort; for the external cohorts, the Polish cohort comprised 363 patients and the Spanish cohort comprised 239 patients. The OPT did not recommend imatinib for patients with GISTs of gastric origin measuring less than 15·9 cm with a mitotic count of less than 11·5 mitoses per 5 mm2 or for those with small GISTs (<5·4 cm) of any site with a count of less than 11·5 mitoses per 5 mm2. In this cohort, the OPT cutoffs had a sensitivity of 92·7% (95% CI 82·4-98·0) and a specificity of 33·9% (22·3-47·0). The application of these cutoffs in the two external cohorts would have spared 38 (29%) of 131 patients in the Spanish cohort and 44 (35%) of 126 patients in the Polish cohort from unnecessary treatment with imatinib. Meanwhile, the risk of undertreating patients in these cohorts was minimal (sensitivity 95·4% [95% CI 89·5-98·5] in the Spanish cohort and 92·4% [88·3-95·4] in the Polish cohort). The OPT tested 33 different durations of imatinib treatment (<5 years) and found that 5 years of treatment conferred the most benefit.

INTERPRETATION

If the identified patient subgroups were applied in clinical practice, as many as a third of the current cohort of candidates who do not benefit from adjuvant imatinib would be encouraged to not receive imatinib, subsequently avoiding unnecessary toxicity on patients and financial strain on health-care systems. Our finding that 5 years is the optimal duration of imatinib treatment could be the best source of evidence to inform clinical practice until 2028, when a randomised controlled trial with the same aims is expected to report its findings.

FUNDING

National Cancer Institute.

Establishment of nomogram to predict overall survival and cancer-specific survival of local tumor resection in patients with colorectal cancer liver metastasis with unresectable metastases: a large population-based analysis

BACKGROUND AND PURPOSE

The tumour-node metastasis (TNM) classification is a common model for evaluating the prognostic value of tumour patients. However, few models have been used to predict the survival outcomes of patients with colorectal cancer liver metastasis (CRLM) with unresectable metastases who received the primary local surgery. Thus, we utilized the Surveillance, Epidemiology, and End Results (SEER) database to establish novel nomograms for predicting the overall survival (OS) and cancer-specific survival (CSS) of these patients.

METHODS

Extracted primary data on CRLM patients by local surgery from SEER database. All prognostic factors of OS and CSS were determined by Cox regression analysis. The concordance index (C-index), receiver operating characteristic (ROC) curves and calibration curves were used to further evaluate the accuracy and discrimination of these nomograms. Decision curve analysis (DCA) was executed to evaluate the nomograms for the clinical net benefit. Risk stratification analysis (RSA) was used to evaluate the reliability of them in clinical.

RESULTS

3622 eligible patients were screened and assigned to training cohort (1812) or validation cohort (1810). The age, chemotherapy, tumour grade, primary tumour site, tumour size, lymph node positive rate (LNR), marital status, and carcinoembryonic antigen (CEA) were independent prognostic factors of OS. Additionally, the age, chemotherapy, tumour grade, primary tumour site, tumour size, LNR, and CEA were independent prognostic factors of CSS. The results of C-indexes and ROC curves indicated that the established nomograms exhibited better discrimination power than TNM classification. The calibration curves demonstrated excellent agreement between the predicted and actual survival rates for 1-, 3-, and 5 year OS and CSS. Meanwhile, the validation cohort demonstrated similar results. Background the clinic context, the DCA showed that these nomograms have higher net benefits, and the RSA showed that patients were further divided into low risk, medium risk, and high risk groups according to the predicted scores from nomograms. And, the Kaplan-Meier curve and log-rank test showed that the survival differences among the three groups are statistically significant.

CONCLUSIONS

The prognostic nomograms showed very high accuracy, identifiability, and clinical practicality in predicting the OS and CSS of CRLM patients with unresectable metastases treated by local surgery at 1-, 3-, and 5 years, which might improve individualized predictions of survival risks and help clinicians formulate treatment plans.

Adjuvant imatinib in high-risk resected gastrointestinal stromal tumors: Merely delaying the inevitable?

INTRODUCTION

Patients with high-risk resected gastrointestinal stromal tumors (GIST) receiving adjuvant imatinib have improved recurrence-free survival (RFS), however whether a complete cytocidal effect exists is unknown. We investigated this using a normalized recurrence timeline measured from end of oncologic treatment (EOOT), defined as the later of resection or end of adjuvant therapy.

METHODS

We reviewed patients with resected high-risk GIST at our cancer center from 2003 to 2018. RFS (measured from resection and EOOT), overall survival (OS), and time to imatinib resistance (TTIR) were analyzed using Kaplan-Meier analysis and multivariable Cox proportional hazards modeling. The performance of the Memorial Sloan Kettering (MSK) GIST nomogram was assessed.

RESULTS

We identified 86 patients with high-risk GIST with a median 106 months of postsurgical follow-up. One-third (n = 29; 34%) did not receive adjuvant imatinib, while 57 (66%) did for a median of 3 years. The MSK nomogram-predicted 5-year RFS for patients receiving adjuvant imatinib was similar to those who did not (29% vs. 31%, p = 0.64). When RFS was measured from EOOT, the MSK-predicted RFS was independently associated with EOOT RFS (hazard ratio 0.22, p = 0.02), while adjuvant imatinib receipt and duration were not. Neither receipt nor duration of adjuvant imatinib were associated with TTIR or OS (all p > 0.05).

CONCLUSIONS

Treatment with adjuvant imatinib delays, but does not clearly impact ultimate recurrence, TTIR, or OS, suggesting many patients with high-risk GIST may receive adjuvant imatinib unnecessarily. Additional studies are needed to establish the benefit of adjuvant therapy versus initiating therapy at first radiographic recurrence.

Developing Novel Genomic Risk Stratification Models in Soft Tissue and Uterine Leiomyosarcoma

PURPOSE

Leiomyosarcomas (LMS) are clinically and molecularly heterogeneous tumors. Despite recent large-scale genomic studies, current LMS risk stratification is not informed by molecular alterations. We propose a clinically applicable genomic risk stratification model.

EXPERIMENTAL DESIGN

We performed comprehensive genomic profiling in a cohort of 195 soft tissue LMS (STLMS), 151 primary at presentation, and a control group of 238 uterine LMS (ULMS), 177 primary at presentation, with at least 1-year follow-up.

RESULTS

In STLMS, French Federation of Cancer Centers (FNCLCC) grade but not tumor size predicted progression-free survival (PFS) or disease-specific survival (DSS). In contrast, in ULMS, tumor size, mitotic rate, and necrosis were associated with inferior PFS and DSS. In STLMS, a 3-tier genomic risk stratification performed well for DSS: high risk: co-occurrence of RB1 mutation and chr12q deletion (del12q)/ATRX mutation; intermediate risk: presence of RB1 mutation, ATRX mutation, or del12q; low risk: lack of any of these three alterations. The ability of RB1 and ATRX alterations to stratify STLMS was validated in an external AACR GENIE cohort. In ULMS, a 3-tier genomic risk stratification was significant for both PFS and DSS: high risk: concurrent TP53 mutation and chr20q amplification/ATRX mutations; intermediate risk: presence of TP53 mutation, ATRX mutation, or amp20q; low risk: lack of any of these three alterations. Longitudinal sequencing showed that most molecular alterations were early clonal events that persisted during disease progression.

CONCLUSIONS

Compared with traditional clinicopathologic models, genomic risk stratification demonstrates superior prediction of clinical outcome in STLMS and is comparable in ULMS.

Small Bowel Gastrointestinal Stromal Tumors: The Value of CT Enterography in Assessing Pathological Aggressiveness

OBJECTIVE

This study aimed to characterize the computed tomography (CT) enterography features of the small bowel gastrointestinal stromal tumors (GIST) and to determine the association with pathological aggressiveness.

METHODS

Computed tomography enterography images of 30 patients with the histologically confirmed small bowel GIST were retrospectively enrolled. Tumor size, location, border, growth pattern, enhancement pattern, necrosis, calcification, ulceration, internal air, nodal metastasis, liver metastasis, peritoneal metastasis, and draining vein were evaluated. Relationships between imaging features and pathological aggressiveness were analyzed using χ2 test or Fisher exact test. Correlations among CT features were analyzed using Spearman correlation analysis.

RESULTS

There were significant differences in tumor size between different risk levels (F = 8.388, P < 0.001). There were statistically significant differences in the 5 imaging manifestations of necrosis, ulcer, tumor boundary, drainage vein, and intratumoral gas (P < 0.05). There was a significant negative correlation between tumor size and enhancement type as well as clear tumor boundary. There was a significant positive correlation between tumor size and necrosis, ulcer, drainage vein, intratumoral gas, liver metastasis, and peritoneal metastasis.

CONCLUSIONS

Some CT enterography imaging features might be useful in the determination of the pathological aggressiveness in the patients with small bowel GIST.

Hybrid surgical approach excision of gastrointestinal stromal tumor (GIST): A case report of GIST at an unusual location and review of the literature

Gastrointestinal stromal tumors are the most common malignant subepithelial lesions involving the gastrointestinal tract. Surgical techniques have been the mainstay of treatment, however, in recent times hybrid surgeries are being introduced yielding better clinical outcomes.

Development and validation of a preoperative risk nomogram prediction model for gastric gastrointestinal stromal tumors

BACKGROUND AND STUDY AIMS

Gastrointestinal stromal tumors (GIST) carry a potential risk of malignancy, and the treatment of GIST varies for different risk levels. However, there is no systematic preoperative assessment protocol to predict the malignant potential of GIST. The aim of this study was to develop a reliable and clinically applicable preoperative nomogram prediction model to predict the malignant potential of gastric GIST.

PATIENTS AND METHODS

Patients with a pathological diagnosis of gastric GIST from January 2015 to December 2021 were screened retrospectively. Univariate and multivariate logistic analyses were used to identify independent risk factors for gastric GIST with high malignancy potential. Based on these independent risk factors, a nomogram model predicting the malignant potential of gastric GIST was developed and the model was validated in the validation group.

RESULTS

A total of 494 gastric GIST patients were included in this study and allocated to a development group (n = 345) and a validation group (n = 149). In the development group, multivariate logistic regression analysis revealed that tumor size, tumor ulceration, CT growth pattern and monocyte-to- lymphocyte ratio (MLR) were independent risk factors for gastric GIST with high malignancy potential. The AUC of the model were 0.932 (95% CI 0.890-0.974) and 0.922 (95% CI 0.868-0.977) in the development and validation groups, respectively. The best cutoff value for the development group was 0.184, and the sensitivity and specificity at this value were 0.895 and 0.875, respectively. The calibration curves indicated good agreement between predicted and actual observed outcomes, while the DCA indicated that the nomogram model had clinical application.

CONCLUSIONS

Tumor size, tumor ulceration, CT growth pattern and MLR are independent risk factors for high malignancy potential gastric GIST, and a nomogram model developed based on these factors has a high ability to predict the malignant potential of gastric GIST.

Leiomyosarcoma of the rectum: A systematic review of recent literature

Leiomyosarcomas (LMSs) are rare tumors originating from the muscular layer. We performed a literature review of cases of confirmed rectal leiomyosarcomas (rLMSs) to clarify the history of such an infrequent tumor arising at such an uncommon location. In this research local recurrence was related to poorly differentiated rLMS and no other association between recurrence and any criteria was found. Concerning overall survival (OS), rLMS patients developing recurrence presented shorter longevity compared with the group without.

Recurrent Gastrointestinal Stromal Tumor With Chondroid Differentiation After Imatinib Therapy: An Unusual Case and Literature Review

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the gastrointestinal tract and is most commonly seen in the stomach. The standard treatment for patients with advanced GISTs include both surgical resection and imatinib therapy. There have been cases that document the alterations of patients' GIST histomorphology both with primary GIST prior to imatinib therapy and with recurrent GIST after imatinib therapy. However, there has been no documented case of a patient who has recurrent GIST with chondroid differentiation at the primary site after imatinib therapy. In this article, we report an incidental finding of a 58-year-old patient who had two treatments of imatinib therapy prior to surgical resection of her recurrent GIST in her stomach. We also explore through a mini-literature review the various cases of GIST with chondroid differentiation that have been reported to compare the histomorphology, immunophenotype, and patient demographic of these cases. This article is significant for reporting a rare finding of GIST after imatinib therapy and highlights the various presentations that GIST could acquire after imatinib therapy that exclude another malignant process, such as chondrosarcoma.

KIT/PDGFRA Variant Allele Frequency as Prognostic Factor in Gastrointestinal Stromal Tumors (GISTs): Results From a Multi-Institutional Cohort Study

BACKGROUND

The patient selection for optimal adjuvant therapy in gastrointestinal stromal tumors (GISTs) is provided by nomogram based on tumor size, mitotic index, tumor location, and tumor rupture. Although mutational status is not currently used to risk assessment, tumor genotype showed a prognostic influence on natural history and tumor relapse. Innovative measures, such as KIT/PDGFRA-mutant-specific variant allele frequency (VAF) levels detection from next-generation sequencing (NGS), may act as a surrogate of tumor burden and correlate with prognosis and overall survival of patients with GIST, helping the choice for adjuvant treatment.

PATIENTS AND METHODS

This was a multicenter, hospital-based, retrospective/prospective cohort study to investigate the prognostic role of KIT or PDGFRA-VAF of GIST in patients with radically resected localized disease. In the current manuscript, we present the results from the retrospective phase of the study.

RESULTS

Two-hundred (200) patients with GIST between 2015 and 2022 afferent to 6 Italian Oncologic Centers in the EURACAN Network were included in the study. The receiver operating characteristic (ROC) curves analysis was used to classify "low" vs. "high" VAF values, further normalized on neoplastic cellularity (nVAF). When RFS between the low and high nVAF groups were compared, patients with GIST with KIT/PDGFRA nVAF > 50% showed less favorable RFS than patients in the group of nVAF ≤ 50% (2-year RFS, 72.6% vs. 93%, respectively; P = .003). The multivariable Cox regression model confirmed these results. In the homogeneous sub-population of intermediate-risk, patients with KIT-mutated GIST, the presence of nVAF >50% was statistically associated with higher disease recurrence.

CONCLUSION

In our study, we demonstrated that higher nVAF levels were independent predictors of GIST prognosis and survival in localized GIST patients with tumors harboring KIT or PDGFRA mutations. In the cohort of intermediate-risk patients, nVAF could be helpful to improve prognostication and the use of adjuvant imatinib.

Prognostic value of mitotic count in leiomyosarcoma: A comprehensive monocentric retrospective study

BACKGROUND

Leiomyosarcomas (LMSs) include heterogeneous entities with different clinical courses not entirely predicted by known prognostic factors. In particular, the value of mitotic count as independent prognostic factor in LMS has been poorly investigated.

METHODS

We retrospectively analyzed all patients with a diagnosis of LMS who accessed to our Institution from June 1999 to May 2022 for which mitotic count was numerically expressed within the pathology report. Univariate and multivariate analyses were conducted to explore the prognostic value of mitotic count along with other clinical and histological variables.

RESULTS

We identified 121 eligible patients, with a median follow-up of 91.03 months (range 0.62-275.2 months). Median progression-free survival (mPFS) was 16.7 months, and median overall survival (mOS) was 105.6 months. In univariate analysis, mitotic count showed a significant impact on PFS and OS, with an hazard ratio per mitotic unit of 1.03 (1.01-1.04, p < 0.001) and 1.03 (1.01-1.04, p = 0.007), respectively. Similar results were found for locally advanced and metastatic patients, separately. Other significant prognostic factors for PFS were stage at diagnosis, performance status, tumor size and Ki-67, while differentiation, necrosis, grade, stage at diagnosis, tumor size, performance status and age at diagnosis were identified for OS. In multivariate analysis, the only significant factors were mitotic count and the presence of metastases at diagnosis for PFS, whereas the same two factors plus age at diagnosis were identified for OS.

CONCLUSION

Mitotic count represented the most important histological prognostic factor for OS and PFS in localized and metastatic LMS.

External validation of a nomogram predicting conditional survival after tri-modality treatment of esophageal cancer

BACKGROUND

A conditional survival nomogram was developed at a single high-volume center to predict 5-year overall survival for esophageal cancer patients after neoadjuvant chemoradiation and esophagectomy. The aim of this study was to externally validate the nomogram in a cohort of patients with esophageal adeno- or squamous cell carcinoma from another high-volume center.

METHODS

Consecutive patients with an esophageal adeno- or squamous cell carcinoma who had undergone esophagectomy after being treated with preoperative chemoradiation between 2004 and 2016 were selected from a prospectively maintained institutional database. The level of discrimination for prediction of 5-year overall survival was quantified by Harrell's C statistic. Calibration of the conditional survival nomogram was visualized by plotting predicted 5-year survival and observed 5-year survival for comparison.

RESULTS

Of the 296 patients examined, the probability of 5-year overall survival directly after surgery was 45% and increased to 51%, 68%, 78%, and 89% for each additional year survived. The predicted 5-year overall survival differed from the observed survival, with a calibration slope of 0.54, 0.55, 0.59, 0.73, and 1.09 directly after surgery and 1, 2, 3, and 4 years of survival after surgery, respectively. The nomogram's discrimination level for 5-year survival was moderate, with a C statistic of 0.65 compared to the 0.70 reported in the original study.

CONCLUSION

The nomogram model has moderate predictive discrimination and accuracy, supporting its applicability to external cohorts to predict conditional survival. Further validation studies should empirically assess the model for predictive performance.

Re-appraisal of the universal definition of tumor rupture among patients with high-risk gastrointestinal stromal tumors

Aim

Tumor rupture has been indicated as a risk factor for recurrence of gastrointestinal stromal tumors (GISTs). The universal definition of tumor rupture was proposed. This study evaluated whether the universal definition was more accurate in identification of GISTs with high recurrent risk than subjective judgment.

Methods

The study included 507 patients with high-risk GISTs who underwent complete resection between December 2012 and December 2015. We conducted a questionnaire survey in participating institutes to re-diagnose tumor rupture based on the universal definition according to their surgical and pathological findings. We compared the clinical outcomes of tumor rupture based on the definition to those based on the surgeon's judgment and clarified the clinical importance of the rupture.

Results

Sixty-four patients were initially registered to have tumor rupture by surgeon's judgment, and it became 90 patients who had tumor rupture after reevaluation. Although there were significant differences in recurrence-free survival (RFS) between no rupture and rupture for both initial registration and reevaluation (p = 0.002, <0.001, respectively), a significant difference in overall survival was only observed after reevaluation (p = 0.011). Tumor rupture was significantly associated with large tumor size, mixed cell type in histology, R1 resection, frequent adjuvant therapy and recurrence, but not with location, mitosis, and genotype. Adjuvant therapy more than 3 years improved RFS of patients with tumor rupture.

Conclusion

This study suggested that tumor rupture based on the universal definition more accurately identified GISTs with poor prognostic outcomes than the subjective judgment.

Guideline-Based Follow-Up Outcomes in Patients With Gastrointestinal Stromal Tumor With Low Risk of Recurrence: A Report From the Italian Sarcoma Group

Importance

Gastrointestinal stromal tumor (GIST) follow-up is recommended by international guidelines, but data on the role of follow-up in patients with low relapse risk are missing. For these patients, the potential benefit of anticipating recurrence detection should be weighed against psychological burden and radiologic examination loads in terms of costs and radiation exposure.

Objective

To evaluate the outcomes of guideline-based follow-up in low-risk GIST.

Design, Setting, and Participants

This multi-institutional retrospective cohort study involving Italian Sarcoma Group reference institutions evaluated patients with GIST who underwent surgery between January 2001 and June 2019. Median follow-up time was 69.2 months. Data analysis was performed from December 15, 2022, to March 20, 2023. Patients with GIST at low risk according to Armed Forces Institute of Pathology criteria were included provided adequate clinical information was available: primary site, size, mitotic index, surgical margins, and 2 or more years of follow-up.

Exposures

All patients underwent follow-up according to European Society for Medical Oncology (ESMO) guidelines.

Main Outcomes and Measures

The primary outcome was the number of tests needed to identify a relapse according to ESMO guidelines follow-up plan. Secondary outcomes included relapse rate, relapse timing, disease-free survival (DFS), overall survival (OS), GIST-specific survival (GIST-SS), postrelapse OS, secondary tumor rates, and theoretical ionizing radiation exposure. An exploratory end point, new follow-up schedule proposal for patients with low-risk GIST according to the observed results, was also assessed.

Results

A total of 737 patients (377 men [51.2%]; median age at diagnosis, 63 [range, 18-86] years) with low-risk GIST were included. Estimated 5-year survival rates were 95.5% for DFS, 99.8% for GIST-SS, and 96.1% for OS. Estimated 10-year survival rates were 93.4% for DFS, 98.1% for GIST-SS, and 91.0% for OS. Forty-two patients (5.7%) experienced disease relapse during follow-up (9 local, 31 distant, 2 both), of which 9 were detected after 10 or more years. This translated into approximately 1 relapse detected for every 170 computed tomography scans performed, with a median radiation exposure of 80 (IQR, 32-112) mSv per patient. Nongastric primary tumor (hazard ratio [HR], 2.09; 95% CI, 1.14-3.83; P = .02), and KIT mutation (HR, 2.77; 95% CI, 1.05-7.27; P = .04) were associated with a higher risk of relapse. Second tumors affected 187 of 737 patients (25%), of which 56 were detected during follow-up and represented the primary cause of death in these patients.

Conclusions and Relevance

In this cohort study on patients affected by low-risk GISTs, the risk of relapse was low despite a follow-up across 10 or more years. These data suggest the need to revise follow-up schedules to reduce the anxiety, costs, and radiation exposure of currently recommended follow-up strategy.

Novel Genomic Risk Stratification Model for Primary Gastrointestinal Stromal Tumors (GIST) in the Adjuvant Therapy Era

PURPOSE

Traditional risk stratification schemes in gastrointestinal stromal tumors (GIST) were defined in the pre-imatinib era and rely solely on clinicopathologic metrics. We hypothesize that genomic-based risk stratification is prognostically relevant in the current era of tyrosine kinase inhibitor (TKI) therapeutics.

EXPERIMENTAL DESIGN

Comprehensive mutational and copy-number profiling using MSK-IMPACT was performed. We integrated clinicopathologic and genomic parameters and utilized an elastic-net penalized Cox proportional hazards machine learning model for outcome risk stratification.

RESULTS

A 3-tier genomic risk stratification model for recurrence-free survival (RFS) in 152 primary localized gastric and 80 small bowel GISTs was proposed. Gastric GISTs were classified as high risk if chr1p deletion or SDHB loss was present, and intermediate risk if chr14q deletion was present or KIT exon 11 mutation was absent. Small bowel GISTs were classified as high risk if MAX/MGA/MYC, CDKN2A, or RB1 alterations were present, and intermediate risk if chr1p deletion or chr5q amplification was present. Compared with conventional risk stratification, genomic risk stratification both upgrades and downgrades, suggesting that conventional risk stratification may underestimate or overtreat some high-risk and low-risk patients, respectively. Longitudinal sequencing detected most KIT-independent genomic alterations at baseline. Subanalysis in 26 SDH-deficient GISTs revealed that presence of TP53 mutations or chr1q amplifications portends worse RFS and disease-free survival.

CONCLUSIONS

We developed a novel, next-generation genomic risk stratification model for primary gastric and small bowel GISTs, complementing traditional clinicopathologic models. Future independent validation of our model in external cohorts is essential.

Impact of Tumor Size and Management on Survival in Small Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Society guidelines remain inconsistent on the role of endoscopic and radiographic surveillance as an alternative to surgical resection of small gastric gastrointestinal stromal tumors (GISTs). Herein, we aimed to assess survival among patients with gastric GISTs undergoing observation versus surgical resection, stratified by tumor size.

METHODS

The National Cancer Database (NCDB) was queried for gastric GISTs < 2 cm diagnosed from 2010-2017. Patients were stratified by management strategy-observation vs surgical resection. The primary outcome, overall survival (OS), was examined with Kaplan-Meier and multivariable Cox proportional hazard methods. Subgroup analyses were conducted on tumors < 1 cm and 1-2 cm in size.

RESULTS

Altogether, 1208 patients were identified: 439 (36.3%) undergoing observation and 769 (63.7%) receiving surgical resection. In the overall cohort, patients undergoing surgical resection demonstrated improved survival (93.6 vs. 88.8% 5-year OS, p=0.02). In multivariable analysis, upfront surgical resection was not associated with a reduction in mortality; however, there was a significant interaction with tumor size. For patients with tumors < 1 cm, there was no difference in survival based on management strategy. However, resection of tumors 1-2 cm was associated with improved survival relative to surveillance.

CONCLUSIONS

While surgical resection and surveillance were associated with similar survival for patients with gastric GISTs < 1 cm, this NCDB analysis suggests that patients with tumor size ≥ 1 cm may benefit from upfront surgical resection. Prospective studies comparing these two approaches and their impact on recurrence-free and disease-specific survival are needed to better align consensus guidelines and recommendations.

An interpretable AI model for recurrence prediction after surgery in gastrointestinal stromal tumour: an observational cohort study

Background

There are several models that predict the risk of recurrence following resection of localised, primary gastrointestinal stromal tumour (GIST). However, assessment of calibration is not always feasible and when performed, calibration of current GIST models appears to be suboptimal. We aimed to develop a prognostic model to predict the recurrence of GIST after surgery with both good discrimination and calibration by uncovering and harnessing the non-linear relationships among variables that predict recurrence.

Methods

In this observational cohort study, the data of 395 adult patients who underwent complete resection (R0 or R1) of a localised, primary GIST in the pre-imatinib era at Memorial Sloan Kettering Cancer Center (NY, USA) (recruited 1982-2001) and a European consortium (Spanish Group for Research in Sarcomas, 80 sites) (recruited 1987-2011) were used to train an interpretable Artificial Intelligence (AI)-based model called Optimal Classification Trees (OCT). The OCT predicted the probability of recurrence after surgery by capturing non-linear relationships among predictors of recurrence. The data of an additional 596 patients from another European consortium (Polish Clinical GIST Registry, 7 sites) (recruited 1981-2013) who were also treated in the pre-imatinib era were used to externally validate the OCT predictions with regard to discrimination (Harrell's C-index and Brier score) and calibration (calibration curve, Brier score, and Hosmer-Lemeshow test). The calibration of the Memorial Sloan Kettering (MSK) GIST nomogram was used as a comparative gold standard. We also evaluated the clinical utility of the OCT and the MSK nomogram by performing a Decision Curve Analysis (DCA).

Findings

The internal cohort included 395 patients (median [IQR] age, 63 [54-71] years; 214 men [54.2%]) and the external cohort included 556 patients (median [IQR] age, 60 [52-68] years; 308 men [55.4%]). The Harrell's C-index of the OCT in the external validation cohort was greater than that of the MSK nomogram (0.805 (95% CI: 0.803-0.808) vs 0.788 (95% CI: 0.786-0.791), respectively). In the external validation cohort, the slope and intercept of the calibration curve of the main OCT were 1.041 and 0.038, respectively. In comparison, the slope and intercept of the calibration curve for the MSK nomogram was 0.681 and 0.032, respectively. The MSK nomogram overestimated the recurrence risk throughout the entire calibration curve. Of note, the Brier score was lower for the OCT compared to the MSK nomogram (0.147 vs 0.564, respectively), and the Hosmer-Lemeshow test was insignificant (P = 0.087) for the OCT model but significant (P < 0.001) for the MSK nomogram. Both results confirmed the superior discrimination and calibration of the OCT over the MSK nomogram. A decision curve analysis showed that the AI-based OCT model allowed for superior decision making compared to the MSK nomogram for both patients with 25-50% recurrence risk as well as those with >50% risk of recurrence.

Interpretation

We present the first prognostic models of recurrence risk in GIST that demonstrate excellent discrimination, calibration, and clinical utility on external validation. Additional studies for further validation are warranted. With further validation, these tools could potentially improve patient counseling and selection for adjuvant therapy.

Funding

The NCI SPORE in Soft Tissue Sarcoma and NCI Cancer Center Support Grants.

Adjuvant Targeted Therapy in Solid Cancers: Pioneers and New Glories

Targeted therapy (TT) has revolutionized cancer treatment, successfully applied in various settings. Adjuvant TT in resected early-stage gastrointestinal stromal tumors (GIST), melanoma, non-small cell lung cancer (NSCLC), and breast cancer has led to practice-changing achievements. In particular, standard treatments include BRAF inhibitors for melanoma, osimertinib for NSCLC, hormone therapy or HER2 TT for breast cancer, and imatinib for GIST. Despite the undeniable benefit derived from adjuvant TT, the optimal duration of TT and the appropriate managing of the relapse remain open questions. Furthermore, neoadjuvant TT is emerging as valuable, particularly in breast cancer, and ongoing studies evaluate TT in the perioperative setting for early-stage NSCLC. In this review, we aim to collect and describe the large amount of data available in the literature about adjuvant TT across different histologies, focusing on epidemiology, major advances, and future directions.

High spindle and kinetochore-associated complex subunit-3 expression predicts poor prognosis and correlates with adverse immune infiltration in hepatocellular carcinoma

BACKGROUND

Spindle and kinetochore-associated complex subunit 3 (SKA3) is a malignancy-associated gene that plays a critical role in the regulation of chromosome separation and cell division. However, the molecular mechanism through which SKA3 regulates tumor cell proliferation in hepatocellular carcinoma (HCC) has not been fully elucidated.

AIM

To investigate the molecular mechanisms underlying the role of SKA3 in HCC.

METHODS

SKA3 expression, clinicopathological, and survival analyses were performed using multiple public database platforms, and the results were verified by Western blot and immunohistochemistry staining using collected clinical samples. Functional enrichment analyses were performed to evaluate the biological functions and molecular mechanisms of SKA3 in HCC. Furthermore, the Tumor Immune Estimation Resource and single-sample Gene Set Enrichment Analysis (ssGSEA) algorithms were utilized to investigate the abundance of tumor-infiltrating immune cells in HCC. The response to chemotherapeutic drugs was evaluated by the R package "pRRophetic".

RESULTS

We found that upregulated SKA3 expression was significantly correlated with poor prognosis in patients with HCC. Multivariable Cox regression analysis indicated that SKA3 was an independent risk factor for survival. GSEA revealed that SKA3 expression may facilitate proliferation and migratory processes by regulating the cell cycle and DNA repair. Moreover, patients with high SKA3 expression had significantly decreased ratios of CD8+ T cells, natural killer cells, and dendritic cells. Drug sensitivity analysis showed that the high SKA3 group was more sensitive to sorafenib, sunitinib, paclitaxel, doxorubicin, gemcitabine, and vx-680.

CONCLUSION

High SKA3 expression led to poor prognosis in patients with HCC by enhancing HCC proliferation and repressing immune cell infiltration surrounding HCC. SKA3 may be used as a biomarker for poor prognosis and as a therapeutic target in HCC.

Gastrointestinal Stromal Tumors: Our Ten-Year Experience of a Single-Center Tertiary Hospital

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal neoplasms of the gastrointestinal tract. They have variable clinical presentation, prognosis, and molecular characteristics. Here, we present the results of our retrospective study including patients operated on for GIST during the last decade.

METHODS

All the patients who underwent GIST resection during the decade 2008-2018 were included in the study. The diagnosis was based on the pathology report. All the data were collected and analyzed statistically using the Statistical Package for Social Science v25.0. Finally, after having applied the proper search terms, a comprehensive review of articles published in the Medline database was held.

RESULTS

Thirty-two patients (sixteen women) were included in the study with a mean age of 69.6 years old (SD = 13.9). Twenty-one patients had a GIST in the stomach, eight in the small intestine, and three had an extra GIST. Of the 29 patients contacted, 21 were alive with a mean survival time of 74.3 months (SD = 49.6 months, min: 3.0 months, max: 161.0 months), whereas eight patients passed away. Finally, 13 patients were treated with tyrosine kinase inhibitors (TKIs) of whom only one died, while 9 patients passed away from those treated with surgery alone (p = 0.031).

CONCLUSIONS

Our results were in concordance with the existing data in the literature. GISTs require patient-based therapeutical management depending on the histology of the tumors. Gastric tumors present a better prognosis than those localized in the intestine, while the use of TKIs has led to an improvement in patient survival rate.

Gastrointestinal stromal tumors of the upper GI tract: population-based analysis of epidemiology, treatment and outcome based on data from the German Clinical Cancer Registry Group

BACKGROUND

Gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors. They are most frequently located in the stomach but are also found in the esophagus and the gastroesophageal junction (GEJ). Information regarding the prognostic factors associated with upper gastrointestinal GIST is still scarse.

METHODS

In this study, datasets provided by the German Clinical Cancer Registry Group, including a total of 93,069 patients with malignant tumors in the upper GI tract (C15, C16) between 2000 and 2016 were analyzed to investigate clinical outcomes of GIST in the entire upper GI tract.

RESULTS

We identified 1361 patients with GIST of the upper GI tract. Tumors were located in the esophagus in 37(2.7%) patients, at the GEJ in 70 (5.1%) patients, and in the stomach in 1254 (91.2%) patients. The incidence of GIST increased over time, reaching 5% of all UGI tumors in 2015. The median age was 69 years. The incidence of GIST was similar between males and females (53% vs 47%, respectively). However, the proportion of GIST in female patients increased continuously with advancing age, ranging from 34.7% (41-50 years) to 71.4% (91-100 years). Male patients were twice as likely to develop tumors in the esophagus and GEJ compared to females (3.4% vs. 1.9% and 6.7% vs. 3.4%, respectively). The median overall survival of upper gastrointestinal GIST was 129 months. The 1-year, 5-year, and 10-year OS was 93%, 79%, and 52% respectively. Nevertheless, tumors located in the esophagus and GEJ were associated with shorter OS compared to gastric GIST (130 vs. 111 months, p = 0.001). The incidence of documented distant metastasis increased with more proximal location of GIST (gastric vs. GEJ vs. esophagus: 13% vs. 16% vs. 27%) at presentation.

CONCLUSION

GIST of the esophagus and GEJ are rare soft tissue sarcomas with increasing incidence in Germany. They are characterized by worse survival outcomes and increased risk of metastasis compared to gastric GIST.

Case Report: Should Regorafenib be prescribed as a continuous schedule in gastrointestinal stromal tumors? Three case reports on Regorafenib personalized schedule

Introduction

Regorafenib is a tyrosine kinase inhibitor (TKI) approved in metastatic gastrointestinal stromal tumor (GIST), colorectal cancer, and hepatocarcinoma. Anyway, the toxicity profile of Regorafenib standard schedule is associated with poor compliance and a high rate of discontinuation. For this reason, there is a growing need for a Regorafenib personalized schedule emerging from the scientific community.

Objective

The aim of this case series was to describe the experience of our sarcoma referral center with the continuous administration of Regorafenib as an alternative regimen to treat metastatic GIST patients.

Methods

We retrospectively collected clinical, pathological, and radiological data of patients with metastatic GIST treated with daily personalized Regorafenib at a single tertiary referral center from May 2021 to December 2022.

Results

We identified three patients fulfilling the inclusion criteria. The average follow-up since the start of Regorafenib was 19.1 months (12-25 months). All three patients had started a standard third-line Regorafenib schedule according to guidelines. The reasons for switching to a continuous schedule were as follows: exacerbation of symptoms during week-off treatment in the first patient, a serious adverse event (AE) in the second patient, and a combination of both conditions in the third. After switching, none of the patients reported severe AEs, and they improved control of tumor-related symptoms. Two of the patients experienced disease progression after 16 months (9 months of which is continuous schedule) and 12 months (8.1 months of which is continuous schedule) of Regorafenib, respectively; the third patient is still receiving continuous Regorafenib at the time of writing, with a progression-free survival of 25 months (14 months after the modified schedule start).

Conclusion

With a similar efficacy and lower toxicities, a daily, personalized Regorafenib schedule seems to be a promising alternative to the standard regimen for metastatic GIST patients, including the frail ones. Further prospective analyses are needed to confirm the safety and efficacy of such regimen.

Nutritional and immune-related indicators-based Nomogram for predicting overall survival of surgical oral tongue squamous cell carcinoma

Oral tongue squamous cell carcinoma (OTSCC) is one of the most aggressive oral tumors. The aim of this study was to establish a nomogram to predict overall survival (OS) of TSCC patients after surgery. 169 TSCC patients who underwent surgical treatments in the Cancer Hospital of Shantou University Medical College were included. A nomogram based on Cox regression analysis results was established and internally validated using bootstrap resampling method. pTNM stage, age and total protein, immunoglobulin G, factor B and red blood cell count were identified as independent prognostic factors to create the nomogram. The Akaike Information Criterion and Bayesian Information Criterion of the nomogram were lower than those of pTNM stage, indicating a better goodness-of-fit of the nomogram for predicting OS. The bootstrap-corrected concordance index of nomogram was higher than that of pTNM stage (0.794 vs. 0.665, p = 0.0008). The nomogram also had a good calibration and improved overall net benefit. Based on the cutoff value obtained from the nomogram, the proposed high-risk group had poorer OS than low-risk group (p < 0.0001). The nomogram based on nutritional and immune-related indicators represents a promising tool for outcome prediction of surgical OTSCC.

Prognostic analysis and nomogram establishment in patients with early esophageal cancer receiving endoscopic therapy: a population-based study

Background

The growing numbers of early esophageal cancer (EEC) have increased the demand for endoscopic therapy.

Objectives

To clarify the influential factors for the prognosis of patients with EEC receiving endoscopic surgery, and to construct a nomogram to evaluate the prognostic value of endoscopic therapy.

Design

Prognostic analysis study.

Methods

Clinical data of EEC patients who received endoscopic therapy between 2004 and 2015 were collected from the Surveillance, Epidemiology, and End Results database and used to construct the nomogram. The prognosis was analyzed by R language; the nomogram was constructed by Cox survival analysis; and the accuracy of the nomogram was verified by C index and the receiver operating characteristic (ROC) and calibration curves. X-Tile software was used to stratify the risk of patients.

Results

Our study constructed the nomogram of the prognosis of patients with EEC treated by endoscopic surgery, including 1118 patients and 5 independent prognostic factors of esophageal cancer-specific survival. The C index and the area under the ROC curve (AUC) of the training and verification cohorts were all >0.75. The calibration curve also reflected the good consistency of the model in predicting survival. Significant difference in the risk of patients from different stratifications with the same T staging existed, and the model had a better C index than that of the T staging.

Conclusion

Our study reports potential influential factors affecting the prognosis of EEC patients who received endoscopic therapy and establishes a reliable nomogram to predict the risk and prognosis, which has certain advantages compared with traditional TNM staging system.

Diagnosis and management of high risk gastrointestinal stromal tumor in first trimester pregnancy: A case report and review of the literature

Objective

There are less than 20 reported cases of gastrointestinal stromal tumors in pregnancy. Of these reported cases, there are only two that detail GIST in the first trimester. We report our experience with the third known GIST diagnosis in the first trimester of pregnancy. Notably, our case report highlights the earliest known gestational age at time of GIST diagnosis.

Methods

We conducted a literature review of GIST diagnosis in pregnancy via PUBMED, using a combination of the following terms: (pregnancy or gestation) and (GIST). We utilized Epic for chart review of our patient's case report.

Results

A 24 year old G3P1011 presented to the Emergency Department at 4w6d by last menstrual period (LMP) with worsening abdominal cramping, bloating, and associated nausea. Physical exam revealed a large, mobile, nontender mass palpated in the right lower abdomen. Transvagianl ultrasound noted the presence of a large pelvic mass of unknown etiology. Pelvic magnetic resonance imaging (MRI) was obtained for further characterization, revealing a 7.3× 12.4 × 12.2 cm mass with multiple fluid levels, centered in the anterior mesentery. Exploratory laparotomy was performed with en bloc resection of small bowel and pelvic mass, with pathology demonstrating a 12.8 cm spindle cell neoplasm compatible with GIST and notable for a mitotic rate of 40 mitoses/50 high power field (HPF). Next generation sequencing (NGS) was pursued in order to predict tumor responsiveness to Imatinib, which revealed a mutation at KIT exon 11, suggesting a response to tyrosine kinase inhibitor therapy. The patient's multidisciplinary treatment team, consisting of medical oncologists, surgical oncologists, and maternal fetal medicine specialists, made the recommendation for adjuvant Imatinib therapy. The patient was offered termination of pregnancy with immediate initiation of Imatinib, as well as continuation of pregnancy with either immediate or delayed treatment. Interdisciplinary counseling focused on both the maternal and fetal implications of each proposed management plan. She ultimately elected termination of pregnancy, and underwent an uncomplicated dilation and evacuation.

Conclusions

GIST diagnosis in pregnancy is exceedingly rare. Patients with high-grade disease encounter a multitude of decision-making dilemmas, often with competing maternal and fetal interests. As additional cases of GIST in pregnancy are added to the literature, clinicians will be able to implement evidence-based options counseling for their patients. Shared decision-making is contingent upon patient understanding of diagnosis, risk of recurrence, available treatment options, and the treatment-related implications on maternal and fetal outcomes. A multidisciplinary approach is crucial for optimization of patient-centered care.

Efficacy of post-first-line agents for advanced gastrointestinal stromal tumors following imatinib failure: A network meta-analysis

BACKGROUND

Imatinib is the standard first-line treatment for advanced gastrointestinal stromal tumors (GISTs); however, most patients eventually develop imatinib resistance, leading to considerable clinical challenges. Few direct comparisons have been made between different post-first-line therapies on clinical efficacy in advanced GIST following imatinib failure.

METHODS

Databases including PubMed, Embase, Scopus, Google Scholars, and Cochrane Library from inception to February 2023 were retrieved for randomized controlled trials evaluating the clinical efficacy of different post-first-line agents for advanced GIST following imatinib failure. Network and conventional meta-analysis were carried out using Stata/MP 16.0.

RESULTS

Ripretinib showed significant improvement in progression-free survival (PFS) rates from the 2nd to the 12th month compared to placebo, while there was virtually no evidence that the rest active agents had a significant benefit at the 12th month. Masitinib, ripretinib, sunitinib, regorafenib, and pimitespib exhibited significantly longer median PFS than placebo, and pairwise comparisons indicated there were no significant differences among masitinib, ripretinib, and sunitinib. These post-first-line agents decreased the risk of disease progression or death by 65% (HR = 0.35, 95% CI: 0.26-0.47) compared to placebo. Ripretinib and sunitinib came into effect earlier and exhibited more consistent overall survival (OS) rate improvements than masitinib and pimitespib, while pairwise comparisons revealed no significant differences in these four active agents concerning the improvement in OS rate. These post-first-line agents decreased the risk of death by 39% (HR = 0.61, 95% CI: 0.44-0.83) over placebo for advanced GIST following imatinib failure.

CONCLUSION

The active agents in our analysis as post-first-line therapies are able to provide superior clinical efficacy, with improved PFS rate and OS rate at certain time points, as well as absolute values of PFS and OS for advanced GIST. Ripretinib might be the optimal recommendation as a post-first-line treatment for advanced GIST following imatinib failure.

Mucosal Ulceration in Gastrointestinal Stromal Tumor is an Independent Predictor of Progression-Free Survival

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. Known prognostic features of GISTs include tumor mitotic rate, size, and location, yet one common feature of primary GISTs for which prognostic significance is unknown, is mucosal ulceration. This study aims to investigate the significance of mucosal ulceration in GISTs.

MATERIALS AND METHODS

A retrospective study was conducted of 513 patients at a tertiary referral center with a suspected or documented diagnosis of primary GIST between the years of 2000 and 2020. Ulceration was confirmed by definitive documentation in the endoscopic or histopathologic report. The significance of ulceration in GIST was compared to other prognostic factors.

RESULTS

Of the 513 patients reviewed, 310 primary GIST patients with known ulceration and disease status were identified. Of those, 27.4% (n = 85) demonstrated mucosal ulceration. Mucosal ulceration in GISTs is associated with GI bleeding, mitotic rate, tumor size, and exon 11 mutations. After a median follow-up of 35.4 (interquartile range = 17.1-62.2) mo, patients with ulcerated GISTs experienced higher rates of tumor progression (40.0% versus 14.2%, P < 0.0001). In multivariate analysis, ulceration of GISTs was highly associated with disease progression (P < 0.0001) and progression-free survival (hazard ratio = 2.4 [1.2-4.7], P = 0.01).

CONCLUSIONS

Mucosal ulceration in GISTs is associated with GI bleeding, mitotic rate, tumor size, and exon 11 mutations. Overall, ulceration in GISTs is associated with elevated risk of tumor progression and is an independent prognostic factor. In multivariate analysis, ulceration in GIST remains an independent risk factor for disease progression.

Development and validation of a prognostic nomogram for overall and disease-specific survival in patients with sarcomatoid urothelial carcinoma

INTRODUCTION

Sarcomatoid urothelial carcinoma (SUC) is a rare and aggressive variant of bladder cancer with limited data guiding prognosis. In this study, we present the first prognostic nomograms in the literature for 3- and 5-year overall survival (OS) and disease-specific survival (DSS), for patients with SUC derived from the surveillance, epidemiology and end results database (SEER).

MATERIALS AND METHODS

Patients with SUC were identified by using the ICD-10 topography codes C67.0-C67.9 (bladder cancer), and the morphologic code 8122 (SUC). Patients were randomly divided into a training cohort (TC) and a validation cohort (VC) (7:3 ratio). Variables significantly associated with OS and DSS were identified with multivariate Cox regression and were used to build the nomograms. Harrel's C-statistic with bootstrap resampling and calibration curves were used for internal (TC) and external (VC) validation. Clinical utility of the nomograms was assessed with the decision curve analysis (DCA). Goodness of fit between the nomograms and the AJCC 8th edition staging system was compared with the likelihood ratio test.

RESULTS

A total of 741 patients with SUC were included (507 TC, 234 VC). No statistically significant differences in baseline characteristics were identified between the 2 cohorts. Sex, SEER stage, radical cystectomy and chemotherapy were common variables for the OS and the DSS nomograms with the addition of age in the former. Optimism-corrected C-statistic for the nomograms was 0.68 and 0.67 for OS and DSS respectively. In comparison, C-statistic for AJCC was 0.59 for OS and 0.60 for DSS (P < 0.001). Calibration curves constructed for the nomograms showed appropriate consistency between predicted and actual survival. The nomograms demonstrated optimal clinical utility in the DCA, outperforming the AJCC staging system, by maintaining a higher clinical net benefits than treat all, treat none and AJCC curves, across threshold probabilities.

CONCLUSION

We present the first prognostic nomograms developed in patients with SUC. Our models demonstrated superior prognostic performance to the AJCC system, by utilizing a set of variables readily available in daily practice and may serve as useful tools for the individualized risk assessment of these patients.

Nomogram model predicting the overall survival for patients with primary gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Increasingly extranodal marginal B-cell lymphoma of mucosa-associated lymphoid tissue, known as mucosa-associated lymphoid tissue (MALT) lymphoma, is a type of non-Hodgkin’s lymphoma. The prognosis of primary gastric MALT (GML) patients can be affected by many factors. Clinical risk factors, including age, type of therapy, sex, stage and family hematologic malignancy history, also have significant effects on the development of the disease. The available data are mainly focused on epidemiology; in contrast, few studies have investigated the prognostic variables for overall survival (OS) in patients with primary GML. Based on the realities above, we searched a large amount of data on patients diagnosed with primary GML in the Surveillance, Epidemiology and End Results (SEER) database. The aim was to develop and verify a survival nomogram model that can predict the overall survival prognosis of primary GML by combining prognostic and determinant variables.

AIM

To create an effective survival nomogram for patients with primary gastric GML.

METHODS

All data of patients with primary GML from 2004 to 2015 were collected from the SEER database. The primary endpoint was OS. Based on the LASSO and COX regression, we created and further verified the accuracy and effectiveness of the survival nomogram model by the concordance index (C-index), calibration curve and time-dependent receiver operating characteristic (td-ROC) curves.

RESULTS

A total of 2604 patients diagnosed with primary GML were selected for this study. A total of 1823 and 781 people were randomly distributed into the training and testing sets at a ratio of 7:3. The median follow-up of all patients was 71 mo, and the 3- and 5-year OS rates were 87.2% and 79.8%, respectively. Age, sex, race, Ann Arbor stage and radiation were independent risk factors for OS of primary GML (all P < 0.05). The C-index values of the nomogram were 0.751 (95%CI: 0.729-0.773) and 0.718 (95%CI: 0.680-0.757) in the training and testing cohorts, respectively, showing the good discrimination ability of the nomogram model. Td-ROC curves and calibration plots also indicated satisfactory predictive power and good agreement of the model. Overall, the nomogram shows favorable performance in discriminating and predicting the OS of patients with primary GML.

CONCLUSION

A nomogram was developed and validated to have good survival predictive performance based on five clinical independent risk factors for OS for patients with primary GML. Nomograms are a low-cost and convenient clinical tool in assessing individualized prognosis and treatment for patients with primary GML.

Nomogram for Predicting Recurrence-Free Survival of Primary Localized Gastrointestinal Stromal Tumor

Purpose: This study aimed to establish a new nomogram that predicts recurrence-free survival (RFS) after a complete surgical resection of primary localized gastrointestinal stromal tumors (GISTs); it also aimed to evaluate the discrimination, calibration, and clinical utility of the decision-making nomogram. Methods: The clinicopathological data of patients with primary localized GISTs at the First Affiliated Hospital of Chongqing Medical University from January 2000 to June 2022 were retrospectively analyzed. The clinicopathological data were randomly split into two sets (7:3 ratio) for training and validation. Suitable variables for the construction of a nomogram for the 1-, 3-, and 5-year RFS were selected using univariate and multivariate Cox regression analyses. Receiver operating characteristic (ROC) analysis and a concordance index (C-index) were used to quantify the discrimination of the nomogram and were compared with four commonly used prognostic scoring systems: Memorial Sloan Kettering Cancer Center prognostic nomogram, National Institutes of Health–Fletcher staging system, Chen’s prognostic nomogram, and Air Forces Institute of Pathology risk criteria–Miettinen staging system. The calibration and clinical utility for the decision-making nomogram were validated using calibration curves and decision curves, respectively. Results: In total, 641 patients were screened and analyzed in this retrospective, observational study. RFS was significantly related to tumor size, mitotic count, gender, DOG-1, and adjuvant therapy with imatinib according to the results of the multivariate and univariate Cox analyses. The nomogram was constructed using the above variables (all p < 0.05) for the 1-, 3-, and 5-year RFS. In the training set, the 1-, 3-, and 5-year ROC and C-index values of the nomogram were 0.868, 0.838, 0.816, and 0.830, respectively. For internal validation, we performed model fitting on the validation set, and the 1-, 3-, and 5-year ROC and C-indices were 0.977, 0.845, 0.869, and 0.849, respectively. Among the five GIST prognostic scoring systems, our nomogram had almost all the largest area under these decision curves and had a good calibration capability. Conclusions: The newly constructed nomogram based on tumor size, gender, mitotic count, DOG-1, and adjuvant treatment with imatinib exhibited an excellent performance and may serve as a prognostic scoring system to support therapeutic decision-making and individualized treatment for GISTs in China.

Counting mitoses in gastrointestinal stromal tumours (GISTs): variable practices in the real-world setting and their clinical implications

Mitotic count (MC) is an important prognostic indicator in gastrointestinal stromal tumours (GISTs). Though MC evaluation was initially proposed in 50 HPFs, recent international guidelines recommend that MC be performed on 5 mm² because HPFs may have different areas depending on the ocular field number (FN) of the utilized light microscope. Performing MC on different areas leads to a non-standardized evaluation and erroneous risk stratification. The aim of the study was to audit real-life MC practices with special emphasis on possible risk stratification errors. A survey was administered to Italian pathologists to evaluate the following: method used for MC (5 mm² versus 50 HPF); FN of the light microscope; prognostic scheme for risk stratification. Based on the results of the survey, 100 GISTs (25/risk class using Miettinen prognostic scheme) were retrieved and MC performed using 5 mm² versus the corresponding mm² area sizes of 50 HPFs with variable FNs (18, 20, 22). The survey demonstrated that the majority of pathologists (64.5%) use 50 HPFs with various FNs leading to excessive area size. The most frequently used prognostic scheme is that by Miettinen. Using this prognostic scheme and counting mitoses in 5 mm² versus 50 HPFs with FNs 18, 20 and 22, a change in risk class was identified ranging from 10 to 41%, depending on FN. In conclusion, this study demonstrates that MC is still frequently performed on 50 HPF, with area sizes exceeding the specified 5 mm² by far.

Dataset for reporting of gastrointestinal stromal tumours: recommendations from the International Collaboration on Cancer Reporting (ICCR)

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract and are among the most frequent sarcomas. Accurate diagnosis, classification, and reporting are critical for prognostication and patient management, including selection of appropriate targeted therapy. Here we report on international consensus-based datasets for the pathology reporting of biopsy and resection specimens of GIST. The datasets were produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of major international pathology and cancer organizations. An international expert panel consisting of pathologists, a surgical oncologist, and a medical oncologist produced a set of core and noncore data items for biopsy and resection specimens based on a critical review and discussion of current evidence. All professionals involved were subspecialized soft tissue tumour experts and affiliated with tertiary referral centres. Commentary was provided for each data item to explain its clinical relevance and the rationale for selection as a core or noncore element. Following international public consultation, the datasets, which include synoptic reporting guides, were finalized and ratified, and published on the ICCR website. These first international datasets for GIST are intended to promote high-quality, standardised pathology reporting. Their widespread adoption will improve consistency of reporting, facilitate multidisciplinary communication, and enhance comparability of data, all of which will ultimately help to improve the management of patients with GIST. All the ICCR datasets, including these on GIST, are freely available worldwide on the ICCR website (www.iccr-cancer.org/datasets).

Genomic Complexity as a Biomarker to De-Escalate Adjuvant Imatinib Treatment in High-Risk Gastrointestinal Stromal Tumor

PURPOSE

Adjuvant imatinib treatment is recommended for patients with localized gastrointestinal stromal tumor (GIST) at high risk of recurrence. Almost half of high-risk patients are cured by surgery alone, indicating a need for improved selection of patients for adjuvant therapy. The aim of this study was to investigate if genomic tumor complexity could be used as a prognostic biomarker.

METHODS

The discovery cohort consisted of patients who underwent resection of primary GIST at Oslo University Hospital between 1998 and 2020. Karyotypes were categorized as simple if they had ≤ 5 chromosomal changes and complex if there were > 5 chromosomal aberrations. Validation was performed in an independent patient cohort where chromosomal imbalances were mapped using comparative genomic hybridization.

RESULTS

Chromosomal aberrations were detected in 206 tumors, of which 76 had a complex karyotype. The most frequently observed changes were losses at 14q, 22q, 1p, and 15q. The 5-year recurrence-free survival (RFS) in patients classified as very low, low, or intermediate risk was 99%. High-risk patients with a simple tumor karyotype had an estimated 5-year RFS of 94%, and patients with a complex karyotype had an estimated 5-year RFS of 51%. A complex karyotype was associated with poor RFS in patients with and without adjuvant imatinib treatment and in multivariable analysis adjusted for tumor site, size, mitotic count, and rupture. The prognostic impact of genomic complexity was confirmed in the validation cohort. In both cohorts, the 5-year disease-specific survival was > 90% for high-risk patients with genomically simple tumors.

CONCLUSION

Genomic tumor complexity is an independent prognostic biomarker in localized, high-risk GIST. Recurrences were infrequent for tumors with simple karyotypes. De-escalation of adjuvant imatinib treatment should be explored in patients with cytogenetically simple GISTs.

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.

Reassessment of the recurrence risk of primary gastrointestinal stromal tumour after complete resection

OBJECTIVES

The modified National Institutes of Health (NIH) risk criteria for gastrointestinal stromal tumours (GISTs) have some limitations and need to be improved.

METHODS

Patients who underwent radical resection of primary GIST were retrospectively reviewed. Peripheral blood indices including the neutrophil-to-lymphocyte ratio (NLR) and prognostic nutritional index (PNI) were analysed. Recurrence-free survival (RFS) was calculated and compared. Multivariate analysis was conducted. Area under the receiver operating characteristic curve (ROC) was calculated.

RESULTS

A total of 492 patients were enrolled. Tumour size, mitotic index (MI), tumour location and PNI were independent prognostic factors. The modified NIH criteria could not distinguish among very low-, low- and intermediate-risk patients, and PNI was the only independent prognostic factors for them. The five-year RFS rate in the high risk (HR) group was significantly lower. A further modification to the NIH risk criteria was proposed (the 'NIH-PNI stratification'). Non-high risk (NHR) patients were divided into the NHR-PNI-H group (PNI > 48.05) and the NHR-PNI-L group (PNI ≤ 48.05), respectively. HR patients were divided according to tumour size and MI: the HR1, HR2 and HR3 groups. The five-year RFS rates of the NHR-PNI-H, NHR-PNI-L, HR1, HR2 and HR3 groups were 97.3%, 93.5%, 74.1%, 61.7% and 24.4%, respectively (p < .001). The area under the curve (AUC) for the NIH-PNI stratification, modified NIH criteria, NIH criteria (2002), AFIP criteria and nomogram were 0.857, 0.807, 0.817, 0.843 and 0.831, respectively.

CONCLUSION

The proposed NIH-PNI stratification was able to distinguish among five groups in terms of risk of recurrence.

Nomogram model predicts the risk of visual impairment in diabetic retinopathy: a retrospective study

BACKGROUND

To develop a model for predicting the risk of visual impairment in diabetic retinopathy (DR) by a nomogram.

METHODS

Patients with DR who underwent both optical coherence tomography angiography (OCTA) and fundus fluorescein angiography (FFA) were retrospectively enrolled. FFA was conducted for DR staging, swept-source optical coherence tomography (SS-OCT) of the macula and 3*3-mm blood flow imaging by OCTA to observe retinal structure and blood flow parameters. We defined a logarithm of the minimum angle of resolution visual acuity (LogMAR VA) ≥0.5 as visual impairment, and the characteristics correlated with VA were screened using binary logistic regression. The selected factors were then entered into a multivariate binary stepwise regression, and a nomogram was developed to predict visual impairment risk. Finally, the model was validated using the area under the receiver operating characteristic (ROC) curve (AUC), calibration plots, decision curve analysis (DCA), and clinical impact curve (CIC).

RESULTS

A total of 29 parameters were included in the analysis, and 13 characteristics were used to develop a nomogram model. Finally, diabetic macular ischaemia (DMI) grading, disorganization of the retinal inner layers (DRIL), outer layer disruption, and the vessel density of choriocapillaris layer inferior (SubVD) were found to be statistically significant (P < 0.05). The model was found to have good accuracy based on the ROC (AUC = 0.931) and calibration curves (C-index = 0.930). The DCA showed that risk threshold probabilities in the (3-91%) interval models can be used to guide clinical practice, and the proportion of people at risk at each threshold probability is illustrated by the CIC.

CONCLUSION

The nomogram model for predicting visual impairment in DR patients demonstrated good accuracy and utility, and it can be used to guide clinical practice.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2200059835. Registered 12 May 2022, https://www.chictr.org.cn/edit.aspx?pid=169290&htm=4.

Lymph Node Metastases in Gastrointestinal Stromal Tumors: an Uncommon Event

BACKGROUND

Lymph node (LN) metastases are uncommon among gastrointestinal stromal tumors (GISTs), and their presence has not been utilized in disease prognostication. This study was designed to examine factors associated with GIST nodal metastases and their impact on survival.

PATIENTS AND METHODS

Patients undergoing surgical resection of GIST with nodal evaluation were selected from the National Cancer Database. Logistic regression was utilized to evaluate factors associated with LN metastases. Survival was assessed for patients with and without nodal involvement and Cox regression was used to evaluate the impact of LN metastases while adjusting for other prognostic factors.

RESULTS

Out of 5018 patients, 301 (6.0%) had LN involvement. Nodal metastases occurred most frequently among tumors of the stomach (49.5%), followed by the small bowel (43.2%), colorectum (6.0%), and esophagus (1.3%). On multivariable analysis, male sex (OR 1.34), high mitotic rate (OR 2.10), tumor size (OR 1.02), and a primary tumor located in the small bowel (OR 1.36) were all significantly associated with nodal metastases. LN metastases were significantly associated with decreased overall survival (OS) for tumors arising in the small bowel (log-rank p < 0.01) and the colorectum (log-rank p < 0.01). Within a multivariable model adjusting for established prognostic factors, LN metastases remained independently associated with decreased survival (HR 1.60, p < 0.001).

CONCLUSIONS

For GISTs, LN metastases occur more often in males and were associated with tumor size and mitotic activity. Nodal involvement is associated with decreased survival, independent of other well-established prognostic factors.

Five decades of sarcoma care at Memorial Sloan Kettering Cancer Center

Early studies of the management of soft tissue sarcoma at Memorial Sloan Kettering Cancer Center were influenced by development of robust prospective long-term databases. Increasing capacity for molecular diagnostics has identified a myriad of subtypes with definable natural history. Accurate identification of tissue-specific risk of recurrence and disease-specific survival have increasingly allowed selective use of surgery, radiation therapy, and target-specific cytotoxic and immune therapies.

Long-term adjuvant therapy for high-risk gastrointestinal stromal tumors in the real world

PURPOSE

Three years of adjuvant imatinib is the standard therapy for gastrointestinal stromal tumors (GISTs) with high-risk features. The prognostic effects of long-term adjuvant therapy are unknown.

PATIENTS AND METHODS

The prospective registry study recruited 515 patients with high-risk GISTs between Dec. 2012 and Dec. 2015 were analyzed. The primary endpoint was recurrence-free survival (RFS), and secondary endpoints include overall survival (OS) and safety. The study was designed to compare RFS after 3.5 years of 3-year adjuvant therapy (3.0 ± 0.5 years: 3-year group) with that of more than 3.5 years (median 5.2 years: longer group).

RESULTS

Five-year RFS and 5-year OS were 68.2% (95% confidence interval [CI] 63.8-72.1) and 92.3% (95% CI 89.5-94.4), respectively. The recurrence rate during adjuvant was estimated to be 2.9/100 person-years (95% CI 2.0-4.1) and those after the end of adjuvant, which appeared similar irrespective of the adjuvant duration or reason to stop adjuvant, were estimated 12.0/100 person-years (95% CI 10.2-14.0). The 5-year RFS rates of 3-year and longer groups were 78.7% (95% CI 70.8-84.7) and 92.7% (95% CI 85.2-96.4), respectively. RFS after 3.5 years of the longer group was significantly better than that of the 3-year group (adjusted hazard ratio [HR] 0.56; 95% CI 0.39-0.78; P < 0.001).

CONCLUSION

The recurrence risk of high-risk GISTs after adjuvant therapy is similar irrespective of the adjuvant duration and imatinib adjuvant may not cure but may delay recurrence. RFS after long-term adjuvant therapy appeared better than that after 3-year adjuvant.

A rare rectal gastrointestinal stromal tumor with indolent biological behavior: A case study

The overall incidence of rectal gastrointestinal stromal tumor (RGIST) has risen, but it remains a rare disease. Furthermore, tumor rupture is associated with poor prognosis. The present study reported a rare case of RGIST with indolent biological behavior. The biological behavior of this RGIST was analyzed and its malignant potential was evaluated using a guideline-based risk stratification assessment. The patient was diagnosed with a rectal tumor at the Third Affiliated Hospital of Qiqihar Medical University (Qiqihar, China) in April 2020 and a partial resection biopsy was then performed. This resection counts as a rupture. The biopsy confirmed RGIST and the patient refused further examination and treatment due to economic concerns. However, the patient survives with no tumor progression and metastasis until now, May 2022. In conclusion, based on the present case, tumor rupture in indolent RGIST is not necessarily associated with poor outcome.

GIST: Correlation of risk classifications and outcome

In clinical practice, there are often discrepancies between the oncological prognosis of gastrointestinal stromal tumors (GIST) and the actual clinical course. This study aimed to check with our collective how reliably the current classifications (Miettinen, Fletcher) predict the prognosis of GIST and to evaluate whether an extension of the classifications by the parameter proliferation activity could make sense. This prospective study enrolled 58 patients who underwent surgery on GIST from 01/2006 to 12/2016. The postoperative course (curation, recurrence, progress) was correlated with the identified risk classification and the proliferative activity. Coincidences with other tumors were strikingly common in patients with GIST (43%). Based on the risk group assignment of GIST, no assessment of the probability of the occurrence of second neoplasia could be derived. Individual patients were under- or over-graduated concerning the assessment of biological behavior based on the standard risk classifications. The inclusion of proliferative activity did not allow for a more precise predictive power - neither to the risk of recurrence and metastasis nor to the development of a second neoplasia. The study showed that there is currently no parameter or logarithm that reliably predicts the biological behavior of GIST. Due to the frequency of coincidence of second neoplasia and (rare) distant metastases, for everyday clinical practice, appropriate staging diagnostic and regular follow-up care should also be used for benign GIST.

Gastrointestinal Stromal Tumors and the General Surgeon

Gastrointestinal stromal tumors (GISTs) are rare malignancies of the gastrointestinal tract but are the most common sarcoma. This review covers aspects of the care of patients with GIST relevant to surgeons. In particular, management of sub-2 cm GISTs, the utility of neoadjuvant and adjuvant therapy for primary GISTs, and indications for surgery in the setting of metastatic disease are discussed.

Refining Prognosis in Localized Gastrointestinal Stromal Tumor: Clinical Significance of Phosphatase and Tensin Homolog Low Expression and Gene Loss

To investigate the use of PTEN biomarker to improve prognostic stratification in patients with localized gastrointestinal stromal tumor (GIST).

Neoadjuvant tyrosine kinase inhibitor therapy for patients with gastrointestinal stromal tumor: A propensity-matched analysis

BACKGROUND

Tyrosine kinase inhibitor (TKI) neoadjuvant therapy (NAT) is often given in gastrointestinal stromal tumors (GISTs) with the goal to facilitate less morbid resections and improve oncologic outcomes; however, the use of NAT for GIST is poorly studied.

METHODS

We reviewed patients with resected nonmetastatic GIST from 2003 to 2019. Overall (OS) and recurrence-free survival (RFS) were assessed with Kaplan-Meier modeling. We performed 1:1 propensity-matching for relevant clinicopathologic variables for receipt of NAT.

RESULTS

We identified 254 patients. Propensity 1:1 matching resulted in 33 patients per group. The median follow-up was 77 months with no difference in 10-year OS (68% vs. 73%), 5-year RFS (13% vs. 10%), or median RFS (24 vs. 27 months) for patients treated with NAT versus upfront resection (all P > 0.9). Hospital length-of-stay (both median 7 days) and Clavien-Dindo ≥ III complications (12% vs. 3%) were not different between groups (both P ≥ 0.35).

DISCUSSION

TKI NAT can be used to facilitate resection in select patients with surgically higher-risk GIST, however it does not result in an independent oncologic benefit.

Mesenchymal tumors of the stomach: radiologic and pathologic correlation

Mesenchymal tumors of the stomach are uncommon, with gastrointestinal stromal tumor (GIST) being the most common among them. Majority of the tumors may arise from cells of Cajal, smooth muscle cells, neural cells, totipotent stem cells, adipocytes or fibroblasts. Imaging plays an important role not only in staging but also in characterizing these tumors. Many of these tumors have characteristic imaging features. GISTs usually present as large cavitating and necrotic tumors with exophytic component. Presence of fat tissue within the tumor suggests a lipoma or a teratoma, early phase hyperenhancement indicates glomus tumor and hemangioma, and delayed contrast enhancement is seen in schwannoma. Their differentiation from epithelial tumors like carcinoma and neuroendocrine tumors is often possible based on the location (mesenchymal tumors are intramural), spread, morphological appearance and enhancement patterns. However, overlapping features exist between these tumors with imaging often being only suggestive. A biopsy is necessary for a definitive diagnosis in many cases.

Clinicopathologic Characteristics and Prognosis of PDGFRA-Mutant Gastrointestinal Stromal Tumors: A Large-Scale, Multi-Institutional, Observational Study in China

INTRODUCTION

To evaluate clinicopathologic features and prognosis of post-complete resection in patients with PDGFRA-mutant gastrointestinal stromal tumor (GIST), and even to establish a relapse-free survival (RFS) prognostic model for this subgroup.

METHODS

This retrospective study used data from patients with primary PDGFRA-mutant GIST who underwent complete resection (2005-2019) at 16 large-scale medical centers in China. Stepwise multivariate Cox regression models were performed to build the prediction model, in which the potential predictors were available in routine clinical practice and using the risk score functions. The prediction model was cross-validated by calibration histogram and time-dependent receiver operating characteristic curves.

RESULTS

A total of 280 patients with PDGFRA-mutant (172 D842V-mutant and 108 non-D842V-mutant) GIST after complete resection were enrolled. Most tumors originated in the stomach (89.6%). The 1-, 3-, and 5-year RFS rates were 95.9%, 91.2%, and 89.5%, respectively. The RFS of the non-D842V-mutant group was superior to that of the D842V group (P = 0.033). Multivariate analysis demonstrated that D842V mutation (P = 0.017), non-gastric tumor (P < 0.001), and Ki-67 > 5% (P = 0.005) were the independent variables influencing the prognosis of patients with PDGFRA-mutant GIST. The scoring model showed the predicted and actual cumulative 1-, 3- and 5-year follow-up relapse rates fit well.

CONCLUSIONS

PDGFRA-mutant GIST mostly originated in the stomach and had a favorable prognosis after surgery. Non-D842V-mutant patients might have better prognoses than D842V-mutant patients. The prognostic model demonstrated favorable prediction accuracy, suggesting its clinical utility.

The GIST of Advances in Treatment of Advanced Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin and a compelling clinical and biologic model for the rational development of molecularly targeted agents. This is because the majority of GISTs are driven by gain-of-function mutations in KIT or PDGFRA receptor tyrosine kinases. Specific GIST mutations circumscribe well-defined molecular subgroups that must be determined during the diagnostic work-up to guide clinical management, including therapeutic decisions. Surgery is the cornerstone treatment in localized disease and can also be clinically relevant in the metastatic setting. The correct combination and sequence of targeted agents and surgical procedures improves outcomes for patients with GIST and should be discussed individually within multidisciplinary expert teams. All currently approved agents for the treatment of GIST are based on orally available tyrosine kinase inhibitors targeting KIT and PDGFRA oncogenic activation. Although first-line imatinib achieves remarkable prolonged disease control, the benefit of subsequent lines of treatment is more modest. Novel therapeutic strategies focus on overcoming the heterogeneity of KIT or PDGFRA secondary mutations and providing more potent inhibition of specific challenging mutations. This article reviews the current understanding and treatment of GIST, with an emphasis on recent advances.