New fronts in the adjuvant treatment of GIST. Cancer Chemother Pharmacol. 2013;72:715-723. [PMID: 23934322 DOI: 10.1007/s00280-013-2248-0]

Outcomes of systemic targeted therapy in recurrent renal cell carcinoma treated with adjuvant sunitinib

OBJECTIVE

To assess the efficacy and tolerability of rechallenge with sunitinib and other targeted therapies (TTs) in patitents with relapsed recurrent renal cell carcinoma (RCC) in the advanced setting.

METHODS

In this multi-institutional retrospective study, patients with relapsed RCC were rechallenged with sunitinib or other systemic TTs as a first-line therapeutic approach after failed adjuvant sunitinib treatment. Patient characteristics, treatments and clinical outcomes were recorded. The primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate (ORR) and overall survival (OS).

RESULTS

A total of 34 patients with relapses were recorded, and 25 of these (73.5%) were men. Twenty-five patients were treated with systemic TT: 65% of patients received TT against the vascular endothelial growth factor pathway (including sunitinib), 21.7% received mammalian target of rapamycin inhibitors and 13% received immunotherapy. The median (interquartile range) time to relapse was 20.3 (5.2-20.4) months from diagnosis, and 7.5 months (1.0-8.5) from the end of adjuvant suntinib treatment. At a median follow-up of 23.5 months, 24 of the 25 patients had progressed on first-line systemic therapy. The median PFS was 12.0 months (95% confidence interval [CI] 5.78-18.2). There were no statistical differences in PFS between different treatments or sunitinib rechallenge. PFS was not statistically different in patients relapsing on or after adjuvant suntinib treatment (≤ 6 or >6 months after adjuvant suntinib ending). The ORR was 20.5%. The median OS was 29.1 months (95% CI 16.4-41.8).

CONCLUSIONS

Rechallenge with sunitinib or other systemic therapies is still a feasible therapeutic option that provides patients with advanced or metastastic RCC with additional clinical benefits with regard to PFS and OS after failed response to adjuvant sunitinib.

Resection of liver metastases in patients with gastrointestinal stromal tumors in the imatinib era: A nationwide retrospective study

INTRODUCTION

Liver metastases are common in patients with gastrointestinal stromal tumors (GIST). In the absence of randomized controlled clinical trials, the effectiveness of surgery as a treatment modality is unclear. This study identifies safety and outcome in a nationwide study of all patients who underwent resection of liver metastases from GIST.

METHODS

Patients were included using the national registry of histo- and cytopathology (PALGA) of the Netherlands from 1999. Kaplan Meier survival analysis was used for calculating survival outcome. Univariate and multivariate regression analyses were carried out for the assessment of potential prognostic factors.

RESULTS

A total of 48 patients (29 male, 19 female) with a median age of 58 (range 28-81) years were identified. Preoperative and postoperative tyrosine kinase inhibitor therapy was given to 30 (63%) and 36 (75%) patients, respectively. A minor liver resection was performed in 32 patients, 16 patients underwent major liver resection. Median follow-up was 27 (range 1-146) months. Median progression-free survival (PFS) was 28 (range 1-121) months. One-, three-, and five-year PFS was 93%, 67%, and 59% respectively. Median overall survival (OS) was 90 (range 1-146) months from surgery. The one-, three-, and five-year OS was 93%, 80%, and 76% respectively. R0 resection was the only independent significant prognostic factor for DFS and OS at multivariate analysis.

CONCLUSION

Resection of liver metastases in GIST patients combined with imatinib may be associated with prolonged overall survival when a complete resection is achieved.

[Gastrointestinal stromal tumors: diagnostics and therapy]

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of the gastrointestinal tract. The standard therapy is complete surgical resection with safety margins of 1-2 cm. Intraoperative rupture of the tumor capsule must be avoided because this carries a very high risk of tumor spread. A lymph node dissection is not routinely indicated as lymph node metastases very rarely occur with GIST. Smaller GISTs can normally be removed laparoscopically according to the rules of tumor surgery. Depending on the size of the tumor, the mitosis index and the localization of the primary tumor, the risk of recurrence after potentially curative resection is considerable in many cases. Patients with intermediate and high risks according to Miettinen's classification should receive adjuvant treatment with the tyrosine kinase inhibitor imatinib. Exceptions are those patients whose tumors exhibit the mutation D842V in exon18 of the PDGFRA gene. According to current European Society for Medical Oncology (ESMO) guidelines this therapy should be continued for 3 years. This leads to a significant improvement in progression-free survival compared to a 1-year therapy, and more important to an improvement in overall survival.

Expression profile of microRNAs in gastrointestinal stromal tumors revealed by high throughput quantitative RT-PCR microarray

AIM: To investigate the microRNA (miRNA) expression profile in gastrointestinal stromal tumor (GIST) tissues that could serve as a novel diagnostic biomarker for GIST detection.

METHODS: We performed a quantitative real-time quantitative reverse transcriptase polymerase chain reaction assay to analyze the expression of 1888 miRNAs in a sample set that included 54 GIST tissue samples.

RESULTS: We found that dysregulation of several miRNAs may be related to the malignant potential of GISTs. Six of these miRNAs, hsa-let-7c, miR-218, miR-488#, miR-4683, miR-34c-5p and miR-4773, were selected as the final list of biomarkers to separate the malignant GISTs (M group) from the benign GISTs (B group). In addition, MiR-29b-2#, hsa-let-7c, miR-891b, miR-218, miR-204, miR-204-3p, miR-628-5p, miR-744, miR-29c#, miR-625 and miR-196a were used to distinguish between the borderline (BO group) and M groups. There were 11 common miRNAs selected to separate the benign and borderline (BB) group from the M group, including hsa-let-7c, miR-218, miR-628-5p, miR-204-3p, miR-204, miR-891b, miR-488#, miR-145, miR-891a, miR-34c-5p and miR-196a.

CONCLUSION: The identified miRNAs appear to be novel biomarkers to distinguish malignant from benign GISTs, which may be helpful to understand the mechanisms of GIST oncogenesis and progression, and to further elucidate the characteristics of GIST subtypes.

Effective Downsizing of a Large Oesophageal Gastrointestinal Stromal Tumour with Neoadjuvant Imatinib Enabling an Uncomplicated and without Tumour Rupture Laparoscopic-Assisted Ivor-Lewis Oesophagectomy

Neoadjuvant imatinib for gastrointestinal stromal tumours (GISTs) is increasingly used nowadays. As oesophagectomy is associated with high morbidity and mortality, a preoperative downsizing of an oesophageal GIST to limit the extent of resection would be ideal. Because these tumours are rare and neoadjuvant treatment with imatinib is recent, there is limited literature available regarding neoadjuvant administration of imatinib in patients with oesophageal GISTs. A 50-year-old woman presented with total dysphagia. An upper endoscopy and biopsy revealed a large submucosal KIT-positive GIST obstructing the mid oesophagus. CT confirmed a lesion measuring 99 mm × 50 mm × 104 mm. Because the size and location of the tumour increased the risk of intraoperative rupture, it was decided to administer preoperative imatinib. The patient had an excellent clinical and radiological response. Her dysphagia gradually resolved and the follow-up CT scans of the first 10 months showed a gradually reducing tumour size to 54 mm × 33 mm × 42 mm. The patient underwent an uneventful laparoscopic-assisted Ivor-Lewis oesophagectomy. Postoperatively, the patient continued with adjuvant imatinib. At the last follow-up, 1 year from operation and 38 months from the diagnosis, the patient is disease free.

microRNA-218 increase the sensitivity of gastrointestinal stromal tumor to imatinib through PI3K/AKT pathway

To detect the expressions of microRNA-218 (miR-218) in an imatinib mesylate-sensitive human gastrointestinal stromal tumor (GIST) cells (GIST882) and an imatinib mesylate-resistant cell line (GIST430) and explore the roles of miR-218 and GIST cells in the sensitivity of gastrointestinal stromal tumor to imatinib mesylate and its potential signaling pathways, with an attempt to provide new insights for the treatment of GIST. The GIST cell lines (GIST882 and GIST430) were cultured in vitro. Quantitative real-time PCR (qRT-PCR) was utilized to determine the expression profiles of miR-218 in both GIST cell lines. Forty-eight hours after the transfection of the miR-218 mimic or miR-218 inhibitor in the GIST cells, the changes in the expression of miR-218 in the GIST cells were detected with qRT-PCR. The effects of the ectopic expression of miR-218 in GIST882 or GIST430 cells on the imatinib mesylate-induced GIST cell viability were determined by MTT. The effects of miR-218 ectopic expression on the apoptosis of imatinib mesylate-induce GIST cells were determined by Annexin V/PI double staining method and flow cytometry. The effects of miR-218 ectopic expression on the AKT and phospho-AKT (p-AKT) expressions of imatinib mesylate-induce GIST cells were determined by Western blot and flow cytometry with the PI3K pathway inhibitor Wortmannin. As shown by qRT-PCR, compared with that in the imatinib mesylate-sensitive GIST882, the expression of miR-218 in imatinib mesylate-resistant GIST430 was significantly decreased (P < 0.01). Compared with the control group, the expression of miR-218 significantly increased in the GIST882 48 h after the transfection of miR-218 mimic (P < 0.01) and significantly declined after the transfection of miR-218 inhibitor (P < 0.01). As shown by MTT and flow cytometry, after the expression of miR-218 was inhibited in GIST882 under the effect of imatinib mesylate, the cell viability significantly increased (P < 0.01) and the number of apoptotic cells significantly decreased (P < 0.05); on the contrary, the over-expression of miR-218 in GIST430 under the effect of imatinib mesylate resulted in the significantly decreased cell viability (P < 0.01) and the significantly increased number of apoptotic cells (P < 0.05). Western blot and flow cytometry showed that, in comparison to the control group, Wortmannin could significantly inhibit the expression of p-AKT in GIST430 cells (P < 0.01) and stimulated apoptosis (P < 0.01). The expression of miR-218 is down-regulated in an imatinib mesylate-resistant GIST cell line (GIST430), whereas miR-218 over-expression can improve the sensitivity of GIST cells to imatinib mesylate, with PI3K/AKT signaling pathway possibly involved in the mechanism.