Elderly patients with gastrointestinal stromal tumour (GIST) receive less treatment irrespective of performance score or comorbidity - A retrospective multicentre study in a large cohort of GIST patients

Drug resistance mechanisms and treatment strategies mediated by Ubiquitin-Specific Proteases (USPs) in cancers: new directions and therapeutic options

Drug resistance represents a significant obstacle in cancer treatment, underscoring the need for the discovery of novel therapeutic targets. Ubiquitin-specific proteases (USPs), a subclass of deubiquitinating enzymes, play a pivotal role in protein deubiquitination. As scientific research advances, USPs have been recognized as key regulators of drug resistance across a spectrum of treatment modalities, including chemotherapy, targeted therapy, immunotherapy, and radiotherapy. This comprehensive review examines the complex relationship between USPs and drug resistance mechanisms, focusing on specific treatment strategies and highlighting the influence of USPs on DNA damage repair, apoptosis, characteristics of cancer stem cells, immune evasion, and other crucial biological functions. Additionally, the review highlights the potential clinical significance of USP inhibitors as a means to counter drug resistance in cancer treatment. By inhibiting particular USP, cancer cells can become more susceptible to a variety of anti-cancer drugs. The integration of USP inhibitors with current anti-cancer therapies offers a promising strategy to circumvent drug resistance. Therefore, this review emphasizes the importance of USPs as viable therapeutic targets and offers insight into fruitful directions for future research and drug development. Targeting USPs presents an effective method to combat drug resistance across various cancer types, leading to enhanced treatment strategies and better patient outcomes.

Comparing gastrointestinal stromal tumor outcomes between geriatric and non-geriatric patients: A population-based analysis

BACKGROUND

Gastrointestinal Stromal Tumors (GISTs) are the most common mesenchymal tumors of the GI tract. SEER is an extensive cancer database which proves useful in analyzing population trends. This analysis investigated GIST outcomes between geriatric & non-geriatric patients.

METHODS

SEER*STAT 8.4.0.1 was used to extract relevant GIST data from 2000 to 2019. Geriatric age was defined as ≥70 years. Variables included age, sex, surgery, cancer-specific death, and overall survival. Statistical tests included univariate analysis using KM survival estimate (95% confidence interval) to calculate 5-year survival (5YS). Log-Rank tests determined statistical significance. Multivariable Cox's PH regression estimated the geriatric hazard death ratio adjusted for sex, stage, and surgery.

RESULTS

The number of patients included was 13,579, yielding overall 5YS of 68.6% (95% CI 67.7-69.5). Cancer-specific death was 39.11% in 2000 & 3.33% in 2019. Non-geriatric & geriatric patient data yielded 5YS of 77.4% (76.4%-78.3%) and 53.3% (51.7%-54.8%) respectively (p < 0.0001). For no surgery/surgery, younger patient data yielded 5YS of 48.7% (45.8%-51.4%) and 83.7% (82.7%-84.7%) respectively (p < 0.0001); geriatric data yielded 5YS of 29.3% (26.5%-32.1%) and 62.8% (60.8%-64.6%) respectively (p < 0.0001). Multivariable analysis yielded a geriatric hazard death of 2.56 (2.42-2.70) (p < 0.0001).

CONCLUSIONS

Cancer-specific death decreased since 2000, indicating an improvement in survival & treatment methods. Observed lower survival rates overall in the geriatric group. Surgery appeared to enhance survival rates in both groups, suggesting that surgery is an important factor in GIST survival regardless of age. Large prospective studies will help define clinical management for geriatric patients.

Referral patterns of GIST patients: data from a nationwide study

BACKGROUND

This study compares the characteristics, referral and treatment patterns and overall survival (OS) of gastrointestinal stromal tumor (GIST) patients treated in reference and non-reference centers in the Netherlands.

PATIENTS AND METHODS

This retrospective cohort study on patients diagnosed between 2016 and 2019, utilises data from the Netherlands Cancer Registry and the Dutch Nationwide Pathology Database. Patients were categorized into two groups: patients diagnosed in or referred to reference centers and patients diagnosed in non-reference centers without referral.

RESULTS

This study included 1,550 GIST patients with a median age of 67.0 in reference and 68.0 years in non-reference centers. Eighty-seven per cent of patients were diagnosed in non-reference centers, of which 36.5% (493/1,352) were referred to a reference center. Referral rates were higher for high-risk (62.2% [74/119]) and metastatic patients (67.2% [90/134]). Mutation analysis was performed in 96.9% and 87.6% of these cases in reference and in non-reference centers (p < 0.01), respectively. Systemic therapy was given in reference centers versus non-reference in 89.5% versus 82.0% (p < 0.01) of high-risk and in 94.1% versus 65.9% (p < 0.01) of metastatic patients, respectively. The proportion of positive resection margins and tumor rupture did not differ between reference and non-reference centers. Median OS was not reached.

CONCLUSION

A substantial amount of metastatic GIST patients in non-reference centers did not receive systemic treatment. This might be due to valid reasons. However, optimisation of the referral strategy of GIST patients in the Netherlands could benefit patients. Further research is needed to explore reasons for not starting systemic treatment in metastatic GIST patients.

Should Advanced Age Preclude Surgical Treatment of Gastrointestinal Stromal Tumor?

Introduction: Surgical resection is a gold standard treatment for gastrointestinal stromal tumors (GISTs). It can be performed by minimally invasive surgery approach in most of the patients. It has been shown that advanced age is not a clear poor prognostic factor in patients who underwent surgery for GIST. We hypothesized that elderly patients undergo elective surgery less often compared to younger population. We aim to evaluate the safety, efficacy and oncological results of GIST treatment in the elderly population in our Medical Center. Materials and Methods: All patients who underwent surgery for GIST in Shamir Medical Center from January 1, 2016, to July 31, 2023, were included in the study. The patients were divided into 2 groups. Group 1 included patients younger than 75 years, while patients older than 75 years were included in Group 2. The groups were compared according to demographics, clinical and surgical parameters, complications, and pathology results. Results: Overall, 49 patients were included in the study. Group 1 included 28 patients and Group 2 included 21 patients. Group 2 patients more often underwent emergency surgery (52.4% versus 14.3%, P < .05) and had increased open surgery rate (19% versus 0%, P < .05). No difference between the groups was noted in surgical parameters, complications, and length of hospital stay. Tumor size, number of mitoses, level of ki67%, and involvement of surgical margins were not significantly different. However, in Group 2 patients, tumor size was larger and there was a trend toward higher rate of ki67 > 5%. Conclusion: Elderly patients with GIST are less frequently undergoing electively surgery and relatively often undergo open surgery. Frequency of complications is similar in elderly patients compares to younger patients group.

Deubiquitylation of Rab35 by USP32 promotes the transmission of imatinib resistance by enhancing exosome secretion in gastrointestinal stromal tumours

Imatinib is a tyrosine kinase inhibitor that is widely used to combat gastrointestinal stromal tumours (GISTs). However, secondary resistance to imatinib is an important challenge in GIST treatment. Recent studies have demonstrated that cancer-derived nanosized exosomes play a key role in intercellular communication, but little is known about the roles of exosomes in imatinib-resistant GISTs. Here, we reveal that exosomes released from imatinib-resistant GISTs transmit drug resistance to imatinib-sensitive tumours. By using iTRAQ technology, we demonstrate that Ras-related protein Rab-35 (Rab35) is upregulated differentially in imatinib-resistant GISTs. Loss of Rab35 decreases exosome secretion, thereby hampering the transmission of imatinib resistance to sensitive tumours. Mechanistically, we showed that the ubiquitin‒proteasome system is involved in elevated Rab35 expression and that ubiquitin-specific protease 32 (USP32), a deubiquitylating enzyme, is bound to Rab35. Further experiments demonstrate that this protease protects Rab35 from proteasomal degradation by reducing Lys48 (K48)-ubiquitination. Additionally, we found that the transcription factor ETV1, which is a lineage survival factor in GISTs, promotes USP32 expression. Collectively, our results reveal that exosomes transmit imatinib resistance in GISTs and that deubiquitylation plays a key role in regulating the transmission process. The USP32-Rab35 axis provides a potential target for interventions to reduce the occurrence of imatinib resistance in GISTs.

Imatinib use for gastrointestinal stromal tumors among older patients in Japan and Taiwan

Tyrosine kinase inhibitors (TKIs) improve the prognosis of patients with gastrointestinal stromal tumors (GISTs). We conducted a retrospective cohort study using cancer registries linked with health utilization data in Japan and Taiwan to assess TKI usage in older and non-older patients. Patients diagnosed with GIST (2012-2014) were categorized into the following: adjuvant and advanced/metastatic settings. The duration and patterns of imatinib therapy were compared between the older (aged ≥ 75 years) and non-older (< 75 years) groups. We included 232 Japanese and 492 Taiwanese patients in the adjuvant setting, and 235 Japanese and 401 Taiwanese patients in the advanced/metastatic setting. Older patients had higher proportions of starting with lower doses (< 400 mg/day) than the non-older patients (adjuvant: 22.5% vs. 4.3% [Japan]; 22.5% vs. 10.9% [Taiwan]; advanced/metastatic: 29.6% vs. 7.2% [Japan]; 32.6% vs. 8.1% [Taiwan]; all p < 0.01). The median time to stop imatinib was shorter in the older than in the non-older patients (adjuvant: 301 vs. 975 days [Japan], 366 vs. 1028 days [Taiwan]; advanced/metastatic: 423 vs. 542 days [Japan]; 366.5 vs. 837 days [Taiwan]). More older patients with GIST tended to have TKIs at a lower initial dose and a shorter imatinib duration than the non-older patients.

Efficacy and Safety of Endoscopic Resection for Small Gastric Gastrointestinal Stromal Tumors in Elderly Patients

Background

Gastrointestinal stromal tumors (GISTs) are prevalent in elderly patients. Endoscopic resection has become popular for treating small (≤5 cm) gastric GISTs. However, little is known about the outcomes of endoscopic resection in elderly patients.

Aim

To assess the efficacy and safety of endoscopic resection for small (≤5 cm) gastric GISTs in elderly patients (≥65 years old).

Methods

A total of 260 patients (265 lesions) with gastric GISTs treated via endoscopic resection from January 2011 to May 2020 were retrospectively analyzed. Among them, 65 patients were ≥65 years old (elderly group), and 195 patients were <65 years old (nonelderly group). Clinicopathological characteristics, postoperative complications, and tumor recurrence rates between the two age groups were compared.

Results

A total of 260 patients with primary small (≤5 cm) gastric GISTs were treated with endoscopic resection. The median ages of the elderly and nonelderly groups were 68 (range 65-83) years and 55 (range 32-64) years, respectively. Elderly patients showed a higher incidence of comorbidities compared with nonelderly patients (61.5% versus 32.3%s, respectively; p < 0.001). All elderly patients and 99.0% of nonelderly patients underwent en bloc resection; only two nonelderly patients received piecemeal resection. No significant differences were found regarding postoperative complications or tumor recurrence rates between the two groups.

Conclusions

Although elderly patients had more comorbidities than nonelderly patients, both groups had similar postoperative complications and recurrence rates. We suggest that endoscopic resection performed by experienced endoscopists is safe and effective for treating small (≤5 cm) gastric GISTs in elderly patients.

Health-Related Quality of Life and Side Effects in Gastrointestinal Stromal Tumor (GIST) Patients Treated with Tyrosine Kinase Inhibitors: A Systematic Review of the Literature

BACKGROUND

The introduction of tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of gastrointestinal stromal tumors (GISTs), resulting in a substantial gain in median overall survival. Subsequently, health-related quality of life (HRQoL) has become more relevant. Here, we systematically review the available literature on HRQoL issues and side effects of different TKIs registered for the treatment of GIST.

METHODS

A search through five databases was performed. Full reports in English describing HRQoL outcomes and/or side effects in GIST patients on TKI therapy were included.

RESULTS

A total of 104 papers were included; 13 studies addressed HRQoL, and 96 studies investigated adverse events. HRQoL in patients treated with imatinib, regorafenib, and ripretinib remained stable, whereas most sunitinib-treated patients reported a decrease in HRQoL. Severe fatigue and fear of recurrence or progression were specifically assessed as HRQoL issues and had a negative impact on overall HRQoL as well as psychological and physical well-being. The majority of studies focused on physician-reported side effects. Nearly all GIST patients treated with a TKI experienced at least one adverse event, mostly mild to moderate.

CONCLUSIONS

Despite the fact that almost all patients treated with a TKI experienced side effects, this did not seem to affect overall HRQoL during TKI therapy. In daily practice, it are the side effects that hamper a patient's HRQoL resulting in treatment adjustments, suggesting that the reported side effects were underestimated by physicians, or the measures used to assess HRQoL do not capture all relevant issues that determine a GIST patient's HRQoL.

National Utilization of Imatinib in the Management of Resected Gastrointestinal Stromal Tumors

BACKGROUND

Imatinib decreases recurrence risk and improves overall survival (OS) in localized gastrointestinal stromal tumors (GISTs); however, the extent to which patients receive appropriate treatment in the US has not been well characterized.

METHODS

Patients with non-metastatic, resectable GIST were included in this study (National Cancer Database, 2010-2015). Those with a low-risk of recurrence were classified as receiving overtreatment or guideline-concordant treatment, while those with a high-risk of recurrence were classified as receiving undertreatment or guideline-concordant treatment. Multivariable logistic regression was used to determine factors associated with non-concordant treatment. The association between non-concordant treatment and OS was evaluated using multivariable Cox regression and propensity score matching.

RESULTS

Among 3088 patients with high-risk GIST, 41% were undertreated, and among 3908 patients with low-risk GIST, 18.8% were overtreated. For patients with high-risk GIST, age > 60 years, African American race, and treatment at a community or comprehensive cancer program were associated with undertreatment. Among low-risk patients, small bowel primary, tumor size > 2 cm, and tumors with > 1 mitotic figure per 50 high-power fields were more likely to be overtreated. After propensity score matching, guideline-concordant therapy was associated with an 8.8% improvement in 5-year OS (81.9% vs. 73.1%, p = 0.002) for those with high-risk GIST and decreased risk of death (hazard ratio 0.63, 95% confidence interval 0.47-0.84). There was no statistically significant difference in survival for patients with low-risk GIST with the addition of imatinib overtreatment (overtreatment 93.9% vs. 89.6%, p = 0.053).

CONCLUSIONS

Nearly 30% of GIST patients do not receive guideline-concordant treatment and future work is needed to understand the factors driving non-concordant treatment.

Taste, smell and mouthfeel disturbances in patients with gastrointestinal stromal tumors treated with tyrosine-kinase inhibitors

CONTEXT

Taste, smell, and mouthfeel disturbances are underrated and underreported, but important side effects of anti-cancer medication. These symptoms are associated with a lower quality of life (QoL). The prevalence and the impact of taste, smell, and mouthfeel disturbances on daily life in patients with a gastrointestinal stromal tumor (GIST) are largely unknown.

OBJECTIVES

This exploratory study assessed the prevalence and type of taste, smell, and mouthfeel disturbances and their impact on daily life and QoL in patients with a GIST treated with a tyrosine-kinase inhibitor (TKI).

METHODS

Patients currently treated with TKIs for GIST completed a standardized questionnaire. The questionnaire addressed changes in taste, smell, and mouthfeel and, if changes occurred, impact on daily life and QoL. Statistics are descriptive.

RESULTS

A total of 65 GIST patients on TKI treatment completed the questionnaire. Of these patients, 79%, 12%, and 9% currently used imatinib, sunitinib, and regorafenib respectively. Taste, smell, and mouthfeel disturbances were reported by 25 (38%), 15 (23%), and 36 (55%) patients respectively. Salty and sweet tastes were mostly affected, respectively in 14 and 13 patients. A dry mouth was experienced by 29 (45%) patients. Taste disturbances were more often reported to have impact on daily life and QoL (80% and 60%) than smell (47% and 31%) and mouthfeel disturbances (47% and 30%).

CONCLUSION

Taste, smell, and mouthfeel disturbances are frequent side effects of TKIs in GIST patients. Daily life and QoL are affected in a considerable number of those patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NL7827 (2019-06-25).

Treatment of Metastatic Gastrointestinal Stromal Tumors (GIST): A Focus on Older Patients

Gastrointestinal stromal tumors (GIST) originating in the Cajal cells are the most common mesenchymal neoplasms of the gastrointestinal tract. The median age of patients with this diagnosis is 65 years, and over 20% of cases affect people over the age of 70 years. The effectiveness and tolerability of systemic treatment with tyrosine kinase inhibitors in older patients with GIST seem to be similar to that in younger patients, but some studies have shown that treatment of older patients is suboptimal. Disability, frailty, comorbidities, and concomitant medications may influence treatment decisions, and toxicities also more often lead to treatment discontinuation. The known safety profile and oral administration route of the tyrosine kinase inhibitors used in GIST may allow maximization of treatment and the best efficacy, especially in older patients. This review summarizes the efficacy data for the systemic treatment of GIST, including data for older patients and from real-world experiences, if available and significant. The reported safety data and general rules for toxicity management, including appropriate patient selection and the need for careful monitoring during treatment, are also discussed.

Surgical resection of gastric gastrointestinal stromal tumors (GIST) in octogenarians

BACKGROUND

Localized gastrointestinal stromal tumors (GISTs) are rare tumors typically managed with surgery, but outcomes among octogenarians remain less studied.

METHODS

Octogenarian patients with stage I-III gastric GISTs were identified from the National Cancer Database and classified by resection status. Cox regression and Kaplan-Meier survival analyses analyzed 5-year overall survival (OS). Ninety-day mortality was analyzed following 1:1 propensity score matching.

RESULTS

Identified octogenarians (N = 949) who underwent resection (N = 632) had improved adjusted OS (71% vs 59.6%, HR 0.75, p 0.049) as compared to non-resected patients. Following matching, 90-day mortality was 5.7% and 11% in resected and non-resected patients (p 0.052), respectively. After exclusion of patients with 90-day mortality, resected patients maintained an OS advantage (77.3% vs 71.1%, HR 0.64, p 0.028).

CONCLUSIONS

The majority of octogenarians with localized gastric GIST are treated with surgery portending improved survival but an appreciable mortality, suggesting a necessity for careful selection of older patients for surgery.

Resection of a large gastrointestinal stromal tumor in the stomach after imatinib treatment in a 90-year-old patient

A 90-year-old woman presented with a 1-month history of progressive abdominal fullness. Contrast computed tomography (CT) showed a large 17-cm mass located adjacent to the antrum of the stomach without metastatic lesions. She underwent endoscopic ultrasound-guided fine-needle aspiration for diagnosis. Aspiration specimens revealed spindle-shaped cells positive for KIT by immunohistochemistry, with exon 11 mutations of the c-kit gene according to a genetic test. We ultimately diagnosed her with gastrointestinal stromal tumor (GIST). We judged the feasibility of imatinib treatment based on physiological and comprehensive geriatric assessments. We administered imatinib to reduce the tumor size and expected an excellent response based on genetic testing. After 5 months of imatinib administration with therapeutic drug monitoring (TDM), the tumor shrank by 42%. Six months later, there was no significant uptake of 18F-fluorodeoxyglucose on positron emission tomography. We successfully performed partial gastrectomy as conversion surgery, and she was carefully observed without any medication for 10 months after surgery. Here, we report a super elderly patient aged 90 years with a large GIST harboring an exon 11 mutation who underwent surgery after imatinib treatment with appropriate dose reduction during TDM after comprehensive geriatric assessment.

Gastrointestinal Stromal Tumours (GIST) in Young Adult (18-40 Years) Patients: A Report from the Dutch GIST Registry

Gastrointestinal stromal tumour (GIST) is a disease of older adults and is dominated by KIT/PDGFR mutations. In children, GIST is rare, predominantly occurs in girls, has a stomach location and generally lacks KIT/PDGFR mutations. For young adults (YA), aged 18 to 40 years, the typical phenotypic and genotypic patterns are unknown. We therefore aimed to describe the clinical, pathological and molecular characteristics of GIST in in YA. YA GIST patients registered in the Dutch GIST Registry (DGR) were included, and data were compared to those of older adults (OA). From 1010 patients in the DGR, 52 patients were YA (54% male). Main tumour locations were stomach (46%) and small intestine (46%). GIST genetic profiles were mutations in KIT (69%), PDGFRA (6%), SDH deficient (8%), NF1 associated (4%), ETV6-NTRK3 gene fusion (2%) or wildtype (10%). Statistically significant differences were found between the OA and YA patients (localisation, syndromic and mutational status). YA presented more often than OA in an emergency setting (18% vs. 9%). The overall five-year survival rate was 85%. In conclusion, YA GISTs are not similar to typical adult GISTs and also differ from paediatric GISTs, as described in the literature. In this series, we found a relatively high percentage of small intestine GIST, emergency presentation, 25% non-KIT/PDGFRA mutations and a relatively good survival.

Clinicopathological Outcomes and Prognosis of Elderly Patients (≥ 65 Years) with Gastric Gastrointestinal Stromal Tumors (GISTs) Undergoing Curative-Intent Resection: a Multicenter Data Review

BACKGROUND

The most common site of gastrointestinal stromal tumors (GISTs) is the stomach, and gastric GISTs (gGISTs) occur most often in elderly patients. However, the clinicopathological features, treatment patterns, and prognosis of elderly patients with gGISTs remain unclear.

METHODS

We retrospectively collected clinicopathological and prognostic data for patients with primary gGISTs who underwent curative-intent resection at 10 medical centers in China from 1998 to 2015.

RESULTS

Over the 18 years, 10 medical centers treated 1846 patients with primary gGISTs by curative-intent resection. The median age was 59 (range 18-91) years. The patients were classified into two groups according to age, namely an elderly group (≥ 65 years of age) and a nonelderly group (< 65 years of age). The elderly group had more comorbidities (40.7% vs 23.5%, p = 0.011), a higher rate of postoperative complications (14.4% vs 8.7%, p = 0.031), and a lower proportion of intermediate/high-risk patients who received adjuvant therapy (30.0% vs 66.8%, p = 0.001) than did the nonelderly group. Regarding pathological outcomes, a significant difference in tumor necrosis was observed between the two groups (p = 0.002), and more cases of tumor necrosis occurred in the elderly group than in the nonelderly group. Regarding postoperative recovery outcomes, no significant difference was observed between the two groups. Univariate analysis showed that age, postoperative complications, adjuvant therapy, tumor size, mitotic count, modified National Institutes of Health (NIH) risk category, and tumor necrosis were factors that affected disease-free survival (DFS). Multivariate analysis showed that modified NIH risk category was the only independent factor affecting DFS. The 5-year DFS rates in the nonelderly and elderly groups were 88.1% and 81.4%, respectively (p = 0.034), and the 5-year overall survival (OS) rates were 90.4% and 85.5% (p = 0.038), respectively.

CONCLUSIONS

Currently, the treatment patterns for elderly patients with gGISTs remain the same as those for young patients with gGISTs. Elderly gGIST patients had more comorbidities and postoperative complications than did nonelderly gGIST patients, and fewer elderly gGIST patients received postoperative adjuvant therapy. Elderly gGIST patients also had a higher rate of tumor necrosis and worse DFS and OS than did young gGIST patients. Further exploration into the diagnosis and treatment patterns of elderly patients is therefore essential.

Metastatic pattern and prognosis of gastrointestinal stromal tumor (GIST): a SEER-based analysis

PURPOSE

This SEER-based study aimed to explore and analyze the relationship of metastasis of liver, lung and bone of GIST patients and their prognosis.

METHODS

The data of GIST patients were from Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015 and all the statistical analyses were conducted by statistical software package SPSS (Version 22.0).

RESULTS

A total of 4224 GIST patients were identified, of which 388 (9.19%) patients with liver metastasis, 20 (0.47%) patients with bone metastasis and 32 (0.76%) patients with lung metastasis. There was no significant difference of risk of bone or lung metastasis between patients with and without liver metastasis (P = 0.935). The median overall survival of patients with liver, bone, or lung metastasis was, respectively, 49 months, 18 months, and 20 months, which were all shorter than that of patients without metastasis. The overall survival of patients with both liver and bone metastasis and those with metastasis of all three sites was not significantly different from that of patients with only liver metastasis. The multivariate analysis showed age of less than 65 years, female patients, married status and receiving surgery were all the beneficial factors for prognosis of GIST patients with liver metastasis.

CONCLUSIONS

Patients with metastasis had a poorer prognosis than those without. Liver metastasis might have no relationship with bone or lung metastasis and liver might play a more dominant role than the other two sites in the prognosis of GIST patients with metastasis. So, more attention should be paid to liver status in diagnosis and treatment of GIST patients.

Clinicopathological features and prognosis of 276 cases of primary small (≤ 2 cm) gastric gastrointestinal stromal tumors: a multicenter data review

BACKGROUND

Till present, there are still controversies over the epidemiology, pathological features, types of surgical treatment, and prognoses of primary small gastric GISTs (gGISTs).

METHODS

From January 1998 to January 2015, patients with primary small gGIST admitted from four high-volume medical centers of the Southern China were enrolled and their data were analyzed to evaluate their clinicopathological features, treatment and prognostic factors to provide evidence-based medical experience for clinical practice.

RESULTS

A total of 276 primary small gGIST cases over a period of 18 years were investigated and had a median age of 60 years (range 27-91 years old). Regarding the tumor sites, 24 (8.7%) cases were in the cardia of the stomach, 107 (38.8%) in the fundus, 117 (42.4%) in the gastric body, and 28 (10.1%) in the gastric antrum. Eleven patients (4.0%) underwent a preoperative biopsy. A total of 137 (49.6%), 75 (27.2%), and 64 (23.2%) patients underwent laparoscopic, open resection, and endoscopic resection, respectively. Sixty-four patients (23.2%) had local endoscopic resection, 172 (62.3%) had wedge resection, 7 (2.5%) had proximal gastrectomy, 19 (6.9%) had distal gastrectomy, and 14 (5.1%) had total gastrectomy. Mitotic counts were ≤ 5/50, (5-10)/50, and > 10/50 per HPF in 259 (93.8%), 7 (2.5%), and 10 (3.6%) cases, respectively. There were 259 cases (97.1%) of spindle cell type, 7 (2.5%) epithelial cell types and one case (0.4%) of mixed type. Immunohistochemistry showed 74.6% (206/276), 98.2% (271/276), and 97.4% (269/276) of the patients had co-expression of CD34+, CD117+, and DOG-1+, respectively. Thirty-nine patients underwent genetic testing (39/276, 14.1%). Three patients (1.1%) had positive resection margin. Five high-risk patients received follow-up treatment with imatinib with a median follow-up time of 38 months (range 3-156 months). The overall 1-, 3-, and 5-year overall survival rates were 100%, 99.6%, and 99.1%, respectively.

CONCLUSION

Though the incidence of primary small gGISTs increased per annum, the overall survival prognoses were high. Surgery or endoscopic resection was the primary mode of treatment. Pathological features of primary small gGISTs were similar to large gGISTs, and to achieve a timely surgical intervention, the identification of intermediate- and high-risk cases should be a future focus of study.

Surgical and medical management of small bowel gastrointestinal stromal tumors: A report of the Dutch GIST registry

BACKGROUND

A cohort of 201 patients with small bowel gastrointestinal stromal tumors (GIST) treated between January 1st, 2009 and December 31st, 2016 in five GIST expertise centers in the Netherlands was analyzed. Goal of this study was to describe the clinical, surgical and pathological characteristics of this rare subpopulation of GIST patients, registered in the Dutch GIST registry.

METHODS

Clinical outcomes and risk factors of patients with small bowel GIST who underwent surgery or treated with systemic therapy were analyzed. A classification was made based on disease status at diagnosis (localized vs. metastasized).

RESULTS

201 patients with small bowel GIST were registered of which 138 patients (69%) were diagnosed with localized disease and 63 patients (31%) with metastatic disease. Approximately 19% of the patients had emergency surgery, and in 22% GIST was an accidental finding. In patients with high risk localized disease, recurrence occurred less often in patients who received adjuvant treatment (4/32) compared to patients who did not (20/31, p < 0.01). Disease progression during palliative imatinib treatment occurred in 23 patients (28%) after a median of 20.7 (range 1.8-47.1) months. Ongoing response was established in 52/82 patients on first line palliative treatment with imatinib after a median treatment time of 30.6 (range 2.5-155.3) months.

CONCLUSION

Patients with small-bowel GIST more frequently present with metastatic disease when compared to patients with gastric GIST in literature. We advocate for Prospective registration of these patients and investigate the use of surgery in patients with limited metastatic disease.

Treatment outcomes in older patients with advanced gastrointestinal stromal tumor (GIST)

BACKGROUND

The aim of the study was to analyze the treatment results of advanced GIST in the largest, homogenous series of older patients.

METHODS

Between 2001 and 2016, 686 patients with metastatic/unresectable GIST were treated initially with imatinib and 656 were included in the analysis. Subsequently 232 patients were treated with sunitinib after imatinib failure. We have analyzed the outcomes of patients who have been treated with the tyrosine kinase inhibitor at the age ≥ 70 years and compared to control group of patients younger than 70 years old.

RESULTS

In the group of patients treated with imatinib, 139 (21%) started therapy at the age of at least 70 years (median age of the entire cohort: 60). Median progression-free survival (PFS) on 1st line imatinib did not differ between patients ≥70 yo (years old) and < 70yo (38.5 vs 44.9 months), but median overall survival (OS) was significantly better for younger patients (81 months vs. 50; p = 0.0001; although disease-specific survival - DSS was similar). Distribution of primary tumor mutational status was generally similar in older and younger patients. Permanent dose reduction (300-100 mg/day) was required for 23 patients (16.9%) in the older group and was significantly more frequent as compared to younger patients (5%). Drug-related adverse events were mainly of grades 1/2, but grade 3/4 toxicity occurred more frequently in older (14.7%) than in younger patients (3.8%). Similarly in group of patients treated with second-line sunitinib median PFS and DSS were comparable in groups of patients ≥70 yo (n = 55) and < 70yo (9.7 months vs 10.3 months; p = 0.7, and 21.5 vs 22.9 months). >40% of patients in both groups required dose adjustments to 37.5-25 mg daily.

CONCLUSIONS

Our study confirms that current therapy of advanced GIST with tyrosine kinase inhibitors (both in 1st and 2nd line) in older patients enable to achieve the similar disease control rate and final outcomes as in younger patients, but it demands close cooperation of experienced oncologist with patients for dose modifications and side effects management. Limitation of our study is that the patients did not undergo a comprehensive geriatric assessment, what might be helpful for personalized management of patients. Nevertheless, we confirm that older patients with GIST should not receive less treatment irrespective of comorbidities.