Localized gastrointestinal stromal tumor of the rectum: An uncommon primary site with prominent disease and treatment-related morbidities

Pathologic Features of Primary Colon, Rectal, and Anal Malignancies

In USA, colorectal cancer is the third most commonly diagnosed cancer in men, second in women, as well as the third leading cause of cancer deaths (Siegel et al. in Cancer J Clin 73:1-112, 2023 [109]). Worldwide, colorectal cancer is the second leading cause of death and causes almost 916,000 deaths each year (Ferlay in Global cancer observatory: cancer today. International Agency for Research on Cancer, Lyon, 2020 [28]). Fortunately, due to the colon's surgical and endoscopic accessibility and functional redundancy, colorectal cancer is very treatable. Colonoscopic surveillance has the potential for not only providing tissue for the diagnosis of precancerous polyps and invasive carcinoma, but also preventing development of invasive carcinoma by the removal of precancerous lesions. This chapter discusses the clinical and pathologic features of the spectrum of epithelial, hematolymphoid, and mesenchymal malignant tumors of the colon, rectum, appendix, and anus.

Assessing prognostic factors of long-term survival after surgery for colorectal gastrointestinal stromal tumours

AIM

Due to their rarity, the management of colorectal gastrointestinal stromal tumours (CR GISTs) is still under debate. The aim of this study was to assess prognostic factors.

METHOD

We performed a retrospective review of patients who underwent surgery with curative intent for CR GIST at our centre from 2002 to 2019. Factors associated with overall (OS) and recurrence-free survival (RFS) were analysed.

RESULTS

Fifty-six patients were included [median age 63 years, 29 (52%) female, 30 (54%) Miettinen high-risk, 40 (71%) with rectal GIST]. Nineteen (34%) patients received perioperative (neoadjuvant and/or adjuvant) imatinib. All cases of colonic GIST had an R0 resection, compared with 28 (70%) of rectal GISTs. After a median follow-up of 97 months (interquartile range 48-155 months), 14 (25%) deaths and 14 (25%) recurrences occurred. In the high-risk cohort, factors associated with improved RFS were R0 resection (OR 0.19, 95% CI 0.1-0.5, p = 0.002) and perioperative imatinib (OR 0.33, 95% CI 0.42-0.97, p = 0.04). Patients who had received perioperative imatinib had longer RFS (60% vs. 11% at 5 years, p = 0.006) but not OS. In rectal GISTs, 5-year OS was 85% for R0 and 70% for R1 resections (p = 0.164) and 5-year RFS was 85% for R0 and 12% for R1 resection (p < 0.001). When stratifying patients by perioperative imatinib, there were no differences in OS or RFS in the R0 or R1 groups.

CONCLUSION

Perioperative imatinib and R0 resection were associated with improved RFS in high-risk patients with CR GIST. In patients with rectal GIST, R1 resection was associated with worse RFS irrespective of perioperative imatinib treatment.

Local excision and radical excision for rectal gastrointestinal stromal tumors: a meta-analysis protocol

Background

To date, several studies have compared the surgical and oncological outcomes of local excision (LE) and radical excision (RE) for rectal gastrointestinal stromal tumors (GISTs), but some have limited numbers of small series. This protocol outlines the planned scope and methods for a systematic review and meta-analysis that will compare the surgical and oncological outcomes of LE and RE in patients with rectal GISTs.

Methods

This protocol is presented in accordance with the PRISMA-P guideline. PubMed, Embase, Web of Science, Cochrane Library and Wanfang database will be systematically searched. Furthermore, reference lists of all included articles will be screened manually to add other eligible studies. We will include randomized controlled trials (RCTs) and non-randomized studies (NRS) in this study. The primary outcomes evaluated will be R0 resection rate and disease-free survival, while the secondary outcomes will contain overall survival, length of stay, tumor rupture rate and complications. Two reviewers will independently screen and select studies, extract data from the included studies, and assess the risk of bias of the included studies. Preplanned subgroup analyses and sensitivity analyses are detailed within this protocol. The strength of the body of evidence will be assessed using GRADE.

Discussion

This review and meta-analysis will provide a comprehensive evaluation of the current evidence concerning the application of LE and RE in patients with rectal GISTs. The findings from this review will serve as a foundation for future research and emphasize the implications for clinical practice.

Systematic review registration

PROSPERO (CRD42017078338), https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=387409, PROSPERO CRD42017078338.

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.

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.

Gastrointestinal Stromal Tumor

Over the past 20 years, gastrointestinal stromal tumor (GIST) has evolved into an increasingly complex clinical entity with ever more challenges. While surgical resection is the gold standard, advancements in genetic testing, therapeutic options, immunotherapy, and management of metastatic disease necessitate a comprehensive, multimodal approach for these tumors. This chapter highlights the importance of genomic testing of GIST, the use of neoadjuvant and adjuvant therapy for localized disease, surgical principles for GIST, as well as current and new approaches for addressing metastatic disease.

Different Medical Features and Strategies of Large Rectal Gastrointestinal Stromal Tumor: A Multi-Central Pooling Analysis

Purpose

The rectum is a rare site for gastrointestinal stromal tumors (GISTs). Tumors in this critical anatomical site are prone to develop local recurrence, and this occurs at a high level even in low-risk tumors. Previous studies found that high-risk was the most common category in rectal gastrointestinal stromal tumors (RGISTs), and size was the most important factor affecting the long-term prognosis. We aimed to find out the most influential factor on clinical outcomes, and describe demographics, oncological differences, and surgical procedures in patients with poor prognosis.

Patients and Methods

Data on consecutive patients with RGIST, who were diagnosed at Peking University People’s Hospital, Shandong Province Hospital, and The First Affiliated Hospital of Shandong First Medical University from 2010 to 2020, were retrospectively evaluated. Further, a literature search was conducted by retrieving data from PubMed, EMBASE, and the Cochrane Library databases from inception up to March 20, 2020.

Results

In all, 50 patients were diagnosed with RGIST at three medical centers, and 86 published records were finally included in the literature review. Combined analysis of the whole individual patient data showed that 5.5 cm was deemed an appropriate cut-off value for L-RGIST, and that patients usually showed a male predominance (67.59%), younger age at onset (56.61 years), higher operative difficulty, and poorer prognosis.

Conclusion

Separation of patients with large RGIST from general patients may contribute to the recognition of the oncological characteristics and clinical management of this rare type of tumor.

Spindle cell proliferations of the sigmoid colon, rectum and anus: a review with emphasis on perineurioma

A wide range of spindle cell proliferations are found uncommonly in the sigmoid colon, rectum and anus. They usually present as polyps, and include reactive lesions and benign and malignant neoplasms which may be primary or metastatic. They are less frequently described in the literature compared to those in the upper gastrointestinal tract, and may be underdiagnosed. The widespread use of sigmoidoscopy in symptomatic patients and bowel cancer screening programmes means that histopathologists must be aware of, and adopt a logical approach to, diagnosing spindle cell proliferations in biopsy and polypectomy specimens. This is particularly relevant given the strong association of some mesenchymal polyps with hereditary cancer syndromes. This review article will focus on perineurioma and the recent debate in relation to its overlap with fibroblastic polyp. The clinical, endoscopic, histological and immunohistochemical features of spindle cell proliferations which should be considered in the differential diagnosis of perineurioma will be discussed. There is also a brief reference to malignant spindle cell tumours of diagnostic importance.

Frequent rectal gastrointestinal stromal tumor recurrences in the imatinib era: Retrospective analysis of an International Patient Registry

INTRODUCTION

Rectal gastrointestinal stromal tumor (GIST) is rare and comprises about 3% of GIST.

METHODS

Registry data was collected by the Life Raft Group June 1976 to November 2017. All patients had a histologic GIST diagnosis. Demographic, clinicopathologic, and clinical outcome data were patient reported. Recurrence-free survival (RFS) was analyzed using the Kaplan-Meier method and Cox regression analysis.

RESULTS

Of 1798 patients in the database, 48 had localized rectal GIST (2.7%). Patients were frequently male (58.3%) and non-Hispanic whites (58.3%). Median age at diagnosis was 52 years. Most patients (77%) were diagnosed in the imatinib era (2001 to current). Over half (54.2%) of the cohort had mutation testing and all profiled tumors possessed KIT mutations (exon 9: 7.7%, exon 11: 88.5%, and exon 13: 3.8%). Most evaluable patients (26/28; 92.9%) had high-risk disease (modified NIH criteria) and nearly all patients (95.8%) received imatinib. Median follow-up was 8.8 years (range, 0.3-30.7) and overall RFS was 8.0 years (95% CI, 2.9-13.1). Thirty-two percent (12/37) of patients in the post-imatinib era developed recurrent disease. Diagnosis in the imatinib era was associated with improved RFS (HR = 0.22, 95% CI, 0.08-0.62; P = .004) in the multivariable model.

CONCLUSION

We find that disease recurrence remains prevalent in one-third of patients treated during the imatinib-era.

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.

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 GIST-Outcomes and viewpoint from a tertiary cancer center

INTRODUCTION

There is scarce data relating to methods to improve sphincter preservation in rectal gastrointestinal stromal tumor (GIST). Increasing the duration of neoadjuvant (NA) imatinib resulting in improved sphincter preservation rate has not been established. This retrospective analysis looks at the rates of sphincter preservation in rectal GIST with NA imatinib and effect of duration of NA imatinib on the same to find out optimum duration of NA with respect to sphincter preservation in rectal GIST patients.

METHODS

Twenty-three cases of GIST of lower third of rectum were treated at our centre from 2005 till 2015. NA imatinib was used in a dose of 400 mg. Response evaluation was done every 3 months with a pelvic magnetic resonance imaging. Surgical management was determined by a team of experienced gastrointestinal oncosurgeons.

RESULTS

Five patients underwent upfront surgery which included local resection in four patients and abdominoperineal resection in one patient. NA imatinib was used in 69.5 % (16/23) patients. Median duration of NA imatinib was 15 months (3-84 months). Amongst who underwent a sphincter-salvage surgery median duration of NA imatinib was 13 months whereas 18 months in patients who required a sphincter-sacrificing surgery (p = 0.683). The radiologic response included partial response in 75 % (12/16) patients, stable disease in 18.7 % (3/16) and one with progressive disease. Definitive surgical resection was possible in 13 patients (81.3 %) after NA imatinib. Median progression-free survival (PFS) was 120 months in the whole cohort whereas median overall survival (OS) was not reached. Four-year estimated PFS and OS was 81 % and 100 %, respectively. Median disease-free survival in upfront surgery group vs. neoadjuvant imatinib group was 70 vs. 120 months, respectively (p = 0.039).

CONCLUSION

Neoadjuvant imatinib appears to be a useful option in improving chances of sphincter preservation without adversely affecting the outcome. Use of neoadjuvant imatinib leads to improvement in progression-free survival in patients with GIST of lower third of the rectum.

Pathologic Features of Primary Colon, Rectal, and Anal Malignancies

In the United States, colorectal cancer is the third most commonly diagnosed cancer in both men and women, as well as the third leading cause of cancer deaths (Colorectal cancer facts & figures 2014–2016, 2014 [2]). Worldwide, colorectal cancer is the fourth leading cause of death and causes almost 700,000 deaths each year (Cancer: fact sheet No. 297, 2015 [55]). This chapter discusses the clinical and pathologic features of the spectrum of epithelial, hematolymphoid, and mesenchymal malignant tumors of the colon, rectum, appendix, and anus.

Surgical treatment of gastrointestinal stromal tumour of the rectum in the era of imatinib

BACKGROUND

Gastrointestinal stromal tumours (GISTs) of the rectum often require radical surgery to achieve complete resection. This study investigated the management and outcome of surgery for rectal GISTs and the role of imatinib.

METHODS

A cohort study was undertaken of patients identified from a database at one tertiary sarcoma referral centre over a continuous period, from January 2001 to January 2013.

RESULTS

Over 12 years, 19 patients presented with a primary rectal GIST. Median age was 57 (range 30-77) years. Neoadjuvant imatinib was used in 15 patients, significantly reducing mean tumour size from 7·6 (95 per cent c.i. 6·1 to 9·0) to 4·1 (2·8 to 5·3) cm (P < 0·001). Nine of these patients underwent surgical resection. Imatinib therapy enabled sphincter-preserving surgery to be undertaken in seven patients who would otherwise have required abdominoperineal resection or pelvic exenteration for tumour clearance. Neoadjuvant imatinib treatment also led to a significant reduction in mean(s.d.) tumour mitotic count from 16(16) to 4(9) per 50 high-power fields (P = 0·015). Imatinib was used only as adjuvant treatment in two patients. There were three deaths, all from unrelated causes. Eleven of the 13 patients who underwent resection were alive without evidence of recurrence at latest follow-up, with a median disease-free survival of 38 (range 20-129) months and overall survival of 62 (39-162) months.

CONCLUSION

The use of neoadjuvant imatinib for rectal GISTs significantly decreased both tumour size and mitotic activity, which permitted less radical sphincter-preserving surgery.