Laparoscopic sphincter-preserving surgery (intersphincteric resection) after neoadjuvant imatinib treatment for gastrointestinal stromal tumor (GIST) of the rectum

A systematic review and meta-analysis of neoadjuvant imatinib use in locally advanced and metastatic gastrointestinal stromal tumors

BACKGROUND

Several doubts remain regarding the optimal use of neoadjuvant imatinib in gastrointestinal stromal tumors (GISTs), such as ideal treatment duration, patient selection, and long-term survival outcomes. This manuscript provides a comprehensive review on neoadjuvant imatinib treatment outcomes and facilitate evidence-based decision-making for the use of imatinib therapy in GISTs.

METHODS

Four databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched from inception to September 9, 2023. Meta-analyses of proportions were performed for the outcomes of R0 resection, disease responses, and 1-year, 3-year, and 5-year overall survival (OS) as well as 1-year, 3-year, and 5-year disease free survival (DFS). Sensitivity analyses in the form of leave-one-out analyses, meta-regression, and subgroup analyses were performed for outcomes with substantial statistical heterogeneity.

RESULTS

The search yielded 1254 articles, and 36 studies were included in our analysis. Meta-analysis of proportions revealed that 1-year, 3-year, and 5-year OS was 100%, 94%, and 88%, while 1-year, 3-year and 5-year DFS was 99%, 89%, and 79%, respectively. An R0 resection rate of 89% and a disease response rate of 67% was achieved after a mean duration of treatment of 8.41 ± 0.367 months. KIT exon 9 mutation was significantly associated with poorer 5-year DFS.

CONCLUSION

This study quantified key outcomes for neoadjuvant imatinib in locally advanced and metastatic or recurrent GIST. Patients with gastric and rectal tumous stand to benefit from neoadjuvant imatinib with an optimal treatment duration of 8 months. Furthermore, the potential utility of mutational analysis in guiding treatment with neoadjuvant imatinib was demonstrated.

Short-term and long-term outcomes after robotic radical surgery for rectal gastrointestinal stromal tumor

BACKGROUND

The optimal approach for ensuring both complete resection and preservation of anal function in rectal gastrointestinal stromal tumor (GIST) remains unknown. The aim of this study was to clarify short-term and long-term outcomes after robotic radical surgery for rectal GIST.

METHODS

A total of 13 patients who underwent robotic radical surgery for rectal GIST between December 2011 and April 2022 were included. All robotic procedures were performed using a systematic approach. A supplemental video of robotic radical surgery for rectal GIST is attached. The short-term outcome was the incidence of postoperative complications during the first 30 days after surgery. Surgical outcomes were retrieved from a prospective database. Long-term outcomes, including overall survival and recurrence-free survival, were determined in all patients.

RESULTS

Median distance from the tumor to the anal verge was 4.0 cm. Surgical margins were negative in all patients. Two patients underwent neoadjuvant imatinib therapy. All patients underwent sphincter-preserving surgery. None underwent conversion to open or laparoscopic surgery. The incidence of postoperative Clavien-Dindo grade II and grade ≥ III complications was 7.7% and 0%, respectively. The median postoperative hospital stay was 7 days. Twelve patients (92.3%) underwent stoma closure within 5 months of the initial surgery. Median follow-up time was 76 months. The 5-year overall survival and recurrence-free survival rates were both 100%. None of the patients had recurrence.

CONCLUSION

Short-term and long-term outcomes after radical robotic surgery for rectal GIST were favorable. Robotic surgery might be a useful surgical approach for rectal GIST.

Gastrointestinal stromal tumors arising in the perianal and perineal region: Two case reports and literature review

INTRODUCTION AND IMPORTANCE

Gastrointestinal stromal tumor (GIST) is rare because of its variable clinical incidence reported (from 0.4 to 2/100,000 per year) in the literature, mainly occurs primarily in the stomach and small intestine. GISTs in the perianal and perineal regions have been reported in a few pieces of literature. GIST located in the perianal and perineal regions may be misdiagnosed and missed due to atypical symptoms. We report two cases of GIST in rare sites and hope to reduce the occurrence of such events through a review of the relevant literature.

CASE DESCRIPTION

We reported two cases of GIST located in the perianal and perineal regions with different symptoms. One case underwent an emergency procedure to stop bleeding and resect the mass, and the other case was discovered during the physical examination and slowly grew in the follow-up. Following the completion of the relevant examination, the patient underwent surgical resection. Both cases were finally diagnosed as GIST by immunohistochemistry.

CLINICAL DISCUSSION AND CONCLUSION

Due to atypical clinical symptoms of perianal and perineal GIST, definitive diagnosis depends on pathology and immunohistochemistry, which can lead to misdiagnosis and missed diagnosis. Surgical resection is the preferred option for localized masses. Surgical resection of GIST located in the perianal and perineal regions requires an appropriate surgical approach based on the patients' actual condition, taking into account the protection of anal function and complete resection of the mass. Masses located in perianal and perineal region should be taken seriously by clinicians.

Gastrointestinal Stromal Tumours (GIST) of the Rectum: A Systematic Review and Meta-Analysis

Background: Rectal gastrointestinal stromal tumours (GISTs) have many treatment options, but uncertainty remains regarding the best treatment regimen for this rare pathology. The aim of this review is to assess the optimal management approach including timing of chemotherapy. Methods: PubMed, EMBASE, and Cochrane databases were searched for relevant articles comparing the impact of radical vs. local excision, and neoadjuvant vs. adjuvant therapy had on outcomes in the management of rectal GISTs. We specifically evaluated the influence that the aforementioned factors had on margins, recurrence, overall survival, 5-year disease-free survival, and hospital length of stay. Results: Twenty-eight studies met our predefined criteria and were included in our study, twelve of which were included in the quantitative synthesis. When comparing neoadjuvant versus adjuvant chemotherapy, our meta-analysis noted no significance in terms of margin negativity (R0) (odds ratio [OR] 2.01, 95% confidence interval [CI], 0.7−5.79, p = 0.20) or recurrence rates (OR 0.22, 95% CI, 0.02−1.91, p = 0.17). However, there was a difference in overall 5-year survival in favour of neoadjuvant therapy (OR 3.19, 95% CI, 1.37−7.40, * p = 0.007). Comparing local excision versus radical excision, our meta-analysis observed no significance in terms of overall 5-year survival (OR1.31, 95% CI, 0.81−2.12, p = 0.26), recurrence (OR 0.67, 95% CI, 0.40−1.13, p = 0.12), or 5-year disease-free survival (OR 1.10, 95% CI, 0.55−2.19, p = 0.80). There was a difference in length of hospital stay with a reduced mean length of stay in local excision group (mean difference [MD] 6.74 days less in the LE group; 95% CI, −6.92−−6.56, * p =< 0.00001) as well as a difference in R0 rates in favour of radical resection (OR 0.68, 95% CI, 0.47−0.99, * p = 0.05). Conclusion: Neoadjuvant chemotherapy is associated with improved overall 5-year survival, while local excision is associated with reduced mean length of hospital stay. Further large-volume, prospective studies are required to further define the optimal treatment regimen in this complex pathology.

Efficacy and safety of neoadjuvant imatinib therapy for patients with locally advanced rectal gastrointestinal stromal tumors: A multi-center cohort study

Background: Several issues on neoadjuvant imatinib therapy remain controversial despite its widespread application for rectal gastrointestinal stromal tumors (GIST). We aimed to describe the clinicopathological characteristics of this specific population, and compare the surgical and oncologic outcomes between patients with or without neoadjuvant imatinib therapy.

Patients and methods: A cohort of 58 consecutive locally advanced rectal GIST patients receiving surgical treatment between January 2007 and July 2019 at Sun Yat-sen University Cancer Center and Yunnan Cancer Hospital was retrospectively analyzed. Recurrence-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method.

Results: There were 33 (56.9%) patients who received neoadjuvant imatinib therapy. Among them, 20 (60.6%) patients had partial response (PR) as their best response, 11 (33.3%) patients had stable disease (SD), and 2 (6.1%) patients had progressive disease (PD). The median tumor size reduced from 5.2 to 4.0 cm after treatment (p < 0.001), and an attained “maximal response” was primarily achieved (32/33) on the 12th month after treatment. The most common adverse event was anemia. There were 27 adverse events occurred, most of which were grade 1 (19/27). With respect to intraoperative and postoperative surgical outcomes, no significant difference was found between patients with or without neoadjuvant Imatinib therapy except that patients with neoadjuvant treatment had a significant higher rate of preventive ileostomy (p = 0.004). Patients received neoadjuvant treatment had a superior 2-years RFS outcome than those without, though the difference was no significant (91.7% vs. 78.9%, p = 0.203). There were no significant differences in the 2-years OS rates (95.2% vs. 91.3%, p = 0.441).

Conclusion: Neoadjuvant imatinib therapy is an effective and safe treatment for locally advanced rectal GISTs. Further studies are warranted to validate the long-term prognostic benefit for patients with rectal GISTs receiving neoadjuvant imatinib therapy.

Trans-anal surgery with the taTME technique for rectal gastrointestinal stromal tumors: a retrospective study

PURPOSE

Rectal gastrointestinal stromal tumors (GISTs) surgery is often challenging owing to the anatomical constraints of the narrow pelvis and tumor hugeness. Despite the increasing number of patients undergoing trans-anal total mesorectal excision (taTME) globally, the feasibility of trans-anal surgery with the taTME technique for rectal GISTs remains unclear. We aimed to evaluate the feasibility of trans-anal surgery with the taTME technique for rectal GISTs.

METHODS

Using a prospectively collected database, we retrospectively analyzed the clinical findings, surgical outcomes, pathological outcomes, urinary and anal functions, and prognoses of patients who underwent trans-anal surgery with the taTME technique for primary rectal GISTs at the National Cancer Center Hospital East from September 2014 to March 2020.

RESULTS

Twenty-one patients with primary rectal GISTs were included in this study. The median distance from the anal verge to the lower edge of the tumor was 40 mm (range, 15-60 mm), and the median tumor size was 59 mm (range, 11-175 mm). Moreover, seven and 14 patients underwent one-team and two-team surgeries, respectively, with curative intent. Nineteen patients (90.5%) underwent anus-preserving surgery, and the urinary tracts were preserved in all cases. Two-team surgery showed a significantly lower blood loss volume and shorter operation time than one-team surgery (58 vs. 222 mL, P = 0.017; 184 vs 356 min, P = 0.041, respectively). The pathological negative-margin resection rate was 100%. During the follow-up period, no patient developed local GIST recurrence and one (4.8%) developed distant metastasis.

CONCLUSION

Trans-anal surgery with the taTME technique is feasible for rectal GISTs, and two-team surgery may be more advantageous than one-team surgery in terms of operation time and blood loss.

Laparoscopic Versus Open Surgery for Rectal Gastrointestinal Stromal Tumor: A Multicenter Propensity Score-Matched Analysis

BACKGROUND

The safety and feasibility of laparoscopic surgery for the management of rectal gastrointestinal stromal tumors are unknown.

OBJECTIVE

This study aimed to compare the surgical and oncologic results of laparoscopic versus open surgery for the treatment of rectal gastrointestinal stromal tumors.

DESIGN

This was a retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the difference between surgery strategies.

SETTINGS

Eleven Chinese tertiary hospitals participated in this study.

PATIENTS

A total of 364 patients with pathologically confirmed rectal gastrointestinal stromal tumors were retrospectively analyzed.

MAIN OUTCOME MEASURES

Relapse-free survival, postoperative hospital stay length, and 30-day postoperative complication rate were the main outcome measures.

RESULTS

We enrolled 214 patients who underwent surgical operation for primary localized rectal gastrointestinal stromal tumors. After propensity score matching, 134 cases involved in the comparison (67 laparoscopic vs 67 open surgery) were randomly matched (1:1) by sex, age, tumor size, tumor site, and neoadjuvant therapy. The laparoscopic surgery group had superior relapse-free survival (χ2 = 4.46, p = 0.04), and fewer complications (6.0% vs 25.4%, p = 0.002). No significant difference was found in the length of postoperative hospital stay between the laparoscopic surgery and open surgery groups (9.66 ± 5.42 vs. 10.64 ± 4.93, p = 0.28). Subgroup analysis showed that the laparoscopic surgery group had superior relapse-free survival (χ2 = 4.14, p = 0.04) and fewer complications after surgery (2.9% vs 24.4%, p = 0.01) in the rectal gastrointestinal stromal tumors ≤5 cm subgroup.

LIMITATIONS

This study was limited by the nature of retrospective reviews and relatively short follow-up period.

CONCLUSIONS

Laparoscopic surgery offers a safe and feasible option for the radical resection of primary localized rectal gastrointestinal stromal tumors, especially for patients with rectal gastrointestinal stromal tumors ≤5 cm. See Video Abstract at http://links.lww.com/DCR/B764.

CIRUGA LAPAROSCPICA VERSUS CIRUGA ABIERTA PARA TUMORES DEL ESTROMA GASTROINTESTINAL DE RECTO UN ANLISIS MULTICNTRICO EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:Se desconoce la seguridad y factibilidad de la cirugía laparoscópica para el tratamiento de los tumores del estroma gastrointestinal de recto.OBJETIVO:Comparar los resultados quirúrgicos y oncológicos de la cirugía laparoscópica versus cirugía abierta para el tratamiento de los tumores del estroma gastrointestinal de recto.DISEÑO:Estudio retrospectivo multicéntrico emparejado por puntuación de propensión para minimizar la heterogeneidad entre los grupos y centrarse en las diferencias entre las estrategias quirúrgicas.AJUSTES:Once hospitales terciarios de la China participaron en este estudio.PACIENTES:Se analizaron retrospectivamente un total de 364 pacientes con tumores del estroma gastrointestinal de recto confirmados patológicamente.PRINCIPALES MEDIDAS DE VALORACION:Supervivencia sin recidiva, duración de la estancia hospitalaria postquirúrgica y tasa de complicaciones postquirúrgicas a los 30 días.RESULTADOS:Inscribimos a 214 pacientes que fueron sometidos a cirugía por tumores primariamente localizados del estroma gastrointestinal de recto. Después del emparejamiento por puntaje de propensión, 134 casos involucrados en la comparación (67 laparoscópicos versus 67 cirugía abierta) fueron emparejados aleatoriamente (1: 1) por sexo, edad, tamaño del tumor, sitio del tumor y terapia neoadyuvante. El grupo de cirugía laparoscópica tuvo una supervivencia sin recidiva superior (χ2 = 4,46, p = 0,04) y menos complicaciones (6,0% frente a 25,4%, p = 0,002). No se encontraron diferencias significativas en la duración de la estancia hospitalaria postquirúrgica entre los grupos de cirugía laparoscópica y cirugía abierta (9,66 ± 5,42 frente a 10,64 ± 4,93, p = 0,28). El análisis de subgrupos mostró que el grupo de cirugía laparoscópica tuvo una supervivencia sin recidiva superior (χ2 = 4,14, p = 0,04) y menos complicaciones después de la cirugía (2,9% frente a 24,4%, p = 0,01) en el subgrupo de tumores del estroma gastrointestinal de recto ≤ 5 cm.LIMITACIONES:La naturaleza de la revisión retrospectiva y el período de seguimiento relativamente corto son limitaciones de este estudio.CONCLUSIONES:La cirugía laparoscópica ofrece una opción segura y factible para la resección radical de tumores primariamente localizados del estroma gastrointestinal de recto, especialmente para pacientes con tumores ≤5 cm. Consulte Video Resumen en http://links.lww.com/DCR/B764.

Recent Advancements in the Treatment of Rectal Gastrointestinal Stromal Tumor: In Era of Imatinib

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor of the gastrointestinal tract, with an annual incidence of 10–15 cases per million. However, rectal GIST has a low incidence, accounting for approximately 0.1% of all rectal tumors. The treatment of rectal GISTs is still controversial and the relative unified guidelines and consensus opinions are inadequate. Treatment is based primarily on the clinical experience of the physician. The widespread application of neoadjuvant imatinib therapy allows diversification of treatment, especially in the choice of surgical methods. Herein, we reviewed the most recent literature and summarized the new progress in rectal tumor treatment, with the aim of providing patients with more systematic and individualized therapeutic strategies.

OUP accepted manuscript

Background

Method

Results

Conclusion

The effect of neoadjuvant imatinib therapy on outcome and survival in rectal gastrointestinal stromal tumors: A multiinstitutional study

BACKGROUND AND OBJECTIVES

This study aimed to characterize the efficacy of neoadjuvant imatinib in rectal gastrointestinal stromal tumors (GISTs) and the prognostic characteristics of patients after surgery.

METHODS

Patients with rectal GISTs who received neoadjuvant imatinib between 2000 and 2019 were selected from 11 large-scale tertiary hospitals in China. The best response to neoadjuvant imatinib was assessed. Propensity score matching (PSM) was conducted to reduce confounders. Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method.

RESULTS

Of the 100 patients, 75, 18, and 7 had a partial response (PR), stable disease (SD), and progressive disease (PD), respectively. The median tumor size decreased from 5 cm before treatment to 4 cm after treatment (p < 0.001). A total of 31 patients underwent genetic testing after surgery; 23 of patients with exon 11 mutation had PR and 2 had SD. One of the patients with exon 9 mutation had PR, 2 had SD, and 1 had PD. Two patients with the wild type GIST had PD. A total of 86 patients underwent surgery of which 85 underwent complete resection; 72 underwent anal preservation and 40 underwent local excision (LE). After PSM, patients who received neoadjuvant therapy had higher rates of LE (p = 0.001) and anal preservation (p = 0.033) than those of patients without neoadjuvant therapy. The median follow-up time was 37 months. Nine patients experienced recurrence and one patient died. The 3-year RFS and OS rates were 95.0% and 100%, respectively. After PSM, we found that there was no significant difference in RFS between patients who received or did not receive neoadjuvant therapy (p = 0.623). Univariate analysis showed postneoadjuvant tumor size (p = 0.469) and mitotic count (p = 0.294) were not associated with the RFS in patients who received neoadjuvant imatinib.

CONCLUSIONS

Neoadjuvant imatinib can shrink rectal GIST size, increasing the possibility of complete resection and anal preservation. Further studies are warranted to understand the long-term outcomes of rectal GISTs in patients receiving neoadjuvant imatinib.

Transanal approach after preoperative imatinib treatment of a rectal gastrointestinal stromal tumors with external anal sphincter invasion: A case report

INTRODUCTION AND IMPORTANCE

Rectal gastrointestinal stromal tumors (GISTs) are rare, and preserving anorectal function can be challenging. We report the case of a patient with rectal GIST with external anal sphincter invasion, treated via the laparoscopic and transanal approaches.

CASE PRESENTATION

A 61-year-old man with locally advanced GIST in the right anterolateral wall of the lower rectum was examined. Lower endoscopy revealed a 50-mm submucosal tumor located 4 cm from the anal verge. On immunohistochemistry, the biopsy specimen tested positive for CD34 and C-KIT, and the patient was diagnosed with GIST. Abdominal magnetic resonance imaging (MRI) revealed external anal sphincter infiltration. Because of the large tumor size and proximity to the anal verge, preserving the anus was challenging, and colorectal resection was avoided. Instead, neoadjuvant therapy with imatinib was administered to facilitate local resection of the tumor. Post-treatment MRI showed a reduction in tumor size (30 × 20 × 30 mm), and surgery was performed. We identified an appropriate resection line for diplomatic sphincter resection of the infiltrated area by laparoscopy alone. Thus, we performed a hybrid surgery using the laparoscopic and transanal approaches. The patient had an unremarkable postoperative course and was discharged on postoperative day 23.

CLINICAL DISCUSSION

No study has reported cases of rectal GIST with external anal sphincter invasion wherein anal function was preserved. Here, imatinib was administered preoperatively, and hybrid surgery was performed using the transanal and laparoscopic approaches.

CONCLUSION

Preoperative treatment and surgery preserved anorectal function in a patient with a massive rectal GIST.

The Combination of Neoadjuvant Therapy and Surgical Resection: A Safe and Effective Treatment for Rectal Gastrointestinal Stromal Tumors

Background

Rectal gastrointestinal stromal tumors (GISTs) are rare digestive tumors. The treatment methods of rectal GISTs are diverse, while no standardized treatment was recommended. The aim of this study was to report the treatment mode of rectal GISTs in our center.

Methods

Patients with pathologically confirmed rectal GISTs who received neoadjuvant therapy and surgical resection were retrospectively collected. Perioperative complications and long-term prognosis were evaluated.

Results

From January 2010 to December 2019, 36 patients were pathologically diagnosed with primary rectal GISTs. After excluding patients who were treated with surgery or imatinib alone, 21 patients received neoadjuvant therapy and surgery was enrolled. During neoadjuvant treatment, tumors shrank significantly (6.53cm to 4.68cm, p<0.001) without toxicities over grade 2. The total postoperative complication rate was 42.9% (all grade). R0 resection was achieved in 76.2% patients. Transanal resection had advantages on anus preservation and postoperative recovery. No patients died during the follow-up period, 4 patients relapsed and the relapse-free survival was 81.0%.

Conclusion

The combination of neoadjuvant therapy and surgical resection was a safe and effective treatment for rectal gastrointestinal stromal tumors.

Neoadjuvant tyrosine kinase inhibitors in rectal gastrointestinal stromal tumours: a provision for enhanced oncological and functional outcomes

Background

The role of tyrosine kinase inhibitors (TKI) in the neoadjuvant setting and the optimal duration of therapy remains poorly defined. As such, we aim to evaluate the impact of neoadjuvant TKI on oncological and functional outcomes in our cohort of patients with rectal GISTs.

Methods

A retrospective analysis of 36 consecutive patients who underwent treatment for rectal GIST at the National Cancer Centre Singapore from February 1996 to October 2017 was analysed. Surgical, recurrence and survival outcomes between the groups who underwent neoadjuvant therapy and those who underwent upfront surgery were compared.

Results

Patients who received neoadjuvant treatment had significantly larger tumours (median size 7.1 vs. 6.0 cm, p = 0.04) and lower mitotic count (> 10 per 50 HPF, 14 vs. 70%, p = 0.03) when compared with the non-neoadjuvant group. With TKI pre-treatment (median duration 8.8 months), majority of patients (82%) achieved at least partial response to the therapy coupled with a significant downsizing effect of up to 39% (median size of 7.1–3.6 cm), resulting in similar rates of sphincter-sparing surgery (75 vs. 76%, p = 0.94) when compared with the non-neoadjuvant group. In general, neoadjuvant group had lower rates of local recurrence (0 vs. 69%, p = 0.04) and higher overall survival (7.4 vs. 5.7 years, p = 0.03) as compared to the non-neoadjuvant group.

Conclusions

Neoadjuvant TKI has the benefit of downsizing unresectable rectal GIST to benefit from sphincter-sparing procedure and also confers protection against local recurrence and improves overall survival.

Hybrid resection of massive rectal gastrointestinal stromal tumor using laparoscopic and transanal approaches

Rectal gastrointestinal stromal tumors (GISTs) are rare, and radical surgery such as abdominoperineal resection is necessary for large rectal GISTs to obtain tumor-free resection margins. Here, we describe a 77-year-old man with a locally advanced non-metastatic GIST in the left anterolateral wall of the lower rectum. Tumor size was estimated to be 73 mm, and invasion of the left seminal vesicle and prostate was suspected. Chemotherapy with imatinib mesylate reduced the tumor size, creating a slight gap between the tumor and anterior organs. Therefore, we performed sphincter-sparing partial rectal resection using a hybrid method of laparoscopic and transanal approaches. The postoperative course was uneventful, and the patient remains disease-free on adjuvant chemotherapy 12 months after surgery. This case suggests that a hybrid method of laparoscopic and transanal surgery allows oncological and function-preserving excision of large rectal GISTs.

Gastrointestinal stromal tumor of the rectum resected by transanal total mesorectal excision after neoadjuvant imatinib treatment: A case report

This report describes the combination of a transanal total mesorectal excision (TaTME) and neoadjuvant therapy with Imatinib mesylate (IM) for a gastrointestinal stromal tumor (GIST) of the lower rectum. A 49-year-old man presented with a submucosal tumor with ulcer located 3 cm above the anal verge. Histopathologically, a biopsy showed spindle-shape cells, positive for C-kit and CD34, negative for smooth muscle actin, desmin and S-100 protein. Genetically, this GIST had the mutation in KIT exon 11. IM (400 mg/d) was administered as neoadjuvant therapy for 80 days. The GIST shrank from 4.7 to 3.3 cm in diameter. Abdominal and transanal approach were started at the same time. The tumor was resected by TaTME successfully. The manometric pressure data and anal function were preserved before and after surgery. TaTME and neoadjuvant therapy with IM provide a treatment option which can preserve anal function for the lower rectal GIST.

Is nonanatomic rectal resection a valid therapeutic option for rectal gastrointestinal stromal tumors? A proposed decision algorithm

BACKGROUND AND OBJECTIVES

The best surgical approach to rectal gastrointestinal stromal tumors (GISTs) is still debated, and both nonanatomic rectal resection (NARR) and anatomic rectal resection (ARR) are applied. The aim of this study was to evaluate the feasibility and oncological outcomes of NARR and ARR for rectal GISTs (R-GISTs).

METHODS

Through a large French multicentre retrospective study, 35 patients were treated for R-GIST between 2001 and 2013. Patients who underwent NARR and ARR were compared.

RESULTS

There were 23 (65.7%) patients in group ARR and 12 (34.3%) in group NARR. Significantly more patients in the group with ARR had a neoadjuvant treatment (86%) with tyrosine kinase inhibitor (TKI) (imatinib) compared to those with NARR (25%) (p < .01). The median preoperative tumor size was significantly different between the groups without and with neoadjuvant TKI: 30 ± 23 mm versus 64 ± 44.4 mm, respectively (p < .001). Overall postoperative morbidity was 20% (n = 7) (26% for ARR vs. 8% for NARR; p = .4). After a median follow-up of 60.2 (3.2-164.3) months, the 5-year disease-free survival rates were 79.5% (confidence interval [CI] 95%: 54-100) for the NARR group and 68% (CI 95%: 46.4-89.7) for the ARR group (p = .697), respectively.

CONCLUSION

The use of NARR for small R-GIST's does not seem to impair the oncological prognosis.

Comparison of prognostic prediction models for rectal gastrointestinal stromal tumor

BACKGROUND

Rectal gastrointestinal stromal tumors (RGISTs) are biologically characterized tumors that are relatively rare. Thus, few studies have reported a specific prognostic system for this subset of tumors but integrated it into parallel systems, such as small intestine. Our aim is to develop a new predictive staging system nomogram (named FD-ZS system) for RGISTs.

RESULTS

Tumor size and mitotic rate were independent risk factors for tumor recurrence in RGISTs according to univariate and multivariate survival analyses. A prognostic predictive nomogram was developed, and a cut-off value of 65 points was calculated by X-tile to discriminate risk based on tumor size and mitotic rate. The C-indices for the FD-ZS, FD-Hou, NIH, and WHO systems were 0.706, 0.693, 0.687, and 0.680, respectively.

CONCLUSION

In the present study, a concise two-tier grading system (FD-ZS) for prognostic prediction of RGISTs that is simpler to several reported systems was developed, and a cut-off value was established to help RGIST patients determine whether to undergo adjuvant imatinib treatment.

METHODS

A nomogram was employed, and its predictive accuracy and discriminative ability were determined by concordance index (C-index) and calibration curve analyses. The nomogram was then compared with three stratification systems used for GISTs (FD-Hou, NIH, and WHO).

Preoperative imatinib and laparoscopic intersphincteric resection for large rectal gastrointestinal stromal tumor: A case report

INTRODUCTION

Anus-preserving surgery for a large rectal gastrointestinal stromal tumor (GIST) may be difficult because of the location of the tumor in the pelvis. Therefore, rectal GIST might require extensive surgery, such as abdominoperineal resection. In recent years, preoperative imatinib therapy has been used to reduce tumor size and preserve the anus in some cases. However, there have been few reports of laparoscopic anal-preserving surgery for giant rectal GIST.

PRESENTATION OF A CASE

We present the case of a 55-year-old man who was referred to our hospital for examination of a 10-cm pelvic mass in the lower rectum. Endoscopic ultrasound with fine needle aspiration was performed, and the pathological findings resulted in a diagnosis of GIST. The mass had spread to the prostate and left levator ani muscles, and as a result, surgery was deemed difficult to perform without damaging the pseudo-capsule. Therefore, preoperative chemotherapy with imatinib mesylate (IM) was performed for 8 months. The mass was reduced to 7.8 cm, and laparoscopic intersphincteric resection (ISR) was performed.

DISCUSSION

We also review prior cases of rectal GIST where patients had undergone anal-preserving surgery following preoperative chemotherapy with IM. Our case represented the largest tumor size in a review of cases of patients who had successful anal-preserving laparoscopic surgery following preoperative chemotherapy with IM.

CONCLUSION

Preoperative chemotherapy with imatinib mesylate was effective for reducing the rectal GIST, and laparoscopic ISR was useful for anal preservation, even when a tumor is large.

Radical excision versus local resection for primary rectal gastrointestinal stromal tumors. Cohort Study

BACKGROUND

Rectal gastrointestinal stromal tumor (GIST) is a rare digestive disease that originates in mesenchymal tissues and has malignant tendencies. At present, no standard treatment has been developed, and surgical approaches and the resection scope for rectal GISTs are controversial.

METHODS

The clinical, surgical, pathological and prognosis data of patients with primary rectal GIST in our center from January 2008 to January 2019 were retrospectively collected. The patients were divided into the radical excision (RE) and local resection (LR) groups.

RESULTS

A total of 537 GIST cases were collected, and 64 patients with primary rectal GIST were included in this study, including 25 cases in the RE group and 39 cases in the LR group. Tumor size (p = 0.013), distance from the anus (p = 0.038), National Institutes of Health (NIH) criteria (p = 0.001), preoperative adjuvant therapy (p = 0.016), postoperative adjuvant therapy (p = 0.028), blood loss (p = 0.048), operative time (p = 0.020) and the duration of hospitalization (p = 0.021) were statistically different between these 2 groups. The mean overall follow-up time was 46 months (range, 1-122 months). Disease recurrence was observed in 12 patients. No statistical differences were observed in 5-year disease-free survival (DFS) (93.3% vs 92.6%, p = 0.952) or overall survival (OS) (90.0% vs 91.6%, p = 0.832) between the RE group and the LR group.

CONCLUSION

Our study showed that LR has a similar prognosis to that of RE with respect to DFS and OS. For appropriate cases, LR has the advantages of a short operative time, less bleeding, and a quick recovery. Especially when combined with neoadjuvant therapy, LR can also achieve better perioperative efficacy. Therefore, LR is an effective method for resection of rectal GISTs and warrants clinical endorsement.

Open transanal resection of low rectal stromal tumor following neoadjuvant therapy of imatinib mesylate: Report of 11 cases and review of literature

OBJECTIVE

The global burden of rectal gastrointestinal stromal tumor (GIST) is increasing. However, a limited number of reports hinder our ability to reach a definitive conclusion regarding the current treatment and prognosis. In this study, we outline our experience with open transanal resection of rectal GIST following neoadjuvant therapy with imatinib mesylate (IM).

PATIENTS AND METHODS

We retrospectively analyzed 11 patients with rectal GISTs treated with neoadjuvant IM therapy and open transanal resection between April 2011 and April 2017 in Shanghai Changzheng Hospital.

RESULTS

The patients had 400-600 mg/day IM once daily for a median of 7 months (range: 3-9 months). Tumor size, distance from the lower margin of the tumor to the anal verge (AV), mitotic rates and mutation analysis were assessed on pretreatment biopsy. After reassessment, all 11 patients underwent transanal R0 resection. With median follow-up of 28 months (range: 8-80 months), there was no tumor recurrence or metastasis.

CONCLUSION

Open transanal resection of rectal GIST after neoadjuvant treatment with IM has good surgical and survival outcomes.

Surgery for Gastrointestinal Stromal Tumors: State of the Art of Laparoscopic Resection and Surgery for M1 Tumors

BACKGROUND

The principles of surgery for primary gastrointestinal stromal tumor (GIST) are resection with clear margins without lymphadenectomy, thus enabling organ-preserving resection in many cases. Tumor rupture needs to be avoided, because it entails peritoneal sarcomatosis. Given these preconditions, there is a rationale for laparoscopic resection of primary GIST. In metastatic GIST, surgery cannot achieve cure, but constitutes an important cornerstone of treatment. Resection can be performed either for residual lesions in responding patients, for focally progressive lesions, or as palliative measure in generalized progression.

METHODS

Selective literature review.

RESULTS

There is ample evidence on laparoscopic resection of gastric GIST, but none from randomized trials. The studies show favorable perioperative outcomes and suggest adequate oncological results; however, a direct comparison to open resection is difficult. For surgery in M1 stages, survival outcomes are better for resection in generalized response than in focal progression. Perioperative morbidity is acceptable. Surgery in generalized progression does not prolong survival and bears relevant morbidity risks.

CONCLUSION

Laparoscopy seems an adequate surgical approach for primary gastric GIST, as long as the surgical principles relevant for this entity are respected. For other tumor sites, there is no sufficient evidence available. In M1 stages, selected patients may benefit from surgery. Survival differences between resection at different stages probably mirror the biology of the disease rather than the effect of the timing of the operation.

Radiotherapy for Gastrointestinal Stromal Tumors

OBJECTIVE

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal tract, which frequently cause intraabdominal metastases. The current standard of care is surgery for localized cases, and adjuvant imatinib is recommended for tumors with a high risk of recurrence. To date, radiotherapy has not been commonly accepted as a part of multimodality treatment approach other than palliation. However, recently published case reports and some small series suggest that radiotherapy is a valuable option for controlling locally progressive, drug-resistant disease. The aim of this review is to provide a viewpoint from a radiation oncologist concerning the management of GISTs, especially rectal GIST, and clarify the role and technical aspects of radiotherapy in the treatment approach.

DATA SOURCES

A comprehensive search in PubMed using the keywords "radiotherapy for rectal GIST" and "rectal GIST" was undertaken. The literature search included the related articles after 1995.

STUDY SELECTION

The main articles including rectal GIST case reports and GIST series containing rectal cases were the primary references.

RESULTS

Surgery is the mainstay of treatment. However, to date, radiotherapy is included in the multidisciplinary treatment strategy of rectal GISTs in some circumstances with palliative, adjuvant, or definitive intent using different treatment doses and fields.

CONCLUSIONS

Recently reported long-term local control rates indicate that GIST is a radiosensitive disease. This makes radiotherapy a valuable alternative in GIST management with curative intent, especially in patients who (1) cannot tolerate or are resistant to chemotherapy agents, (2) have an unresectable disease, (3) have a gross or microscopic residual disease after surgery, and (4) have a recurrent disease.

Gastrointestinal stromal tumors: A multidisciplinary challenge

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors located in the alimentary tract. Its usual manifestation is gastrointestinal bleeding. However, small asymptomatic lesions are frequently detected as incidental finding. Characteristically, most GISTs (> 95%) are positive for the KIT protein (CD117) by IHC staining and approximately 80%-90% of GISTs carry a mutation in the c-KIT or PDGFRA genes. Mutational analysis should be performed when planning adjuvant and neoadjuvant therapy, due to its possible resistance to conventional treatment. The arise of tyrosine kinase inhibitor has supposed a revolution in GISTs treatment being useful as adjuvant, neoadjuvant or recurrence disease treatment. That is why a multidisciplinary approach to this disease is required. The correct characterization of the tumor at diagnosis (the diagnosis of recurrences and the evaluation of the response to treatment with tyrosine kinase inhibitors) is fundamental for facing these tumors and requires specialized Endoscopist, Radiologists and Nuclear Medicine Physician. Surgery is the only potentially curative treatment for suspected resectable GIST. In the case of high risk GISTs, surgery plus adjuvant Imatinib-Mesylate for 3 years is the standard treatment. Neoadjuvant imatinib-mesylate should be considered to shrink the tumor in case of locally advanced primary or recurrence disease, unresectable or potentially resectable metastasic tumors, and potentially resectable disease in complex anatomic locations to decrease the related morbidity. In the case of Metastatic GIST under Neoadjuvant treatment, when there are complete response, stable disease or limited disease progression, complete cytoreductive surgery could be a therapeutic option if feasible.

Management of rectal gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. However, rectal GIST is rare, the incident rate of it is approximately 5% of all GISTs. Rectal GIST symptoms generally include bleeding and/or pain and occasionally, urinary symptoms. Immunohistochemical evaluation finds that most rectal GIST tumors are CD117 (KIT) positive, and are sometimes CD34, platelet-derived growth factor receptor alpha (PDGFRA), smooth muscle actin, S-100, or vimentin positive. The National Institutes of Health (NIH) classifies rectal GIST as very-low risk, low risk, intermediate risk, or high risk, and the frequencies have been estimated as 0-23.8% for very-low risk, 0-45% for low risk, 0-34% for intermediate risk, and 21-100% for high risk tumors. The first-line treatment for localized GIST is curative resection, but is difficult in rectal GIST because of anatomical characteristics such as the deep, narrow pelvis and proximity to the sphincter muscle or other organs. Several studies noted the efficacy of the minimally invasive surgery, such as trans-anal, trans-sacral, trans-vaginal resection, or laparoscopic resection. The appropriate surgical procedure should be selected depending on the case. Imatinib mesylate (IM) is indicated as first-line treatment of metastatic or unresectable GIST, and clinical outcomes are correlated with KIT mutation genotype. However, the KIT mutation genotypes in rectal GIST are not well known. In this review, as in other GISTs, a large proportion (59-100%) of rectal GISTs carry exon 11 mutations. Although curative resection is indicated for localized rectal GIST, a high rate of local recurrence is a problem. Multimodal therapy including perioperative IM may improve postoperative outcomes, contributing to anus-preserving surgery. Moreover, KIT mutation analysis before IM treatment is important. This review summarizes current treatment strategies for rectal GIST.

Rectal Gastrointestinal Stromal Tumor (GIST) in the Era of Imatinib: Organ Preservation and Improved Oncologic Outcome

BACKGROUND

Approximately 5% of gastrointestinal stromal tumors (GISTs) originate in the rectum, and historically, radical resection was commonly performed. Little is known about the outcome for rectal GIST in the era of imatinib.

METHODS

Using a prospectively maintained database, this study retrospectively analyzed 47 localized primary rectal GISTs treated at our center from 1982 to 2016, stratified by when imatinib became available in 2000. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were analyzed by the Kaplan-Meier method.

RESULTS

Rectal GISTs represented 7.1% of 663 primary GISTs. The findings showed 17 patients in the pre-imatinib era and 30 patients in the imatinib era. The two groups had similar follow-up evaluation, age, gender, Miettinen risk, and distance to the anal verge. In the imatinib era, tumors were smaller at diagnosis (median 4 vs. 5 cm; p = 0.029), and 24 of the 30 patients received perioperative imatinib. In the high-risk patients, organ preservation and negative margins were more common among the 13 patients treated with neoadjuvant imatinib than among the 21 patients treated directly with surgery. High-risk patients who received perioperative imatinib (n = 15) had greater (or nearly significantly greater) 5-year OS, DSS, local RFS, and distant RFS than those who did not (n = 19) (91, 100, 100, and 71% vs. 47, 65, 74, and 41%; p = 0.049, 0.052, 0.077, 0.051, respectively). In the imatinib era, no patient has had a local recurrence or death due to GIST.

CONCLUSIONS

The use of imatinib is associated with organ preservation and improved oncologic outcome for patients with rectal GIST.

Laparoscopic resection of gastrointestinal stromal tumors: Does laparoscopic surgery provide an adequate oncologic resection?

Gastrointestinal stromal tumors (GISTs) are rare tumors of the GI tract. Surgical resection remains the mainstay of non-metastatic disease. However, the ability to provide an adequate oncologic resection using laparoscopic surgery is still an area of debate. This is a thorough review of the current literature, looking particularly at the use of laparoscopic surgery for larger GISTs and the long-term oncologic outcomes compared to the results of open surgery. Laparoscopic resections provide an adequate oncologic result for GISTs of all sizes, including those greater than 5 cm in size.

Laparoscopic Total Pelvic Exenteration After Neoadjuvant Imatinib Therapy for Gastrointestinal Stromal Tumor of the Rectum: A Case Report

Total pelvic exenteration (TPE) may be the only curative procedure for locally advanced rectal gastrointestinal stromal tumor (GIST) that is contiguous with the adjacent organs and pelvic wall. There is no previous report of laparoscopic TPE for advanced rectal GIST. Here, we describe our experience of performing laparoscopic TPE on a locally advanced rectal GIST after neoadjuvant imatinib chemotherapy. A 62-year-old Japanese man was diagnosed with locally advanced rectal GIST that was contiguous with the seminal vesicles, prostate, and left pelvic sidewall. He received imatinib mesylate for 5 months, after which the mass had shrunk but was still contiguous with adjacent organs. We therefore needed to perform TPE, and we accomplished the operation laparoscopically. The total operative time was 540 minutes and estimated blood loss was 280 mL. There were no intraoperative complications and not required conversion to open surgery. The patient had his first stool on the first postoperative day and discharged on the 21st postoperative day with no major complication. Pathologic examination of the resected specimen revealed negative margins. The patient had further adjuvant imatinib chemotherapy and had no recurrence for 20 months postoperatively. Laparoscopic TPE appears to be minimally invasive surgery and safe in the present case of rectal GIST. This is the first report of a case in the world that underwent laparoscopic TPE for advanced rectal GIST.

Diagnosis and treatment of gastrointestinal stromal tumor extending to prostate: A case report and literature review

RATIONALE

Gastrointestinal stromal tumor (GIST) is the neoplasm of gastrointestinal tract.

PATIENT CONCERNS

The patient complained about the retention of urinary.

DIAGNOSES

GIST.

INTERVENTIONS

radical prostatectomy and the imatinib therapy.

OUTCOMES

No recurrence and metastasis have been found during a 14-month follow-up.

LESSONS

comprehensive treatment is necessary for the GIST treatment. Furthermore, we summarize a review of the literature of GIST occurring in the prostate gland treated by different methods and 4 kinds of rare diseases in prostate.

Laparoscopic excision of large lower rectal gastrointestinal stromal tumour (GIST): A case report

Gastrointestinal stromal tumour (GIST) involving rectum is rare. No definite method of treatment has been established because of a small number of cases being reported. It is usually managed with invasive or ablative surgery, such as abdominoperineal resection (APR). The acceptance of minimally invasive (laparoscopic) surgery in colorectal disease plays a pivotal role in improving the postoperative quality of life. We report a case of a large lower rectal GIST who underwent laparoscopic excision of tumour through a subserosal approach whilst preserving the anal sphincter and without any rectal resection.

Transanal minimally invasive surgery (TAMIS) approach for large juxta-anal gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GISTs) are rarely found in the rectum. Large rectal GISTs in the narrow pelvis sometimes require extended abdominal surgery to obtain free resection margins, and it is a challenge to preserve sufficient anal sphincter and urogenital function. Here we present a 56-year-old male with a locally advanced juxta-anal non-metastatic GIST of approximately 10 cm in diameter. Therapy with imatinib reduced the tumour size and allowed partial intersphincteric resection (pISR). The patient underwent an electrophysiology-controlled nerve-sparing hybrid of laparoscopic and transanal minimally invasive surgery (TAMIS) in a multimodal setting. The down-to-up approach provided sufficient dissection plane visualisation and allowed the confirmed nerve-sparing. Lateroterminal coloanal anastomosis was performed. Follow-up showed preserved urogenital function and good anorectal function, and the patient remains disease-free under adjuvant chemotherapy as of 12 months after surgery. This report suggests that the TAMIS approach enables extraluminal high-quality oncological and function-preserving excision of high-risk GISTs.

Multimodality therapy of rectal gastrointestinal stromal tumors in the era of imatinib-an Indian series

BACKGROUND

Primary objective was to determine if sphincter preservation is possible with the use of neoadjuvant imatinib in cases of rectal gastrointestinal stromal tumor (GIST). Secondary objectives were to determine clinicopathological characteristics and intermediate term oncological outcomes of the cases of rectal GIST.

METHODS

This is a retrospective review of 13 cases of GIST of the rectum diagnosed between January 1, 2010 and June 30, 2015 at Tata Memorial Centre, Mumbai, India. Clinical parameters that were assessed were duration of the neoadjuvant imatinib therapy, type of surgery performed as well as perioperative morbidity. Pathological parameters that were assessed included the size of the tumor, completeness of resection, mitotic count and mutational analysis.

RESULTS

Of the 13 patients included, 11 were nonmetastatic at the time of presentation. All the patients received neoadjuvant imatinib in view of locally advanced nature of the tumors. Median distance from anal verge was 2 cm. Median duration of imatinib was 9 months. Of the 9 patients who underwent surgery, three had sphincter preserving surgery (33%) whereas the rest had abdomino-perineal resection. Two patients had perineal wound infections. All the operated patients received adjuvant imatinib therapy for 3 years. Median follow up period was 34 months. One patient developed distant metastasis; otherwise rest had no local or distant recurrence.

CONCLUSIONS

In cases of rectal GIST, sphincter preservation may not be possible in spite of neoadjuvant therapy with imatinib.

Transanal endoscopic microsurgery following treatment with imatinib : a case report of a patient with a rectal gastrointestinal stromal tumor

BACKGROUND

Gastrointestinal stromal tumors (GIST) of the rectum are a challenge for the colorectal surgeon. In case of a locally advanced rectal GIST, an extended or multivisceral resection with significant morbidity and -mortality is often necessary. Literature is lacking on the combined modality of transanal endoscopisc microsurgery (TEM) following imatinib for these patients.

METHODS

We describe a combined approach for a locally advanced GIST of the rectum with preoperative imatinib -treatment and subsequent local excision using the TEM procedure.

RESULTS

After six months of treatment with imatinib the TEM procedure was successfully performed with a radical -resection of the remnant tumor. Twenty-four months after surgery this patient has no evidence of disease.

CONCLUSIONS

A TEM procedure following treatment with imatinib may safely be performed in selected patients with a locally advanced GIST.

Sphincter sparing resection of a large obstructive distal rectal gastrointestinal stromal tumour after neoadjuvant therapy with imatinib (Glivec)

Gastrointestinal stromal tumours (GISTs) are generally rare but are known to be the most common mesenchymal tumours of the gastrointestinal tract. We present a case of a patient who presented with persistent obstructive gastrointestinal and urological symptoms, a sense of incomplete evacuation and bleeding per rectum. A colonoscopy was performed and a biopsy was taken of a submucosal mass in the distal rectum that revealed a GIST with positive KIT immunostaining. A positron emission tomography (PET)/CT scan showed a large metabolically active distal rectal tumour of 8 cm with macroscopic invasion of surrounding structures. Neoadjuvant therapy with receptor tyrosine kinase inhibitor imatinib (400 mg orally daily) was initiated and an excellent partial response consisting of a significant decrease in the size of the tumour with complete metabolic resolution was observed within 3 months. Six months after initiation of the neoadjuvant therapy a rectum resection with manual side-to-end coloanal anastomosis was performed. Pathology showed a GIST of 5 cm located 0.1 cm from the distal section plane. Our case shows that in patients with a large invasive distal rectal GIST, neoadjuvant imatinib therapy can facilitate anal sphincter sparing surgery.

Transsacral excision with pre-operative imatinib mesylate treatment and approach for gastrointestinal stromal tumors in the rectum: A report of two cases

Gastrointestinal stromal tumors (GISTs) are rare in the rectum. Radical surgery, such as an abdominoperineal resection, is necessary for large rectal GISTs, which can result in the loss of function of involved organs. Imatinib mesylate can be used as perioperative therapy and may reduce tumor size, and it is now approved for use in the adjuvant therapy of locally resected anorectal GISTs. The present study describes two cases of large rectal GISTs, for which abdominoperineal resections were initially planned. The two patients received pre-operative imatinib mesylate treatment, and the therapeutic response was assessed by magnetic resonance imaging. Finally, transsacral local resection was successfully performed for these two GISTs. A macroscopically complete resection was achieved, and microscopically, the resection margin was negative. One patient experienced the complication of rectal leakage, which was successfully managed by drainage. No recurrence occurred in the two patients after more than two years. Pre-operative imatinib mesylate therapy with subsequent transsacral local resection for selected rectal GISTs is a feasible treatment modality and can prevent extended surgery.

Laparoscopic resection of a gastrointestinal stromal tumor of the lower rectum in a patient with coronary artery disease following long-term neoadjuvant imatinib treatment and anticoagulation therapy

Surgery is the mainstay of treatment for gastrointestinal stromal tumors (GISTs). However, complete resection of rectal GISTs is sometimes difficult because of bulkiness and/or anatomical reasons. Neoadjuvant imatinib therapy has gained attention as an alternative treatment to increase the chance of en bloc resection of rectal GISTs, although it usually takes several months. In this case report, we first demonstrated that neoadjuvant imatinib therapy can be performed safely not only to downsize tumors, but also to allow adequate time for the effective treatment of major comorbid illnesses. A 74-year-old man was diagnosed with a 45 mm GIST of the lower rectum. He also had severe stenosis in the proximal segment of the left anterior descending coronary artery. Following the implantation of a drug-eluting stent, the patient received imatinib together with dual anti-platelet therapy for 12 months without obvious side effects. Follow-up image studies revealed tumor shrinkage as well as stent patency. En bloc resection of the GIST was performed laparoscopically, which preserved the anus. The patient is currently alive without any evidence of relapse for 12 months after surgery.

Laparoscopic local excision and rectoanal anastomosis for rectal gastrointestinal stromal tumor: modified laparoscopic intersphincteric resection technique

BACKGROUND

Rectal GI stromal tumor is uncommon. Local excision with free resection margins provides adequate treatment, but extended surgery such as abdominoperineal resection has been frequently performed because of technical difficulties in the confined pelvic space.

OBJECTIVE

We aimed to report the technical details of a new method of local excision for rectal GI stromal tumor: the modified laparoscopic intersphincteric resection technique.

DESIGN

This study was a retrospective analysis.

SETTING

This study was performed at a single institute.

PATIENTS

We included 3 patients with rectal GI stromal tumor who underwent this procedure following neoadjuvant imatinib therapy.

INTERVENTION

Medial-to-lateral retroperitoneal dissection was begun near the sacral promontory, and rectal dissection while preserving autonomic nerves was performed down to the pelvic floor into the anal canal without dividing the inferior mesenteric artery. Dissection between the tumor and prostate was meticulously performed under laparoscopic magnified view. Next, circumferential connection between the laparoscopic and transanal dissections was performed through a transanal approach, and the rectum was extracted through the anus. Circular full-thickness local excision of the rectum and handsewn straight rectoanal anastomosis was performed.

MAIN OUTCOME MEASURES

The safety and feasibility of this procedure were the primary outcomes measured by this study.

RESULTS

The median operative time was 180 minutes, and the median estimated blood loss was 115 mL. There were no conversions or intraoperative complications, and there was 1 postoperative intestinal obstruction that recovered with conservative therapy. All patients had negative resection margins (R0), including 1 pathological complete response.

LIMITATIONS

The study was limited by the small number of patients.

CONCLUSIONS

This modified laparoscopic intersphincteric resection technique is a novel and safe method for local excision of rectal GI stromal tumors located very close to the anus (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A139).

Advances in research of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, arising from the interstitial cells of Cajal (ICCs), primarily in the stomach and small intestine. The growth of most GISTs is driven by the mutations of genes encoding oncogenic receptor tyrosine kinase KIT or platelet derived growth factor receptor alpha (PDGFRα). The pathogenesis of GISTs may involve ICCs, microRNAs (miRNAs), signaling pathways, DNA methylation, and KIT or PDGFRα gene mutations. This article systematically describes the advances in research of GISTs in terms of clinical features, imaging characteristics, endoscopic features, histopathological features, diagnosis and therapies.

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.