Cytoreductive surgery in patients with recurrent or metastatic gastrointestinal stromal tumors sensitive to imatinib: a retrospective analysis of two Russian cancer centers

Background

The role of cytoreductive surgery for patients with recurrent or metastatic gastrointestinal stromal tumors (mGISTs) responding to imatinib (IM) has not yet been established. We carried out a retrospective analysis of the outcomes of patients with mGISTs in two Russian cancer centers. We compared two cohorts: treated (Group S) or not treated with surgery (Group NS) after a partial response (PR) or stable disease (SD) while on IM.

Methods

A total 44 patients treated by IM as first line treatment were included in our analysis. Prognostically similar patients only sensitive to IM cases with hepatic or peritoneal metastases as well as durable response to IM lasting more than 12 months were included in a control arm. Patients in Group NS received only IM until disease progression. Patients in Group S were treated additionally with metastasectomy after having response or SD on IM.

Results

The baseline characteristics were similar between the groups with several trends: a higher proportion of patients achieved a PR in Group S (87% vs. 55%, P=0.165), and greater number of patients had peritoneal metastases in Group NS (45% vs. 27%, P=0.759). The median time to surgery from the initiation of IM was 8 months. Progression-free survival (PFS) and overall survival (OS) were significantly longer in Group S than Group NS: the median PFS was 78 vs. 35 months (P=0.088); the median OS was 141 vs. 80 months (P=0.154).

Conclusions

The surgical resection of residual lesions after disease control with IM is likely to be beneficial to patients with mGISTs.

Utilization of Neoadjuvant Therapy in Gastrointestinal Stromal Tumors of the Stomach: Analysis of the 2006-2018 National Cancer Database

BACKGROUND

Neoadjuvant tyrosine kinase inhibitor (TKI) therapy has reduced tumor burden and improved survival in both primary and recurrent gastrointestinal stromal tumors (GISTs). However, no clear guidelines exist on optimal patient selection for neoadjuvant therapy (NAT). Our aim was to analyze factors and outcomes associated with the therapeutic sequence of TKI therapy before and/or after surgery for gastric GISTs.

METHODS

We performed a retrospective study of patients surgically treated for a gastric GIST utilizing the 2006-2018 National Cancer Database. We examined demographic, clinical, and pathological characteristics associated with NAT versus adjuvant therapy (AT) using logistic regression.

RESULTS

Of the 3732 patients, 20.4% received NAT and 79.6% had AT. Among patients receiving therapy, NAT significantly increased over our study period (12% to 30.7%). A majority of the AT group received a partial gastrectomy (77.9%) compared with the NAT group who received more near-total/total gastrectomy or gastrectomy with en bloc resection (p < 0.001). In a multivariable model, patients were more likely to receive NAT when insured (private, aOR: 2.37, 95% CI: 1.31-4.29), treated at an academic/research program (aOR: 1.83, 95% CI: 1.49-2.56), had tumors located in the proximal stomach (aOR: 1.40, 95% CI: 1.06-1.86), tumor size > 10 cm (aOR: 1.88, 95% CI: 1.41-2.51), and received near-total/total gastrectomy (aOR: 1.81, 95% CI: 1.42-2.29). There were no differences in outcomes.

CONCLUSION

NAT for gastric GIST has increased in utilization. NAT was used in patients with larger tumors and who underwent more extensive resection. Despite these factors, outcomes were similar to patients receiving only AT. More studies are required to determine the therapeutic sequence for gastric GISTs.

An unusual paraesophageal and diaphragmatic SDHA-deficient gastrointestinal stromal tumor (GIST) metastases case report

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and have diverse tumor biology. Succinate dehydrogenase (SDH)-deficient GIST, comprise less than 10% of all GIST, with mutational loss of the catalytic SDHA subunit being the most common subtype. Contrary to typical GISTs harboring inactivating mutations in KIT/PDGFRA, SDH-deficient GIST has varying biology and behavior, occurring at a younger age, often metastatic on presentation and frequently refractory to conventional tyrosine kinase inhibitors (TKI). Liver and peritoneum are their most common sites of metastases, and extra-abdominal spread to the diaphragm or mediastinum has not been previously described.

Case Description

Herein, we present a case of a 44-year-old female patient with a history of SDHA-deficient GISTs with multiple previous metastasectomies who presented with recurrence to the paraesophageal region and diaphragm which was identified upon routine positron emission tomography (PET) surveillance. Patient subsequently underwent a robotic assisted metastasectomy using a thoracic approach. Follow up was obtained 2 months following procedure and there was no evidence of recurrence.

Conclusions

SDHA-deficient GISTs have unique tumor biology and management of metastatic lesions remains an area of debate and discovery. Overall, this report highlights the need for comprehensive knowledge of the disease, a skilled surgical team, and multi-disciplinary involvement in order to optimize care and ensure favorable outcomes in this patient population.

Fourth-line targeted drugs for the long-term treatment of patients with secondary gastrointestinal stromal tumors with multisite mutations: a case report

BACKGROUND

The surgical treatment of small intestinal stromal tumors is mainly based on the common experience of gastrointestinal stromal tumors (GISTs). The biological characteristics of tumors and secondary gene mutations during disease progression cause many difficulties in clinical treatment. Advanced GISTs usually have no chance to surgery especially after multiple lines of drug therapy and multiple surgeries. This case report provides a good example of rensformational surgery for advanced GIST.

CASE DESCRIPTION

In this report, we describe the case of a patient that is male 57 years old with a small intestinal stromal tumor (stage IV) treated in our center (The First Medical Centre, Chinese PLA General Hospital, Beijing, China) who underwent more than 20 years of first- to fourth-line tyrosine kinase inhibitor (TKI) drug treatment and three rounds of surgical treatment. In June 2020, the patient developed extensive metastases in the abdominal cavity, pelvic cavity, and liver, and could not be treated surgically. The patient was enrolled in the "two-arm clinical trial of bridge therapy with ripretinib and sunitinib in China", started four cycles of ripretinib drug therapy and tumor evaluation, and eventually achieved tumor remission. The patient received surgical treatment following conversion therapy and postoperative tumor recurrence. After continued targeted therapy with TKIs, disease progression was controlled, and the patient's survival was prolonged.

CONCLUSIONS

Type II TKIs such as ripretinib and avapritinib have enhanced the typically expected therapeutic effects of many advanced GISTs. For the late-line treatment of advanced GIST, new TKI drugs can be tried for conversion therapy while monitoring the whole process, grasp the timing of surgery to provide more effective treatment.

Impact of surgical resection for gastrointestinal stromal tumor (GIST) patients with initially diagnosed synchronous hepatic metastases on long-term survival outcomes

BACKGROUND

The effect of surgical resection on the long-term outcome of GIST patients with initially diagnosed synchronous hepatic metastases in the targeted therapy era is still uncertain. The main aims of this study were to investigate the role of surgery in the treatment of these patients and establish clinical predictive models for assessing prognosis.

METHODS

We identified these patients from the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2018. The selection bias in comparisons was minimized by performing propensity score matching (PSM). The risk factors associated with long-term survival outcomes were identified by a Cox proportional hazards model and thus used to establish the nomograms. Nomograms were validated by concordance indexes (C-indexes), time-dependent receiver operator characteristic (ROC) curves, calibration plots, and decision curve analyses (DCA).

RESULTS

Of these 523 eligible patients, there were 187 (35.8%) and 336 (64.2%) patients in the surgical and nonsurgical groups, respectively. Multivariate analysis revealed that surgical resection was an independent prognostic factor for OS (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.44-0.88, p = 0.0068) and CSS (HR 0.51; 95% CI 0.33 - 0.77, p = 0.0016). After PSM, it was found that surgical resection still showed significantly improved OS (5-year 54.9% vs 38.8%, p = 0.028) and CSS (5-year 65.8% vs 50.3%, p = 0.077). In addition, the C-indexes of the nomograms for OS and CSS prediction were 0.692 and 0.705, respectively, and the nomograms showed good consistency.

CONCLUSION

This study revealed that surgical resection has a favorable impact on the long-term outcome of patients with synchronous GIST liver metastases, and the nomograms showed remarkable prediction performance for OS and CSS.

Mutation Status and Immunohistochemical Correlation of EGFR Mutations in Gastrointestinal Stromal Tumors

Being one of the leading causes of cancer deaths worldwide and their resistance to conventional treatment methods, made gastrointestinal stromal tumors (GISTs) one of the hot topics in medical research areas in the past decade. To investigate molecular alterations underlying the tumor is of great importance to be able to develop new, targeted treatment options. In this study, GIST samples obtained from 40 Turkish patients were analyzed for actionable epidermal growth factor receptor (EGFR) mutations that are related to treatment regimes in non small cell lung cancer (NSCLC) to understand whether EGFR expression is altered in GISTs. Established alterations in EGFR can make the use of tyrosine kinase inhibitors possible, which are currently used in cancer therapy, especially in NSCLC. Our results indicated that EGFR mutations are rare in GISTs. Further research is needed to sequence whole coding regions of the gene to investigate new actionable mutations in EGFR in an increased sample size.

Oncogene mutational analysis in imatinib naive population of gastrointestinal stromal tumor patients

There are very scanty reports on gastro-intestinal stromal tumors (GISTs), a very common tumor of mesenchymal cells in GIT track primary resistance to imatinib. This comprehensive study identifies the prevalence, clinical presentation and GIST genotype association in the imatinib naïve population. Prospectively a record of anthropometric, baseline demographic data and clinical details for the patients diagnosed with GIST were scrutinized. Pathological information included the presence or absence of necrosis, tumor size, mitotic counts, immune-histochemical staining for CD 34, CD 117 and DOG1 was performed using biopsy sample. Selected exon genes of KIT, PDGFRA and BRAF were amplified and subjected to mutation analysis by direct sequencing. Appropriate statistical analyses were performed. The male/female ratio was 1.8:1 among 54 patients with GIST. The mean GIST size was comparatively bigger in females (2.49±0.855) than males (2.26±1.13). The stomach was the most common site for GIST followed by the Small bowel and rectum. The majority of the tumours were spindle cell. This study reports 12 different types of mutation among 39 KIT, 8 PDGFRA and 7 BRAF mutations. In KIT, the most prevalent was exon 11 mutation with the KITdelinc557/558 (14/30) being the major exon 11 type mutation. In PDGRFA, five exons 18 with p.D842V substitution and three exons 12 deletion mutation was reported. Seven patients had strong or diffuse BRAF staining having V600E type mutation as major BRAF type mutation. Drug-resistant GIST due to acquired mutations remains a serious issue, therefore genetic information of such mutational related to drug-resistant may provide the imperative clue for diagnosis and clinical treatment. These mutations are pivotal for prognosis and associated with imatinib as not all of them but only a few are reported resistant to the imatinib.

A ruptured jejunal gastrointestinal stromal tumor with hemoperitoneum mimicking ovarian carcinoma

BACKGROUND

Gastrointestinal stromal tumor (GIST) of the small bowel is a rare malignancy and accounts for only 0.1-3% of all gastrointestinal neoplasms. GISTs may mimic gynecologic tumors. The authors present an unusual case of ruptured jejunal GIST with hemoperitoneum mimicking ovarian carcinoma.

CASE PRESENTATION

A 57-year-old postmenopausal woman presented with progressive, generalized low abdominal pain for 3 months. Computed tomography (CT) imaging depicted a 9.6 cm-sized, complex and solid mass on the left pelvic cavity and a 3.7 cm-sized heterogeneous, enhancing mass on the right adnexa, suspicious for ovarian cancer accompanied by hemoperitoneum. There was no active bleeding. Laboratory examination revealed a low level of serum hemoglobin (6.7 g/dL), and a raised serum level of CA-125 (107.0 U/mL). Based on CT imaging findings and an elevated serum level of CA-125, bilateral ovarian cancer was suspected. The patient underwent exploratory laparotomy, and frozen section of the excised mass indicated malignancy originating from the small bowel jejunum. Consequently, small bowel segmental resection with mesenteric resection was done, and a debulking operation including hysterectomy, BSO, BPLD, omentectomy, and excision of multiple metastatic masses in the peritoneum was performed. Subsequent histopathologic examination confirmed the final diagnosis of high risk GISTs of the primary small bowel jejunum. The patient's postoperative course was uneventful, and adjuvant Imatinib was administered.

CONCLUSION

The authors report an unusual case of ruptured jejunal GIST with hemoperitoneum mimicking ovarian carcinoma. Therefore, GIST, in addition to ovarian cancer, should be considered in patients with an increased serum level of CA-125 and an abdominopelvic mass.

Orbital metastasis from a gastrointestinal stromal tumor: A case report

Background

Gastrointestinal stromal tumor (GIST) is the most common primary mesenchymal tumor. The most common metastasis sites are the liver and the surface of the peritoneum. In this study, we present a case of orbital GIST metastasis.

Case presentation

A 43-year-old woman who had a history of small intestinal stromal tumor 4 years ago suffered GIST metastasis to the left orbit. MRI confirmed the presence of a lacrimal gland lesion with isointense on T1 and hyperintense on T2 weighted images. Histopathology analysis of the tumor showed predominantly spindle or oval cells with nuclear pleomorphism and increased mitoses. The tumor also stained positive for c-KIT (CD117) upon immunochemistry, confirming the diagnosis.

Conclusions

GISTs typically occur as sporadic solitary tumors, and their common metastasis sites are the liver and the surface of the peritoneum. Orbital involvement is extremely rare. The orbital GIST metastatic tumor has special imaging properties, as evidenced by histopathology, immunochemistry, and magnetic resonance imaging (MRI).

Gastrointestinal stromal tumors in the imatinib era: 15 years' experience of a tertiary center

Gastrointestinal stromal tumors (GISTs) were associated with a disease free survival rate of disease of 50% at 5 years, but the actual natural history since the advent of imatinib is poorly described. Our objective was to evaluate the evolution in the treatment and prognosis of patients with GISTs since the start of imatinib. Retrospective analysis of GISTs diagnosed between January 2000 and June 2015 in a Portuguese large volume center. We included 131 patients, 55% female, with a mean age of 64±14 years, followed for a median of 30 months; 64% of cases had gastric involvement; 92% of the tumors were c-Kit positive; 95% of patients were operated. Imatinib was initiated in 25% of patients, as adjuvant therapy in 69%; 75% reported adverse effects, and 16% developed resistance. The recurrence rate was 4%, and was associated with age at diagnosis (P=0.037), tumor size (P=0.028), presence of metastases (P=0.019) and high-risk lesions (P=0.036). Survival at 1, 3 and 5 years was 87%, 71% and 61%, respectively. One year's mortality was significantly associated with tumor size (P=0.021), stage IV at diagnosis (P=0.003), non-complete resection (P=0.002) and palliation with imatinib (P=0.035). Similar associations were observed at the 3 and 5 years. In the imatinib era there is an increased long-term survival in comparison with previous epidemiological data, and reduced recurrence rates. In more advanced cases survival remains limited in the short term.

Distinctive features of gastrointestinal stromal tumors arising from the colon and rectum

Background

Colon and rectal gastrointestinal stromal tumors (GISTs) are rare and poorly characterized. Because the majority of treatment guidelines for GISTs are extrapolated from tumors of gastric and small bowel origin, our aim was to better characterize the unique clinicopathologic features and prognostic factors of colon and rectal GISTs to guide clinical care.

Methods

The National Cancer Data Base (NCDB) was queried from 2006 to 2013 for cases of GISTs in the stomach, colon, and rectum. Patient demographics, clinical characteristics, and survival were compared.

Results

A total of 11,302 gastric GISTs were compared to 398 colon and 393 rectal GISTs. After propensity matching, compared to gastric GISTs, rectal GISTs had improved overall survival (HR =0.695, P=0.0264), while colon GISTs had worse overall survival (HR =1.6, P=0.0005). Surgical treatment for rectal GISTs was more likely to be local excision compared to colonic GISTs (51.1% vs. 8.4%, P<0.0001). Colon and gastric GISTs were less likely to receive systemic therapy compared to rectal GISTs (34.2% vs. 34.0% vs. 55.2%, P<0.0001). Adjuvant systemic therapy conveyed a survival advantage to rectal GISTs (HR =0.47, P=0.042) but not colon GISTs. There was a negative impact of adjuvant therapy on survival for colon GISTs <5 cm (HR =3.41, P=0.032).

Conclusions

Patients with rectal GISTs live longer than those with colon and gastric GISTs, and adjuvant therapy prolongs their survival. Many patients with colon GISTs are treated with adjuvant therapy despite a detrimental effect on survival. Tumor biology of colon and rectal GISTs needs to be better studied to tailor treatment.

Two new KIT exon 13 mutations in one gastric gastrointestinal stromal tumor (GIST)

Gastrointestinal stromal tumors (GISTs) are the most frequently mesenchymal tumors found in the gastrointestinal tract. These tumors are usually composed of spindle-shaped cells. More than 80% of GISTs harbor mutations of KIT gene which encodes for an important receptor tyrosine kinase (RTK) type III. Within KIT gene mutations, the mutation of exon 13 is very rare. Here we described a case of GIST in a 42-year-old male which carried two new KIT exon 13 mutations (R634W and N655T). This patient was diagnosed with upper digestive tract hemorrhage and later CT scan revealed a 2.2 cm × 4.0 cm soft-tissue mass on the posterior wall of the stomach. The patient went through a laparoscopic gastrectomy. Following pathological examination revealed this tumor to be a low-risk GIST. Gene sequencing analysis shown that the tumor had two mutations in KIT exon 13, which were not found in the literature. The postoperative course was uneventful and no recurrence was observed after 6 months. Furthermore, we also gave a short review of previously published papers describing KIT exon 13 mutations.

Imatinib mesylate in clinically suspected gastric stromal tumors

Gastrointestinal stromal tumors (GISTs) occur most frequently in the stomach. Diagnosis of gastric GIST is not always clear before surgery. Flexible endoscopy may suggest the nature of the lesion (a bulky tumor with preserved mucosa); however, biopsy is rarely diagnostic. Therefore, diagnostic medication with safe drugs may provide a feasible way under such conditions after an informed consent is obtained. Based on the excellent efficacy of imatinib mesylate (IM) in the treatment of GIST, we successfully applied it in the diagnostic medication of two patients with clinically suspected gastric stromal tumors. In conclusion, the diagnostic medication with IM can be an alternative option for patients with suspected GIST that can not be confirmed pathologically.