Katja Gaarenstroom

Dr. Katja Gaarenstroom


Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
22 April 2019 in Nature Medicine
Verified
Journal Article
Closed access
PDF file
OKOded Kopper
Oded Kopper
CWChris J. de Witte
Chris J. de Witte
KLKadi Lõhmussaar
Kadi Lõhmussaar
JVJose Espejo Valle-Inclan
Jose Espejo Valle-Inclan
NHNizar Hami
Nizar Hami
Hans CleversHans Clevers
Hans Clevers

20 February 2008 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
AZAte G.J. Van der Zee
Ate G.J. Van der Zee
MOMaaike H. Oonk
Maaike H. Oonk
JHJoanne A. De Hullu
Joanne A. De Hullu
AAAnca C. Ansink
Anca C. Ansink
IVIgnace Vergote
Ignace Vergote
WSWim J. Sluiter
Wim J. Sluiter
Purpose: To investigate the safety and clinical utility of the sentinel node procedure in early-stage vulvar cancer patients. Patients and Methods: A multicenter observational study on sentinel node detection using radioactive tracer and blue dye was performed in patients with T1/2 (< 4 cm) squamous cell cancer of the vulva. When the sentinel node was found to be negative at pathologic ultrastaging, inguinofemoral lymphadenectomy was omitted, and the patient was observed with follow-up for 2 years at intervals of every 2 months. Stopping rules were defined for the occurrence of groin recurrences. Results: From March 2000 until June 2006, a sentinel node procedure was performed in 623 groins of 403 assessable patients. In 259 patients with unifocal vulvar disease and a negative sentinel node (median follow-up time, 35 months), six groin recurrences were diagnosed (2.3%; 95% CI, 0.6% to 5%), and 3-year survival rate was 97% (95% CI, 91% to 99%). Short-term morbidity was decreased in patients after sentinel node dissection only when compared with patients with a positive sentinel node who underwent inguinofemoral lymphadenectomy (wound breakdown in groin: 11.7% v 34.0%, respectively; P < .0001; and cellulitis: 4.5% v 21.3%, respectively; P < .0001). Long-term morbidity also was less frequently observed after removal of only the sentinel node compared with sentinel node removal and inguinofemoral lymphadenectomy (recurrent erysipelas: 0.4% v 16.2%, respectively; P < .0001; and lymphedema of the legs: 1.9% v 25.2%, respectively; P < .0001). Conclusion: In early-stage vulvar cancer patients with a negative sentinel node, the groin recurrence rate is low, survival is excellent, and treatment-related morbidity is minimal. We suggest that sentinel node dissection, performed by a quality-controlled multidisciplinary team, should be part of the standard treatment in selected patients with early-stage vulvar cancer.

1 July 2016 in Laboratory Investigation
Verified
Journal Article
Open access
AHA Marijne Heeren
A Marijne Heeren
SPSimone Punt
Simone Punt
MBMaaike C.G. Bleeker
Maaike C.G. Bleeker
KGKatja Gaarenstroom
Katja Gaarenstroom
JVJacobus van der Velden
Jacobus van der Velden
Ekaterina S. JordanovaEkaterina S. Jordanova
Ekaterina S. Jordanova
Programmed death-ligand 1 (PD-L1) is expressed in various immune cells and tumor cells, and is able to bind to PD-1 on T lymphocytes, thereby inhibiting their function. At present, the PD-1/PD-L1 axis is a major immunotherapeutic target for checkpoint inhibition in various cancer types, but information on the clinical significance of PD-L1 expression in cervical cancer is largely lacking. Here, we studied PD-L1 expression in paraffin-embedded samples from two cohorts of patients with cervical cancer: primary tumor samples from cohort I (squamous cell carcinoma, n=156 and adenocarcinoma, n=49) and primary and paired metastatic tumor samples from cohort II (squamous cell carcinoma, n=96 and adenocarcinoma, n=31). Squamous cell carcinomas were more frequently positive for PD-L1 and also contained more PD-L1-positive tumor-associated macrophages as compared with adenocarcinomas (both P<0.001). PD-L1-positive tumor-associated macrophages were found to express CD163 and/or CD14 by triple fluorescent immunohistochemistry, demonstrating an M2-like phenotype. Interestingly, disease-free survival (P=0.022) and disease-specific survival (P=0.046) were significantly poorer in squamous cell carcinoma patients with diffuse PD-L1 expression as compared with patients with marginal PD-L1 expression (i.e., on the interface between tumor and stroma) in primary tumors. Disease-specific survival was significantly worse in adenocarcinoma patients with PD-L1-positive tumor-associated macrophages compared with adenocarcinoma patients without PD-L1-positive tumor-associated macrophages (P=0.014). No differences in PD-L1 expression between primary tumors and paired metastatic lymph nodes were detected. However, PD-L1-positive immune cells were found in greater abundance around the metastatic tumors as compared with the paired primary tumors (P=0.001 for squamous cell carcinoma and P=0.041 for adenocarcinoma). These findings point to a key role of PD-L1 in immune escape of cervical cancer, and provide a rationale for therapeutic targeting of the PD-1/PD-L1 pathway.

1 January 2016 in Gynecologic Oncology
Verified
Journal Article
Closed access
NGN.C. Te Grootenhuis
N.C. Te Grootenhuis
AZA.G.J. van der Zee
A.G.J. van der Zee
HDH.C. van Doorn
H.C. van Doorn
JVJ. van der Velden
J. van der Velden
IVI. Vergote
I. Vergote
MOMaaike H.M. Oonk
Maaike H.M. Oonk

14 June 2016 in Clinical Cancer Research
Verified
Journal Article
Closed access
PDF file
CHCharlotte E.S. Hoogstins
Charlotte E.S. Hoogstins
QTQuirijn R.J.G. Tummers
Quirijn R.J.G. Tummers
KGKatja Gaarenstroom
Katja Gaarenstroom
CKCor D. de Kroon
Cor D. de Kroon
JTJ. Baptist M.Z. Trimbos
J. Baptist M.Z. Trimbos
AVAlexander Vahrmeijer
Alexander Vahrmeijer
Purpose: Completeness of cytoreductive surgery is a key prognostic factor for survival in patients with ovarian cancer. The ability to differentiate clearly between malignant and healthy tissue is essential for achieving complete cytoreduction. Using current approaches, this differentiation is often difficult and can lead to incomplete tumor removal. Near-infrared fluorescence imaging has the potential to improve the detection of malignant tissue during surgery, significantly improving outcome. Here, we report the use of OTL38, a near-infrared (796 nm) fluorescent agent, that binds folate receptor alpha, which is expressed in >90% of epithelial ovarian cancers. Experimental Design: We first performed a randomized, placebo-controlled study in 30 healthy volunteers. Four single increasing doses of OTL38 were delivered intravenously. At fixed times following drug delivery, tolerability and blood/skin pharmacokinetics were assessed. Next, using the results of the first study, three doses were selected and administered to 12 patients who had epithelial ovarian cancer and were scheduled for cytoreductive surgery. We measured tolerability and blood pharmacokinetics, as well as the ability to detect the tumor using intraoperative fluorescence imaging. Results: Intravenous infusion of OTL38 in 30 healthy volunteers yielded an optimal dosage range and time window for intraoperative imaging. In 12 patients with ovarian cancer, OTL38 accumulated in folate receptor alpha–positive tumors and metastases, enabling the surgeon to resect an additional 29% of malignant lesions that were not identified previously using inspection and/or palpation. Conclusions: This study demonstrates that performing real-time intraoperative near-infrared fluorescence imaging using a tumor-specific agent is feasible and potentially clinically beneficial. Clin Cancer Res; 22(12); 2929–38. ©2016 AACR.

1 July 2010 in The Lancet Oncology
Verified
Journal Article
Closed access
MOMaaike H Oonk
Maaike H Oonk
BHBettien M van Hemel
Bettien M van Hemel
HHHarry Hollema
Harry Hollema
JHJoanne A de Hullu
Joanne A de Hullu
AAAnca C Ansink
Anca C Ansink
AZAte G van der Zee
Ate G van der Zee