Sunitinib for the treatment of metastatic gastrointestinal stromal tumors: the effect of TDM-guided dose optimization on clinical outcomes.

BACKGROUND: Sunitinib is an oral anticancer drug approved for the treatment of among others gastrointestinal stromal tumor (GIST). Previous analyses demonstrated an exposure-response relationship at the standard dose, and minimum target levels of drug exposure have been defined above which better treatment outcomes are observed. Therapeutic drug monitoring (TDM) could be used as a tool to optimize the individual dose, aiming at sunitinib trough concentrations ≥37.5 ng/ml for continuous dosing. Nonetheless, data on the added value of TDM-guided dosing on clinical endpoints are currently lacking. Therefore, we evaluate the effect of TDM in patients with advanced and metastatic GIST treated with sunitinib in terms of efficacy and toxicity. PATIENTS AND METHODS: A TDM-guided cohort was compared to a non-TDM-guided cohort in terms of median progression-free survival (mPFS) and overall survival (mOS). Also, mPFS between patients with and without dose-limiting toxicities (DLTs) was compared. Patients in the prospective cohort were included in two studies on TDM-guided dosing (the DPOG-TDM study and TUNE study). The retrospective cohort consisted of patients from the Dutch GIST Registry who did not receive TDM-guided dosing. RESULTS: In total, 51 and 106 patients were included in the TDM-guided cohort and non-TDM-guided cohort, respectively. No statistical difference in mPFS was observed between these two cohorts (39.4 versus 46.9 weeks, respectively; P = 0.52). Patients who experienced sunitinib-induced DLTs had longer mPFS compared to those who did not (51.9 versus 28.9 weeks, respectively; P = 0.002). CONCLUSIONS: Our results do not support the routine use of TDM-guided dose optimization of sunitinib in patients with advanced/metastatic GIST to improve survival.

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.

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.

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.

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.

Analysis of 105.000 patients with cancer: have they been discussed in oncologic multidisciplinary team meetings? A nationwide population-based study in the Netherlands.

INTRODUCTION: For optimal oncological care, it is recommended to discuss every patient with cancer in a multidisciplinary team meeting (MDTM). This is a time consuming and expensive practice, leading to a growing demand to change the current workflow. We aimed to investigate the number of patients discussed in MDTMs and to identify characteristics associated with not being discussed. METHODS: Data of patients with a newly diagnosed solid malignant tumour in 2015 and 2016 were analysed through the nationwide population-based Netherlands Cancer Registry (NCR). We clustered tumour types in groups that were frequently discussed within a tumour-specific MDTM. Tumour types without information about MDTMs in the NCR were excluded. Multivariable logistic regression analyses were used to analyse factors associated with not being discussed. RESULTS: Out of 105.305 patients with cancer, 91% were discussed in a MDTM, varying from 74% to 99% between the different tumour groups. Significantly less frequently discussed were patients aged ≥75 years (odds ratio [OR] = 0.7, 95% confidence interval [CI] = 0.6-0.7), patients diagnosed with disease stage I (OR = 0.5, 95% CI = 0.5-0.6), IV (OR = 0.4, 95% CI = 0.4-0.4) or unknown (OR = 0.2, 95% CI = 0.2-0.2) and patients who received no treatment (OR = 0.3, 95% CI = 0.3-0.3). Patients who received a multidisciplinary treatment were more likely to be discussed in contrary to a monodisciplinary treatment (OR = 4.6, 95% CI = 4.2-5.1). CONCLUSION: In general, most patients with cancer were actually discussed in a MDTM, although differences were observed between tumour groups. Factors associated with not being discussed may, at least partially, reflect the absence of a multidisciplinary question. These results form a starting point for debate on a more durable and efficient new MDTM strategy.

Predictive factors for toxicity and survival of second-line sunitinib in advanced gastrointestinal stromal tumours (GIST).

Introduction: Sunitinib is a standard second-line treatment in advanced gastrointestinal stromal tumours (GIST). We aimed to search for predictive factors for grade 3 and 4 toxicity, progression-free survival (PFS) and overall survival (OS) in a GIST reference center patient population, outside clinical trials.Methods: A retrospective analysis was performed of patients treated in two European Comprehensive Cancer Centers between January 2005 and December 2015. Demographic and clinical features, tumour characteristics and biological parameters were investigated. Logistic regression models were used to find factors associated with grade 3 and 4 toxicity. To identify predictive factors for PFS and OS, variables that were statistically significant in univariate analysis were used in the multivariate Cox proportional hazards model.Results: Ninety-one patients were included in this analysis. Age >60 years (HR 5.0, p = .006) and body weight ≤70 kg (HR 4.7, p = .009) were predictive factors for grade 3 and 4 toxicity. When divided into two categories, non-haematological grade 3 and 4 toxicity was predicted by age >60 years (HR 3.8, p = .012) and body weight ≤70 kg (HR 3.3, p = .025) whereas haematological toxicity had no significantly associated predictive factors. The median PFS and OS with sunitinib were 8.8 months and 27.5 months, respectively. The use of imatinib less than six months compared to 6-12 months (HR 0.2, p = .013) and to >12 months (HR 0.3, p = .016) and liver and/or peritoneal metastases (HR 0.1, p < .001, HR 0.2, p = .003 and HR 0.2, p = .004) compared to locally advanced disease only were predictive for longer PFS. High neutrophil (HR 3.1, p = 0.04) and platelet count (HR 2.4, p = .046) predicted a shorter OS. Flexible sunitinib dosing was associated with superior OS (p = .021).Conclusion: In advanced GIST patients treated with sunitinib, older and low-weight patients are at risk for grade 3 and 4 toxicity. Clinical (prior imatinib use and metastases), biological (neutrophil and platelet count) and treatment characteristics independently predict PFS and OS.

Targeting angiosarcomas of the soft tissues: A challenging effort in a heterogeneous and rare disease.

Angiosarcomas are rare malignant tumors with a heterogeneous clinical presentation and generally poor prognosis. It has been difficult to establish consistent molecular characteristics and driver events in angiosarcoma development. Oncogenic and angiogenesis-related pathways have been investigated pre-clinically and clinically with varying results. A few promising responses to checkpoint inhibitors have been described, but immunological features require further elucidation. With this review we present an overview of the critical biological pathways and processes affected in angiosarcoma, and their potential role in novel, non-cytotoxic, systemic treatments.

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

BACKGROUND: A cohort of 201 patients with small bowel gastrointestinal stromal tumors (GIST) treated between January 1st, 2009 and December 31st, 2016 in five GIST expertise centers in the Netherlands was analyzed. Goal of this study was to describe the clinical, surgical and pathological characteristics of this rare subpopulation of GIST patients, registered in the Dutch GIST registry. METHODS: Clinical outcomes and risk factors of patients with small bowel GIST who underwent surgery or treated with systemic therapy were analyzed. A classification was made based on disease status at diagnosis (localized vs. metastasized). RESULTS: 201 patients with small bowel GIST were registered of which 138 patients (69%) were diagnosed with localized disease and 63 patients (31%) with metastatic disease. Approximately 19% of the patients had emergency surgery, and in 22% GIST was an accidental finding. In patients with high risk localized disease, recurrence occurred less often in patients who received adjuvant treatment (4/32) compared to patients who did not (20/31, p < 0.01). Disease progression during palliative imatinib treatment occurred in 23 patients (28%) after a median of 20.7 (range 1.8-47.1) months. Ongoing response was established in 52/82 patients on first line palliative treatment with imatinib after a median treatment time of 30.6 (range 2.5-155.3) months. CONCLUSION: Patients with small-bowel GIST more frequently present with metastatic disease when compared to patients with gastric GIST in literature. We advocate for Prospective registration of these patients and investigate the use of surgery in patients with limited metastatic disease.

Drug-drug interactions with aprepitant in antiemetic prophylaxis for chemotherapy.

In the current guidelines to prevent hemotherapyinduced nausea and vomiting, multiple antiemetic drugs are administered simultaneously. In patients who receive highly emetogenic chemotherapy, aprepitant, an NK1-receptor antagonist, is combined with ondansetron and dexamethasone. Aprepitant can influence the pharmacokinetics of other drugs, as it is an inhibitor and inducer of CYP3A4. Some anticancer drugs and other co-medication frequently used in cancer patients are CYP3A4 or CYP29C substrates. We give an overview of the metabolism and current data on clinically relevant drug-drug interactions with aprepitant during chemotherapy. Physicians should be aware of the potential risk of drug-drug interactions with aprepitant, especially in regimens with curative intent. More research should be performed on drug-drug interactions with aprepitant and their clinical consequences to make evidence-based recommendations.

Systemic treatment in adult uterine sarcomas.

Uterine sarcomas (US) are rare mesenchymal tumours of the uterus and are divided mainly into uterine leiomyosarcoma (uLMS), low grade endometrial stromal sarcoma (LG-ESS), high grade endometrial stromal sarcoma (HG-ESS), adenosarcomas and high grade undifferentiated sarcoma (HGUS). US are often high-grade tumours with a high local recurrence rate and metastatic risk. We here discuss the current standard of care and knowledge of systemic therapy for adult uterine sarcomas, in particular uLMS, LG-ESS, HG-ESS and HGUS, in both the adjuvant as well as the metastatic setting.

Fatal microscopic pulmonary tumour embolisms in patients with breast cancer: necessary knowledge for future medical practice.

Microscopic pulmonary tumour embolisms (MPTE) are a rare but life-threatening phenomenon in patients with a history of adenocarcinoma. Due to the nonspecific symptoms, diagnostic difficulty, and rapid progression, this condition is often fatal. We describe two patients who previously completed breast cancer treatment, and now present with fatal MPTE and we provide a comprehensive review of the literature.

Kidney injury during VEGF inhibitor therapy.

Antiangiogenic therapy targeting vascular endothelial growth factor (VEGF) or its receptor (VEGFR) has proven its effect in the treatment of several types of cancer, including renal cell carcinoma (RCC). However, treatment can be accompanied by notable adverse effects. Mild proteinuria and hypertension are often seen, but sometimes nephrotic range proteinuria and÷or renal insufficiency develop. In recent years insight into the toxic effects of anti-VEGF therapy in the kidney has increased. A few biopsies have been done and thrombotic microangiopathy is reported in the majority of cases. However, other patterns of kidney injury have been described as illustrated by the case of a 62-year-old patient who presented two years after initiation of the VEGFR inhibitor cediranib with a nephrotic syndrome and acute renal failure. Kidney biopsy disclosed focal segmental glomerulosclerosis (FS GS) and interstitial nephritis. Partial remission was achieved after stopping the cediranib and a short course of prednisone. We review the different forms of kidney injury that could be caused by anti-VEGF therapy.

Functional MRI techniques demonstrate early vascular changes in renal cell cancer patients treated with sunitinib: a pilot study.

OBJECTIVE: To assess the early vascular effects of sunitinib in patients with renal cell carcinoma (RCC) with diffusion-weighted magnetic resonance imaging (DWI), dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and T2* perfusion MRI. PATIENTS AND METHODS: In 10 patients with abdominal RCC lesions, DWI, DCE-MRI and T2* perfusion MRI measurements at 3 Tesla were performed at baseline, 3 and 10 days after start of sunitinib. VEGF-A plasma levels were measured on days 0, 3 and 10. RESULTS: DWI showed a significant increase in the apparent diffusion coefficient (×10(-6) s/mm(2)) from baseline (mean 1158, range 814-2003) to day 3 (mean 1306, range 1008-2097, P = 0.015) followed by a decrease to baseline levels at day 10 (mean 1132, range 719-2005, P = 0.001). No significant changes were found in mean DCE-MRI parameters. T2* perfusion MRI showed a significant decrease in relative tumor blood volume (rBV) and relative tumor blood flow (rBF) at day 3 (rBV P = 0.037, rBF P = 0.018) and day 10 (rBV P = 0.006, rBF P = 0.009). VEGF-A plasma levels significantly increased after 10 days, but did not correlate with MRI parameters. CONCLUSIONS: Sunitinib induces antiangiogenic effects as measured by DWI and T2*-perfusion MRI, 3 and 10 days after the start of the initial treatment. DCE-MRI did not show significant changes. In the near future, early functional MRI-based evaluation can play an important role in tailoring treatment to the individual patient with RCC. Further investigation is warranted.

A new, simple and objective prognostic score for phase I cancer patients.

AIM: To ensure safety and optimise efficacy, careful patient selection for participation in oncologic phase I trials is warranted. Therefore, we did a validation study on existing phase I prognostic scores, and subsequently aimed to make an even more simple prognostic score. PATIENTS AND METHODS: We retrospectively analysed characteristics and clinical outcome of 122 patients who participated in eight different phase I studies in our centre. A literature search was performed for existing prognostic scores which were validated in our dataset. Additionally, a simple prognostic score able to predict overall survival (OS), progression free survival (PFS), 90-d mortality and duration of participation was developed. RESULTS: In our population the median OS was 31 (range 4-241) weeks, median PFS was 10 (range 3-119) weeks. Thirteen patients (11%) died within 90-d and median participation duration was 11 (range 1-119) weeks. Two out of five existing prognostic scores could be validated in this dataset for OS. Based on multivariate analyses a new, objective and simple score, consisting of LDH, sodium and haemoglobin, was tested. High score (2-3 points) compared to low score (0-1) significantly predicted OS (HR 1.878, p = 0.003), PFS (HR 1.156, p = 0.038), participation duration (HR 1.858, p = 0.004) and 90-d mortality (OR 4.200, p = 0.022). CONCLUSION: We propose a new prognostic model, using LDH, sodium and haemoglobin, helpful to predict OS, PFS, participation duration and 90-d mortality. Larger multicentre studies are needed to validate this score.