Prediction of morbidity following cytoreductive surgery for metastatic gastrointestinal stromal tumour in patients on tyrosine kinase inhibitor therapy

Surgical outcomes of locally advanced gastrointestinal stromal tumors after multivisceral resection: A retrospective study of 64 patients at a single institution

To analyze the outcome in patients who have undergone multivisceral resection (MVR) for locally advanced gastrointestinal stromal tumors (GISTs), and identify the risk factors for tumor recurrence and postoperative morbidity. Sixty-four patients who operated for locally advanced GISTs with MVR in PPeking University Cancer Hospital Sarcoma Center (PUCHSC) between 2013 and 2021 were identified. Clinicopathologic characteristics, surgical outcomes, recurrence, and 5-year recurrence-free and overall survival were evaluated. The mean age of the patients was 60 years. Mean tumor size was 11.1 cm. Complete resection was achieved in all patients. The estimated 5-year recurrence-free and overall survival were 86.6% and 90.0%, respectively. Independent factor of recurrence following surgery was mitotic count on multivariate analysis. Overall postoperative morbidity was 53.1% (n = 34). Severe morbidity was 21.9% (n = 14). The most common severe complication was clinically relevant pancreatic fistula (n = 12, 18.8%), followed by anastomotic leakage (n = 4, 6.3%) and Intraabdominal abscess (n = 4, 6.3%). Multivariate analysis showed that preoperative imatinib therapy could reduce overall morbidity. Long operation time, combined colectomy and pancreatectomy were independent risk factors for postoperative severe morbidity. Compared to partial pancreatectomy, pancreaticoduodenectomy (PD) was significantly increased the incidence of severe morbidity. In conclusion, compared to systemic therapy alone, the outcome of locally advanced GISTs after MVR was more favorable. Despite the high overall morbidity, the postoperative severe morbidity and mortality of MVR were acceptable. Preoperative imatinib therapy should be recommended whenever possible. Combined pancreatectomy and colectomy are associated with significant postoperative severe morbidities. PD should be thoroughly discussed and be subject to MDT approach before surgery.

Cytoreductive Surgery may be beneficial for highly selected patients with Metastatic Gastrointestinal Stromal Tumors receiving Regorafenib facing Local Progression: A Case Controlled Study

Background: Current evidence have shown surgery may provide progression-free survival (PFS) benefit for selected patients with metastatic gastrointestinal stromal tumor (GIST) who received first line imatinib and second line sunitinib. However, impact of cytoreductive surgery for GIST patients receiving third line regorafenib facing progression is not yet reported.

Methods: Between 2014 and 2019, 41 patients with metastatic GIST received regorafenib and 37 of them facing progression.

Results: 37 of 41 (90.2%) pre-treated GIST patients receiving regorafenib who experienced progression of disease after a median follow-up of 12.42 months after regorafenib use and 15 out of 37 (40.5%) patients with local progression underwent cytoreductive surgery (local progression and operation, LPOP). All the patients facing local progression (LP) were significantly younger with more exon 17 mutation than diffuse progression (DP). The complication rate for cytoreductive surgery was 33.3% (5/15). Cytoreductive surgery provided PFS prolongation of 5.52 months. Patients underwent cytoreductive surgery, compared with control group (local progression and no operation (LPNOP) and DP), may gain a significant PFS (12.91 versus 2.33 versus 5.29 months, p = 0.0001) and overall survival (OS) benefit (32.33 versus 5.26 versus 12.42 months, p = 0.004).

Conclusions: Cytoreductive surgery might be feasible in highly selected patients with pre-treated GIST who are being treated with regorafenib experiencing LP.

Surgical Management of Metastatic Gastrointestinal Stromal Tumors

OPINION STATEMENT

Treatment with the tyrosine kinase inhibitor (TKI), imatinib is the standard first-line treatment for metastatic gastrointestinal stromal tumors (GISTs). Unfortunately, acquired c-kit mutations cause secondary resistance to imatinib in a median of 18-24 months. Sunitinib and regorafenib are multi-kinase inhibitors that can be used as second-line or third-line therapy in imatinib-resistant or -intolerant GISTs, respectively. Ripretinib (a switch-control tyrosine kinase inhibitor) has recently been approved for fourth-line treatment in metastatic GIST. The TKI avapritinib has been approved for metastatic GIST harboring the imatinib-resistant PDGFRA exon 18 mutation. Although TKI therapies have revolutionized the treatment of metastatic GISTs, they cannot cure metastatic GISTs. Therefore, cytoreductive surgery is of considerable interest and has been accordingly investigated. Retrospective non-randomized studies demonstrated the feasibility and safety of continuous TKI therapy and surgical resection. Most studies demonstrate response to TKI therapy, completeness of resection, extent of disease, and surgical complexity as predictors of outcomes. Most TKIs can be stopped shortly before surgery and restarted shortly after. There is no known survival benefit from debulking operations or R2 resections and this should not be considered. However, debulking/palliative surgery may be necessary for patients with complications of hemorrhage, pain, or intestinal obstruction. SDH-deficient GISTs have an indolent natural history despite metastatic disease and may be another uncommon subgroup that would benefit from surgical debulking (R2 resection). At the time of operation, care should be taken to avoid tumor rupture. After surgical resection, patients should resume tyrosine kinase inhibitor (TKI) therapy as soon as possible and be monitored for disease progression. In all patients with metastatic GIST, the decision to pursue metastasectomy for GIST should be made in a multidisciplinary setting and be individualized according to patient age, comorbidities, functional status, symptoms, mutation status, extent of disease, completeness of resection, TKI response, and goals of the patient.

Surgical Management of Sarcoma Metastatic to Liver

Sarcomas are rare mesenchymal tumors with a propensity for hematogenous metastasis. Gastrointestinal stromal tumor (GIST) is the most common histologic subtype and the most common source of hepatic metastases. In the case of metastatic GIST, neoadjuvant imatinib can be used as a selection tool for the judicious application of surgery, where treatment-responsive patients who undergo resection to prevent the development of treatment-resistant clones have associated 10-year actuarial survival of 40%. Further advances for many of the non-GIST sarcoma subtypes will depend on the development of improved systemic therapies and evaluation of their activity in subtype or molecularly defined trials.

Gastrointestinal Stromal Tumors of the Stomach and Esophagus

Gastrointestinal stromal tumors (GISTs) arise anywhere along the gastrointestinal tract, most commonly as a result of c-kit or PDGFRA proto-oncogene mutations. Surgical resection is an important component of treatment. However, molecular profiling of GISTs has provided many insights into adjuvant and neoadjuvant therapy options. Imatinib, the most frequently studied medical therapy, has been shown in numerous studies to provide benefit to patients in both the neoadjuvant and adjuvant setting. Interval imaging is an important component of the treatment of GISTs and national surveillance recommendations should be followed.

Prospective Evaluation of Neoadjuvant Imatinib Use in Locally Advanced Gastrointestinal Stromal Tumors: Emphasis on the Optimal Duration of Neoadjuvant Imatinib Use, Safety, and Oncological Outcome

Background: Neoadjuvant imatinib therapy has been proposed for routine practice with favorable long-term results for patients with locally advanced gastrointestinal stromal tumors (GISTs). However, clarification of the optimal duration, safety, and oncological outcomes of neoadjuvant imatinib use before surgical intervention remains necessary. Methods: We prospectively analyzed the treatment outcomes of 51 patients with locally advanced, nonmetastatic GISTs treated with neoadjuvant imatinib followed by surgery. The optimal duration was defined as the timepoint when there was a <10% change in the treatment response or a size decrease of less than 5 mm between two consecutive computed tomography scans. Results: Primary tumors were located in the stomach (23/51; 45%), followed by the rectum (17/51; 33%), ileum/jejunum (9/51; 18%), and esophagus (2/51; 4%). The median maximal shrinkage time was 6.1 months, beyond which further treatment may not be beneficial. However, the maximal shrinkage time was 4.3 months for the stomach, 8.6 months for the small bowel and 6.9 months for the rectum. The R0 tumor resection rate in 27 patients after neoadjuvant imatinib and surgery was 81.5%, and 70.4% of resection procedures succeeded in organ preservation. However, 10 of 51 patients (19.6%) had complications following neoadjuvant imatinib use (six from imatinib and four from surgery). Conclusion: Our analysis supports treating GIST patients with neoadjuvant imatinib, which demonstrated favorable long-term results of combined therapy. However, careful monitoring of complications is necessary. The optimal duration of neoadjuvant imatinib use before surgical intervention is, on average, 6.1 months.