Combined Therapy of Gastrointestinal Stromal Tumors

Advanced and Metastatic Gastrointestinal Stromal Tumors Presenting With Surgical Emergencies Managed With Surgical Resection: A Case Series

Advanced and metastatic gastrointestinal stromal tumors (GISTs) presenting with surgical emergencies are rare. Neoadjuvant imatinib being the treatment of choice for non-metastatic advanced disease with a proven role in downstaging the disease may not be feasible in patients presenting with bleeding and obstruction. We present a case series with retrospective analysis of a prospectively maintained database of patients with advanced and metastatic GISTs presenting with surgical emergencies. Clinical characteristics, imaging and endoscopic findings, surgical procedures, histological findings, and outcomes in these patients were studied. Four patients were included in this case series, with three males and one female (age range: 24-60 years). Two patients presented with melena; one with hemodynamic instability despite multiple blood transfusions underwent urgent exploratory laparotomy for bleeding gastric GIST, while the other underwent surgical exploration after careful evaluation given the recurrent, metastatic disease with a stable metabolic response on six months of imatinib. One patient with metastatic jejunal GIST who presented with an umbilical nodule and intestinal obstruction was given a trial of non-operative management for 72 hours, but due to non-resolution of obstruction, segmental jejunal en bloc resection with the dome of the urinary bladder with reconstruction and metastasectomy was needed. The patient with advanced gastric GIST who presented with gastric outlet obstruction was resuscitated, and an attempt of endoscopic naso-jejunal tube placement was tried, which failed, and exploration was needed. The mean length of hospital stay was 7.5 days. Histopathological examination confirmed GIST in all four patients with microscopic negative resection margins. All patients were started on imatinib with dose escalation to 800 mg in the patient with recurrent and metastatic disease; however, the patient with bleeding gastric GIST experienced severe adverse effects of imatinib and discontinued the drug shortly. All four patients are disease-free on follow-ups of 15 months, 48 months for the patient with advanced non-metastatic disease, and six and 24 months for the patients with metastatic disease. In the era of tyrosine kinase inhibitor (TKI) therapy for advanced and metastatic disease, upfront surgery is usually reserved for surgical emergencies only. Surgical resection, the cornerstone for the treatment of resectable GIST, may also be clinically relevant in metastatic settings, although it requires a careful and individualized approach.

Minimally Invasive Approach to Gastric GISTs: Analysis of a Multicenter Robotic and Laparoscopic Experience with Literature Review

Simple Summary

Gastrointestinal stromal tumors (GISTs) represent about 1–3% of all gastrointestinal malignancies, of which 50–60% are gastric GISTs (GGs). To the date, surgery represents the best therapeutic option, and the robotic gastric surgery could gain an important role, overcoming many laparoscopic drawbacks. The aim of this study is to evaluate safety and effectiveness of minimally invasive surgery (MIS) for GGs, reporting 10-year experience of three different centers. We included a population of 81 patients who underwent MIS approaches (36 laparoscopy vs. 45 robotic surgery). Seventy-two (72) patients were enrolled in a follow-up program to evaluate the long-term oncological outcomes. Furthermore, we discussed some technical notes and also we analyzed the operative and peri-operative outcomes. In conclusion, our results suggest that the robotic approach might be a suitable treatment, especially for GISTs >5 cm, even located in unfavorable places, despite longer operative time and costs than laparoscopic approach.

Abstract

Background: Gastrointestinal stromal tumors (GISTs) are most frequently located in the stomach. In the setting of a multidisciplinary approach, surgery represents the best therapeutic option, consisting mainly in a wedge gastric resection. (1) Materials and methods: Between January 2010 to September 2020, 105 patients with a primary gastrointestinal stromal tumor (GISTs) located in the stomach, underwent surgery at three surgical units. (2) Results: A multi-institutional analysis of minimally invasive series including 81 cases (36 laparoscopic and 45 robotic) from 3 referral centers was performed. Males were 35 (43.2%), the average age was 66.64 years old. ASA score ≥3 was 6 (13.3%) in the RS and 4 (11.1%) in the LS and the average tumor size was 4.4 cm. Most of the procedures were wedge resections (N = 76; 93.8%) and the main operative time was 151 min in the RS and 97 min in the LS. Conversion was necessary in five cases (6.2%). (3) Conclusions: Minimal invasive approaches for gastric GISTs performed in selected patients and experienced centers are safe. A robotic approach represents a useful option, especially for GISTs that are more than 5 cm, even located in unfavorable places.

Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Drug-Resistant Gastrointestinal Stromal Tumors: A Feasibility Study

Background

As an emerging clinical problem, locally advanced drug-resistant gastrointestinal stromal tumors (LADRGISTs) has relatively few therapeutic schemes. Although radiotherapy is not often considered for GISTs, it could be a valuable contributing modality. The aim of our study is to explore a safe and effective radiation regimen for LADR-GISTs.

Methods

Three patients with LADR-GISTs were treated with simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) plans. In the SIB-IMRT plans, gross target volume (GTV) was divided into GTV-outer, GTV-mid, and GTV-center. And the prescribed dose of planning gross target volume (PGTV) and GTV-outer were both set to 50.4 Gy in 28 fractions. GTV-mid and GTV-center were simultaneously boosted to 60–62 Gy and 62–64 Gy respectively. For comparison purposes, conventional IMRT (Con-IMRT) plans with uniform dose distribution were generated for same optimization objectives without a dose boost to GTV-mid and GTV-center. All plans were optimized to make sure that deliver at least 95% of the prescription dose was delivered to PGTV. Isodose distribution, dose profiles, conformity indexes (CIs), monitor units (MUs), and dose volume histogram (DVH) was evaluated for each individual patient. After the three patients were treated with SIB-IMRT plans, the relative changes in the tumor size and CT values by CT scanning were also tracked.

Results

Compared with Con-IMRT plans, SIB-IMRT plans saw a significant increase from D₉₅ to D₂ of the GTV. With steeper dose gradients in the dose profiles, SIB-IMRT plans had GTV-mid and GTV-center accumulated with higher dose mainly by delivering extra 93 MUs in average. However, there was no significant difference in CIs and organs at risks (OARs) DVH. The relative changes in tumor size and CT values of the three patients in follow up were up to the Choi criteria and the three patients were all assessed as partial response.

Conclusions

The proposed SIB-IMRT may be a potential technique for achieving objective response and prolonging survival of selected GISTs patients.

The analysis of 3-year adjuvant therapy with imatinib in patients with high-risk molecular profiled gastrointestinal stromal tumors (GIST) treated in routine practice

INTRODUCTION

The real-world data on adjuvant imatinib therapy in high-risk primary GIST are scarce.

METHODS

We have analysed the data of 107 consecutive patients with gastrointestinal stromal tumour (GIST) after resection treated with adjuvant imatinib (for planned 3 years with initial dose 400 mg daily, started not later than 4 months after operation) in 6 oncological centres in 2013-2018. All patients were required to have high risk of recurrence (at least 50% according to NCCN/AFIP criteria), known mutational status to exclude PDGFRA D842V mutants and KIT/PDGFRA-wild type cases from therapy without any further selection. Median follow-up time was 27 months.

RESULTS

The most common primary localization of GIST was small bowel (63 patients; 59%), followed by the stomach (40 patients; 37%). The majority of GIST cases harboured exon 11 KIT mutations (88 cases, 82%), 11 cases had exon 9 KIT mutations (10%), 8 had other KIT/PDGFRA mutations potentially sensitive to imatinib. Forty patients (37%) finished 3-year adjuvant imatinib therapy as planned, 48 (45%) still continue therapy, 5 (4.5%) patients had finished adjuvant therapy prematurely due to toxicity, 6 (6%) due to disease progression on treatment and 8 (7.5%) due to other reasons. The disease relapse was detected in 19 patients, of them in 5 cases in exon 9 KIT mutants (45%), and 14 cases in patients with exon 11 KIT mutations (11%) [p < 0.01]. Estimated 4-year relapse-free survival (RFS) rate is 78%.

CONCLUSIONS

The early results of adjuvant therapy with imatinib in routine practice outside clinical trials in high-risk mutation-driven GIST patients only confirm high efficacy of this therapy with better tolerability than in clinical trials. We found overrepresentation of exon 9 KIT mutants and ruptured tumors in a group of patients with disease relapse.

The Landmark Series: Systemic Therapy for Resectable Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Complete resection is the only potentially curative treatment, although recurrence is common, occurring in approximately 40–50% of patients. The introduction of effective molecularly targeted therapies for GISTs has dramatically changed the clinical management paradigms for, and prognosis of, patients with intermediate- and high-risk GISTs, as well as those with locally advanced and metastatic disease. In this article, we review landmark studies that evaluated the use and efficacy of the tyrosine kinase inhibitors imatinib and sunitinib in the adjuvant and neoadjuvant settings for resectable primary and limited resectable metastatic GISTs.

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.

Macroscopic Evaluation of Gastric Specimens After Laparoscopic Sleeve Gastrectomy-an Optimum Screening Test for Incidental Pathologies?

Introduction

Obesity is a serious lifestyle disease with various comorbidities and an augmented risk of cancer. Laparoscopic sleeve gastrectomy (LSG) has recently become the most popular bariatric procedure worldwide. While the cost-effectiveness is a major healthcare providers’ concern, the point of histological exam of each resected tissue may be questioned.

Material/Methods

We prospectively included patients who underwent LSG. Before the surgery, gastroscopy and abdominal sonography were performed to exclude malignancies. The gastric specimen was cut open after the surgery and inspected macroscopically, then sent for a microscopic examination.

Results

In 5 cases out of 115, macroscopic evaluation of the resected specimen performed by the surgeon suggested existing pathology, confirmed by a microscopic evaluation in 3 out of 5 cases. In the remaining 2 cases, pathological analysis did not reveal abnormalities. In 110 cases, the gastric specimen was recognized to be unchanged by the surgeon, 109 out of which were confirmed by the pathologist to be normal, in 1 case a hyperplastic polyp was found. The sensitivity of macroscopic evaluation reached 75% (95% CI, 19.4–99.4%, p = 0.625), with specificity of 98.2% (95% CI, 93.6–99.8%, p < 0.0001), and negative predictive value of 99.1% (95% CI, 95–99.9%, p < 0.0001).

Conclusions

During LSG, a thorough visual inspection of the peritoneal cavity along with a macroscopic surgical evaluation of specimen in patients who had preoperative endoscopy with no findings allows to achieve very good specificity and good sensitivity. Therefore, this procedure may be useful as a screening test for incidental pathologies in bariatric patients and may exclude unnecessary histological examination.

Is the Surgical Margin in Gastrointestinal Stromal Tumors Different?

Background

Radical surgical excision is the mainstay of therapy of primary, nonmetastatic gastrointestinal stromal tumors (GIST) and margin status after surgery is a significant prognostic factor.

Methods and Results

The aim of this paper is to review principles in primary GIST surgery, i.e. differences between R0, R1, and R2 resection, to describe how surgical margin status and tumor intraperitoneal rupture influence the patients' outcome, and how this may be effected by neoadjuvant and adjuvant treatment in locally advanced tumors. A systematic search of literature published between 2000 and 2018 was performed regarding this topic.

Conclusion

Correct interpretation of margin status after surgery can be affected by many factors during operation and preparation of tissue.

Non-Coding RNAs and Resistance to Anticancer Drugs in Gastrointestinal Tumors

Non-coding RNAs are important regulators of gene expression and transcription. It is well established that impaired non-coding RNA expression especially the one of long non-coding RNAs and microRNAs is involved in a number of pathological conditions including cancer. Non-coding RNAs are responsible for the development of resistance to anticancer treatments as they regulate drug resistance-related genes, affect intracellular drug concentrations, induce alternative signaling pathways, alter drug efficiency via blocking cell cycle regulation, and DNA damage response. Furthermore, they can prevent therapeutic-induced cell death and promote epithelial-mesenchymal transition (EMT) and elicit non-cell autonomous mechanisms of resistance. In this review, we summarize the role of non-coding RNAs for different mechanisms resulting in drug resistance (e.g., drug transport, drug metabolism, cell cycle regulation, regulation of apoptotic pathways, cancer stem cells, and EMT) in the context of gastrointestinal cancers.

Evaluation for therapeutic measures to small gastric stromal tumor: A retrospective study of 90 cases

Surgery and regular follow-up are two main measures for small gastric stromal tumors (sGST) less than 2cm in diameter, while there is no sound evidence to prove which treatment is more beneficial to sGST patients. In this study, we reviewed the clinical and pathological features of patients with sGST receiving surgery and discussed the value of surgical intervention. In all, 90 patients who were diagnosed as sGST(less than 2cm) and accepted surgical treatment were enrolled, correspondently, another 104 patients with GSTs between 2-5cm and 74 patients with GSTs >5cm were collected as Control groups 1 and 2, respectively, and all of them received surgical treatment. Results showed that there were no significant difference among 3 groups in terms of gender, age, clinical features, tumor locations, and mutations of the exon 9 or 11 in C-kit gene, and immunohistochemical results of CD117, CD34, and DOG-1 proteins (P > 0.05). However, we observed growing percentage of medium-/high-risk GSTs and nucleus mitotic counts >5/50 HPF in Control groups (P < 0.05). Patients with sGST were more suitable for minimally invasive procedures than the other 2 groups, with shorter hospital stay (P < 0.05). During the follow-up period (medium 45.4 months), the recurrence rate was also associated with tumor size, which surged from 1.11% in sGST group to 7.69% and 17.56% in Control groups 1 and 2, respectively. In all, we concluded that patients with sGST experienced low proportions of medium-/high-risk tumors; however, they still suffered from potential risk of tumor progression. Due to satisfied surgical outcome, surgical treatment could be suggested for sGST.

The analysis of the long-term outcomes of sorafenib therapy in routine practice in imatinib and sunitinib resistant gastrointestinal stromal tumors (GIST)

Aim of the study

was to analyze the outcome of treatment and factors predicting results of sorafenib therapy in inoperable/metastatic CD117-positive GIST patients after failure on imatinib and sunitinib.

Material and methods

We identified 60 consecutive patients (40 men, 20 women) with advanced inoperable/metastatic GIST after failure on at least imatinib and sunitinib treated in one sarcoma center with sorafenib at initial dose 2 × 400 mg daily in 2007-2015 (in 56 cases it was 3^rd line therapy). Median follow-up time was 39 months.

Results

One year progression-free survival (PFS; calculated from the date of the start of sorafenib to disease progression) rate was 23% and median PFS = 7.7 months. The median overall survival (OS) was 13.5 months calculated from sorafenib start (1-year OS rate = 57%) and 7 years from imatinib start. Three patients (5%) had objective partial responses to therapy, 31 patients (52%) had stabilization of disease > 4 months. Primary tumor mutational status was known in 43 cases (73%), but we have not identified the differences in PFS between tumors carrying different KIT/PDGFRA mutations. The most common adverse events were: diarrhoea, hand and foot syndrome, fatigue, loss of weight and skin reactions; grade 3-5 toxicity occurred in 35% of patients. 23 patients required sorafenib dose reductions due to AEs.

Conclusions

We confirmed that many advanced GIST patients benefit from sorafenib therapy after imatinib/sunitinib failure with OS > 1 year.

Bariatric surgery and incidental gastrointestinal stromal tumors - a single-center study: VSJ Competition, 1st place

INTRODUCTION

Gastrointestinal stromal tumors (GISTs), originating from Cajal cells, are most commonly located in the stomach; therefore they can be found in the specimens excised during bariatric operations. The global prevalence of GISTs is about 130 cases per million population. Morbidity differs depending on geographical latitude. Although surgery is the treatment of choice for GISTs, 40-50% of patients after radical surgical treatment will have a relapse or metastases.

AIM

To analyze the incidence of GISTs in patients undergoing bariatric surgery and to verify whether an operation performed according to the bariatric protocol is oncologically radical in case of GIST.

MATERIAL AND METHODS

A single-center retrospective study. The study group comprised 1252 obese patients qualified for bariatric procedures, with no upper gastrointestinal tract neoplasms found during preoperative diagnostic examinations. In case of suspicious macroscopic pathologies (n = 81) present during the operation, tissue specimens underwent histopathological examination with further investigation performed if GISTs were found, including tumor size and localization, mitotic index and immunohistochemical analysis.

RESULTS

Gastrointestinal stromal tumors were found in 16 cases, and benign tumors of various histological origin in 33 cases. All cases of GIST found came from stomach specimens, 7 from the gastric corpus vs. 9 from the fundus. Fourteen GISTs were found during laparoscopic sleeve gastrectomies (LSGs) vs. 2 during laparoscopic Roux-en-Y gastric bypasses (LRYGBs).

CONCLUSIONS

In case of incidental findings of GISTs during bariatric surgery, tumor resection with negative margins of incision may be considered as complete oncological treatment if there was very low/low risk stratification of GIST's recurrence after surgery.

Molecular profiling of sarcomas: new vistas for precision medicine

Sarcoma is a large and heterogeneous group of malignant mesenchymal neoplasms with significant histological overlap. Accurate diagnosis can be challenging yet important for selecting the appropriate treatment approach and prognosis. The currently torrid pace of new genomic discoveries aids our classification and diagnosis of sarcomas, understanding of pathogenesis, development of new medications, and identification of alterations that predict prognosis and response to therapy. Unfortunately, demonstrating effective targets for precision oncology has been elusive in most sarcoma types. The list of potential targets greatly outnumbers the list of available inhibitors at the present time. This review will discuss the role of molecular profiling in sarcomas in general with emphasis on selected entities with particular clinical relevance.

Potentials of Long Noncoding RNAs (LncRNAs) in Sarcoma: From Biomarkers to Therapeutic Targets

Sarcoma includes some of the most heterogeneous tumors, which make the diagnosis, prognosis and treatment of these rare yet diverse neoplasms especially challenging. Long noncoding RNAs (lncRNAs) are important regulators of cancer initiation and progression, which implies their potential as neoteric prognostic and diagnostic markers in cancer, including sarcoma. A relationship between lncRNAs and sarcoma pathogenesis and progression is emerging. Recent studies demonstrate that lncRNAs influence sarcoma cell proliferation, metastasis, and drug resistance. Additionally, lncRNA expression profiles are predictive of sarcoma prognosis. In this review, we summarize contemporary advances in the research of lncRNA biogenesis and functions in sarcoma. We also highlight the potential for lncRNAs to become innovative diagnostic and prognostic biomarkers as well as therapeutic targets in sarcoma.

Genetic progression in gastrointestinal stromal tumors: mechanisms and molecular interventions

Gastrointestinal stromal tumors (GISTs) are the most common sarcomas in humans. Constitutively activating mutations in the KIT or PDGFRA receptor tyrosine kinases are the initiating oncogenic events. Most metastatic GISTs respond dramatically to therapies with KIT/PDGFRA inhibitors. Asymptomatic and mitotically-inactive KIT/PDGFRA-mutant "microGISTs" are found in one third of adults, but most of these small tumors never progress to malignancy, underscoring that a progression of oncogenic mutations is required. Recent studies have identified key genomic abnormalities in GIST progression. Novel insights into the genetic progression of GISTs are shedding new light on therapeutic innovations.