Controversies in the management of gastrointestinal stromal tumors

Prognostic Analysis of Duodenal Gastrointestinal Stromal Tumors

AIM

This study aims to analyze factors possibly related to the prognosis of duodenal gastrointestinal stromal tumors (DGISTs).

METHODS

We collected and retrospectively analyzed clinical and pathological data of 62 patients with primary DGISTs. All the patients were hospitalized and received complete surgical resection at Shanghai Ruijin Hospital from September 2003 to April 2015. We followed up the patients to determine survival outcomes. We also analyzed the effect of clinical and pathological factors on disease-free survival (DFS) and overall survival (OS) of the patients.

RESULTS

Kaplan-Meier univariate survival analysis demonstrated that tumor size, mitotic index, Ki-67 index, and pathological risk were correlated with the DFS and OS of the patients (DFS P = 0.039, 0.001, <0.001, and 0.005, resp.; OS P = 0.027, 0.007, <0.001, and 0.012, resp.). Cox multivariate regression analysis revealed that Ki-67 index was an independent prognostic factor affecting DFS and OS (P = 0.007 and 0.028, resp.). Moreover, Kaplan-Meier survival analysis showed that imatinib treatment for patients with recurrence was correlated with prolonged OS (P = 0.002).

CONCLUSION

Prognosis for DGIST treated by R0 resection is favorable. High level of Ki-67 can be an independent risk factor of DGIST prognosis. Adjuvant imatinib therapy for patients with tumor recurrence could probably lead to prolonged survival.

Adjuvant imatinib for patients with high-risk gastrointestinal stromal tumors: a retrospective cohort study

The duration of adjuvant imatinib for high-risk patients with gastrointestinal stromal tumors (GISTs) is still controversial. Therefore, we retrospectively analyzed the data of high-risk patients with GISTs to investigate the appropriate duration. All 185 patients were divided into 4 groups: <1 year (Group A), 1–2 years (Group B), 2–3 years (Group C) and >3 years (Group D). The mean recurrence-free survival (RFS) in Groups A, B, and C were 44.3, 62.1, and 86.8 months, respectively (P < 0.001); the mean overall survival (OS) in Groups A, B and C was 75.2, 88.1, and 94.7 months, respectively (P = 0.009). The 5-year RFS in Groups A, B, C, and D was 15%, 26%, 83%, and 100%, respectively (P < 0.001); and the 5-year OS was 64%, 88%, 88%, and 100%, respectively (P < 0.001). The greatest impact on unfavorable outcomes was the tumor mitotic rate (HR, 2.01, 95% CI, 1.38–2.94; P < 0.001). Duration of adjuvant imatinib was the only favorable factor (HR, −0.95, 95% CI, 0.93–0.97; P < 0.001). For high-risk patients with high tumor size or mitotic rate, or non-gastric GISTs, we recommend that more than 3 years of adjuvant imatinib is feasible.

Regorafenib: A Review of Its Use in Patients with Advanced Gastrointestinal Stromal Tumours

Regorafenib (Stivarga(®)) is an orally administered small molecule inhibitor of multiple protein kinases, including kinases involved in oncogenesis and tumour angiogenesis. It was initially approved for use in patients with previously treated metastatic colorectal cancer. Based on the findings of the phase III GRID clinical trial, approval for regorafenib has been expanded to include the treatment of advanced gastrointestinal stromal tumours (GISTs) following the failure of imatinib and sunitinib. In the GRID trial, regorafenib significantly improved progression-free survival and was associated with a significantly higher disease control rate than placebo. No significant between-group difference was observed in overall survival (OS) in the trial; however, the high proportion of patients who crossed over from placebo to regorafenib likely impacted the OS analysis. Regorafenib has an acceptable tolerability profile, with most adverse events being manageable with dose modification and/or supportive measures. The most commonly reported drug-related adverse events among patients receiving regorafenib in the GRID trial were hand-foot skin reaction, hypertension, diarrhoea and fatigue. In conclusion, regorafenib presents a valuable new tool in the treatment of patients with advanced GISTs following the failure of imatinib and sunitinib.

Diagnosis and surgical treatment of esophageal gastrointestinal stromal tumors

AIM: To retrospectively evaluate our experience with the diagnosis and surgical resection of esophageal gastrointestinal stromal tumors (GISTs).

METHODS: Between January 2003 and August 2014, five esophageal GIST cases were admitted to our hospital. In this study, the hospital records, surgery outcomes, tumor recurrence and survival of these patients were retrospectively reviewed.

RESULTS: The median age of the patients was 45.6 years (range: 12-62 years). Three patients presented with dysphagia, and one patient presented with chest discomfort. The remaining patient was asymptomatic. Four patients were diagnosed with esophageal GISTs by a preoperative endoscopic biopsy. Three patients underwent esophagectomy, and two patients underwent video-assisted thoracoscopic surgery. The mean operating time was 116 min (range: 95-148 min), and the mean blood loss was 176 mL (range: 30-300 mL). All tumors were completely resected. The mean length of postoperative hospital stay was 8.4 d (range: 6-12 d). All patients recovered and were discharged successfully. The median postoperative follow-up duration was 48 mo (range: 29-72 mo). One patient was diagnosed with recurrence, one patient was lost to follow-up, and three patients were asymptomatic and are currently being managed with close radiologic and clinical follow-up.

CONCLUSION: Surgery is the standard, effective and successful treatment for esophageal GISTs. Long-term follow-up is required to monitor recurrence and metastasis.

Interstitial cells of Cajal and biliary system diseases

Interstitial cells of Cajal (ICCs) were first identified using histological staining techniques and best described in the gastrointestinal tract by Santiago Rarnon Cajal, who was a Spanish neuroanatomist, in 1893. Over the past about 100 years, studies have demonstrated that ICCs mainly exist in the esophagus, stomach, proximal duodenum wall, small and large bowel, ileum, appendix, colon and so on. They generate electrical pacemaker activity in gastrointestinal smooth muscles, propagating digestive tract slow wave, mediating and regulating gastrointestinal tract neurotransmitters. In recent years, ICCs have also been found and confirmed to be present in the biliary system, including the gallbladder and extrahepatic biliary duct, the cystic duct and the common bile duct, both in the guinea pigs and humans. Recent studies have confirmed that ICCs in the biliary system are closely related with producing and spreading the gallbladder spontaneous rhythm, adjusting the gallbladder contraction and gallbladder movement. Besides, ICCs play an important role in a variety of diseases of the biliary system, such as cholelithiasis and biliary system malignant tumors. This paper reviews ICCs in the biliary system in terms of their distribution, morphology, ultrastructure, and role in pathophysiology of biliary system diseases.