Local excision with adjuvant imatinib therapy for anorectal gastrointestinal stromal tumors

Adjuvant therapy for rare rectal gastrointestinal stromal tumors: A case report

Key Clinical Message

Anorectal gastrointestinal stromal tumors are extremely rare, constituting less than 0.1% of rectal tumors. Surgical resection using a transanal wide excision followed by adjuvant therapy with tyrosine kinase inhibitors can be a successful treatment combination to remove the mass and prevent recurrence while preserving the integrity of the anal sphincter.

Abstract

Gastrointestinal stromal tumors (GISTs) are a rare subset of neoplasms, accounting for about 1%-2% of primary gastrointestinal malignancies. The stomach is the most common site for GISTs, with anorectal GISTs being exceptionally rare, representing only 0.1% of all rectal tumors. The standard approach for managing localized GIST involves complete surgical excision to achieve negative microscopic margins (R0) while preserving the tumor capsule and maintaining anal sphincter function. Surgical resection with transanal wide excision followed by adjuvant therapy using tyrosine kinase inhibitors can successfully remove the mass, prevent recurrence, and preserve the anal sphincter's integrity. Adjuvant therapy with imatinib is the recommended treatment for all localized GISTs assessed to have an intermediate or high risk of relapse. Here, we report a case of a 63-year-old male with a rectal GIST who underwent transanal wide excision followed by adjuvant therapy with tyrosine kinase inhibitors.

Rare rectal gastrointestinal stromal tumor case: A case report and review of the literature

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract accounting for less than 1% of all gut tumors. GISTs occurring in the rectum are extremely rare, and these usually present at an advanced stage compared with other sites.

CASE SUMMARY

A 60-year-old male who presented with features of sensations of rectal tenesmus was referred to our department with a mass in the lower rectum that was detected during a routine checkup. Colonoscopy, transrectal ultrasound, perianal magnetic resonance imaging and ultrasonic contrast were used to diagnose the rectum GIST, and then the patient underwent complete transanal resection using the ultrasonic scalpel. The patient was discharged ten days after the operation and was defined as low risk. Therefore, he had no need to receive subsequent adjuvant therapies, and he had not suffered any anal dysfunction or had any evidence of recurrence at follow up.

CONCLUSION

Surgical resection with histologically negative margins is the standard curative treatment for rectal GISTs. Appropriate surgical techniques based on the location, size, and resectability of the tumor should attract great attention from clinicians.

Anal canal gastrointestinal stromal tumour (GIST)

SummaryGastrointestinal stromal tumours (GISTs) are malignant mesenchymal tumours that originate from the interstitial pacemaker cells of Cajal. They are particularly rare, comprising only 5% of all GISTs, and often present at an advanced stage. Treatment for these tumours is still a topic of debate due to their low incidence and insidious location. A woman in her mid-70s presented with rectal bleeding and anal discomfort. A 4.5×4 cm anal GIST was diagnosed. A local excision was performed and the patient was further treated with tyrosine kinase inhibitors. At a 6-month follow-up, the MRI showed that she was disease free. Anorectal GISTs are unusual and tend to be aggressive. Surgical resection is the first-line treatment for primary, localised GISTs. However, the appropriate surgical technique for these tumours is still a topic of debate. Further studies are needed to fully understand the oncologic behaviour of these rare neoplasms.

Outcomes of Local Excision Compared to Radical Excision of Rectal Gastrointestinal Stromal Tumors: A Propensity-Score Matched Analysis of the NCDB

BACKGROUND

Gastrointestinal stromal tumors (GISTs) account for <1% of gastrointestinal cancers. The present study aimed to assess the outcomes of local and radical excision of non-metastatic rectal GISTs.

METHODS

This study was a retrospective cohort analysis of patients with non-metastatic rectal GISTs in the NCDB. Patients were divided according to the surgical approach into local and radical excision and were compared in regard to the baseline characteristics and outcomes. A propensity-score matched analysis was performed to match the two groups for baseline confounders. The main outcomes were 5-year overall survival (OS), surgical margins, hospital stay, short-term mortality, and readmission.

RESULTS

228 patients (54.8% male) with rectal GISTs were included. Before matching, 127 (55.7%) patients underwent local excision and 101 (44.3%) had radical excision. Patients who underwent local excision had more cT1-T2 and low-grade GISTs whereas patients who had radical excision received more neoadjuvant systemic treatment. After matching for clinical T stage, tumor grade, and neoadjuvant systemic therapy, 52 patients were included in each group. Local excision had a significantly higher rate of positive resection margins (42.2% vs. 19.1%, p = 0.02) and a shorter hospital stay (0 vs. 3 days, p < 0.001) than radical excision. The two groups had similar mean OS (139.8 vs. 133.1 months, p = 0.52).

CONCLUSIONS

Local excision was associated with a significantly higher incidence of positive resection margins and shorter hospital stay, yet similar overall survival to radical excision.

Transvaginal excision of rectal stromal tumors: case reports and a literature review

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Rectal locations are very rare, and minimally invasive surgery is a good choice for the treatment of rectal GISTs.

Case presentation

Two women each had a mass located on the lower vaginal-rectal space as determined by transvaginal ultrasound (TV-US), pelvis MR imaging, and colonoscopy. The patients successfully underwent transvaginal excision. The spindle-shaped cells were found in pathological test. The immunohistochemical analysis showed that CD117 and Dog-1 were stained positively. These results confirmed the masses as GISTs. The postoperative period was uneventful without anal dysfunction. Two patients were received adjuvant treatment with imatinib after surgery.

Conclusion

Transvaginal excision could be a minimally invasive and safe alternative treatment in the management of rectal GISTs in lower locations.

Management of low rectal gastrointestinal stromal tumor with neoadjuvant therapy and transanal excision: a rare case report and review of the literature

Background

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. However, rectal GISTs represent only 5% of this category. We report a case of a rectal GIST treated with local excision after neoadjuvant therapy.

Case presentation

A 41-year-old male patient presented with anal bleeding. Colonoscopy revealed a mass located 5 cm from the anal verge. Histological examination showed a GIST with immunohistochemical positivity for CD117 and CD34. Transanal local excision was performed after neoadjuvant therapy.

Conclusion

Neoadjuvant immunotherapy for GISTs with unfavorable localization may facilitate local excision and avoid complications of more demanding operations.

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.

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.

The efficacy of adjuvant imatinib therapy in improving the prognosis of patients with colorectal gastrointestinal stromal tumours

INTRODUCTION

Although it has now been accepted that imatinib is a valid treatment for gastrointestinal stromal tumour (GIST) patients in the adjuvant setting, information on its clinical efficacy in improving the prognosis for patients with colorectal GISTs is limited.

METHODS

The clinical and follow-up records of 42 colorectal GIST patients who underwent surgical resection at our institution between January 2004 and December 2013 were reviewed retrospectively. The effect of postoperative imatinib treatment on recurrence free survival and overall survival time was analysed with the Kaplan-Meier method and the multivariate Cox proportional hazards model.

RESULTS

Sixteen patients were assigned to imatinib treatment (imatinib group) after surgical tumour resection while twenty-six patients did not receive any adjuvant treatment (control group). The one, three and five-year recurrence free survival rates were 100%, 90% and 77% respectively. This was significantly higher than in the control group (92%, 53% and 36%) (logrank test, p=0.012). The one, three and five-year overall survival rates were 100%, 91% and 68% in the imatinib group compared with 96%, 77% and 39% in the control group (logrank test, p=0.021). Analysis with the multivariate Cox regression model yielded similar results on the efficacy of adjuvant imatinib in prolonging both recurrence free survival (hazard ratio [HR]: 0.23, 95% confidence interval [CI]: 0.07-0.80) and overall survival (HR: 0.20, 95% CI: 0.05-0.91).

CONCLUSIONS

Adjuvant imatinib therapy seems to be effective in decreasing the risk of tumour occurrence and prolonging the overall survival time in colorectal GIST patients.

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 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).