Exon 11 mutations, Ki67, and p16(INK4A) as predictors of prognosis in patients with GIST

Huge spindle cell sarcoma of esophagus in a middle-aged man with a recent-onset dysphagia: Case report

INTRODUCTION

Esophageal sarcoma is a rare neoplasm of the gastrointestinal tract. The majority of the esophageal neoplasms have an epithelial origin. In this report, we present a case of a middle-aged man with an enormous spindle cell sarcoma whose symptoms initiated only a few weeks before diagnosis.

PRESENTATION OF CASE

A 41-year-old man with an unremarkable past medical history and physical examination presented with recent aggravation of cough and severe, progressive dysphagia to solid foods resulting in a 25-kilogram weight loss without any prior symptoms. He had no history of cigarette smoking and alcohol consumption. The CT scan showed a huge soft tissue mass with heterogeneous enhancement from the proximal esophagus to 4 cm above the gastro-esophageal junction, causing luminal bulging. Trans-hiatal esophagectomy and gastric pull-up were performed. Pathology report confirmed the diagnosis of sarcoma. Further pathological evaluation using immune-histochemical studies, confirmed the tumor as spindle cell sarcoma. The postoperative period was uneventful, and there were no signs and symptoms related to tumor recurrence one year after surgery.

DISCUSSION

The most challenging aspect of diagnosing sarcomas is differentiating them from other pathologies, such as gastrointestinal stromal tumors, synovial sarcomas, sarcomatoid carcinomas, melanomas, and solitary fibrous tumors. Immunohistochemical studies play a vital role in this differentiation. Additionally, cytokeratin AE1/AE3 has been introduced as a marker of epithelial differentiation and can verify the presence of the epithelial component in tumors, such as in carcinosarcomas.

CONCLUSION

Considering the potential for an unusual size, sarcoma should be considered in a differential diagnosis for huge esophageal masses.

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.

Gastrointestinal Stromal Tumor in Monozygotic Twins Shows Distinct Mutational Status: A Case Report

Case series

Patients: Female, 62-year-old • Female, 62-year-old

Final Diagnosis: Gastrointestinal stromal tumor (GIST)

Symptoms: Abdominal pain • fatigue

Medication: —

Clinical Procedure: Genetic analysis

Specialty: Oncology

Association of ki67 Index with Recurrence in Gastrointestinal Stromal Tumors

PURPOSE

Gastrointestinal stromal tumors (GIST) have the potential to recur and metastasize. Several prognostic schemes have been developed but none are precise enough and most times the pathologist faces a small biopsy where it is not possible to evaluate the mitotic count. Our aim was to determine the influence of ki67 index and other clinicopathologic characteristics in the recurrence of GIST.

METHODS

Forty-three consecutive cases of GIST were studied. The cases presented with non-metastatic disease. We compared the clinicopathologic features of cases with recurrence against those with non-recurrence. The ki67 index was determined by square-millimeters.

RESULTS

The median age was 55 years (IQR 45-63), the most frequent site of involvement was the stomach with 21 (48.8%) cases, and the median of tumor diameter was 10 cm (IQR 5.5-17.5). Twenty-six (60.5%) cases were spindle cell, 13 (30.2%) were mixed, and 4 (9.3%) were epithelioid. The median mitosis count for 50 high power fields was 4 (IQR 0-16), while per square millimeter it was 1 (IQR 0-5, range 0-32). The median of the ki67 proliferation index was 5% (IQR 1-20). During the period of study, 11 (25.6%) patients recurred. The only significant differences between patients with GIST with recurrence and without recurrence were the sex and tumor size.

CONCLUSION

We did not find an association of the ki67 index with recurrence. The factors associated with recurrence were a high tumor size (> 10 cm) and male sex.

KIT exon 11 and PDGFRA exon 18 gene mutations in gastric GIST: proposal of a short panel for predicting therapeutic response

Background

GIST is the most common mesenchymal tumor of gastrointestinal tract and is more frequent in stomach. Its main mutations affect KIT and PDGFRA genes. Full genetic analysis panels are currently used to study mutations in GIST and other tumors. Considering that in gastric GIST KIT gene mutations in exon 11 are sensitive to IM whereas PDGFRΑ gene mutations in exon 18 (D842V) are resistant to the same drug, the aim of this study is to focus on these two molecular targets as a short alternative panel for predicting therapeutic response in gastric GIST which might optimize resources.

Methods

The genotypes of 38 cases of primary GIST were determined by performing bidirectional DNA sequencing.

Results

Exon 11 of KIT gene showed mutations in 65.3% and the exon 18 of PDGFRA gene showed 9% of cases. So it was possible to determine a subgroup of tumors which presented mutations in KIT exon 11 and PDGFRA exon 18.

Conclusion

Considering all of the foregoing analyzed globally, the application of short panel has impact on the cost and time of release of results to the physician, allowing a rapid approach to patients eligible for treatment with the target therapy.

Ki-67 labeling index may be a promising indicator to identify "very high-risk" gastrointestinal stromal tumor: a multicenter retrospective study of 1022 patients

We sought to determine whether Ki-67 labeling index (LI) was an independent prognostic factor for gastrointestinal stromal tumor (GIST). A multicenter cohort of 1022 patients undergoing surgical resection of primary GIST between August 2004 and October 2015 was retrospectively analyzed. Immunohistochemical analysis was performed to evaluate expression of Ki-67 in their paraffin-embedded tissue samples. The optimal cutoff value of Ki-67 LI was determined as 6% by receiver operating characteristics curve analysis. Multivariate analysis showed that Ki-67 LI was a significant predictor of overall survival (OS) (hazard ratio: 1.793; 95% confidence interval, 1.240-2.593; P=.002). When stratified by modified National Institutes of Health classification, it was still independently associated with OS in high-risk and non-high-risk patients (P=.001 and P=.055, respectively). Of note, the prognostic significance of Ki-67 LI was also maintained when stratified by tumor size, mitotic index, tumor site, and histological subtype (all Ps<.05). In addition, high-risk patients with Ki-67 LI >6% exhibited a significantly poorer OS rate than those with Ki-67 LI ≤6% (53.6% versus 88.7%, respectively; P=.001). The area under the receiver operating characteristics curve for Ki-67 LI was higher than that of modified National Institutes of Health classification component in high-risk patients (P=.029). Therefore, Ki-67 LI is a promising predictor of outcome in GIST, especially in high-risk patients, and it may have important clinical utility in identifying "very high-risk" patients for rational targeted therapy.

Characterizing gastrointestinal stromal tumors and evaluating neoadjuvant imatinib by sequencing of endoscopic ultrasound-biopsies

AIM

To evaluate endoscopic ultrasound (EUS)-guided biopsies for the pretreatment characterization of gastrointestinal stromal tumors (GIST) to personalize the management of patients.

METHODS

All patients with lesions suspected to be GIST who were referred for EUS-sampling at a tertiary Swedish center were eligible for inclusion 2006-2015. During the observational study phase (2006-2011), routine fine-needle-aspiration (EUS-FNA) was performed. In 2012-2015, we converted to an interventional, randomized protocol with dual sampling EUS-FNA and fine-needle-biopsy-sampling (EUS-FNB) for all lesions. c-KIT- and DOG-1-immunostaining was attempted in all samples and a manual count of the Ki-67-index was performed. FNB-sampled tissue and the resected specimens were subjected to Sanger sequencing of the KIT and platelet-derived growth factor alpha (PDGFRA) genes.

RESULTS

In all, 64 unique patients with GIST were included, and of these, 38 were subjected to pretreatment dual sampling. EUS-FNB had a higher diagnostic sensitivity when compared head-to-head with EUS-FNA (98% vs 58%, P < 0.001) and was more adequate for Ki-67-indexing (Ki-67_EUS) (92% vs 40%, P < 0.001). Sequencing of EUS-biopsies was successful in 43/44 (98%) patients, and the mutation profiles (KIT-mutation 73%, PDGFRA-mutation 18%, wild-type 7%) were fully congruent with those detected in the corresponding resected specimens. In imatinib-naïve patients, the Ki-67_EUS was comparable with the Ki-67-index in the corresponding surgical specimens (Ki-67_SURG) (2.7% vs 2.9%, P = 0.68). In patients treated with neoadjuvant imatinib who also carried mutations indicating sensitivity, the Ki-67_EUS was higher than the Ki-67_SURG (2.5% vs 0.2%, P = 0.005), with a significant reduction in the Ki-67-index of -91.5% (95%CI: -82.4 to -96.0, P = 0.005).

CONCLUSION

EUS-guided biopsy sampling is accurate for the pretreatment diagnosis and characterization of GISTs and allows the prediction and evaluation of tumor response to neoadjuvant imatinib therapy.

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.

Ki-67 Labeling Index can be used as a Prognostic Marker in Gastrointestinal Stromal Tumor: A Systematic Review and Meta-Analysis

Purpose

The aim of this study was to investigate the prognostic relevance of the Ki-67 labeling index (LI) in gastrointestinal stromal tumor (GIST) through a systematic review, meta-analysis and diagnostic test accuracy review.

Method

The study included 1,967 GIST cases from 24 eligible studies. We investigated the correlation between high Ki-67 LI and survival and the proper criteria for high Ki-67 LI. In addition, a diagnostic test accuracy review was conducted to evaluate the predictive role of high Ki-67 LI for higher risk of tumor recurrence.

Results

A high Ki-67 LI was significantly correlated with worse disease-free survival (DFS) (hazard ratio [HR] 3.658, 95% confidence interval [CI] 2.687-4.979, p<0.001) and overall survival (OS) (HR 3.730, 95% CI 2.819-4.936, p<0.001). With regard to DFS and OS, the subgroup with a cutoff value of >4% for high Ki-67 LI had a higher HR than the subgroup with a ≤4% cutoff. In the diagnostic test accuracy review, a high Ki-67 LI was significantly correlated with higher risk of tumor recurrence (pooled sensitivity = 0.44, pooled specificity = 0.87, area under the curve on the summary receiver operating characteristic curve = 0.656).

Conclusions

Our results showed that a high Ki-67 LI was significantly correlated with worse prognosis and higher risk of tumor recurrence in GIST. Further prospective studies of the prognostic role of Ki-67 LI are necessary prior to application in clinical practice.

Ki67 as a prognostic factor for long-term outcome following surgery in gastrointestinal stromal tumors

OBJECTIVE

This study aimed to examine the value of Ki67 expression along with other potential prognostic factors for predicting overall survival and disease-free survival in patients with gastrointestinal stromal tumors who underwent curative resection.

PATIENTS AND METHODS

Sixty-eight histologically confirmed and operated patients with gastrointestinal stromal tumors were included. Clinical and follow-up data were retrieved from medical records and patients were contacted at the end of the study. The effects of certain clinical and histopathological parameters on survival outcomes were examined.

RESULTS

Sixty-eight patients were followed for a mean duration of follow-up of 2923.3 patient-months. Twelve deaths (17.6%), seven metastasis (10.3%), and two local recurrences (2.9%) occurred. Overall survival was 102.5 months [95% confidence interval (CI), 88.3-116.8] and disease-free survival was 91.8 months (95% CI, 76.5-107.2). Multivariate analyses identified a high Ki67 index (≥ 10%) as an independent predictor of both poor overall survival (hazard ratio, 4.8; 95% CI 1.2-19.2; P=0.027) and poor disease-free survival (hazard ratio, 15.3; 95% CI, 4.7-50.2).

CONCLUSION

A high Ki67 expression seems to be a useful prognostic factor that would aid in predicting disease course in gastrointestinal stromal tumors. These findings deserve further investigation in larger studies.

Clinicopathologic analysis of gastrointestinal stromal tumors in duodenum and small intestine

BACKGROUND

The prognosis about duodenal GISTs is debatable. The purpose of this study is to compare the characteristics and the prognostic factors in patients with gastrointestinal stromal tumor (GIST) located in the duodenum with those located in the small intestine.

METHODS

One hundred-one patients with GIST located in the duodenum (n = 40), or small intestine (n = 61) underwent resection between 1996 and 2010. We analyzed clinicopathologic features, surgical outcomes, and prognostic factors.

RESULTS

Five-year survival rate in patients with GIST located in the duodenum and small intestine were 66.6 and 80.8%, respectively (p = 0.018). After survival analysis, high mitotic count and tumor rupture were identified as independent adverse prognostic factors. Advanced T stage and absence of adjuvant imatinib treatment were adverse prognostic factors with marginal statistical significance. The rate of progressive disease was significantly higher in patients with duodenal GISTs (36.8%) than in those with small intestinal GIST (29.6%) (p = 0.024).

CONCLUSIONS

The clinicopathologic findings of duodenal GIST differ from those of small intestinal GIST. Patients with duodenal GIST have a worse prognosis than those with small intestinal GIST. Aggressive treatment including surgical resection should be considered for duodenal GIST, even if the risk is relatively low.

Prognostic impact of gastrointestinal bleeding and expression of PTEN and Ki-67 on primary gastrointestinal stromal tumors

BACKGROUND

Prognostic indicators for gastrointestinal stromal tumors (GISTs) are under investigation. The latest risk classification criteria may still have room for improvement. This study aims to investigate prognostic factors for primary GISTs from three aspects, including clinicopathological parameters, immunohistochemical (IHC) expression of PTEN, and Ki-67 labeling index (LI), and attempts to find valuable predictors for the malignancy potential of primary GISTs.

METHODS

Tumor samples and clinicopathological data from 84 patients with primary GISTs after R0 resection were obtained. Immunohistochemical analysis was performed based on tissue microarray (TMA) to estimate expression of PTEN and Ki-67 in tumor cells.

RESULTS

The cut-off point of Ki-67 LI was determined as 1%, using a receiver operator characteristic test with a sensitivity of 71.7% and a specificity of 64.5%. Univariate analysis demonstrated the following factors as poor prognostic indicators for relapse-free survival (RFS) against a median follow-up of 40.25 months: gastrointestinal (GI) bleeding (P = 0.009), non-gastric tumor location (P = 0.001), large tumor size (P = 0.022), high mitotic index (P < 0.001), high cellularity (P = 0.012), tumor rupture (P = 0.013), absent or low expression of PTEN (P = 0.036), and Ki-67 LI >1% (P = 0.043). Gastrointestinal bleeding (hazard ratio, 3.85; 95% confidence interval, 1.63 to 9.10; P = 0.002) was a negative independent risk predictor in multivariate analysis, in addition to tumor size (P = 0.023), and mitotic index (P = 0.002). In addition, GI bleeding showed a good ability to predict recurrence potential, when included in our re-modified risk stratification criteria.

CONCLUSIONS

This study suggests that GI bleeding is an independent predictor of poor prognosis for RFS in primary GISTs. Expression of PTEN and Ki-67 are correlated with high risk potential and may predict early recurrence in univariate analysis.

Prognostic value of mutational characteristics in gastrointestinal stromal tumors: a single-center experience in 275 cases

The objective of this study was to investigate the impact of KIT/PDGFRA mutations on the prognosis of gastrointestinal stromal tumors (GISTs). In the present study, genotype analyses were performed based on GIST samples from 275 patients. The relationship between mutation and clinicopathological characteristics were explored. All factors were evaluated for their impacts on relapse-free survival (RFS). Briefly, the results of genotype analyses showed that mutations were identified in 258 (93.8 %) patients, and deletion was the most frequent type of mutation accounting for 47.3 % (122/258) of all mutation cases, followed by substitution (87/258, 33.7 %) and duplication (49/258, 19.0 %). Moreover, for KIT exon 11 mutation, the most frequently involved area was from codon 557 to 560. Deep analyses showed that the mutation types were correlated with tumor location (P = 0.005), tumor size (P = 0.022), mitosis rate (P < 0.001), risk grade (P < 0.001), and relapse (P = 0.004). Furthermore, delW557-K558 correlated with mitosis rate (P = 0.042) and relapse (P = 0.036), and delTyr568/570 correlated with tumor origin (P = 0.018). Most importantly, mitotic rate [HR = 2.901 (95 % CI 1.094-7.695), P = 0.032] and risk grade [HR = 9.629 (95 % CI 1.997-46.416), P = 0.005] would be the representative traditional prognostic factors, and deletion with >3 codons would be an novel independent predictor of poor outcome for RFS in GIST patients with deletion mutation of KIT exon 11 [HR = 7.970 (95 % CI 1.774-35.803), P = 0.007]. All results indicated that mutation determined clinicopathological features and prognosis of GISTs, and more than three codons involvement may be a novel adverse indicator.

SKP2 high expression, KIT exon 11 deletions, and gastrointestinal bleeding as predictors of poor prognosis in primary gastrointestinal stromal tumors

Background and Aims

Considering the indication of adjuvant therapy, the recurrence risk for primary gastrointestinal stromal tumor (GIST) after surgery needs to be accurately estimated. However, current risk stratification schemes may still have room for improvement. This study seeks to analyze prognostic factors for primary GISTs from 3 aspects, including clinicopathological parameters, immunohistochemical biomarkers, and gene mutational status, and attempts to find novel valuable factors predicting the malignancy potential of GISTs.

Methods

Retrospective data from 114 primary GIST patients after R0 resection were collected. Clinicopathological data was obtained from medical records and re-evaluated. Immunohistochemical analysis was performed using the Tissue Microarray method for Ki67, p16, p27, p53, SKP2, CD133, and actin. KIT gene exons 9, 11, 13, and 17 and PDGFRα gene exons 12 and 18 were tested for mutations using PCR.

Results

Univariate analysis revealed the following factors as poor prognostic indicators for relapse-free survival with a median follow-up of 50 months: male gender, gastrointestinal bleeding, mitotic index >5/50HPFs, tumor size >5 cm, non-gastric site, necrosis, epithelioid or mixed cell type, surrounding tissue invasion, Ki67>5%, p16>20%, p53 index >10, SKP2>10%, and KIT exon 11 deletion. Besides mitotic index, tumor size and site, SKP2 high expression (RR = 2.91, 95% CI: 1.41–5.99, P = 0.004) and KIT exon 11 deletion (RR = 2.73, 95% CI: 1.04–7.16, P = 0.041) were also independent risk factors in multivariate analysis, with gastrointestinal bleeding also showing a trend towards significance (RR = 1.88, 95% CI: 0.98–3.64, P = 0.059). In addition, gastrointestinal bleeding and SKP2 high expression showed a good ability to stratify high-risk patients further.

Conclusion

Our results show that gastrointestinal bleeding, SKP2 high expression, and KIT exon 11 deletions may be useful indicators of high recurrence risk for primary GIST patients.