Adherence to imatinib therapy in patients with gastrointestinal stromal tumors

Navigating Ongoing Challenges in GI Stromal Tumors

GI stromal tumors (GISTs) are mesenchymal neoplasms with variable natural histories, originating in the GI tract, most commonly in the stomach. They are frequently characterized by KIT or platelet-derived growth factor receptor alpha (PDGFRA) oncogenic mutations. Surgical resection remains the cornerstone treatment for localized GISTs. Clinical trials have demonstrated the benefits of adjuvant imatinib in patients selected on the basis of recurrence risk and gene mutations, although the optimal duration of therapy is yet to be established. Some data suggest that longer durations of adjuvant imatinib (>3 years) may provide additional benefit, which is being investigated in ongoing trials. Management of imatinib-related adverse effects is essential during treatment, and longitudinal abdominal imaging is mandatory both during and after adjuvant therapy. Once GISTs are more advanced and unresectable, KIT- and PDGFRA-directed tyrosine kinase inhibitors (TKIs) become the key treatment in most patients with KIT mutation. Several TKIs have regulatory approval for advanced GISTs, but in most patients, resistance to TKIs eventually emerges, mainly from secondary resistance mutations in KIT. Each TKI has different coverage of oncogenic KIT mutations, suggested by preclinical and clinical findings, which has given rationale to an ongoing clinical trial that includes molecular selection as eligibility criteria. Furthermore, novel treatment approaches, from TKI combinations to an antibody-drug conjugate, are being investigated. Despite the significant advance in managing GISTs with KIT mutations, those without KIT or PDGFRA mutation, which consists of 10%-15% of patients with GIST, can be a clinical challenge in the advanced setting. These non-KIT/PDGFRA GISTs could be driven by genomic or epigenomic alterations in SDHx, NF1 mutations, and other genomic alterations. Non-KIT/PDGFRA GISTs are less responsive to currently available TKIs than GISTs driven by KIT/PDGFRA mutations, and each subset of non-KIT/PDGFRA GIST has distinctive biology and clinical features. Therefore, individualized, multidisciplinary, biology-based management and consideration for clinical trial enrollment are critical for non-KIT/PDGRFA GISTs.

Imatinib adherence prediction using machine learning approach in patients with gastrointestinal stromal tumor

BACKGROUND

Nonadherence to imatinib is common in patients with gastrointestinal stromal tumor (GIST), which is associated with poor prognosis and financial burden. The primary aim of this study was to investigate the adherence rate in patients with GIST and subsequently develop a model based on machine learning (ML) and deep learning (DL) techniques to identify the associated factors and predict the risk of imatinib nonadherence.

METHODS

All eligible patients completed four sections of questionnaires. After the data set was preprocessed, statistically significance variables were identified and further processed to modeling. Six ML and four DL algorithms were applied for modeling, including eXtreme gradient boosting, light gradient boosting machine (LGBM), categorical boosting, random forest, support vector machine, artificial neural network, multilayer perceptron, NaiveBayes, TabNet, and Wide&Deep. The optimal ML model was used to identify potential factors for predicting adherence.

RESULTS

A total of 397 GIST patients were recruited. Nonadherence was observed in 185 patients (53.4%). LGBM exhibited superior performance, achieving a mean f1_score of 0.65 and standard deviation of 0.12. The predominant indicators for nonadherent prediction of imatinib were cognitive functioning, whether to perform therapeutic drug monitoring (if_TDM), global health status score, social support, and gender.

CONCLUSIONS

This study represents the first real-world investigation using ML techniques to predict risk factors associated with imatinib nonadherence in patients with GIST. By highlighting the potential factors and identifying high-risk patients, the multidisciplinary medical team can devise targeted strategies to effectively address the daily challenges of treatment adherence.

The interplay of knowledge, motivation, and treatment response in medication adherence among patients with chronic myeloid leukemia treated with Imatinib

Chronic Myeloid Leukemia (CML) requires consistent medication adherence to Imatinib (IM) for optimal outcomes, however, adherence to oral chemotherapy is challenging. This observational study explores the relationship between patient knowledge, motivation, and adherence to IM therapy, and their collective impact on clinical outcomes. A prospective, observational study was conducted with 101 CML patients. The 6-Item Morisky Medication Adherence Scale (MMAS-6) was used to assess adherence, motivation, and knowledge levels. The study found that high motivation was significantly associated with lower BCR-ABL expression (p = 0.025). Patients with high knowledge and motivation had a 71% favorable response rate, compared to 0% in those with low knowledge and motivation (p = 0.01). As conclusion both patient motivation and knowledge are crucial for favorable treatment outcomes in CML. High levels of both significantly correlate with better clinical responses. Tailored interventions to enhance patient knowledge and motivation are essential.

Influence of lymph node removal on the prognosis of high malignancy potential gastric gastrointestinal stromal tumors: Insights from population-based study

High malignancy potential gastric gastrointestinal stromal tumors (HMP-gGISTs) generally require surgical resection. However, the necessity of lymph node removal (LR) for patients with such tumors remains unclear. Therefore, we conducted a population-based study to analyze the impact of LR on the long-term prognosis of patients with HMP-gGISTs. Patients with HMP-gGISTs were gathered from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was utilized to address potential selection bias. Overall survival (OS) and cancer-specific survival (CSS) were evaluated using Kaplan-Meier analyses and multivariate Cox proportional hazards models. A total of 840 patients with HMP-gGISTs were included in the study, with 317 undergoing LR and 523 not undergoing LR. The prognosis for OS (P = 0.026) and CSS (P < 0.001) in the LR group was worse compared to the No-LR group. After PSM, 634 patients were matched for comparison. The results showed that the OS (P = 0.028) and CSS (P = 0.006) in the LR group remained poorer than those in the No-LR group. Subgroup analysis further indicated that patients who did not undergo LR had a better prognosis. Our findings suggest that LR may not improve the prognosis of patients with HMP-gGISTs, implying that LR may not be necessary for these patients.

Effect of functionalization on the adsorption performance of carbon nanotube as a drug delivery system for imatinib: molecular simulation study

In this study, efficiency of functionalized carbon nanotube as a potential delivery system for imatinib anti-cancer drug was investigated. Accordingly, carboxyl and hydroxyl functionalized carbon nanotube were inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, possible interactions of imatinib with pure and functionalized carbon nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that pure and functionalized carbon nanotubes can act as imatinib drug adsorbents in gas phase. However, results of association free energy calculations in aqueous solution indicated that only carboxyl and hydroxyl functionalized carbon nanotubes could interact with imatinib. Monte Carlo simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Computed solvation free energies in water showed that the interactions with functionalized carbon nanotubes significantly enhance the solubility of imatinib, which could improve its in vivo bioavailability.

Preoperative prediction of malignant potential of 2-5 cm gastric gastrointestinal stromal tumors by computerized tomography-based radiomics

BACKGROUND

The use of endoscopic surgery for treating gastrointestinal stromal tumors (GISTs) between 2 and 5 cm remains controversial considering the potential risk of metastasis and recurrence. Also, surgeons are facing great difficulties and challenges in assessing the malignant potential of 2-5 cm gastric GISTs.

AIM

To develop and evaluate computerized tomography (CT)-based radiomics for predicting the malignant potential of primary 2-5 cm gastric GISTs.

METHODS

A total of 103 patients with pathologically confirmed gastric GISTs between 2 and 5 cm were enrolled. The malignant potential was categorized into low grade and high grade according to postoperative pathology results. Preoperative CT images were reviewed by two radiologists. A radiological model was constructed by CT findings and clinical characteristics using logistic regression. Radiomic features were extracted from preoperative contrast-enhanced CT images in the arterial phase. The XGboost method was used to construct a radiomics model for the prediction of malignant potential. Nomogram was established by combing the radiomics score with CT findings. All of the models were developed in a training group (n = 69) and evaluated in a test group (n = 34).

RESULTS

The area under the curve (AUC) value of the radiological, radiomics, and nomogram models was 0.753 (95% confidence interval [CI]: 0.597-0.909), 0.919 (95%CI: 0.828-1.000), and 0.916 (95%CI: 0.801-1.000) in the training group vs 0.642 (95%CI: 0.379-0.870), 0.881 (95%CI: 0.772-0.990), and 0.894 (95%CI: 0.773-1.000) in the test group, respectively. The AUC of the nomogram model was significantly larger than that of the radiological model in both the training group (Z = 2.795, P = 0.0052) and test group (Z = 2.785, P = 0.0054). The decision curve of analysis showed that the nomogram model produced increased benefit across the entire risk threshold range.

CONCLUSION

Radiomics may be an effective tool to predict the malignant potential of 2-5 cm gastric GISTs and assist preoperative clinical decision making.

Primary Localized Gastrointestinal Stromal Tumors: Medication Adherence and Prognosis According to Gender

OBJECTIVE

Gender is associated with medication adherence for imatinib, but whether it is related to the prognosis of primary localized gastrointestinal stromal tumors (GISTs) is unclear. The goal of this study was to clarify the relationship between gender and prognosis in GIST patients, with differences in medication adherence considered.

METHODS

The data of 320 GIST patients were retrospectively collected from the First Affiliated Hospital of Chongqing Medical University. Survival analysis was performed using the Kaplan-Meier method (Log rank test) and the risk factors of recurrence were determined using Cox multivariate analysis. Medication adherence-stratified analyses were performed to control for confounding factors.

RESULTS

Kaplan-Meier analysis revealed that among patients who received postoperative adjuvant imatinib therapy, men had a higher recurrence rate than women (P<0.01). Pearson's chi-square test revealed better medication adherence in women than in men (P<0.01). Cox regression analysis revealed that gender was not an independent risk factor for recurrence-free survival (RFS; P=0.25), but medication adherence was (P<0.01). Among GIST patients with a medication possession ratio (MPR) of less than 90%, 62.86% of male patients took imatinib irregularly or not at all due to limited understanding of the disease, whereas 55.74% of female patients' took imatinib irregularly because they could not tolerate adverse drug reactions.

CONCLUSION

Adherence was poorer in male than in female patients, which might explain the worse prognoses of the former among patients who received adjuvant treatment with imatinib. The gender difference in the degree of adherence should be considered in postoperative pharmacotherapy for patients with primary localized GISTs.

Adjuvant Imatinib Treatment for 5-Years vs 3-Years in Patients with Ruptured Localized Gastrointestinal Stromal Tumor: A Retrospective Analysis

Purpose

Three years of adjuvant imatinib is the standard treatment for resected gastrointestinal stromal tumors (GISTs) with rupture, but the recurrence rate is prominently high. We aimed to investigate the efficacy and safety of 5-year adjuvant imatinib compared with 3-year treatment in patients with a ruptured GIST following surgical resection.

Materials and Methods

A total of 51 patients were included in the analysis. The assessment of GIST rupture was based on Nishida’s classification. Twenty patients who were diagnosed before November 2013 were treated with 5 years of imatinib, and 31 patients who were diagnosed after November 2013 were treated with 3 years of imatinib. We retrospectively compared the clinical outcomes of the two groups.

Results

Baseline characteristics and the incidence of the adverse events were generally comparable between the two groups. During a median follow-up duration of 43.8 months and 104.2 months in the 3- and 5-year group, 8 and 9 patients had a disease recurrence, respectively. The 5-year group showed better recurrence-free survival (RFS) than the 3-year group. In multivariate analysis, low mitotic index was a significant independent favorable prognostic factor for RFS, while 5-year imatinib treatment was marginally associated with a favorable RFS.

Conclusion

Five years of adjuvant imatinib treatment in patients with ruptured GIST was associated with favorable survival outcomes with manageable toxicity profiles. Our findings warrant validation and confirmation in future studies.

CT Radiomics Model for Discriminating the Risk Stratification of Gastrointestinal Stromal Tumors: A Multi-Class Classification and Multi-Center Study

Objective

To establish and verify a computed tomography (CT)-based multi-class prediction model for discriminating the risk stratification of gastrointestinal stromal tumors (GISTs).

Materials and Methods

A total of 381 patients with GISTs were confirmed by surgery and pathology. Information on 213 patients were obtained from one hospital and used as training cohort, whereas the details of 168 patients were collected from two other hospitals and used as independent validation cohort. Regions of interest on CT images of arterial and venous phases were drawn, radiomics features were extracted, and dimensionality reduction processing was performed. Using a one-vs-rest method, a Random Forest-based GISTs risk three-class prediction model was established, and the receiver operating characteristic curve (ROC) was used to evaluate the performance of the multi-class classification model, and the generalization ability was verified using external data.

Results

The training cohort included 96 very low-risk and low-risk, 60 intermediate-risk and 57 high-risk patients. External validation cohort included 82 very low-risk and low-risk, 48 intermediate-risk and 38 high-risk patients. The GISTs risk three-class radiomics model had a macro/micro average area under the curve (AUC) of 0.84 and an accuracy of 0.78 in the training cohort. It had a stable performance in the external validation cohort, with a macro/micro average AUC of 0.83 and an accuracy of 0.80.

Conclusion

CT radiomics can discriminate GISTs risk stratification. The performance of the three-class radiomics prediction model is good, and its generalization ability has also been verified in the external validation cohort, indicating its potential to assist stratified and accurate treatment of GISTs in the clinic.

Computed-Tomography-Based Radiomics Model for Predicting the Malignant Potential of Gastrointestinal Stromal Tumors Preoperatively: A Multi-Classifier and Multicenter Study

Background: Our goal was to establish and verify a radiomics risk grading model for gastrointestinal stromal tumors (GISTs) and to identify the optimal algorithm for risk stratification. Methods: We conducted a retrospective analysis of 324 patients with GISTs, the presence of which was confirmed by surgical pathology. Patients were treated at three different hospitals. A training cohort of 180 patients was collected from the largest center, while an external validation cohort of 144 patients was collected from the other two centers. To extract radiomics features, regions of interest (ROIs) were outlined layer by layer along the edge of the tumor contour on CT images of the arterial and portal venous phases. The dimensionality of radiomic features was reduced, and the top 10 features with importance value above 5 were selected before modeling. The training cohort used three classifiers [logistic regression, support vector machine (SVM), and random forest] to establish three GIST risk stratification prediction models. The receiver operating characteristic curve (ROC) was used to compare model performance, which was validated by external data. Results: In the training cohort, the average area under the curve (AUC) was 0.84 ± 0.07 of the logistic regression, 0.88 ± 0.06 of the random forest, and 0.81 ± 0.08 of the SVM. In the external validation cohort, the AUC was 0.85 of the logistic regression, 0.90 of the random forest, and 0.80 of the SVM. The random forest model performed the best in both the training and the external validation cohorts and could be generalized. Conclusion: Based on CT radiomics, there are multiple machine-learning models that can predict the risk of GISTs. Among them, the random forest algorithm had the highest prediction efficiency and could be readily generalizable. Through external validation data, we assume that the random forest model may be used as an effective tool to guide preoperative clinical decision-making.

Assessment of Adherence to Imatinib and Health-Related Quality of Life Among Patients with Gastrointestinal Stromal Tumor: A Cross-Sectional Study in an Oncology Clinic in Malaysia

PURPOSE

To evaluate the rate and predictors of non-adherence to imatinib in gastrointestinal stromal tumor (GIST) patients, as well as to compare the difference in health-related quality of life (HRQOL) between adherent and non-adherent patients.

PATIENTS AND METHODS

A cross-sectional study at the Oncology Clinic, Hospital Kuala Lumpur was conducted from March to August 2018. All patients with metastatic and/or unresectable GIST aged ≥18 years old and on at least 3 months of imatinib were included. Adherence to imatinib was assessed using the 10-item validated Medication Compliance Questionnaire, with a score of <100% indicating non-adherence. Non-adherence predictors were determined by multiple logistic regressions. HRQOL was evaluated by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). The difference in the mean HRQOL scores between adherent and non-adherent groups was determined by multivariate analysis of variance.

RESULTS

A total of 89 patients were enrolled, of which 49 (55.1%) were considered non-adherent. The significant predictors of non-adherence were age (adjusted odds ratio [OR] 0.93; CI 0.89-0.98; P = 0.007), presence of nausea and vomiting (OR 5.63; CI 1.25-25.27; P = 0.024), and presence of comorbidities (OR 4.56; CI 1.44-14.40; P = 0.010). Patients who were in the adherent group showed significantly better score in overall HRQOL, F (15, 73) = 2.09, P < 0.02; Pillai's trace = 0.3, partial eta squared = 0.30.

CONCLUSION

Non-adherence to long-term treatment with imatinib among patients with GIST should not be underestimated. Significant predictors of non-adherence among this population are younger age, presence of nausea and vomiting, as well as comorbidities. Patients with good adherence portrayed better HRQOL.

Striving towards Normality in Daily Life: A Qualitative Study of Patients Living with Metastatic Gastrointestinal Stromal Tumour in Long-Term Clinical Remission

Background

This study explored how patients with metastatic gastrointestinal stromal tumour (GIST) experience the psychosocial challenges associated with their disease and its treatment, as well as how that experience influenced their practical, relational, vocational, and existential life.

Methods

This qualitative study has an explorative design and applied a phenomenological and hermeneutical approach. We conducted in-depth, semistructured interviews with 20 patients with metastatic GIST in long-term clinical remission. The gathered data were interpreted using a thematic analysis.

Results

Living with metastatic GIST, as well as the side effects of the required medication, led to changes that limited the participants' daily life. They expressed how tiredness, impaired memory, and physical challenges were among the detrimental impacts of the disease on their family life, vocational life, social life, and leisure time. Adjustments were necessary to ensure they had sufficient energy to cope with the practical and relational aspects of everyday life. Feelings of uncertainty stemming from drug resistance, disease progression, and the possibility of early death were also experienced as challenging. Half the participants stated that it was difficult to keep negative mental health issues at bay, and all of them considered the time spent waiting for their scheduled follow-up scan to be burdensome.

Conclusions

It is important to focus increased attention on how the daily practical and psychosocial life of patients with chronic cancer, including metastatic GIST, is affected by their disease. Doing so might provide health-care workers with clues regarding how best to guide and support such patients throughout their emotional journey and, therefore, to improve their quality of life. As new medical treatments can also prolong survival and induce long-term clinical remission in relation to several other forms of metastatic cancer, the findings concerning GIST reported in this study might have widespread implications.

Melanoma Cancer Immunotherapy Using PD-L1 siRNA and Imatinib Promotes Cancer-Immunity Cycle

PURPOSE

Cancer-Immunity Cycle is a cascade of anticancer immune responses in the body that continues and fights against the cancer expansion. The Cancer-Immunity Cycle is halted by tumor cell immunosuppression of host T cell through programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) interactions that induce the functional suppression of tumor-reactive cytotoxic T cells and actively promotes the tumorigenesis via the mTOR signaling pathway.

METHODS

Here, we demonstrated that this Cycle could be enhanced by the synergistic knock down of PD-L1 through co-delivery of siRNA-PD-L1 (siPD-L1) and imatinib (IMT) in a liposomal nanoparticle.

RESULTS

The siPDIN effectively downregulated the protein expressions of PD-L1 and significantly knocked down the expression of p-S6k protein at in vitro and in vivo conditions which inhibited tumorigenic mTOR pathway. The combination-based siPDIN exhibited a significantly higher cytotoxic effect compared to that of individual anticancer agents. B16F10 cells treated with siPDIN exhibited a significantly higher cancer cell apoptosis (~60%) compared to cocktail combination of siRNA+IMT (~35%) analyzed by flow cytometer. Importantly, siPDIN significantly delayed the tumor growth with significantly lower tumor-specific growth rate than the animals treated with individual free IMT or siRNA. siPDIN produced a 3-fold higher IFN-γ compared to control in DLNs and 4-fold higher IFN-γ in spleens.

CONCLUSION

Overall, results revealed that the tumors treated with siPDIN restored the immunity of CTLs by potentially inhibiting the immune checkpoint interactions, suppressed the mTOR signaling pathway and exhibited an enhanced anticancer efficacy in melanoma.

Adherence to Adjuvant Imatinib Therapy in Patients with Gastrointestinal Stromal Tumor in Clinical Practice: A Cross-Sectional Study

BACKGROUND

Adherence to imatinib therapy has been significantly associated with disease progression and direct medical costs in gastrointestinal stromal tumor (GIST) patients. However, adherence to oral anticancer drugs is frequently hindered by the influence of various factors. The aim of this study was to evaluate the prevalence of imatinib adherence and its influencing factors among GIST patients in the adjuvant setting.

METHODS

Adherence of GIST patients (receiving imatinib for ≥1 month) was assessed using the 8-item Morisky Medication Adherence Scale (MMAS), with a score <8 indicating nonadherence. Quality of life and social support were evaluated by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ C30) and Social Support Rating Scale (SSRS). Factors associated with nonadherence were identified by multivariate logistic regression analysis. Imatinib plasma concentrations were determined and compared between adherent and nonadherent groups.

RESULTS

A total of 158 GIST patients were enrolled, 92 (58.2%) patients were considered nonadherent. Intentional nonadherence, especially feeling hassled by treatment plan (34.2% of patients), was common. In the multivariate logistic regression analysis, gender (OR 2.68, 95% CI 1.33-5.41; p = 0.0058), place of residence (OR 3.20, 95% CI 1.39-7.35; p = 0.0061), and global health status (OR 1.02, 95% CI 1.00-1.04; p = 0.0378) were significantly associated with nonadherence. Moreover, imatinib plasma concentrations in nonadherent patients were significantly lower than that in the good adherence group (p = 0.0338).

CONCLUSIONS

Poor adherence to imatinib is a notable problem in Chinese GIST patients in the adjuvant therapy setting. The predominant indicators of nonadherence in this study were gender (female), living in a rural area, and harboring a low global health status score. These indicators may aid clinicians in determining where increased efforts in promoting adherence may be beneficial.

Co-delivery of doxorubicin and imatinib by pH sensitive cleavable PEGylated nanoliposomes with folate-mediated targeting to overcome multidrug resistance

Multidrug resistance to chemotherapeutic drugs is a major obstacle to breast cancer treatment. In this study, doxorubicin (DOX) and imatinib (IM) were co-loaded into folate receptor targeted (FR-targeted) pH-sensitive liposomes (denoted as FPL-DOX/IM) to fulfill intracellular acid-sensitive release and reverse drug resistance. FPL-DOX/IM could maintain stability in blood circulation with approximate diameters of 100 nm and rapidly release encapsulated drugs in tumor acidic microenvironment. Moreover, the IM in combination therapy could overcome chemoresistance associated with DOX effectively by inhibiting ABC transporter function and improving chemotherapy sensitivity. The designed liposomes co-loaded with DOX and IM significantly enhanced anti-tumor effects both in vitro and in vivo. These findings suggest that FPL-DOX/IM provides a novel strategy to improve chemotherapeutic efficacy against MDR tumors.

Personalization of regorafenib treatment in metastatic gastrointestinal stromal tumours in real-life clinical practice

Background:

Regorafenib (REG) has now been approved as the standard third-line therapy in metastatic gastrointestinal stromal tumour (GIST) patients at the recommended dose and schedule of 160 mg once daily for the first 3 weeks of each 4-week cycle. However, it has a relevant toxicity profile that mainly occurs within the first cycles of therapy, and dose and schedule adjustments are often required to reduce the frequency or severity of adverse events and to avoid early treatment discontinuation. To date, large amounts of data on the use of REG in metastatic GIST patients in daily clinical practice are not available, and we lack information about how this treatment personalization really affects the quality of life (QoL) of patients. The aim of the present retrospective study is to build a comprehensive picture of all alternative REG strategies adopted in daily clinical practice for use in metastatic GIST patients.

Methods:

Metastatic GIST patients treated with dose adjustment or alternative schedules of REG at seven reference Italian centres were retrospectively included.

Results:

For a total of 62 metastatic GIST patients, we confirmed that REG treatment adjustment is common in clinical practice and that it is very heterogeneous, with approximately 20 different strategies being adopted. Independent of which strategy is chosen, treatment personalization has led to a clinical benefit defined as complete or partial resolution of side effects in almost all patients, affecting the duration of REG treatment.

Conclusions:

The personalization of REG, even if it is heterogeneous, seems to be crucial to maximize the overall treatment duration.

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

OBJECTIVE

Although gastrointestinal stromal tumours (GIST) predominantly occur in older patients, data on treatment patterns in elderly GIST patients are scarce.

METHODS

Patients registered in the Dutch GIST Registry (DGR) from January 2009 until December 2016 were included. Differences in treatment patterns between elderly (≥75 years) and younger patients were compared. Multivariate analyses were conducted using logistic regression.

RESULTS

Data of 145 elderly and 665 non-elderly patients were registered (median age 78 and 60 years respectively). In elderly patients, performance score (WHO-PS) and age-adjusted Charlson comorbidity index (ACCI) were significantly higher (p < 0.05; p < 0.001), and albumin level significantly lower (p = 0.04). Hundred-and-nine (75.2%) elderly and 503 (75.6%) non-elderly patients had only localised disease. Surgery was performed in 57% of elderly versus 84% of non-elderly patients (p = 0.003, OR: 0.26, 95% CI: 0.11-0.63). No differences in surgery outcome or complications were found. Thirty-eight percent of elderly with an indication for adjuvant treatment did receive imatinib versus 68% of non-elderly (p = 0.04, OR: 0.47, 95% CI: 0.23-0.95). Thirty-six elderly and 162 non-elderly patients had metastatic disease. Palliative imatinib was equally given (mean dose 400 mg) and adverse events were mostly minor (p = 0.71). In elderly, drug-related toxicity was in 32.7% reason to discontinue imatinib versus 5.1% in non-elderly (p = 0.001, OR 13.5, 95% CI: 2.8-65.0). Median progression-free survival (PFS) was 24 months in elderly and 33 months in non-elderly (p = 0.10). Median overall survival (OS) was 34 months and 59 months respectively (p = 0.01).

CONCLUSIONS

Elderly GIST patients with localised disease receive less surgery and adjuvant treatment, irrespective of comorbidity and performance score. Drug-related toxicity results more often in treatment discontinuation. This possibly results in poor outcome.

Dose-finding designs for trials of molecularly targeted agents and immunotherapies

Recently, there has been a surge of early phase trials of molecularly targeted agents (MTAs) and immunotherapies. These new therapies have different toxicity profiles compared to cytotoxic therapies. MTAs can benefit from new trial designs that allow inclusion of low-grade toxicities, late-onset toxicities, addition of an efficacy endpoint, and flexibility in the specification of a target toxicity probability. To study the degree of adoption of these methods, we conducted a Web of Science search of articles published between 2008 and 2014 that describe phase 1 oncology trials. Trials were categorized based on the dose-finding design used and the type of drug studied. Out of 1,712 dose-finding trials that met our criteria, 1,591 (92.9%) utilized a rule-based design, and 92 (5.4%; range 2.3% in 2009 to 9.7% in 2014) utilized a model-based or novel design. Over half of the trials tested an MTA or immunotherapy. Among the MTA and immunotherapy trials, 5.8% used model-based methods, compared to 3.9% and 8.3% of the chemotherapy or radiotherapy trials, respectively. While the percentage of trials using novel dose-finding designs has tripled since 2007, the adoption of these designs continues to remain low.

Patients' perceived tolerance of side effects in phase I cancer clinical trials: A qualitative study

This qualitative study aimed to explore cancer patients' perceived tolerance of side effects in phase I drug trials. Patients with solid tumours receiving molecularly targeted agents with/without chemotherapy were eligible for inclusion. In-depth semi-structured interviews were carried out with 17 patients with a median [range] age of 63 [41-72] years. Treatment was discontinued in seven patients. Verbatim transcripts of the audio-taped interviews were analysed using a constructivist grounded theory approach. Four conceptual categories emerged from data analysis, labelled "suffering from side effects" comprising a range of symptoms, psychosocial or role disturbances; "striving to cope with side effects" reflecting psychological strategies for managing side effects; "hoping" reflecting expectations about treatment efficacy and relief from side effects; and "appraisal of care." Among patients remaining in the trial, treatment was currently perceived as fairly tolerable. For most respondents, whether still in a trial or not, treatment discontinuation could not be justified by the non-tolerance of treatment side effects. These results question the adequacy of patient-perceived tolerance reports to determine an optimal drug dose for phase II trials. Confronted with patients' hopes and inappropriate beliefs, communication is challenging in phase I trials and could benefit from facilitating psychosocial interventions.

Partial response to imatinib treatment in a patient with unresectable gastrointestinal stromal tumor: A case report and mini literature review

The aim of the present study was to evaluate the efficacy and safety of imatinib mesylate in unresectable gastrointestinal stromal tumor (GIST) and to discuss its therapeutic regimen. A patient with unresectable GIST is described, and several key clinical studies are reviewed, including the clinical trials B2222 and S0033, which contain recently reported results of the long-term clinical outcome of imatinib in patients with unresectable or metastatic GIST. The recent results of the two studies demonstrate the long-term efficacy and safety of imatinib for unresectable or metastatic GIST. A positive response to imatinib treatment was observed in the present patient, which is consistent with the data of the B2222 and S0033 trials. However, further long-term, large-scale, multicenter and controlled trials are required to determine the relative efficacy of combining imatinib agents with surgical procedures or administering imatinib alone.

Novel imatinib-loaded silver nanoparticles for enhanced apoptosis of human breast cancer MCF-7 cells

In the current study, in vitro biological feature of imatinib-loaded silver nanoparticles (IMAB-AgNPs) on human breast cancer cell line was investigated. The formation of synthesized silver nanoparticles (AgNPs) was characterized by UV-Visible spectroscopy, EDS, TEM imaging, SEM, FTIR, DLS and Zeta potentiometer. The developed IMAB-AgNPs with maximum percentage of loading efficiency was demonstrated in the average of 130 nm and mostly spherical. Additionally, in vitro drug release study showed a slow and continuous release of imatinib over a period of 80 h. We demonstrated that the synthesized IMAB-AgNPs exhibited a dose-dependent cytotoxicity against MCF-7 cell line. Then, real-time PCR method was also applied for the investigation of Bax and Bcl-2 gene expression in the cells. Comparing IMAB-AgNPs to AgNPs and Imatinib revealed the ability of IMAB-AgNPs to up-regulating Bax/Bcl-2 ratio. An induction of apoptosis was evidenced by Annexin-V/PI detection assay. Based on the current obtained data, the IMAB-AgNPs can exhibit inhibitory effect on viability through up regulation of apoptosis in MCF-7 cancer cells, which provides influencing evidence for the green synthesized AgNPs as a promising sustained drug delivery system.

A 2015 update on predictive molecular pathology and its role in targeted cancer therapy: a review focussing on clinical relevance

In April 2013 our group published a review on predictive molecular pathology in this journal. Although only 2 years have passed many new facts and stimulating developments have happened in diagnostic molecular pathology rendering it worthwhile to present an up-date on this topic. A major technical improvement is certainly given by the introduction of next-generation sequencing (NGS; amplicon, whole exome, whole genome) and its application to formalin-fixed paraffin-embedded (FFPE) tissue in routine diagnostics. Based on this 'revolution' the analyses of numerous genetic alterations in parallel has become a routine approach opening the chance to characterize patients' malignant tumors much more deeply without increasing turn-around time and costs. In the near future this will open new strategies to apply 'off-label' targeted therapies, e.g. for rare tumors, otherwise resistant tumors etc. The clinically relevant genetic aberrations described in this review include mutation analyses of RAS (KRAS and NRAS), BRAF and PI3K in colorectal cancer, KIT or PDGFR alpha as well as BRAF, NRAS and KIT in malignant melanoma. Moreover, we present several recent advances in the molecular characterization of malignant lymphoma. Beside the well-known mutations in NSCLC (EGFR, ALK) a number of chromosomal aberrations (KRAS, ROS1, MET) have become relevant. Only very recently has the clinical need for analysis of BRCA1/2 come up and proven as a true challenge for routine diagnostics because of the genes' special structure and hot-spot-free mutational distribution. The genetic alterations are discussed in connection with their increasingly important role in companion diagnostics to apply targeted drugs as efficient as possible. As another aspect of the increasing number of druggable mutations, we discuss the challenges personalized therapies pose for the design of clinical studies to prove optimal efficacy particularly with respect to combination therapies of multiple targeted drugs and conventional chemotherapy. Such combinations would lead to an extremely high complexity that would hardly be manageable by applying conventional study designs for approval, e.g. by the FDA or EMA. Up-coming challenges such as the application of methylation assays and proteomic analyses on FFPE tissue will also be discussed briefly to open the door towards the ultimate goal of reading a patients' tissue as 'deeply' as possible. Although it is yet to be shown, which levels of biological information are most informative for predictive pathology, an integrated molecular characterization of tumors will likely offer the most comprehensive view for individualized therapy approaches. To optimize cancer treatment we need to understand tumor biology in much more detail on morphological, genetic, proteomic as well as epigenetic grounds. Finally, the complex challenges on the level of drug design, molecular diagnostics, and clinical trials make necessary a close collaboration among academic institutions, regulatory authorities and pharmaceutical companies.

Mechanisms of resistance to BCR-ABL TKIs and the therapeutic strategies: A review

BCR-ABL caused by the translocation of t(9,22) with elevated tyrosine-kinase activity could induce leukemia in mice, which established BCR-ABL as the molecular pathogenic event in CML (Chronic myeloid leukemia). In recent years, a variety of tyrosine kinase inhibitors (TKIs) targeting at BCR-ABL specifically and effectively have been developed, which has fundamentally promoted the treatment of CML. However, the efficacy of TKIs was limited by its resistance induced by the development of kinase domain mutations and other mechanisms illustrated. In this review, we summarized BCR-ABL inhibitors approved by Food and Drug Administration (FAD), with the same concerns focus on the resistant mechanisms of BCR-ABL inhibitors and therapeutic resistant strategies.

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.