Levels of circulating tumor DNA correlate with tumor volume in gastro-intestinal stromal tumors: an exploratory long-term follow-up study

Patients with gastro-intestinal stromal tumors (GISTs) undergoing tyrosine kinase inhibitor therapy are monitored with regular computed tomography (CT) scans, exposing patients to cumulative radiation. This exploratory study aimed to evaluate circulating tumor DNA (ctDNA) testing to monitor treatment response and compare changes in ctDNA levels with RECIST 1.1 and total tumor volume measurements. Between 2014 and 2021, six patients with KIT proto-oncogene, receptor tyrosine kinase (KIT) exon-11-mutated GIST from whom long-term plasma samples were collected prospectively were included in the study. ctDNA levels of relevant plasma samples were determined using the KIT exon 11 digital droplet PCR drop-off assay. Tumor volume measurements were performed using a semi-automated approach. In total, 94 of 130 clinically relevant ctDNA samples were analyzed. Upon successful treatment response, ctDNA became undetectable in all patients. At progressive disease, ctDNA was detectable in five out of six patients. Higher levels of ctDNA correlated with larger tumor volumes. Undetectable ctDNA at the time of progressive disease on imaging was consistent with lower tumor volumes compared to those with detectable ctDNA. In summary, ctDNA levels seem to correlate with total tumor volume at the time of progressive disease. Our exploratory study shows promise for including ctDNA testing in treatment follow-up.

Financial difficulties experienced by patients with gastrointestinal stromal tumours (GIST) in the Netherlands: data from a cross-sectional multicentre study

PURPOSE

This study aims to (1) explore the prevalence of patient-reported financial difficulties among GIST patients, differentiating between those currently undergoing tyrosine kinase inhibitor (TKI) treatment and those who are not; (2) investigate associations between financial difficulties and sociodemographic and clinical characteristics, work, cancer-related concerns, anxiety and depression and (3) study the impact of financial difficulties on health-related quality of life.

METHODS

A cross-sectional study was conducted among Dutch GIST patients diagnosed between 2008 and 2018, who were invited to complete a one-time survey between September 2020 and June 2021. Patients completed nine items of the EORTC item bank regarding financial difficulties, seven work-related questions, the Hospital Anxiety and Depression Scale, Cancer Worry Scale and EORTC QLQ-C30.

RESULTS

In total, 328 GIST patients participated (response rate 63.0%), of which 110 (33.8%) were on TKI treatment. Patients currently treated with TKIs reported significantly more financial difficulties compared to patients not on TKIs (17.3% vs 8.7%, p = 0.03). The odds of experiencing financial difficulties was 18.9 (95% CI 1.7-214.7, p = 0.02) times higher in patients who were less able to work due to their GIST diagnosis. Patients who experienced financial difficulties had significantly lower global quality of life and functioning, and more frequently reported psychological symptoms as compared to patients who did not report financial difficulties.

CONCLUSION

Even in a country where the costs of TKIs and follow-up care are covered by health insurance, financial difficulties can be present in GIST patients, especially in patients on TKI treatment, and may negatively influence the quality of life.

Real-world data on the management of pazopanib-induced liver toxicity in routine care of renal cell cancer and soft tissue sarcoma patients

PURPOSE

Pazopanib is known to cause liver toxicity. A relationship between pazopanib exposure and alanine transaminase elevations has been described in clinical trials. This study investigated the relation between pazopanib exposure and liver toxicity in real-world patients and evaluated the management of pazopanib-induced liver toxicity in routine care.

METHODS

A retrospective observational cohort study was performed in patients treated with pazopanib in whom pazopanib exposure was measured. The percentage of patients with and without liver toxicity during treatment with pazopanib was calculated as well as the average pazopanib exposure in both groups. Furthermore, the management of patients with liver toxicity was evaluated.

RESULTS

Liver toxicity was observed in 25 out of the 133 patients included (19%). Pazopanib exposure was comparable in patients with or without liver toxicity (27.7 mg/L versus 28.1 mg/L). Seven patients permanently discontinued pazopanib after the occurrence of liver toxicity. Of the remaining 18 patients, continuation or restart of pazopanib after liver toxicity was successful in 16 patients and half of these patients were able to safely continue pazopanib at the same dose as prior to liver toxicity for the remaining duration of treatment.

CONCLUSION

Our study did not demonstrate a clear relationship between pazopanib exposure and the occurrence of pazopanib-induced liver toxicity. Half of the patients were able to safely continue or restart pazopanib treatment after liver toxicity and received the same dose as prior to drug withdrawal. Successful interventions to address pazopanib-induced toxicity in the clinic led to an algorithm for the management of pazopanib-induced liver toxicity.

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.

Individualized Dosing Patterns in the Treatment of Older Patients with Gastrointestinal Stromal Tumors: Results of a Registry-Based Observational National Cohort Study Including 871 Patients

BACKGROUND

While the effectiveness of tyrosine kinase inhibitors (TKIs) seems similar in older patients with gastrointestinal stromal tumors (GIST) compared with younger patients, toxicities in older patients treated with TKIs more often lead to discontinuation of treatment.

OBJECTIVE

To better understand the age-related pharmacology and pharmacodynamic differences in patients with GIST treated with TKIs, the primary aim of this study was to evaluate TKI dosing patterns in older patients with GIST, while the secondary aims were to evaluate differences in imatinib trough plasma concentrations between age groups and to compare the overall survival (OS) in patients with and without dose reductions in all treatment lines in a palliative setting.

METHODS

Patients (18 years of age or older) with histologically proven GIST diagnosed between January 2009 and June 2021 and treated with one or more lines of TKIs were selected from the Dutch GIST Registry (DGR) database. Age groups were divided into younger patients (age <70 years) and older patients (age ≥70 years). All imatinib trough plasma concentrations of blood withdrawals taken from initiation of imatinib until a maximum of 1 year of treatment with imatinib were collected. Reasons for first adjustment of treatment were classified as adverse event, dose modification, progressive disease and other reasons. The next treatment steps after first adjustment of treatment were defined as dose escalation, dose reduction, dose interruption, or end of treatment. The association of dose reduction and OS was analyzed using the landmark approach.

RESULTS

Overall, 871 patients were included in this study, including 577 younger patients and 294 older patients. Older patients more often had an adverse event as the reason for first adjustment of treatment with both imatinib (45.6%; p < 0.001) and sunitinib (58.6%; p = 0.224) compared with younger patients (19.5% and 42.7%, respectively). Adjustment of imatinib and sunitinib after starting on a standard dose because of an adverse event most often resulted in dose reduction in both age groups. Median trough plasma concentrations of all samples taken within the first year after initiation of imatinib were higher in older patients (1228 ng/mL, interquartile range [IQR] 959-1687) compared with younger patients (1035 ng/mL [IQR 773-1377]; p < 0.001). No significant differences were seen between OS in patients with or without dose reduction in all treatment lines (imatinib: p = 0.270; sunitinib: p = 0.547; and regorafenib: p = 0.784).

CONCLUSION

Older patients showed higher imatinib trough plasma concentrations compared with younger patients and also had earlier and more often adverse events as the reason for first adjustment of treatment with imatinib followed by dose reduction. However, in a landmark analysis, patients with imatinib dose reductions had no poorer outcomes compared with patients not requiring a dose reduction.

Results of the first international quality control programme for oral targeted oncolytics

AIMS

With the rising number of oral targeted oncolytics and growing awareness of the benefits of therapeutic drug monitoring (TDM) within the field of oncology, it is expected that the requests for quantifying concentrations of these drugs will increase. It is important to (cross-)validate available assays and ensure its quality, as results may lead to altered dosing recommendations. Therefore, we aimed to evaluate the performance of laboratories measuring concentrations of targeted oral oncolytics in a one-time international quality control (QC) programme.

METHODS

Participating laboratories received a set of plasma samples containing low, medium and high concentrations of imatinib, sunitinib, desethylsunitinib, pazopanib, cabozantinib, olaparib, enzalutamide, desmethylenzalutamide and abiraterone, with the request to report their results back within five weeks after shipment. Accuracy was defined acceptable if measurements where within 85%-115% from the weighed-in reference concentrations. Besides descriptive statistics, an exploratory ANOVA was performed.

RESULTS

Seventeen laboratories from six countries reported 243 results. Overall, 80.7% of all measurements were within the predefined range of acceptable accuracy. Laboratories performed best in quantifying imatinib and poorest in quantifying desethylsunitinib (median absolute inaccuracy respectively 4.0% (interquartile range (IQR) 1.8%-6.5%) and 15.5% (IQR 8.8%-34.9%)). The poorest performance of desethylsunitinib might be caused by using the stable-isotope-labelled sunitinib instead of desethylsunitinib as an internal standard, or due to the light-induced cis(Z)/trans(E) isomerization of (desethyl)sunitinib. Overall, drug substance and performing laboratory seemed to influence the absolute inaccuracy (F = 16.4; p < 0.001 and F = 35.5; p < 0.001, respectively).

CONCLUSION

Considering this is the first evaluation of an international QC programme for oral targeted oncolytics, an impressive high percentage of measurements were within the predefined range of accuracy. Cross-validation of assays that are used for dose optimization of oncolytics will secure the performance and will protect patients from incorrect advices.

Cost Savings and Waste Reduction Through Redispensing Unused Oral Anticancer Drugs: The ROAD Study

Importance

New strategies targeting waste are required to improve financial and ecologic sustainability of expensive therapies, such as oral anticancer drugs, that frequently remain unused by patients. Redispensing unused oral anticancer drugs seems to be a promising strategy when drug quality is guaranteed.

Objectives

To determine the waste reduction and net cost savings attained by redispensing oral anticancer drugs that go unused by patients compared with the standard practice of disposal.

Design, Settings, and Participants

The ROAD study was a prospective single-group intervention conducted in the outpatient pharmacies of 4 hospitals in the Netherlands from February 1, 2021, to February 1, 2023, with 12-month follow-up of each patient. Patients with cancer and who had a prescription for an oral anticancer drug that could be stored at room temperature were included. Of 2426 eligible patients, 602 did not consent and 601 did not respond. Data analyses were performed from August 25, 2022, to April 19, 2023.

Intervention

Participants received oral anticancer drugs for use at home in special packaging (ie, sealed packaging with time-temperature indicator), to be returned to the pharmacy should these remain unused. The pharmacy ensured quality of returned drugs based on authenticity, appearance, remaining shelf life and adequate storage temperature. Drugs fulfilling quality requirements were redispensed to other patients.

Main Outcome and Measure

Total waste reduction and mean net annual cost savings per patient compared with the standard practice of disposal. Optimization of cost savings was explored by introducing variations in the quality assurance procedure and patient population. All analyses used the average exchange rate for 2021 €1 = US $1.18.

Results

Of 1223 patients with cancer who consented, 1071 participated (median [IQR] age, 70 [62-75] years; 622 [58.1%] were male). In all, 171 patients (16.0%; 95% CI, 13.8%-18.3%) returned 335 unused oral anticancer drug packages. Of the returned drugs, 228 packages were redispensed, which reduced waste by 68.1% (95% CI, 67.7%-68.5%) compared with the standard practice (disposal). Redispensing unused oral anticancer drugs comprised 2.4% (95% CI, 2.2%-2.5%) of total drug costs, providing mean net annual cost savings of US $680 (95% CI, $524-$837) up to $1591 (95% CI, $1226-$2002) per participant.

Conclusions and Relevance

The findings of this multicenter intervention study indicate that redispensing unused oral anticancer drugs is associated with waste reduction and cost savings, which in turn may improve the affordability and sustainability of cancer treatment.

Trial Registration

World Health Organization International Clinical Trials Registry Platform Identifier: NL9208.

Effect of Aprepitant on Etoposide Pharmacokinetics in Patients with Testicular Cancer: A Pharmacokinetic Study to Determine the Absence of a Clinically Relevant Interaction

All patients treated with anticancer agents should receive the most effective anti-emetic regimen. Anti-emetic guidelines provide recommendations but do not take into account possible drug-drug interactions between anti-emetics and anticancer drugs. This study determines the clinical relevance of the potential drug-drug interaction of the neurokinin-1 receptor antagonist, aprepitant, on the pharmacokinetics of etoposide. Aprepitant is a moderate CYP3A4 inhibitor and may increase the systemic exposure of etoposide which is partly metabolized by cytochrome P450 enzyme 3A4 (CYP3A4). In this prospective observational study, the pharmacokinetics of etoposide with and without concomitant use of aprepitant was determined in 12 patients receiving first-line chemotherapy for testicular cancer. The geometric mean (95% confidence interval (CI)) area under the plasma concentration-time curve 0-24 hour (AUC0-24h ) of etoposide with aprepitant was 86.2 (79.7-93.2) mg/L*hour vs. 83.7 (75.8-92.4) mg/L*hour without aprepitant. Geometric mean ratios (90% CIs) of AUC0-24h and maximum plasma concentration (Cmax ) for etoposide with and without aprepitant were 1.03 (0.96-1.10) and 0.96 (0.89-1.03), respectively. This study confirms the absence of a clinically relevant interaction between etoposide and aprepitant. Both drugs can be safely combined without affecting etoposide exposure.

The association of having a monitoring or blunting coping style with psychological distress, health-related quality of life and satisfaction with healthcare in gastrointestinal stromal tumour (GIST) patients

BACKGROUND

There are two main coping styles regarding information seeking under medical threat; monitoring (information-seeking) and blunting (information-avoiding). The aim of this study is to (1) determine factors associated with a monitoring or blunting coping style in gastro-intestinal stromal tumour (GIST) patients and (2) investigate its association with psychological distress, cancer-related concerns, health-related quality of life and satisfaction with healthcare.

METHODS

In a cross-sectional study, Dutch GIST patients completed the shortened version of the Threatening Medical Situations Inventory to determine their coping style, the Hospital Anxiety and Depression Scale, Cancer Worry Scale, EORTC QLQ-C30 and part of the EORTC QLQ-INFO25.

RESULTS

A total of 307 patients were classified as blunters (n = 175, 57%) or monitors (n = 132, 43%). Coping style was not associated with tumour or treatment variables, but being a female (OR 2.5; 95%CI 1.5-4.1; p= <.001) and higher educated (OR 5.5; 95%CI 2.5-11.9, p= <.001) were associated with higher odds of being a monitor. Monitors scored significantly lower on emotional functioning (mean = 86.8 vs mean = 90.9, p=.044), which is considered a trivial difference, more often experienced severe fear of cancer recurrence or progression (53.0% vs 37.7%, p=.007), and had more concerns about dying from GIST in the future (60.6% vs 47.4%, p=.025). Compared to blunters, monitors were less satisfied with the received healthcare and information, and would have liked to receive more information.

CONCLUSION

GIST patients with a monitoring coping style experience a higher emotional burden. Additionally, monitors exhibit a greater need for information. Although this need for information could potentially result in fears and concerns, recognising it may also create an opening for tailored communication and information.

Therapeutic drug monitoring to personalize dosing of imatinib, sunitinib, and pazopanib: A mixed methods study on barriers and facilitators

BACKGROUND

Personalized dosing based on measurement of individual drug levels and adjusting the dose accordingly can improve efficacy and decrease unnecessary toxicity of oncological treatment. For imatinib, sunitinib, and pazopanib, this therapeutic drug monitoring (TDM)-guided dosing is, however, not routinely used, despite accumulating evidence favoring individualized dosing. Therefore, we aimed to identify and quantify (potential) barriers and facilitators in TDM-guided dosing for imatinib, sunitinib, and pazopanib.

METHODS

We performed a mixed methods study among all stakeholders involved: patients, healthcare professionals (HCPs), pharmaceutical companies, and health insurance companies. During the first qualitative part of this study, we performed semi-structured individual interviews and one focus group interview to identify all (potential) barriers and facilitators, and during the second quantitative part of this study, we used a web-based survey to quantify these findings. The interviews addressed the six domains of the implementation of change model of Grol and Wensing: (1) the innovation itself; (2) the HCP; (3) the patient; (4) social context; (5) organizational context; and (6) finances, law, and governance.

RESULTS

In the qualitative study, we interviewed 20 patients, 18 HCPs and 10 representatives of pharmaceutical and health insurance companies and identified 72 barriers and 90 facilitators. In the quantitative study, the survey was responded by 66 HCPs and 58 patients. Important barriers were on the domain of the HCP, such as a lack of experience with TDM (36.4%), on the domain of the patient, such as lack of awareness of TDM (39.7%), and the processing time for measurement and interpretation of the TDM result (40.9%) (organizational domain). Important facilitators were education of HCPs (95.5%), education of patients (87.9%) and facilitating an overview of when and where TDM measurements are being performed (86.4%).

CONCLUSION

We identified and quantified important barriers and facilitators for the implementation of TDM-guided dosing for imatinib, sunitinib, and pazopanib. Based on our results, the implementation strategy should mainly focus on educating both HCPs and patients and on the organizational aspect of TDM.

Personalized Therapy of Sarcomas

Sarcomas are a group of rare malignant mesenchymal tumors [...].

Local treatment in metastatic GIST patients: A multicentre analysis from the Dutch GIST Registry

BACKGROUND

The added value of local treatment in selected metastatic GIST patients is unclear. This study aims to provide insight into the usefulness of local treatment in metastatic GIST by use of a survey study and retrospective analyses in a clinical database.

METHODS

A survey study was conducted among clinical specialists to select most relevant characteristics of metastatic GIST patients considered for local treatment, defined as elective surgery or ablation. Patients were selected from the Dutch GIST Registry. A multivariate Cox-regression model for overall survival since time of diagnosis of metastatic disease was estimated with local treatment as a time-dependent variable. An additional model was estimated to assess prognostic factors since local treatment.

RESULTS

The survey's response rate was 14/16. Performance status, response to TKIs, location of active disease, number of lesions, mutation status, and time between primary diagnosis and metastases, were regarded the 6 most important characteristics. Of 457 included patients, 123 underwent local treatment, which was associated with better survival after diagnosis of metastases (HR = 0.558, 95%CI = 0.336-0.928). Progressive disease during systemic treatment (HR = 3.885, 95%CI = 1.195-12.627) and disease confined to the liver (HR = 0.269, 95%CI = 0.082-0.880) were associated with worse and better survival after local treatment, respectively.

CONCLUSION

Local treatment is associated with better survival in selected patients with metastatic GIST. Locally treated patients with response to TKIs and disease confined to the liver have good clinical outcome. These results might be considered for tailoring treatment, but should be interpreted with care because only specific patients are provided with local treatment in this retrospective study.

Prognostic Factors in Epithelioid Hemangioendothelioma: Analysis of a Nationwide Molecularly/Immunohistochemically Confirmed Cohort of 57 Cases

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular sarcoma with variable aggressive clinical behavior. In this retrospective study, we aimed to investigate prognostic factors based on clinicopathologic findings in a molecularly/immunohistochemically confirmed nationwide multicenter cohort of 57 EHE cases. Patients had unifocal disease (n = 29), multifocal disease (n = 5), lymph node metastasis (n = 8) and/or distant metastasis (n = 15) at the time of diagnosis. The overall survival rate was 71.4% at 1 year and 50.7% at 5 years. Survival did not correlate with sex, age or histopathological parameters. No survival differences were observed between multifocal and metastatic disease, suggesting that multifocality represents early metastases and treatment options are limited in comparison to unifocal disease. In unifocal tumors, survival could be predicted using the risk stratification model of Shibayama et al., dividing the cases into low- (n = 4), intermediate- (n = 15) and high- (n = 3) risk groups. No clinical or histopathological parameters were associated with progressive unifocal disease course. Lymph node metastases at the time of diagnosis occurred in 14.0% of the cases and were mainly associated with tumor localization in the head and neck area, proposing lymph node dissection. In conclusion, our results demonstrate the aggressive behavior of EHE, emphasize the prognostic value of a previously described risk stratification model and may provide new insights regarding tumor focality, therapeutic strategies and prognosis.

Measuring Tumour Imatinib Concentrations in Gastrointestinal Stromal Tumours: Relevant or Redundant?

Imatinib plasma trough concentrations are associated with efficacy for patients treated for advanced or metastatic KIT-positive gastrointestinal stromal tumours (GISTs). This relationship has not been studied for patients treated in the neoadjuvant setting, let alone its correlation with tumour drug concentrations. In this exploratory study we aimed to determine the correlation between plasma and tumour imatinib concentrations in the neoadjuvant setting, investigate tumour imatinib distribution patterns within GISTs, and analyse its correlation with pathological response. Imatinib concentrations were measured in both plasma and in three regions of the resected primary tumour: the core, middle part, and periphery. Twenty-four tumour samples derived from the primary tumours of eight patients were included in the analyses. Imatinib tumour concentrations were higher compared to plasma concentrations. No correlation was observed between plasma and tumour concentrations. Interpatient variability in tumour concentrations was high compared to interindividual variability in plasma concentrations. Although imatinib accumulates in tumour tissue, no distribution pattern of imatinib in tumour tissue could be identified. There was no correlation between imatinib concentrations in tumour tissue and pathological treatment response.

The Prognostic Relevance of MRI Characteristics in Myxofibrosarcoma Patients Treated with Neoadjuvant Radiotherapy

To improve local control, neoadjuvant radiotherapy (nRT) followed by surgery is the standard of care in myxofibrosarcoma (MFS) because of its infiltrative growth pattern. Nevertheless, local recurrence rates are high. Data on prognostic factors for poor clinical outcomes are lacking. This retrospective study thus investigates the prognostic relevance of magnetic resonance imaging (MRI) characteristics before and after nRT in 40 MFS patients, as well as their association with disease-free survival (DFS) and overall survival (OS). A vascular pedicle, defined as extra-tumoral vessels at the tumor periphery, was observed in 12 patients (30.0%) pre-nRT and remained present post-nRT in all cases. Patients with a vascular pedicle had worse DFS (HR 5.85; 95% CI 1.56-21.90; p = 0.009) and OS (HR 9.58; 95% CI 1.91-48.00; p = 0.006). An infiltrative growth pattern, referred to as a tail sign, was observed in 22 patients (55.0%) pre-nRT and in 19 patients (47.5%) post-nRT, and was associated with worse DFS post-nRT (HR 6.99; 95% CI 1.39-35.35; p = 0.019). The percentage of tumor necrosis estimated by MRI was increased post-nRT, but was not associated with survival outcomes. The presence of a tail sign or vascular pedicle on MRI could support the identification of patients at risk for poor clinical outcomes after nRT.

Pros and cons of streamlining and use of computerised clinical decision support systems to future-proof oncological multidisciplinary team meetings

Introduction

Nowadays nearly every patient with cancer is discussed in a multidisciplinary team meeting (MDTM) to determine an optimal treatment plan. The growth in the number of patients to be discussed is unsustainable. Streamlining and use of computerised clinical decision support systems (CCDSSs) are two major ways to restructure MDTMs. Streamlining is the process of selecting the patients who need to be discussed and in which type of MDTM. Using CCDSSs, patient data is automatically loaded into the minutes and a guideline-based treatment proposal is generated. We aimed to identify the pros and cons of streamlining and CCDSSs.

Methods

Semi-structured interviews were conducted with Dutch MDTM participants. With purposive sampling we maximised variation in participants' characteristics. Interview data were thematically analysed.

Results

Thirty-five interviews were analysed. All interviewees agreed on the need to change the current MDTM workflow. Streamlining suggestions were thematised based on standard and complex cases and the location of the MDTM (i.e. local, regional or nationwide). Interviewees suggested easing the pressure on MDTMs by discussing standard cases briefly, not at all, or outside the MDTM with only two to three specialists. Complex cases should be discussed in tumour-type-specific regional MDTMs and highly complex cases by regional/nationwide expert teams. Categorizing patients as standard or complex was found to be the greatest challenge of streamlining. CCDSSs were recognised as promising, although none of the interviewees had made use of them. The assumed advantage was their capacity to generate protocolised treatment proposals based on automatically uploaded patient data, to unify treatment proposals and to facilitate research. However, they were thought to limit the freedom to deviate from the treatment advice.

Conclusion

To make oncological MDTMs sustainable, methods of streamlining should be developed and introduced. Physicians still have doubts about the value of CCDSSs.

Improved Efficacy of First-Line Imatinib in Advanced Gastrointestinal Stromal Tumors (GIST): The Dutch GIST Registry Data

BACKGROUND

Patients with unresectable and metastasized gastrointestinal stromal tumor (GIST) experienced a remarkable improvement of progression-free survival (PFS) and overall survival (OS) after the introduction of imatinib. Our hypothesis is that the outcomes of treatment with imatinib are even better nowadays compared with the registration trials that were performed two decades ago. To study this, we used real-life data from a contemporary registry.

METHODS

A multicenter, retrospective study was performed by exploring clinical data from a prospective real-life clinical database, the Dutch GIST Registry (DGR). Patients with advanced GIST treated with first-line imatinib were included and PFS (primary outcome) and OS (secondary outcome) were analyzed. Results of our study were compared with published results of the European Organisation for Research and Treatment of Cancer (EORTC) 62005 trial, which marked the first era of imatinib in the treatment of GIST.

RESULTS

Overall, 420 of the 435 patients treated with imatinib in the DGR had recorded response evaluation and were included in the analysis. During a median follow-up of 35.0 months (range 2.0-136.0), progression of GIST was eventually observed in 217 patients (51.2%). The DGR cohort showed a longer median PFS (33.0 months, 95% confidence interval [CI] 28.4-37.6) compared with the EORTC 62005 trial (an estimated PFS of 19.5 months). Additionally, the median OS of 68.0 months (95% CI 56.1-80.0) was longer than the exposed median OS (46.8 months) published in the long-term follow-up results of the EORTC 62005 trial (median follow-up duration 10.9 years).

CONCLUSION

This study provides an update on outcomes of imatinib in the treatment of advanced GIST patients and demonstrates improved clinical outcomes since the first randomized studies of imatinib 2 decades ago. Furthermore, these results represent outcomes in real-world clinical practice and can serve as a reference when evaluating effectiveness of imatinib in patients with advanced GIST.

The safety risk of information overload and bureaucracy in oncology clinical trial conduct

Performance of clinical trials has led to major therapeutic developments and substantial improvements in the field of medical oncology. To ensure patient's safety, regulatory aspects for proper clinical trial conduct have been increased over the past two decades but seem to cause information overload and ineffective bureaucracy, possibly even impacting patient safety. To put this in perspective, after the implementation of Directive 2001/20/EC in the European Union, a 90 per cent increase in trial launching time, a 25 per cent decrease in patient participation and a 98 per cent rise in administrative trial costs were reported. The time to initiate a clinical trial has increased from a few months to several years in the past three decades. Moreover, there is a serious risk that information overload with relatively unimportant data endangers the decision-making processes and distracts from essential patient safety information. It is now a critical moment in time to improve efficient clinical trial conduct for our future patients diagnosed with cancer. We are convinced that a reduction of the administrative regulations, information overload, and simplification of the procedures for trial conductance may improve patient safety. In this Current Perspective, we give insight in the current regulatory aspects of clinical research, evaluate the practical consequences of these regulations, and propose specific improvements for optimal clinical trial conduct.

Facilitators and barriers to conducting an efficient, competent and high-quality oncological multidisciplinary team meeting

BACKGROUND

Optimal oncological care nowadays requires discussing every patient in a multidisciplinary team meeting (MDTM). The number of patients to be discussed is rising rapidly due to the increasing incidence and prevalence of cancer and the emergence of new multidisciplinary treatment options. This puts MDTMs under considerable time pressure. The aim of this study is therefore to identify the facilitators and barriers with regard to performing an efficient, competent and high-quality MDTM.

METHODS

Semistructured interviews were conducted with Dutch medical specialists and residents participating in oncological MDTMs. Purposive sampling was used to maximise variation in participants' professional and demographic characteristics (eg, sex, medical specialist vs resident, specialty, type and location of affiliated hospital). Interview data were systematically analysed according to the principles of thematic content analysis.

RESULTS

Sixteen medical specialists and 19 residents were interviewed. All interviewees agreed that attending and preparing MDTMs is time-consuming and indicated the need for optimal execution in order to ensure that MDTMs remain feasible in the near future. Four themes emerged that are relevant to achieving an optimal MDTM: (1) organisational aspects; (2) participants' responsibilities and requirements; (3) competences, behaviour and team dynamics and (4) meeting content. Good organisation, a sound structure and functioning information and communication technology facilitate high-quality MDTMs. Multidisciplinary collaboration and adequate communication are essential competences for participants; a lack thereof and the existence of a hierarchy are hindering factors.

CONCLUSION

Conducting an efficient, competent and high-quality oncological MDTM is facilitated and hindered by many factors. Being aware of these factors provides opportunities for optimising MDTMs, which are under pressure due to the increase in the number of patients to discuss.

The influence of multidisciplinary team meetings on treatment decisions in advanced bladder cancer

OBJECTIVES

To investigate the role of specialised genitourinary multidisciplinary team meetings (MDTMs) in decision-making and identify factors that influence the probability of receiving a treatment plan with curative intent for patients with muscle invasive bladder cancer (MIBC).

PATIENTS AND METHODS

Data relating to patients with cT2-4aN0/X-1 M0 urothelial cell carcinoma, diagnosed between November 2017 and October 2019, were selected from the nationwide, population-based Netherlands Cancer Registry ('BlaZIB study'). Curative treatment options were defined as radical cystectomy (RC) with or without neoadjuvant chemotherapy, chemoradiation or brachytherapy. Multilevel logistic regression analyses were used to examine the association between MDTM factors and curative treatment advice and how this advice was followed.

RESULTS

Of the 2321 patients, 2048 (88.2%) were discussed in a genitourinary MDTM. Advanced age (>80 years) and poorer World Health Organization performance status (score 1-2 vs 0) were associated with no discussion (P < 0.001). Being discussed was associated with undergoing treatment with curative intent (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.9-4.9), as was the involvement of a RC hospital (OR 1.70, 95% CI 1.09-2.65). Involvement of an academic centre was associated with higher rates of bladder-sparing treatment (OR 2.05, 95% CI 1.31-3.21). Patient preference was the main reason for non-adherence to treatment advice.

CONCLUSIONS

For patients with MIBC, the probability of being discussed in a MDTM was associated with age, performance status and receiving treatment with curative intent, especially if a representative of a RC hospital was present. Future studies should focus on the impact of MDTM advice on survival data.

Controversies in the management of patients with soft tissue sarcoma: Recommendations of the Conference on State of Science in Sarcoma 2022

BACKGROUND

Owing to the rarity and heterogeneity in biology and presentation, there are multiple areas in the diagnosis, treatment and follow-up of soft tissue sarcoma (STS), with no, low-level or conflicting evidence.

METHODS

During the first Consensus Conference on the State of Science in Sarcoma (CSSS), we used a modified Delphi process to identify areas of controversy in the field of sarcoma, to name topics with limited evidence-based data in which a scientific and knowledge gap may remain and a consensus statement will help to guide patient management. We determined scientific questions which need to be addressed in the future in order to generate evidence and to inform physicians and caregivers in daily clinical practice in order to improve the outcomes of patients with sarcoma. We conducted a vote on STS key questions and controversies prior to the CSSS meeting, which took place in May 2022.

RESULTS

Sixty-two European sarcoma experts participated in the survey. Sixteen strong consensus (≥95%) items were identified by the experts, as well as 30 items with a ≥75% consensus on diagnostic and therapeutic questions. Ultimately, many controversy topics remained without consensus.

CONCLUSIONS

In this manuscript, we summarise the voting results and the discussion during the CSSS meeting. Future scientific questions, priorities for clinical trials, registries, quality assurance, and action by stakeholders are proposed. Platforms and partnerships can support innovative approaches to improve management and clinical research in STS.

Feasibility of an Individualized Dispensing Program for Patients Prescribed Oral Anticancer Drugs to Prevent Waste

PURPOSE

Waste of oral anticancer drugs (OACDs) causes financial and environmental burdens. This study evaluates the feasibility of an individualized dispensing program to prevent waste of OACDs.

METHODS

Adult patients were dispensed individualized quantities of niraparib, abiraterone, enzalutamide, ruxolitinib, osimertinib, or imatinib as standard care, during the first 6 months of treatment. The first 50 patients participated in an feasibility evaluation conform five domains of Bowen's Framework. (1) implementation: reach (eligible patients included) and protocol fidelity (executions following protocol) assessed from pharmacy data, (2) acceptability: rated from 1 to 10 and agreement with theoretical framework acceptability domains via a survey among patients and pharmacy technicians, (3) practicality: program's costs, (4) effect: compared with previous practice (full package supply per month), defined as difference in unused OACD unit doses and net cost-savings, and (5) demand: potential scale-up of the program by including more OACDs.

RESULTS

Participants' median age was 67 (interquartile range [IQR], 58-71) years, and 76% was male. (1) Implementation: reach and protocol fidelity were 89% and 90%, respectively. (2) Acceptability was high among patients (median, 9; IQR, 8-9) and pharmacy technicians (median, 7; IQR, 6-8). All acceptability domains were agreed on. (3) Practicality: program costs were €4,289. (4) Effect: unused OACD unit doses were reduced by 34%, causing net cost-savings of €693 per discontinued patient. (5) Demand: the program could be scaled up to seven times by including all OACDs.

CONCLUSION

Individualized dispensing for patients prescribed OACDs is feasible for preventing waste in terms of implementation, acceptability, practicality, effect, and demand.

Sex differences in patients with gastrointestinal stromal tumours: do they exist and does it affect survival?

BACKGROUND

Sex differences in cancer have gained attention in recent years. The role of sex as a prognostic factor in gastrointestinal stromal tumours (GIST) has not been well established. The aim of this research was to elucidate potential sex differences in GIST patients and the influence of sex on disease-specific survival (DSS).

METHODS

A review of the literature was carried out to obtain an overview of all literature with sex as a covariate on GIST survival analyses. Furthermore, in the Dutch GIST Registry, GIST characteristics between males and females were compared and the influence of sex on DSS was analysed.

RESULTS

A total of 118 articles from the review of the literature met our selection criteria; 58% of the articles found no sex difference in survival and 42% did find a sex difference. All differences favoured female patients, although there was substantial overlap of individual patients in the various reported groups. The Dutch GIST Registry cohort consisted of 1425 patients (46% female). Compared with female patients, male patients had larger tumours (mean 9.0 cm versus 7.9 cm) and higher mitotic rates (34.4% versus 28.0% >5 mitoses/5 mm²). GIST in males was more often metastasized at diagnosis (21.3% versus 13.7%) and incurable (38.5% versus 31.0%). Male patients less often received surgery of the primary tumour (71.7% versus 78.9%), but did experience more tumour ruptures (18.2% versus 13.3%). Male patients had a worse DSS than females. This was not statistically significant when corrected for differences in GIST characteristics.

CONCLUSIONS

In case of sex differences in GIST in the literature, male patients have a worse outcome. In our Dutch GIST cohort a similar finding was made, but sex was shown not to be an independent factor. Male patients more often had aggressive GISTs, with larger tumours, higher mitotic rates, more tumour ruptures, and metastases, which could explain the sex differences in DSS.

Therapeutic drug monitoring-based precision dosing of oral targeted therapies in oncology: a prospective multicenter study

BACKGROUND

Oral targeted therapies show a high pharmacokinetic (PK) interpatient variability. Even though exposure has been positively correlated with efficacy for many of these drugs, these are still dosed using a one-size-fits-all approach. Consequently, individuals have a high probability to be either underexposed or overexposed, potentially leading to suboptimal outcomes. Therapeutic drug monitoring, which is personalized dosing based on measured systemic drug concentrations, could address these problems.

PATIENTS AND METHODS

Patients were enrolled in this prospective multicenter study (www.trialregister.nl; NL6695) if they started treatment with one of the 24 participating oral targeted therapies. Primary outcome was to halve the proportion of underexposed patients, compared with historical data. PK sampling was carried out after 4, 8 and 12 weeks, and every 12 weeks thereafter. In case of Cmin below the predefined target and manageable toxicity, a pharmacokinetically guided intervention was proposed (i.e. checking compliance and drug-drug interactions, concomitant intake with food, splitting intake moments or dose increments).

RESULTS

In total, 600 patients were included of whom 426 patients are assessable for the primary outcome and 552 patients had ≥1 PK sample(s) available and were therefore assessable for the overall analyses. Pharmacokinetically guided dosing reduced the proportion of underexposed patients at the third PK measurement by 39.0% (95% confidence interval 28.0% to 49.0%) compared with historical data. At the third PK measurement, 110 out of 426 patients (25.8%) had a low exposure. In total, 294 patients (53.3%) had ≥1 PK sample(s) below the preset target at a certain time point during treatment. In 166 of these patients (56.5%), pharmacokinetically guided interventions were carried out, which were successful in 113 out of 152 assessable patients (74.3%).

CONCLUSIONS

Pharmacokinetically guided dose optimization of oral targeted therapies was feasible in clinical practice and reduced the proportion of underexposed patients considerably.

Activity of Cabazitaxel in Metastatic or Inoperable Locally Advanced Dedifferentiated Liposarcoma: A Phase 2 Study of the EORTC Soft Tissue and Bone Sarcoma Group (STBSG)

Importance

Treatment options for patients with unresectable and/or metastatic dedifferentiated liposarcoma (DDLPS) are limited. New drugs are required.

Objective

To assess whether cabazitaxel demonstrated sufficient antitumor activity in patients with metastatic or inoperable locally advanced DDLPS to justify further investigation in a phase 3 setting.

Design, Setting, and Participants

This international multicenter, open-label single-arm phase 2 trial was conducted at 10 institutions in 4 European countries from March 2015 to March 2019. Eligible patients had to have metastatic or locally advanced histologically proven DDLPS with evidence of disease progression within the past 6 months and had to have received no more than 1 previous line of chemotherapy.

Interventions

After mandatory central review of tumor blocks, if the DDLPS diagnosis was confirmed, patients started treatment within 72 hours after registration. Cabazitaxel was administered at a dose of 25 mg/m2 IV infusion over 1 hour every 21 days until intolerance, progression, or withdrawal of consent.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS) rate at 12 weeks per RECIST 1.1. Based on a Simon 2-stage design, at least 4 of 17 (stage 1) and 11 of 37 (stage 2) eligible and evaluable patients who were progression free at 12 weeks were needed. The final analysis report was completed on November 17, 2021.

Results

Forty patients were registered, with 2 patients being ineligible. The number of cycles ranged from 1 to 30, with a median of 5; 26 patients (65%) received at least 4 cycles of cabazitaxel. Progression-free survival at 12 weeks was 55%, achieving the primary study end point. At a median follow-up of 21.6 months, median PFS was 6 months and median OS 21 months. Response rate (RR) was 8% with 1 clinical response (CR) and 2 partial responses (PR). Twenty-three (60.5%) patients had a stable disease (SD). Disease control (PR+SD) was achieved in 26 patients (68%).

Conclusions and Relevance

This nonrandomized phase 2 clinical trial met its primary end point, with 21 of 38 patients (55%) being progression free at 12 weeks. These results suggest important activity of cabazitaxel in patients with metastatic or inoperable locally advanced DDLPS. The drug is worth being further studied in these tumors in a phase 3 setting.

Feasibility of therapeutic drug monitoring of sorafenib in patients with liver or thyroid cancer

INTRODUCTION

Sorafenib is a tyrosine-kinase inhibitor approved for the treatment of renal cell carcinoma, hepatocellular carcinoma, thyroid carcinoma, and desmoid fibromatosis. As high inter-individual variability exists in exposure, there is a scientific rationale to pursue therapeutic drug monitoring (TDM). We investigated the feasibility of TDM in patients on sorafenib and tried to identify sub-groups in whom pharmacokinetically (PK) guided-dosing might be of added value.

METHODS

We included patients who started on sorafenib (between October 2017 and June 2020) at the recommended dose of 400 mg BID or with a step-up dosing schedule. Plasma trough levels (C_trough) were measured at pre-specified time-points. Increasing the dose was advised if C_trough was below the target of 3750 ng/mL and toxicity was manageable.

RESULTS

A total of 150 samples from 36 patients were collected. Thirty patients (83 %) had a C_trough below the prespecified target concentration at a certain time point during treatment. Toxicity from sorafenib hampered dosing according to target C_trough in almost half of the patients. In 11 patients, dosing was adjusted based on C_trough. In three patients, this resulted in an adequate C_trough without additional toxicity four weeks after the dose increase. In the remaining eight patients, dose adjustment based on C_trough did not result in a C_trough above the target or caused excessive toxicity.

CONCLUSIONS

TDM for sorafenib is not of added value in daily clinical practice. In most cases, toxicity restricts the possibility of dose escalations.

Preparing tomorrow's medical specialists for participating in oncological multidisciplinary team meetings: perceived barriers, facilitators and training needs

INTRODUCTION

The optimal treatment plan for patients with cancer is discussed in multidisciplinary team meetings (MDTMs). Effective meetings require all participants to have collaboration and communication competences. Participating residents (defined as qualified doctors in training to become a specialist) are expected to develop these competences by observing their supervisors. However, the current generation of medical specialists is not trained to work in multidisciplinary teams; currently, training mainly focuses on medical competences. This study aims to identify barriers and facilitators among residents with respect to learning how to participate competently in MDTMs, and to identify additional training needs regarding their future role in MDTMs, as perceived by residents and specialists.

METHODS

Semi-structured interviews were conducted with Dutch residents and medical specialists participating in oncological MDTMs. Purposive sampling was used to maximise variation in participants' demographic and professional characteristics (e.g. sex, specialty, training duration, type and location of affiliated hospital). Interview data were systematically analysed according to the principles of thematic content analysis.

RESULTS

Nineteen residents and 16 specialists were interviewed. Three themes emerged: 1) awareness of the educational function of MDTMs among specialists and residents; 2) characteristics of MDTMs (e.g. time constraints, MDTM regulations) and 3) team dynamics and behaviour. Learning to participate in MDTMs is facilitated by: specialists and residents acknowledging the educational function of MDTMs beyond their medical content, and supervisors fulfilling their teaching role and setting conditions that enable residents to take a participative role (e.g. being well prepared, sitting in the inner circle, having assigned responsibilities). Barriers to residents' MDTM participation were insufficient guidance by their supervisors, time constraints, regulations hindering their active participation, a hierarchical structure of relations, unfamiliarity with the team and personal characteristics of residents (e.g. lack of confidence and shyness). Interviewees indicated a need for additional training (e.g. simulations) for residents, especially to enhance behavioural and communication skills.

CONCLUSION

Current practice with regard to preparing residents for their future role in MDTMs is hampered by a variety of factors. Most importantly, more awareness of the educational purposes of MDTMs among both residents and medical specialists would allow residents to participate in and learn from oncological MDTMs. Future studies should focus on collaboration competences.

Factors influencing the quality and functioning of oncological multidisciplinary team meetings: results of a systematic review

Background

Discussing patients with cancer in a multidisciplinary team meeting (MDTM) is customary in cancer care worldwide and requires a significant investment in terms of funding and time. Efficient collaboration and communication between healthcare providers in all the specialisms involved is therefore crucial. However, evidence-based criteria that can guarantee high-quality functioning on the part of MDTMs are lacking. In this systematic review, we examine the factors influencing the MDTMs’ efficiency, functioning and quality, and offer recommendations for improvement.

Methods

Relevant studies were identified by searching Medline, EMBASE, and PsycINFO databases (01–01-1990 to 09–11-2021), using different descriptions of ‘MDTM’ and ‘neoplasm’ as search terms. Inclusion criteria were: quality of MDTM, functioning of MDTM, framework and execution of MDTM, decision-making process, education, patient advocacy, patient involvement and evaluation tools. Full text assessment was performed by two individual authors and checked by a third author.

Results

Seventy-four articles met the inclusion criteria and five themes were identified: 1) MDTM characteristics and logistics, 2) team culture, 3) decision making, 4) education, and 5) evaluation and data collection. The quality of MDTMs improves when the meeting is scheduled, structured, prepared and attended by all core members, guided by a qualified chairperson and supported by an administrator. An appropriate amount of time per case needs to be established and streamlining of cases (i.e. discussing a predefined selection of cases rather than discussing every case) might be a way to achieve this. Patient centeredness contributes to correct diagnosis and decision making. While physicians are cautious about patients participating in their own MDTM, the majority of patients report feeling better informed without experiencing increased anxiety. Attendance at MDTMs results in closer working relationships between physicians and provides some medico-legal protection. To ensure well-functioning MDTMs in the future, junior physicians should play a prominent role in the decision-making process. Several evaluation tools have been developed to assess the functioning of MDTMs.

Conclusions

MDTMs would benefit from a more structured meeting, attendance of core members and especially the attending physician, streamlining of cases and structured evaluation. Patient centeredness, personal competences of MDTM participants and education are not given sufficient attention.

Supplementary information

The online version contains supplementary material available at 10.1186/s12913-022-08112-0.

'I thought I had fibroids, and now I don't': a mixed method study on health-related quality of life in uterine sarcoma patients

Background

Uterine sarcomas are rare subtypes of primary urogenital tumours and need tailored treatment. This study aimed to examine the impact of diagnosis and treatment on health-related quality of life (HRQoL) in patients with uterine sarcoma and measures available to assess HRQoL in this group.

Methods

Thirteen patients with uterine sarcoma and 23 health care professionals were purposively sampled from sarcoma reference centers and participated in a semi-structured interview exploring HRQoL. Patients were also asked to review the EORTC QLQ-C30 and EORTC QLQ-EN24 for relevance. Data were analysed using thematic analysis and descriptive statistics.

Results

The most commonly reported physical health issues were related to sexual dysfunction and urological symptoms. Hormone-related issues and gastrointestinal symptoms were also identified. Cancer-generic issues such as functional problems, fatigue, pain, and treatment-related adverse effects were also reported. Regarding mental health, fears (about having sex, of recurrence, or of death), altered body-image, and dealing with lacking knowledge regarding sarcoma had an impact on HRQoL. Social health issues were related to the impact on relationships with others, limitations in undertaking activities, loss of independence, changes in work or study capacity, and financial difficulties. Most of the items of the EORTC QLQ-C30 and EORTC QLQ-EN24 questionnaires were rated as relevant. Questions about lack of knowledge about sarcoma, shock of diagnosis, and menopausal symptoms were lacking from existing measures.

Conclusions

Uterine sarcoma patients experience a variety of concerns covering the physical, mental, and social domains of HRQoL that are in the main EORTC instruments, but not all of them. Combining cancer-generic, location- and sarcoma-specific items is recommended to assess HRQoL in this patient group.

Trial registration NCT04071704.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01971-5.

Exposure-response analyses of cabozantinib in patients with metastatic renal cell cancer

Aim

In the registration trial, cabozantinib exposure ≥ 750 ng/mL correlated to improved tumor size reduction, response rate and progression free survival (PFS) in patients with metastatic renal cell cancer (mRCC). Because patients in routine care often differ from patients in clinical trials, we explored the cabozantinib exposure–response relationship in patients with mRCC treated in routine care.

Methods

Cabozantinib trough concentrations (C_min) were collected and average exposure was calculated per individual. Exposure–response analyses were performed using the earlier identified target of C_min > 750 ng/mL and median C_min. In addition, the effect of dose reductions on response was explored. PFS was used as measure of response.

Results

In total, 59 patients were included:10% were classified as favourable, 61% as intermediate and 29% as poor IMDC risk group, respectively. Median number of prior treatment lines was 2 (0–5). Starting dose was 60 mg in 46%, 40 mg in 42% and 20 mg in 12% of patients. Dose reductions were needed in 58% of patients. Median C_min was 572 ng/mL (IQR: 496–701). Only 17% of patients had an average C_min ≥ 750 ng/mL. Median PFS was 52 weeks (95% CI: 40–64). No improved PFS was observed for patients with C_min ≥ 750 ng/mL or ≥ 572 ng/ml. A longer PFS was observed for patients with a dose reduction vs. those without (65 vs. 31 weeks, p = .001). After incorporating known covariates (IMDC risk group and prior treatment lines (< 2 vs. ≥ 2)) in the multivariable analysis, the need for dose reduction remained significantly associated with improved PFS (HR 0.32, 95% CI:0.14–0.70, p = .004).

Conclusion

In these explorative analyses, no clear relationship between increased cabozantinib exposure and improved PFS was observed. Average cabozantinib exposure was below the previously proposed target in 83% of patients. Future studies should focus on validating the cabozantinib exposure required for long term efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09338-1.

Analysis of PD-1, PD-L1, and T-cell infiltration in angiosarcoma pathogenetic subgroups

Angiosarcoma (AS) is a rare malignancy with a poor prognosis. It can develop spontaneously or due to previous radiotherapy (RT), ultraviolet (UV) radiation, or lymphoedema (Stewart Treves AS). Novel therapeutic approaches are needed, but progress is hindered because of the heterogeneity and rarity of AS. In order to explore the potential of immune checkpoint inhibition (ICI), we investigated the protein expression of programmed cell death 1 (PD-1), programmed death-ligand 1 (PD-L1), and CD8 + T cells in 165 AS cases in relation to AS subgroups based on clinical classification and in relation to whole-genome methylation profiling based clusters (A1, A2, B1, B2). High PD-L1 and PD-1 expression were predominantly shown in UV-associated, visceral, and soft tissue AS. RT-associated AS showed predominantly high PD-1 expression. CD8 + T cell infiltration was present in the majority of AS samples. Within the UV-associated AS, two different clusters can be distinguished by DNA methylation profiling. Cases in cluster A1 showed higher PD-1 (p = 0.015), PD-L1 (p = 0.015), and CD8 + T cells (p = 0.008) compared to those in cluster B2, suggesting that these UV-AS tumors are more immunogenic than B2 tumors showing a difference even within one subgroup. In soft tissue AS, combined PD-1 and PD-L1 expression showed a trend toward poor survival (p = 0.051), whereas in UV-associated AS, PD-1 expression correlated with better survival (p = 0.035). In conclusion, we show the presence of PD-1, PD-L1, and CD8 + T cells in the majority of AS but reveal differences between and within AS subgroups, providing prognostic information and indicating to be predictive for ICI.

Symptoms reported by gastrointestinal stromal tumour (GIST) patients on imatinib treatment: combining questionnaire and forum data

PURPOSE

Treatment with the tyrosine kinase inhibitor (TKI) imatinib in patients with gastrointestinal stromal tumours (GIST) causes symptoms that could negatively impact health-related quality of life (HRQoL). Treatment-related symptoms are usually clinician-reported and little is known about patient reports. We used survey and online patient forum data to investigate (1) prevalence of patient-reported symptoms; (2) coverage of symptoms mentioned on the forum by existing HRQoL questionnaires; and (3) priorities of prevalent symptoms in HRQoL assessment.

METHODS

In the cross-sectional population-based survey study, Dutch GIST patients completed items from the EORTC QLQ-C30 and Symptom-Based Questionnaire (SBQ). In the forum study, machine learning algorithms were used to extract TKI side-effects from English messages on an international online forum for GIST patients. Prevalence of symptoms related to imatinib treatment in both sources was calculated and exploratively compared.

RESULTS

Fatigue and muscle pain or cramps were reported most frequently. Seven out of 10 most reported symptoms (i.e. fatigue, muscle pain or cramps, facial swelling, joint pain, skin problems, diarrhoea, and oedema) overlapped between the two sources. Alopecia was frequently mentioned on the forum, but not in the survey. Four out of 10 most reported symptoms on the online forum are covered by the EORTC QLQ-C30. The EORTC-SBQ and EORTC Item Library cover 9 and 10 symptoms, respectively.

CONCLUSION

This first overview of patient-reported imatinib-related symptoms from two data sources helps to determine coverage of items in existing questionnaires, and prioritize HRQoL issues. Combining cancer-generic instruments with treatment-specific item lists will improve future HRQoL assessment in care and research in GIST patients using TKI.

Early response evaluation using 18F-FDG-PET/CT does not influence management of patients with metastatic gastrointestinal stromal tumors (GIST) treated with palliative intent

AIM

The aim of this study was to investigate the impact of ¹⁸F-FDG-PET/CT on treatment decision making in metastatic gastrointestinal stromal tumor (GIST) patients.

METHODS

This study retrospectively evaluated ¹⁸F-FDG-PET/CT scans to monitor response of metastatic GIST patients treated with palliative intent. Data from the Dutch GIST Registry was used. Early scans (<10 weeks after start of treatment) and late scans (>10 weeks after start of treatment) were scored on the impact in change of treatment.

RESULTS

Sixty-one PET/CT scans were performed for treatment evaluation in 39 patients with metastatic GIST of which 36 were early scans and 25 were late scans. Early PET/CT scans led to a change in management in 5.6% of patients and late PET/CT scans led to a change in management in 56% of patients. Change in management was more often seen after scans with lack of metabolic response (48% vs. 11% in scans with metabolic response, p=0.002). Neither metabolic response nor change in treatment were more often seen in patients with KIT mutations compared to patients with non-KIT mutations (metabolic response 65% KIT vs. 46% non-KIT, p=0.33, and change in management 28% KIT vs. 21% non-KIT, p=0.74).

CONCLUSION

¹⁸F-FDG-PET/CT is not recommended for early response evaluation in an unselected patient population with metastatic GIST, since it does not influence treatment decisions. ¹⁸F-FDG-PET/CT, however, can be useful for late response assessment, especially in case of indeterminate CT results.

Priorities and preferences of advanced soft tissue sarcoma patients starting palliative chemotherapy: baseline results from the HOLISTIC study

INTRODUCTION

Palliative chemotherapy is the principal treatment of patients with advanced soft tissue sarcomas (STS); however prognosis is limited (median overall survival 12-19 months). In this setting, patient values and priorities are central to personalised treatment decisions.

PATIENTS AND METHODS

The prospective HOLISTIC study was conducted in the UK and the Netherlands assessing health-related quality of life in STS patients receiving palliative chemotherapy. Participants completed a questionnaire before starting chemotherapy, including attitudes towards quality of life (QoL) versus length of life (LoL), decisional control preferences, and decisional conflict. Chi-square and Fisher's exact tests were used to evaluate associations between patient characteristics and preferences.

RESULTS

One hundred and thirty-seven patients with advanced STS participated (UK: n = 72, the Netherlands: n = 65). Median age was 62 (27-79) years. Preference for extended LoL (n = 66, 48%) was slightly more common than preference for QoL (n = 56, 41%); 12 patients (9%) valued LoL and QoL equally (missing: n = 3). Younger patients (age <40 years) prioritised LoL, whereas two-thirds of older patients (aged ≥65 years) felt that QoL was equally or more important than LoL (P = 0.020). Decisional conflict was most common in patients who prioritised QoL (P = 0.024). Most patients preferred an active (n = 45, 33%) or collaborative (n = 59, 44%) role in treatment decisions. Gender, performance status, and country were significantly associated with preferred role. Concordance between preferred and actual role in chemotherapy decision was high (n = 104, 76%).

CONCLUSIONS

Heterogeneous priorities and preferences among advanced STS patients support personalised decisions about palliative treatment. Considering individual differences during treatment discussions may enhance communication and optimise patient-centred care.

Exposure-toxicity relationship of cabozantinib in patients with renal cell cancer and salivary gland cancer

Cabozantinib is registered in fixed 60 mg dose. However, 46% to 62% of patients in the registration studies needed a dose reduction due to toxicity. Improved clinical efficacy has been observed in renal cell carcinoma patients (RCC) with a cabozantinib exposure greater than 750 μg/L. In our study we explored the cabozantinib exposure in patients with different tumour types. We included RCC patients from routine care and salivary gland carcinoma (SGC) patients from a phase II study with ≥1 measured C_min at steady‐state. The geometric mean (GM) C_min at the starting dose, at 40 mg and at best tolerated dose (BTD) were compared between both tumour types. Forty‐seven patients were included. All SGC patients (n = 22) started with 60 mg, while 52% of RCC patients started with 40 mg. GM C_min at the start dose was 1456 μg/L (95% CI: 1185‐1789) vs 682 μg/L (95% CI: 572‐812) (P < .001) for SGC and RCC patients, respectively. When dose‐normalised to 40 mg, SGC patients had a significantly higher cabozantinib exposure compared to RCC patients (C_min 971 μg/L [95% CI: 790‐1193] vs 669 μg/L [95% CI: 568‐788]) (P = .005). Dose reductions due to toxicity were needed in 91% and 60% of SGC and RCC patients, respectively. Median BTD was between 20 to 30 mg for SGC and 40 mg for RCC patients. GM C_min at BTD were comparable between the SGC and the RCC group, 694 μg/L (95% CI: 584‐824) vs 583 μg/L (95% CI: 496‐671) (P = .1). The observed cabozantinib exposure at BTD of approximately 600 μg/L is below the previously proposed target. Surprisingly, a comparable exposure at BTD was reached at different dosages of cabozantinib for SGC patients compared to RCC patients Further research is warranted to identify the optimal exposure and starting dose to balance efficacy and toxicity.

What's new?

Cabozantinib, a potent tyrosine kinase inhibitor that targets multiple signaling pathways, is approved for use against advanced renal cell carcinoma (RCC). Variations in cabozantinib clearance, however, warrant further investigation. Here, the authors evaluated cabozantinib exposure in RCC patients and in patients with salivary gland cancer (SGC). SGC patients were found to have significantly higher cabozantinib exposure compared to RCC patients following a 40 mg dose. However, the best‐tolerated cabozantinib exposure was equivalent (~600 μg/L) for both tumor types and was substantially below the previously proposed target. The findings offer insight on exposure, dose, and the balance between efficacy and toxicity for cabozantinib.

Unravelling the heterogeneity of soft tissue and bone sarcoma patients' health-related quality of life: a systematic literature review with focus on tumour location

Patients with sarcoma experience many physical and psychological symptoms, adversely affecting their health-related quality of life (HRQoL). HRQoL assessment is challenging due to the diversity of the disease. This review aims to unravel the heterogeneity of HRQoL of patients with sarcoma with regard to tumour location and to summarise the used measures in research. English-language literature from four databases published between January 2000 and April 2019 was reviewed. Studies that described adult sarcoma HRQoL outcomes were included and classified according to primary sarcoma location. Eighty-seven articles met the inclusion criteria covering sarcoma of the extremities (n=35), pelvis and axial skeleton (n=9), pelvis and extremities (n=5), head and neck (n=4), retroperitoneum (n=2) and multiple sarcoma locations (n=33), respectively. Urogenital and thoracic sarcoma were lacking. Fifty-four different questionnaires were used, most often cancer-generic or generic HRQoL questionnaires. Patients with sarcoma reported lower HRQoL than the general population. Distinctive patterns of HRQoL outcomes according to tumour location regarding symptoms, physical functioning, disability and psychosocial well-being were identified. In metastatic sarcoma, mostly constitutional symptoms were present. To comprehensively assess HRQoL, a sarcoma-specific measurement strategy should be developed and used covering the heterogeneity of sarcoma including location-specific issues to improve personalised HRQoL assessment in future research and clinical practice.

The impact of a 1-hour time interval between pazopanib and subsequent intake of gastric acid suppressants on pazopanib exposure

Co‐treatment with gastric acid suppressants (GAS) in patients taking anticancer drugs that exhibit pH‐dependant absorption may lead to decreased drug exposure and may hamper drug efficacy. In our study, we investigated whether a 1‐hour time interval between subsequent intake of pazopanib and GAS could mitigate this negative effect on drug exposure. We performed an observational study in which we collected the first steady‐state pazopanib trough concentration (C_min) levels from patients treated with pazopanib 800 mg once daily (OD) taken fasted or pazopanib 600 mg OD taken with food. All patients were advised to take GAS 1 hour after pazopanib. Patients were grouped based on the use of GAS and the geometric (GM) C_min levels were compared between groups for each dose regimen. Additionally, the percentage of patients with exposure below the target threshold of 20.5 mg/L and the effect of the type of PPI was explored. The GM C_min levels were lower in GAS users vs non‐GAS users for both the 800 and 600 mg cohorts (23.7 mg/L [95% confidence interval [CI]: 21.1‐26.7] vs 28.2 mg/L [95% CI: 25.9‐30.5], P = .015 and 26.0 mg/L [95% CI: 22.4‐30.3] vs 33.5 mg/L [95% CI: 30.3‐37.1], P = .006). Subtherapeutic exposure was more prevalent in GAS users vs non‐GAS users (33.3% vs 19.5% and 29.6% vs 14%). Sub‐analysis showed lower GM pazopanib C_min in patients who received omeprazole, while minimal difference was observed in those receiving pantoprazole compared to non‐users. Our research showed that a 1‐hour time interval between intake of pazopanib and GAS did not mitigate the negative effect of GAS on pazopanib exposure and may hamper pazopanib efficacy.

Incorporating the Patient Voice in Sarcoma Research: How Can We Assess Health-Related Quality of Life in This Heterogeneous Group of Patients? A Study Protocol

Sarcomas comprise 1% of adult tumors and are very heterogeneous. Long-lasting and cumulative treatment side-effects detract from the (progression-free) survival benefit of treatment. Therefore, it is important to assess treatment effectiveness in terms of patient-reported outcomes (PROs), including health-related quality of life (HRQoL) as well. However, questionnaires capturing the unique issues of sarcoma patients are currently lacking. Given the heterogeneity of the disease, the development of such an instrument may be challenging. The study aims to (1) develop an exhaustive list of all HRQoL issues relevant to sarcoma patients and determine content validity; (2) determine a strategy for HRQoL measurement in sarcoma patients. We will conduct an international, multicenter, mixed-methods study (registered at clinicaltrials.gov: NCT04071704) among bone or soft tissue sarcoma patients ≥18 years, using EORTC Quality of Life Group questionnaire development guidelines. First, an exhaustive list of HRQoL issues will be generated, derived from literature and patient (n = 154) and healthcare professional (HCP) interviews (n = 30). Subsequently, another group of sarcoma patients (n = 475) and HCPs (n = 30) will be asked to rate and prioritize the issues. Responses will be analyzed by priority, prevalence and range of responses for each item. The outcome will be a framework for tailored HRQoL measurement in sarcoma patients, taking into account sociodemographic and clinical variables.

The route to diagnosis of sarcoma patients: Results from an interview study in the Netherlands and the United Kingdom

INTRODUCTION

Sarcomas are rare tumours. Early diagnosis is challenging, but important for local control and potentially survival and quality of life(QoL). We investigated (1)the route to diagnosis (RtD) experienced by sarcoma patients, including factors contributing to the length of the RtD from patients' perspective; (2)the impact of the RtD on QoL and care satisfaction; and (3)differences in aims 1-2 between English and Dutch patients.

METHODS

Fifteen sarcoma patients from The Royal Marsden Hospital, United Kingdom, and Radboud University Medical Centre, The Netherlands, were interviewed, exploring RtD experiences. Interviews were analysed according to qualitative content analysis.

RESULTS

The main themes were: patient interval, diagnostic interval, reflection on the RtD and recommendations for improvement. Patient interval was long if symptoms were attributed as benign, did not interfere with daily life or were expected to cease. An incorrect working diagnosis, ineffective process of additional investigations, long referral times and lack of a lead clinician lengthened the diagnostic interval. Long waiting times, false reassurance and inadequate information provision led to dissatisfaction and a high emotional burden. Factors for improvement included increasing awareness of patients and healthcare providers, empowering patients, and having a lead clinician.

CONCLUSION

The RtD of sarcoma patients is complex. Increasing awareness of patients and healthcare providers may contribute to shorten the RtD.

Patient and diagnostic intervals of survivors of sarcoma: Results from the SURVSARC study

BACKGROUND

Patients diagnosed with sarcoma are hypothesized to experience a prolonged route to a cancer diagnosis. This route, the total interval, can be divided into a patient interval (the time from the appearance of symptoms to physician consultation) and diagnostic interval (time from the first consultation to diagnosis). In the current study, the authors investigated these intervals among survivors of sarcoma and identified factors associated with prolonged intervals.

METHODS

A cross-sectional study was conducted among adult patients with sarcoma 2 to 10 years after diagnosis. Patients completed a questionnaire regarding their total interval, which was linked to clinical data from the Netherlands Cancer Registry. Descriptive statistics were used to describe intervals. Based on Dutch clinical guidelines, a diagnostic interval ≥1 month was considered to be prolonged and an interval ≥3 months was considered as very long. Multivariable regression analyses investigated associations between patient and tumor characteristics and interval length.

RESULTS

A total of 1099 participants were included (response rate, 58%); approximately 60% reported a patient interval ≥1 month and 36% reported a patient interval ≥3 months. Risk factors for a very long patient interval were sarcoma of the skin or pelvis, liposarcoma, or rhabdomyosarcoma. Stage III disease was associated with a shorter patient interval. The diagnostic interval length was ≥1 month in 55% of patients and ≥3 months in 28% of patients. Risk factors for a very long diagnostic interval were female sex, age <70 years, or having a synovial sarcoma or chordoma.

CONCLUSIONS

The patient and diagnostic interval lengths were prolonged in a substantial percentage of this sarcoma survivorship population. Factors found to be associated with the length of the patient interval or the diagnostic interval differed. Creating awareness among (especially young) patients to consult a physician and awareness among physicians to consider a sarcoma diagnosis will contribute to optimization of the total interval.

Health-related quality of life and symptom burden of epithelioid hemangioendothelioma patients: a global patient-driven Facebook study in a very rare malignancy

Purpose: Epithelioid hemangioendothelioma (EHE) is an ultra-rare vascular sarcoma with unique clinical features. EHE is characterized by an unpredictable, often protracted, clinical course and highly variable clinical presentation. Due to difficulty recruiting ultra-rare cancer patients, health-related quality of life (HRQoL) of EHE patients has not yet been studied. The aim of this study was to assess EHE symptom burden and its impact on HRQoL and psychological distress.Methods: The study was initiated after EHE patients' foundations approached our research group to study HRQoL. Patients were recruited from the international EHE Facebook group from May through October 2018. Data were collected using the online PROFILES registry. Latent class cluster analysis was performed to identify groups based on frequently reported symptoms. Differences in HRQoL (EORTC-QLQ-C30) and psychological distress (Hospital Anxiety and Depression Scale) between symptom-based clusters were examined.Results: Among 115 EHE patients from 20 countries, three clusters were identified, with low-, intermediate- and high-symptom burden, respectively. Highly symptomatic patients (33%) had clinically relevantly lower scores on HRQoL compared to the other two groups (p < 0.001). These patients suffered mostly from pain, insomnia and fatigue. Symptom burden significantly correlated with reduced daily functioning and high levels of psychological distress. Only for highly symptomatic patients, HRQoL and symptom levels were worse compared to healthy individuals.Conclusion: For the first time, we studied HRQoL in a large international cohort of ultra-rare cancer patients with distinct clinical characteristics, enabled by collaboration with patients and use of social media. We showed a considerable number of EHE patients were highly symptomatic, with a significant impact on HRQoL and psychological distress.

The Perceived Impact of Length of the Diagnostic Pathway Is Associated with Health-Related Quality of Life of Sarcoma Survivors: Results from the Dutch Nationwide SURVSARC Study

BACKGROUND

Sarcoma patients often experience a long time to diagnosis, known as the total interval. This interval can be divided into the patient (time from symptoms to doctor consultation) and diagnostic intervals (time from first consultation to diagnosis). In other cancers, a long total interval has been associated with worse outcomes, but its effect on health-related quality of life (HRQoL) has never been investigated among sarcoma patients. This study investigates the association between (1) the actual time to diagnosis and HRQoL; (2) the perceived impact of the diagnostic interval length and HRQoL; (3) the actual length and perceived impact of the length and the HRQoL of sarcoma survivors.

METHODS

A cross-sectional study was performed among sarcoma patients aged ≥18, diagnosed 2-10 years ago in the Netherlands. The participants completed a questionnaire on HRQoL, the time to diagnosis, the perceived impact of the diagnostic interval on HRQoL, and coping.

RESULTS

1099 participants were included (response rate, 58%). The mean time since diagnosis was 67.4 months. More than half reported a patient (60%) or diagnostic interval (55%) ≥1 month. A third (31%) perceived a negative impact of the diagnostic interval length on HRQoL. Patient or diagnostic interval length was not associated with HRQoL. By contrast, participants perceiving a negative impact (32%) had lower HRQoL scores than those perceiving a positive (11%) or no impact (58%) (p = 0.000). This association remained significant in a multivariable model, in which maladaptive coping strategies and tumour characteristics were also found to be associated with HRQoL. Participants perceiving a negative impact of the length of the diagnostic interval related this to high psychological distress levels, more physical disabilities, and worse prognosis.

CONCLUSION

The perceived impact of the diagnostic interval length was associated with the HRQoL of sarcoma survivors, whereas the actual length was not associated with HRQoL. Maladaptive coping strategies were independently associated with HRQoL. This offers opportunities for early intervention to improve HRQoL.

Dose recommendations for anticancer drugs in patients with renal or hepatic impairment

Renal or hepatic impairment is a common comorbidity for patients with cancer either because of the disease itself, toxicity of previous anticancer treatments, or because of other factors affecting organ function, such as increased age. Because renal and hepatic function are among the main determinants of drug exposure, the pharmacokinetic profile might be altered for patients with cancer who have renal or hepatic impairment, necessitating dose adjustments. Most anticancer drugs are dosed near their maximum tolerated dose and are characterised by a narrow therapeutic index. Consequently, selecting an adequate dose for patients who have either hepatic or renal impairment, or both, is challenging and definitive recommendations on dose adjustments are scarce. In this Review, we discuss the effect of renal and hepatic impairment on the pharmacokinetics of anticancer drugs. To guide clinicians in selecting appropriate dose adjustments, information from available drug labels and from the published literature were combined to provide a practical set of recommendations for dose adjustments of 160 anticancer drugs for patients with hepatic and renal impairment.

Health-related quality Of Life n patients with advanced Soft TIssue sarcomas treated with Chemotherapy (The HOLISTIC study): protocol for an international observational cohort study

INTRODUCTION

Chemotherapy is the mainstay of treatment for patients with advanced soft tissue sarcomas (STS). Treatment intent is usually palliative, aiming to improve symptoms, stabilise or reduce tumour burden and extend life. Clinical trials have traditionally used radiological response, time to progression and survival as measures of treatment efficacy. Health-related quality of life (HRQoL) is at least equally important or more important than survival for many patients with advanced cancer. Systematically collecting HRQoL data during chemotherapy can provide greater insight into treatment efficacy from the patient perspective.The primary aims of this study are to evaluate HRQoL in patients with advanced STS treated with chemotherapy over time, explore the decision-making process and patient reflection post-treatment.

METHODS AND ANALYSIS

This is an observational, international cohort study for 132 patients aged ≥18 years with advanced STS treated at eight centres (three in the UK, five in the Netherlands). Patients will be recruited prior to starting first-line or third-line chemotherapy and invited to complete questionnaires using the Patient-Reported Outcomes Following Initial treatment and Long-term Evaluation of Survivorship registry (PROFILES); an established international registry for collection of cancer patient-reported outcomes. Online (or paper) questionnaires will be completed at baseline, each cycle of chemotherapy and 2-3 monthly during follow-up. The questionnaire package includes the Decisional Conflict Scale, Control Preferences Scale, Quality-Quantity Questionnaire, treatment expectations, European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30), EORTC financial toxicity items, Work Ability Index, Functional Assessment of Cancer Therapy-General (FACT-G) items and Decisional Regret Scale. Clinical data will be extracted from patient records and linked with questionnaire responses. The primary outcome measure is the change in global HRQoL from baseline to after cycle 4 of first-line chemotherapy (based on published data showing that patients with advanced STS complete a median number of four cycles of first-line chemotherapy).

ETHICS AND DISSEMINATION

Heath Research Authority and Research Ethics Committee (REC 17/NI/0197). Results from the Health-related quality Of Life In patients with advanced Soft TIssue sarcomas treated with Chemotherapy (HOLISTIC) study will be published in peer-reviewed journals and disseminated at local, national and international conferences. We will also present our findings at any appropriate patient meetings and involve patients in study-related publications.

TRIAL REGISTRATION NUMBER

NCT03621332.

The relationship between sunitinib exposure and both efficacy and toxicity in real-world patients with renal cell carcinoma and gastrointestinal stromal tumour

Aim

Sunitinib is an oral tyrosine kinase inhibitor approved for the treatment of renal cell carcinoma (RCC) and gastrointestinal stromal tumor (GIST). Because of the large interpatient pharmacokinetic variability and established exposure‐response and exposure‐toxicity relationships in clinical trial patients, therapeutic drug monitoring (TDM) seems promising for optimizing sunitinib exposure. We aimed to investigate the relationship between sunitinib exposure and treatment outcome in a real‐world patient cohort.

Methods

We performed a retrospective observational cohort study in 53 patients with metastatic RCC and 18 patients with metastatic GIST treated with sunitinib and receiving TDM‐guided dosing. Time on treatment – as a surrogate for progression‐free survival – in patients who achieved adequate sunitinib exposure was compared with patients who did not. Additionaly, the median sunitinib exposure was compared in patients with or without sunitinib‐induced toxicity leading to dose reduction.

Results

The median time on treatment in patients with RCC who achieved adequate sunitinib exposure (n = 39) was 32 weeks, compared to 15 weeks in patients who did not achieve adequate sunitinib exposure (n = 12) (P = 0.244). In 29 patients (41%) with toxicity leading to dose reduction, sunitinib sum plasma trough concentration (C_trough) until dose reduction was significantly higher compared to patients without toxicity leading to dose reduction (median 60 ng/mL vs 44 ng/mL; P < 0.001) and reduced to comparable levels after dose reduction (44 ng/mL; P = 0.488).

Conclusion

In our real‐world patient cohort, patients with sunitinib‐induced toxicity requiring dose reduction had significantly higher sunitinib exposure compared to patients without toxicity. The threshold for toxicity, however, was lower compared to that previously described in clinical trials.

Olaparib and temozolomide in desmoplastic small round cell tumors: a promising combination in vitro and in vivo

Purpose

Desmoplastic small round cell tumors (DSRCTs) are highly malignant and very rare soft tissue sarcomas with a high unmet need for new therapeutic options. Therefore, we examined poly(ADP-ribose) polymerase 1 (PARP1) and Schlafen-11 (SLFN11) expression in DSRCT tumor tissue and the combination of PARP inhibitor olaparib with the alkylating agent temozolomide (TMZ) in a preclinical DSRCT model.

Methods

PARP1 and SLFN11 have been described as predictive biomarkers for response to PARP inhibition. Expression of PARP1 and SLFN11 was assessed in 16 and 12 DSRCT tumor tissue samples, respectively. Effects of single-agent olaparib, and olaparib and TMZ combination treatment were examined using the preclinical JN-DSRCT-1 model. In vitro, single-agent and combination treatment effects on cell viability, the cell cycle, DNA damage and apoptosis were examined. Olaparib and TMZ combination treatment was also assessed in vivo.

Results

PARP1 and SLFN11 expression was observed in 100% and 92% of DSRCT tumor tissues, respectively. Olaparib treatment reduced cell viability and cell migration in a dose-dependent manner in vitro. Drug synergy between olaparib and TMZ was observed in vitro and in vivo. Combination treatment led to a cell-cycle arrest and induction of DNA damage and apoptosis, even when combined at low dosages.

Conclusion

We show high PARP1 and SLFN11 expression in DSRCT tumor material and antitumor effects following olaparib and TMZ combination treatment in a preclinical DSRCT model. This suggests that olaparib and TMZ combination treatment could be a potential treatment option for DSRCTs.

Electronic supplementary material

The online version of this article (10.1007/s00432-020-03211-z) contains supplementary material, which is available to authorized users.

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.

Immunohistochemical selection of biomarkers for tumor-targeted image-guided surgery of myxofibrosarcoma

Myxofibrosarcoma(MFS) is the most common soft tissue sarcoma(STS) in elderly patients. Surgical resection remains the main treatment modality but tumor borders can be difficult to delineate with conventional clinical methods. Incomplete resections are a common problem and local recurrence remains a clinical issue. A technique that has shown great potential in improving surgical treatment of solid tumors is tumor targeted imaging and image-guided surgery with near-infrared fluorescence. To facilitate this technique, it is essential to identify a biomarker that is highly and homogenously expressed on tumor cells, while being absent on healthy non-malignant tissue. The purpose of this study was to identify suitable molecular targets for tumor-targeted imaging of myxofibrosarcoma. Ten potential molecular targets for tumor targeted imaging were investigated with immunohistochemical analysis in myxofibrosarcoma tissue (n = 34). Results were quantified according to the immunoreactive score(IRS). Moderate expression rates were found for uPAR, PDGFRa and EMA/MUC1. High expression rates of VEGF and TEM1 were seen. Strong expression was most common for TEM1 (88.2%). These results confirms that TEM1 is a suitable target for tumor-targeted imaging of myxofibrosarcoma. Keywords Image-guided surgery; Immunohistochemistry; Molecular imaging; Myxofibrosarcoma; Soft tissue sarcoma; Tumor endothelial marker 1(TEM1), Vascular endothelial growth factor (VEGF).