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Featured researches published by Stijn van Weert.


Oral Oncology | 2013

Adenoid cystic carcinoma of the head and neck: a single-center analysis of 105 consecutive cases over a 30-year period

Stijn van Weert; Elisabeth Bloemena; Isaäc van der Waal; Remco de Bree; D. Rietveld; J. Kuik; C. René Leemans

BACKGROUND Adenoid cystic carcinoma is a rare salivary gland malignancy with a poor disease free survival due to frequent distant metastases and late local recurrences. Previous single-center reports on outcome mostly encompass small series. In this report a relative large series of 105 cases is analyzed, all treated at the VU University Medical Center, Amsterdam, The Netherlands over a 30-year period in which treatment strategies remained unchanged. METHODS All cases of ACC of the head and neck between 1979 and 2009 at our institution were analyzed through a medical chart review. Recurrence patterns and possible prognostic factors (T-stage, N-status, age, gender, type of salivary gland involved, histological grade, surgical margins, perineural invasion (PNI) and postoperative radiotherapy (RT)) were analyzed. RESULTS One-hundred and five cases of ACC of the head and neck were identified. Five-, ten- and twenty-year survival rates for overall survival were 68%, 52% and 28%, respectively. T-stage, N-status, surgical margins, histological subtype and age were highly significant predictors for survival. PNI was not a negative prognosticator. CONCLUSIONS T-stage, N-status, surgical margins, histological grade and age are the main predictors of survival-outcome in ACC of the head and neck. Distant metastasis frequently develop, mainly in the first 5 years post treatment. Local recurrences often develop even later on, warranting long term follow up of patients treated for ACC. Grade III ACC should be considered a specific entity within the group of ACC due to its typical aggressive biological behavior and relatively poor outcome, implicating the need for an improved adjuvant treatment.


Oral Oncology | 2015

Histopathological grading of adenoid cystic carcinoma of the head and neck: analysis of currently used grading systems and proposal for a simplified grading scheme

Stijn van Weert; Isaäc van der Waal; Birgit I. Witte; C. René Leemans; Elisabeth Bloemena

BACKGROUND Histopathological grading of adenoid cystic carcinoma (ACC) is a controversial issue. It is generally agreed that solid type ACC has a relatively poor prognosis. However, the amount of solid regions within this often mixed type tumor that predicts a poor prognosis is not firmly established. Some authors stipulate that the presence of a solid component regardless of the amount is a poor prognosticator where others argue that the amount should be taken into consideration. Two grading systems most commonly used are those described by Perzin et al./Szanto et al. and Spiro et al., respectively. They report that prognosis of ACC is poor if >30% and >50% of the tumor volume has a solid growth pattern, respectively. MATERIAL AND METHODS The described grading systems are applied to a series of 81 surgically treated cases of ACC at the VU University Medical Center, Amsterdam, The Netherlands. Moreover, we introduced an alternative grading system, in which the presence of a solid component, irrespective of its amount, is considered. All three systems of grading were tested for inter-observer concordance and prediction of prognosis. RESULTS Inter-observer concordance for grading ACC according to Perzin et al./Szanto et al. and Spiro et al., proved to be moderate with Kappa Scores of 0.393 and 0.433, respectively. Our alternative grading system yielded inter-observer concordance with a Cohens kappa result of 0.990. All systems were comparable in discriminating patients with poor clinical outcome. Histopathological grade proved to be an independent prognosticator. CONCLUSION The presence of any solid component in ACC is a negative prognosticator, and can histopathologically be diagnosed with a high reliability. These results suggest to merely register the presence or absence of a solid tumor component since its inter-observer variability is very low, its reproducibility is high and its predictive value is comparable to the traditional grading systems used.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2015

Sentinel node biopsy for early‐stage oral cavity cancer: the VU University Medical Center experience

Inne J. den Toom; Derrek A. Heuveling; Géke B. Flach; Stijn van Weert; K. Hakki Karagozoglu; Annelies van Schie; Elisabeth Bloemena; C. René Leemans; Remco de Bree

Sentinel node biopsy (SNB) in head and neck cancer is recently introduced as the staging technique of oral squamous cell carcinoma. We report the results of SNB in patients diagnosed with a T1–T2 oral squamous cell carcinoma and clinically negative (N0) neck in a single center.


Oral Oncology | 2013

Sentinel node identification in laryngeal cancer: Feasible in primary cancer with previously untreated neck

Géke B. Flach; Elisabeth Bloemena; Annelies van Schie; Otto S. Hoekstra; Stijn van Weert; C. René Leemans; Remco de Bree

OBJECTIVES With the current diagnostic techniques a considerable percentage of occult lymph node metastases are missed in the clinically negative (cN0) neck. Therefore, in patients with laryngeal cancer and cN0 neck a total laryngectomy is usually combined with elective neck dissection. Based on the risk of occult lymph node metastases the decision whether to perform a neck dissection or not is difficult. In recurrent laryngeal cancer or second primary tumors previous treatment possibly influences lymphatics and metastatic behavior. In this pilot study we investigated the feasibility of sentinel node (SN) identification and potential accuracy of sentinel node biopsy (SNB) in laryngeal cancer patients undergoing total laryngectomy with elective neck dissection. PATIENTS AND METHODS Patients with cN0 laryngeal cancer were included. During surgery 40MBq (99m)Technetium labeled Nanocolloid was endoscopically injected around the tumor. Lymphoscintigraphy was not performed. We identified the sentinel node (SN) ex vivo in the neck dissection specimen with a gammaprobe. Histopathological examination of the neck dissection specimen served as reference test. RESULTS We included 19 patients, 13 patients with untreated necks and six with prior neck treatment. SN identification was successful in 68.4% (13/19) of patients, and significantly higher in patients with untreated necks (92.3% versus 16.7%, p<0.01). Four of 13 (30.7%) patients would potentially be upstaged by SNB. Sensitivity and negative predictive value would have been 80.0% and 87.5%, respectively. CONCLUSION With the current methodology, SN identification in laryngeal cancer patients undergoing total laryngectomy is feasible in patients with untreated necks. Further studies are needed to determine the exact accuracy of SNB in total laryngectomy patients.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2017

Differences in patterns of survival in metastatic adenoid cystic carcinoma of the head and neck

Stijn van Weert; Rinze Reinhard; Elisabeth Bloemena; Jan Buter; Birgit I. Witte; Marije R. Vergeer; C. René Leemans

We examined the assumption in conventional teaching about metastatic adenoid cystic carcinoma (ACC) being an indolent type of disease.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2016

Management of the clinically N0 neck in squamous cell carcinoma of the maxillary alveolus and hard palate

Alejandra D. van Os; Baris Karakullukcu; C. René Leemans; Gyorgy B. Halmos; Jan Roodenburg; Stijn van Weert; K. Hakki Karagozoglu; Max J. H. Witjes

The purpose of this study was to evaluate active surveillance strategy in the clinically negative neck in maxillary squamous cell carcinoma (SCC).


European Archives of Oto-rhino-laryngology | 2018

Tumors of the parapharyngeal space: the VU University Medical Center experience over a 20-year period

Thijs van Hees; Stijn van Weert; Birgit I. Witte; C. René Leemans

BackgroundTumors of the parapharyngeal space (PPS) are rare, accounting for 0.5–1.5% of all head and neck tumors. The anatomy of the PPS is responsible for a wide variety of tumors arising from the PPS. This series of 99 PPS tumors provides an overview of the clinical course and management of PPS tumors.Materials and methodsThis retrospective study included clinical data from patients treated for PPS tumors from 1991 to 2012 (warranting at least a 4-year follow-up) at the VU University Medical Center, Amsterdam, The Netherlands.ResultsFifty percent were salivary gland tumors, 41% were neurogenic and 9% had a different origin. 18.2% of the PPS tumors were malignant. The most reported symptom at presentation was swelling of the neck and throat. In 14%, the PPS tumor was an accidental finding following imaging for other diagnostic reasons. Cytology showed an accuracy rate of 73.1% (19/26). The positive predictive value of a malignant cytology result was 86% (95% CI 42.1–99.6%). Surgery was performed in 55 patients (56%). The most frequently performed approach (56%) was the cervical–transparotid approach, followed by the cervical (25%), transmandibular (16%) and transoral (2%) approach. Nine patients died of the disease, of which seven patients had a malignant salivary gland tumor, one patient had a pleomorphic adenoma at first diagnosis which degenerated into carcinoma ex pleomorphic adenoma and one patient died of metastatic renal cell carcinoma.ConclusionThis large single-centre report on PPS tumors shows that careful diagnostic work up and proper surgical planning are important in this specific and rare group of head and neck tumors. Surgery was the main treatment (56%) for parapharyngeal tumors. Management of parapharyngeal neurogenic neoplasms generally consists of active surveillance due to peri-operative risk for permanent cranial nerve damage. The histopathological diagnoses were consistent with previous reports.


European Journal of Nuclear Medicine and Molecular Imaging | 2017

The added value of SPECT-CT for the identification of sentinel lymph nodes in early stage oral cancer

Inne J. den Toom; Annelies van Schie; Stijn van Weert; K. Hakki Karagozoglu; Elisabeth Bloemena; Otto S. Hoekstra; Remco de Bree

PurposeTo assess the role of single-photon emission computed tomography with computed tomography (SPECT-CT) for the identification of sentinel lymph nodes (SLNs) in patients with early stage (T1–T2) oral cancer and a clinically negative neck (cN0).MethodsIn addition to planar lymphoscintigraphy, SPECT-CT was performed in 66 consecutive patients with early stage oral cancer and a clinically negative neck. The addition of SPECT-CT to planar images was retrospectively analyzed for the number of additional SLNs, more precise localization of SLNs, and importance of anatomical information by a team consisting of a nuclear physician, surgeon, and investigator.ResultsIdentification rate for both imaging modalities combined was 98% (65/66). SPECT-CT identified 15 additional SLNs in 14 patients (22%). In 2/15 (13%) of these additional SLNs, the only metastasis was found, resulting in an upstaging rate of 3% (2/65). In 20% of the patients with at least one positive SLN, the only positive SLN was detected due to the addition of SPECT-CT. SPECT-CT was considered to add important anatomical information in two patients (3%). In 5/65 (8%) of the patients initially scored SLNs on planar lymphoscintigrams were scored as non-SLNs when SPECT-CT was added. There were four false-negative SLN biopsy procedures in this cohort.ConclusionsThe addition of SPECT-CT to planar lymphoscintigraphy is recommended for the identification of more (positive) SLNs and better topographical orientation for surgery in sentinel lymph node biopsy for early stage oral cancer.


European Archives of Oto-rhino-laryngology | 2018

Evaluation of vascular features of vocal cords proposed by the European Laryngological Society

Robert Šifrer; Johannes A. Rijken; C. René Leemans; Simone E. J. Eerenstein; Stijn van Weert; Jan-Jaap Hendrickx; Elisabeth Bloemena; Derrek A. Heuveling; Rico N. P. M. Rinkel

A newly proposed classification by the European Laryngological Society (ELS) of glottic lesions by narrow-band imaging (NBI) divides their vascular patterns into longitudinal and perpendicular ones. The latter are further subdivided into the wide and narrow patterns. The longitudinal, wide, and narrow patterns are characteristic of benign disease, papilloma, and malignancy, respectively. The aim of the study was to investigate the diagnostic effectiveness of the classification. Forty patients with glottic lesions underwent microlaryngoscopy. The vascular patterns of all vocal cords were defined with NBI. The affected vocal cords were histologically analysed and comprised the arm (A). Unaffected vocal cords were not histologically analysed but followed-up and comprised the arm (B) and were regarded as true negatives if no suspicious changes appeared during the follow-up. The vocal cords from the arm A were categorised into the benign and malignant group according to the histologic result. The ratio of vascular patterns was determined and the groups were statistically compared using the Chi-square test and Fisher’s exact test. Perpendicular changes were observed in 36.6% (9/26) of benign diseases and in 100% (23/23) of cancer conditions (p < 0.001). Wide perpendicular changes appeared only in papillomas (6/6) while narrow ones mostly in malignancies (23/26) and also in benign conditions (3/26) (p < 0.001). The sensitivity, specificity, positive and negative predictive values, and accuracy were 100, 95, 88, 100 and 96%, respectively. The new ELS classification can be used effectively and safely to differentiate malignant from benign disease.


European Archives of Oto-rhino-laryngology | 2017

Additional non-sentinel lymph node metastases in early oral cancer patients with positive sentinel lymph nodes

Inne J. Den Toom; Elisabeth Bloemena; Stijn van Weert; K. Hakki Karagozoglu; Otto S. Hoekstra; Remco de Bree

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C. René Leemans

VU University Medical Center

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Elisabeth Bloemena

VU University Medical Center

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K. Hakki Karagozoglu

Academic Center for Dentistry Amsterdam

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Annelies van Schie

VU University Medical Center

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Birgit I. Witte

VU University Medical Center

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Derrek A. Heuveling

VU University Medical Center

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Isaäc van der Waal

VU University Medical Center

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Otto S. Hoekstra

VU University Medical Center

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D. Rietveld

VU University Medical Center

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