Do microscopic surgical margins matter for primary gastric gastrointestinal stromal tumor?

Prognostic impact of positive microscopic margins (R1 resection) in patients with GIST (gastrointestinal stromal tumours): Results of a multicenter European study

BACKGROUND

Although several prognostic factors in GIST have been well studied such as tumour size, mitotic rate, or localization, the influence of microscopic margins or R1 resection remains controversial. The aim of this study was to evaluate the influence of R1 resection on the prognosis of GIST in a large multicentre retrospective series of patients.

METHODS

From 2001 to 2013, 1413 patients who underwent surgery for any site of GIST were identified from 61 European centers. 1098 patients were included, excluding synchronous metastases, concurrent malignancies, R2 resection or GIST recurrence. Tumour rupture (TR) was reclassified according to the Oslo sarcoma classification. Cox proportional hazards ratio and Kaplan-Meier survival estimates were used to analyse 5-year recurrence-free survival (RFS).

RESULTS

Of 1098 patients, 38 (3%) underwent R1 resection with a risk of TR of 11%. The 5-year RFS was 89.6% with a median follow-up of 81 months [range: 31.2-152 months]. On univariate analysis, lower RFS was significantly associated with R1 resection [HR = 2.13; p = 0.04], high risk score according to the modified NIH classification, administration of adjuvant therapy [HR = 2.24; p < 0.001] and intraoperative complications [HR = 2.82; p < 0.001]. Only intraoperative complications [HR = 1.79; p = 0.02] and high risk according to the modified NIH classification including the updated definition of TR [HR = 3.43; p = 0.04] remained significant on multivariate analysis.

CONCLUSION

This study shows that positive microscopic margins are not an independent predictive factor for RFS in GIST when taking into account the up-dated classification of TR. R1 resection may be considered a reasonable alternative to avoid major functional sequelae and should not lead to reoperation.

Comparative Analysis of Enbloc or Piecemeal Removal After Enbloc Resection of Gastrointestinal Stromal Tumors

OBJECTIVE

To investigate the safety and prognosis of enbloc or piecemeal removal after enbloc resection of a gastric GIST by comparing the clinical data of endoscopic en block resection and piecemeal removal (EP) and en block resection and complete removal (EC) of gastric GISTs.

METHODS

A total of 111 (43 endoscopic piecemeal, and 68 complete removal) patients with gastric GIST's ≥ 2 cm in diameter who underwent endoscopic therapy from January 2016 to June 2020 at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. In all cases, it was ensured that the tumor was intact during the resection, however, it was divided into EP group and EC group based on whether the tumor was completely removed or was cut into pieces which were then removed. The patients' recurrence-free survival rate and recurrence-free survival (RFS) were recorded.

RESULTS

There was no statistically significant difference in RFS rates between the two groups (P = 0.197). The EP group had relatively high patient age, tumor diameter, risk classification, and operation time. However, there was no statistically significant difference in the number of nuclear fission images, postoperative hospitalization time, postoperative fasting time, complication rate and complication grading between the two groups (P > 0.05).

CONCLUSION

Endoscopic piecemeal removal after en block resection of gastric GIST is safe and effective and achieves similar clinical outcomes as complete removal after en block resection.

Impact of tumour rupture risk on the oncological rationale for the surgical treatment choice of gastrointestinal stromal tumours

Tumour rupture of gastrointestinal stromal tumours (GISTs) has been considered to be a remarkable risk factor because of its unfavourable impact on the oncological outcome. Although tumour rupture has not yet been included in the current tumor-node-metastasis classification of GISTs as a prognostic factor, it may change the natural history of a low-risk GIST to a high-risk GIST. Originally, tumour rupture was defined as the spillage or fracture of a tumour into a body cavity, but recently, new definitions have been proposed. These definitions distinguished from the prognostic point of view between the major defects of tumour integrity, which are considered tumour rupture, and the minor defects of tumour integrity, which are not considered tumour rupture. Moreover, it has been demonstrated that the risk of disease recurrence in R1 patients is largely modulated by the presence of tumour rupture. Therefore, after excluding tumour rupture, R1 may not be an unfavourable prognostic factor for GISTs. Additionally, after the standard adjuvant treatment of imatinib for GIST with rupture, a high recurrence rate persists. This review highlights the prognostic value of tumour rupture in GISTs and emphasizes the need to carefully take into account and minimize the risk of tumour rupture when choosing surgical strategies for GISTs.

Therapeutic Effects of 4 Surgical Approaches for Small Gastrointestinal Stromal Tumors: A Network Meta-analysis

This study aims to systematically evaluate the efficacy of endoscopic resection (ER), laparoscopic resection (LR), laparoscopic endoscopic cooperative surgery (LECS), and open surgery (OpS) for gastrointestinal stromal tumors with small diameters (≤5 cm). Relevant studies were collected through Pubmed, Cochrane Library, and Embase databases. Operative time, hospital stays, time to liquid diet, intraoperative bleeding, and complications were used as outcome indicators for meta-analysis. Twenty-four retrospective cohort studies with 2406 participants were analyzed. LR and OpS groups had longer operating time than the ER group. ER, LECS, and LR groups had decreased lengths of hospital stay than the OpS group. Moreover, patients in LR and LECS groups had fewer complications than those in the OpS group. Endoscopic operation for small gastrointestinal stromal tumors contributes to shortened lengths of surgery and hospital stay. This reduces intraoperative blood loss and promotes gastroenteric functional recovery without increasing the risk of complications or tumor recurrence.

Comparison of Prognosis Between Microscopically Positive and Negative Surgical Margins for Primary Gastrointestinal Stromal Tumors: A Systematic Review and Meta-Analysis

Background

This meta-analysis aimed to determine the prognostic impact of microscopically positive margins (R1) on primary gastrointestinal stromal tumors.

Methods

A literature search was performed using PubMed, Embase, Web of Science, and Cochrane Library for studies up to 23 November 2020. The pooled disease-free survival (DFS) and overall survival (OS) between R1 and negative margins (R0) were estimated using a random-effects model.

Results

Twenty studies with 6,465 patients were included. Compared with R0 resection, R1 was associated with poor DFS in patients who did not receive adjuvant Imatinib (HR: 1.62, 95% CI: 1.26-2.09; P = 0.48, I² = 0%; reference: R0). This negative impact of R1 disappeared with the use of adjuvant Imatinib (HR: 1.23, 95% CI: 0.95-1.60; P = 0.38, I2 = 6%; reference: R0). R1 was related to poor DFS in gastric GISTs (HR: 2.15, 95% CI: 1.15-5.02, I² = 0%; reference: R0), which was attenuated in the subgroup of adjuvant Imatinib (HR: 2.24, 95% CI: 0.32-15.60; P = 0.84, I² = 0%; reference: R0). Rectal GIST with R1 margin who even received adjuvant Imatinib still had poor DFS (HR: 3.79, 95% CI: 1.27-11.31; P = 0.54, I² = 0%; reference: R0). Patients who underwent R1 resection had similar OS compared with those underwent R0 resection regardless of the use of adjuvant Imatinib.

Conclusion

R1 was associated with poor DFS for primary GISTs, which was attenuated by adjuvant therapy with Imatinib. Similar result was observed in the gastric GISTs subgroup. Rectal GIST patients with R1 resection had poor DFS even when they received adjuvant Imatinib. The R1 margin did not influence the OS of GISTs.