Publications by authors named "Jan Willem De Groot"

Introduction: The association of body composition with checkpoint inhibitor outcomes in melanoma is a matter of ongoing debate. In this study, we aim to investigate body mass index (BMI) alongside CT-derived body composition metrics in the largest cohort to date.

Methods: Patients treated with first-line anti-PD1 ± anti-CTLA4 for advanced melanoma were retrospectively identified from 11 melanoma centers in The Netherlands.

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Immune checkpoint inhibitor (ICI) treatment has proven successful for advanced melanoma, but is associated with potentially severe toxicity and high costs. Accurate biomarkers for response are lacking. The present work is the first to investigate the value of deep learning on CT imaging of metastatic lesions for predicting ICI treatment outcomes in advanced melanoma.

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Previous studies demonstrated limited efficacy of immune checkpoint inhibitors in unresectable acral melanoma (AM); it remains unclear how this translates to the adjuvant setting. This study investigates clinical outcomes of acral compared to cutaneous melanoma (CM) patients treated with adjuvant anti-PD-1 after complete resection. All stages III-IV AM and CM patients receiving adjuvant anti-PD-1 after complete resection between 2018 and 2022 were included from the prospective nationwide Dutch Melanoma Treatment Registry.

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Article Synopsis
  • In a study comparing neoadjuvant (before surgery) and adjuvant (after surgery) immunotherapy for stage III melanoma, neoadjuvant treatment showed greater effectiveness.
  • The trial involved random assignment of 423 patients to receive either two cycles of neoadjuvant ipilimumab plus nivolumab followed by surgery, or surgery followed by 12 cycles of adjuvant nivolumab.
  • Results indicated a significantly higher 12-month event-free survival rate in the neoadjuvant group (83.7%) compared to the adjuvant group (57.2%), with neoadjuvant therapy leading to better patient outcomes and more major pathological responses despite a higher incidence of severe adverse events.
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Background: The prognosis of advanced melanoma patients has significantly improved over the years. We aimed to evaluate the survival per year of diagnosis.

Methods: All systemically treated patients diagnosed with advanced melanoma from 2013 to 2021 were included from the Dutch Melanoma Treatment Registry.

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Article Synopsis
  • The study highlights the slow implementation of cancer treatment guidelines in the Netherlands, specifically for pancreatic cancer, aiming to improve survival rates through better adherence to best practices.
  • It involved a multicenter trial with 5887 patients, comparing enhanced treatment strategies against usual care from May 2018 to July 2020.
  • Results showed that one-year survival rates were similar between both groups (24% vs 23%) and there wasn't a significant increase in adherence to the recommended treatment practices post-implementation.
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Introduction: Physical activity (PA) is associated with higher quality of life and probably better prognosis among colorectal cancer (CRC) patients. This study focuses on determinants of PA among CRC patients from diagnosis until 5 yr postdiagnosis.

Methods: Sociodemographic and disease-related factors of participants of two large CRC cohort studies were combined.

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Background: Patients diagnosed with haematologic malignancies (HMs) have a higher risk of developing subsequent solid tumours, such as melanoma. Patients with HM were mostly excluded from clinical trials but potentially derive less benefit from immune checkpoint inhibitors (ICIs) due to disease- or treatment-related T- or B-cell dysfunction.

Methods: All advanced melanoma patients treated with anti-PD-1-based treatment or targeted therapy between 2015 and 2021 were included from the prospective nationwide Dutch Melanoma Treatment Registry.

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Article Synopsis
  • This study evaluated the effectiveness and safety of the PD-L1 inhibitor durvalumab in patients with mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) tumors as part of a clinical trial called the Drug Rediscovery Protocol (DRUP).
  • A total of 26 patients with various solid tumors, who had no other treatment options left, were treated with durvalumab, showing a clinical benefit in 50% of them, with a 27% objective response rate.
  • The results suggested that durvalumab was well-tolerated, and specific genetic markers were linked to patients who did not respond well, indicating potential areas for further research in larger studies.
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Background: We studied the added value of digital FDG-PET/CT in disease staging and restaging compared to the standard work-up with contrast enhanced CT (ceCT) and CA19-9 in patients with resectable or borderline resectable pancreatic cancer who received neo-adjuvant therapy. Primary endpoints were tumor response compared to ceCT and CA19.9 as well as the ability to detect distant metastatic disease.

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Background: Immune checkpoint inhibitors and targeted therapies have dramatically improved outcomes in patients with advanced melanoma, but approximately half these patients will not have a durable benefit. Phase 1-2 trials of adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) have shown promising responses, but data from phase 3 trials are lacking to determine the role of TILs in treating advanced melanoma.

Methods: In this phase 3, multicenter, open-label trial, we randomly assigned patients with unresectable stage IIIC or IV melanoma in a 1:1 ratio to receive TIL or anti-cytotoxic T-lymphocyte antigen 4 therapy (ipilimumab at 3 mg per kilogram of body weight).

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Importance: Management of checkpoint inhibitor-induced immune-related adverse events (irAEs) is primarily based on expert opinion. Recent studies have suggested detrimental effects of anti-tumor necrosis factor on checkpoint-inhibitor efficacy.

Objective: To determine the association of toxic effect management with progression-free survival (PFS), overall survival (OS), and melanoma-specific survival (MSS) in patients with advanced melanoma treated with first-line ipilimumab-nivolumab combination therapy.

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Background: Biological sex, gender and age have an impact on the incidence and outcome in patients with metastatic pancreatic cancer. The aim of this study is to investigate whether biological sex, gender and age are associated with treatment allocation and overall survival (OS) of patients with metastatic pancreatic cancer in a nationwide cohort.

Methods: Patients with synchronous metastatic pancreatic cancer diagnosed between 2015 and 2019 were selected from the Netherlands Cancer Registry (NCR).

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Background: Recent reports suggest the limited efficacy of immune checkpoints inhibitors in advanced acral melanoma (AM). This study aims to investigate the clinical outcomes of immune checkpoint inhibitors in patients with stage III and IV AM and compare them to cutaneous melanoma (CM).

Methods: We included patients with advanced AM and CM treated with first-line anti-programmed cell death (PD)-1 monotherapy or ipilimumab-nivolumab registered in the prospective nationwide Dutch Melanoma Treatment Registry.

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Background: A watch-and-wait strategy for patients with rectal cancer with a clinical complete response after neoadjuvant chemoradiotherapy is a valuable alternative for rectal resection. However, there are patients who will have residual tumor or regrowth during watch and wait.

Objective: The aim of this study was to investigate safety and costs for patients who underwent delayed surgery after neoadjuvant chemoradiotherapy.

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There is no consensus on the optimal treatment duration of anti-PD-1 for advanced melanoma. The aim of our study was to gain insight into the outcomes of anti-PD-1 discontinuation, the association of treatment duration with progression and anti-PD-1 re-treatment in relapsing patients. Analyses were performed on advanced melanoma patients in the Netherlands who discontinued first-line anti-PD-1 monotherapy in the absence of progressive disease (n = 324).

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Background: Previous trials suggest no differences in immunotherapy treatment between older and younger patients, but mainly young patients with a good performance status were included. The aim of this study was to describe the treatment patterns and outcomes of "real-world" older patients with metastatic melanoma and to identify predictors of outcome.

Methods: We included patients aged ≥65 years with metastatic melanoma from the Dutch Melanoma Treatment Registry.

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Non operative management of complete clinical responders after neoadjuvant treatment for rectal cancer enjoys an increasing popularity because of the increased functional outcome results. Even a near complete response can evolve in a cCR, and therefore further delaying response assessment is accepted. However, up to 40% of patients will develop a regrowth and will eventually require delayed surgery.

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The COVID-19 pandemic has made unprecedented global demands on healthcare in general and especially the intensive care unit (ICU). the virus is spreading out of control. To this day, there is no clear, published directive for doctors regarding the allocation of ICU beds in times of scarcity.

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Background: Anti-PD-1 antibodies and BRAF/MEK inhibitors are the two main groups of systemic therapy in the treatment of BRAF-mutant advanced melanoma. Until now, data are inconclusive on which therapy to use as first-line treatment. The aim of this study was to use propensity score matching to compare first-line anti-PD-1 monotherapy vs.

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Objective: The aim of this study was to evaluate treatment patterns and overall survival (OS) of patients with BRAFV600 wild-type and BRAFV600-mutant advanced melanoma in the Netherlands.

Methods: We selected patients of 18 years and over, diagnosed between 2016 and 2017 with unresectable stage IIIC or IV melanoma, registered in the Dutch Melanoma Treatment Registry. To assess the association of BRAFV600-mutation status with OS we used the Cox proportional-hazards model.

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Introduction: Since current studies on locally advanced pancreatic cancer (LAPC) mainly report from single, high-volume centers, it is unclear if outcomes can be translated to daily clinical practice. This study provides treatment strategies and clinical outcomes within a multicenter cohort of unselected patients with LAPC.

Materials And Methods: Consecutive patients with LAPC according to Dutch Pancreatic Cancer Group criteria, were prospectively included in 14 centers from April 2015 until December 2017.

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