Surgical management of GIST and intra-abdominal visceral leiomyosarcomas

Lipid profiling of electrosurgical vapors for real-time assistance of soft tissue sarcoma resection

BACKGROUND

Soft tissue sarcomas (STS) constitute a heterogeneous group of rare tumor entities. Treatment relies on challenging patient-tailored surgical resection. Real-time intraoperative lipid profiling of electrosurgical vapors by rapid evaporative ionization mass spectrometry (REIMS) may aid in achieving successful surgical R0 resection (i.e., microscopically negative-tumor margin resection). Here, we evaluate the ex vivo accuracy of REIMS to discriminate and identify various STS from normal surrounding tissue.

METHODS

Twenty-seven patients undergoing surgery for STS at Maastricht University Medical Center+ were included in the study. Samples of resected STS specimens were collected and analyzed ex vivo using REIMS. Electrosurgical cauterization of tumor and surrounding was generated successively in both cut and coagulation modes. Resected specimens were subsequently processed for gold standard histopathological review. Multivariate statistical analysis (principal component analysis-linear discriminant analysis) and leave-one patient-out cross-validation were employed to compare the classifications predicted by REIMS lipid profiles to the pathology classifications. Electrosurgical vapors produced during sarcoma resection were analyzed in vivo using REIMS.

RESULTS

In total, 1200 histopathologically-validated ex vivo REIMS lipid profiles were generated from 27 patients. Ex vivo REIMS lipid profiles classified STS and normal tissues with 95.5% accuracy. STS, adipose and muscle tissues were classified with 98.3% accuracy. Well-differentiated liposarcomas and adipose tissues could not be discriminated based on their respective lipid profiles. Distinction of leiomyosarcomas from other STS could be achieved with 96.6% accuracy. In vivo REIMS analyses generated intense mass spectrometric signals.

CONCLUSION

Lipid profiling by REIMS is able to discriminate and identify STS with high accuracy and therefore constitutes a potential asset to improve surgical resection of STS in the future.

Salvage Hepatectomy for Giant GIST Liver Metastases Unresponsive to Systemic Therapy-Case Report

Therapeutic decision-making for advanced GIST liver metastases is challenging due to limited clinical evidence. This case study aims to demonstrate the survival benefit of resection in non-responsive cases. A 40-year-old male presented with abdominal pain, weight loss, altered general status, massive hepatomegaly, and intermittent melaena. He was diagnosed with stage IV GIST with the primary tumor in the ileal loop and multiple gigantic synchronous bilobar liver metastases. Despite 31 months of tyrosine-kinase inhibitor therapy post-primary tumor resection, the disease remained unresponsive. The patient was admitted to our tertiary center with significant hepatomegaly. A two-stage debulking liver resection was performed after a multidisciplinary team decision. The first operation debulked the left hemiliver through a non-anatomical ultrasound-guided resection of segments 2, 3, and 4. The second operation (7 weeks later) debulked the right hemiliver through a right posterior sectionectomy involving segments 5 and 8. Despite receiving a second line of tyrosine-kinase inhibitor therapy after surgery, the disease progressed both within and outside the liver. However, the patient survived for 55 months, with a postoperative survival benefit of 25 months. In conclusion, this case emphasizes the significant survival benefit achieved through a complex two-stage debulking liver resection for giant liver metastases, even in cases where systemic therapy fails.

Prognostic Factors in Gastrointestinal Leiomyosarcomas: An Analysis Using the Surveillance, Epidemiology, and End Results (SEER) Database

Background Gastrointestinal leiomyosarcomas (LMSs) from intramural smooth muscle are extremely rare, with limited literature. This paper evaluates the epidemiology and survival and prognostic factors in LMSs of the gastrointestinal tract. Methods Clinical data from the Surveillance, Epidemiology and End Results (SEER) 18 registry from 2001 to 2016 with additional treatment fields were compared between primary tumor sites using the chi-squared test for categorical variables and ANOVA for continuous variables. A five-year survival rate analysis was performed for overall and cancer-specific survival. Hazard ratios (HRs) were calculated using univariate and multivariate Cox proportional models using the variables age group, tumor location, grade, stage, surgery, and chemotherapy. Results We identified a total of 523 patients diagnosed with LMSs of the gastrointestinal tract. The median age of diagnosis was 66 years, with no significant difference between tumor sites for age, sex, and race. The five-year overall survival was 77.3%, and the cancer-specific survival was 90.3%. In the multivariate analysis, grade and stage of tumor were the only factors significantly affecting survival in this cohort. Conclusion While surgical status significantly affected survival in the univariate analysis, when adjusted for other factors, the HR for death was not significantly different by surgical therapy. Grade 3 tumors and tumors with distant metastasis at diagnosis were associated with worse survival among these patients.