Guido Lammering

Maastricht Universitair Medisch Centrum, Maestricht, Limburg, Netherlands

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Publications (83)396.59 Total impact

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    ABSTRACT: Chemoradiation (CRT) has been shown to lead to downsizing of an important portion of rectal cancers. In order to tailor treatment at an earlier stage during treatment, predictive models are being developed. Adding blood biomarkers may be attractive for prediction, as they can be collected very easily and determined with excellent reproducibility in clinical practice. The hypothesis of this study was that blood biomarkers related to tumor load, hypoxia and inflammation can help to predict response to CRT in rectal cancer. 295 patients with locally advanced rectal cancer who were planned to undergo CRT were prospectively entered into a biobank protocol (NCT01067872). Blood samples were drawn before start of CRT. Nine biomarkers were selected, based on a previously defined hypothesis, and measured in a standardized way by a certified lab: CEA, CA19-9, LDH, CRP, IL-6, IL-8, CA IX, osteopontin and 25-OH-vitamin D. Outcome was analyzed in two ways: pCR vs. non-pCR and responders (defined as ypT0-2N0) vs. non-responders (all other ypTN stages). 276 patients could be analyzed. 20.7% developed a pCR and 47.1% were classified as responders. In univariate analysis CEA (p=0.001) and osteopontin (p=0.012) were significant predictors for pCR. Taking response as outcome CEA (p<0.001), IL-8 (p<0.001) and osteopontin (p=0.004) were significant predictors. In multivariate analysis CEA was the strongest predictor for pCR (OR 0.92, p=0.019) and CEA and IL-8 predicted for response (OR 0.97, p=0.029 and OR 0.94, p=0.036). The model based on biomarkers only had an AUC of 0.65 for pCR and 0.68 for response; the strongest model included clinical data, PET-data and biomarkers and had an AUC of 0.81 for pCR and 0.78 for response. CEA and IL-8 were identified as predictive biomarkers for tumor response and PCR after CRT in rectal cancer. Incorporation of these blood biomarkers leads to an additional accuracy of earlier developed prediction models using clinical variables and PET-information. The new model could help to an early adaptation of treatment in rectal cancer patients.
    Radiotherapy and Oncology 04/2014; · 4.52 Impact Factor
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    ABSTRACT: New prognostic markers may be of value in determining survival and informing decisions of adjuvant treatment in the heterogeneous group of soft tissue sarcomas known as malignant fibrous sarcomas (MFS). Increased CD44 expression has been associated with a better outcome in cancers such as bladder tumors and could potentially relate to cell-cell interaction as a marker for potential invasion/metastasis. The aim of this pilot study was to determine if there is a correlation between the expression rate of CD44 in adult patients with MFS and clinical outcomes. The clinical outcome of 34 adult MFS patients (19 males and 15 females, average age 62 years, median 63 years, range: 38-88 years) who underwent surgical treatment were evaluated. Twenty-five of these patients had additional adjuvant radiotherapy. Extracted RNA from sarcoma tissues was used to measure the transcripts of CD44s (standard form) and isoform expression.The pooled data for each variant of CD44 was divided in half at the median expression value into two equally sized groups (low and high). Survival modeling and multivariate analysis were used with these two groups to determine if there were differences in survival times and whether this was independent of known factors such as tumor stage/grade, patient age and resection margin status. High CD44s and low of CD44v6 expression significantly correlated with an improved outcome (P <0.05 and P <0.02, respectively) whereas CD44v8 and hCD44 (isoforms) did not. Differences in survival were apparent within 6-12 months of operation with >30% difference in survival between low/high expressions at 5 years. These finding were independent of the other measured MFS survival predictors, though the group was homogenous. High CD44s and low CD44v6 expression may be an independent predictor of improved survival in MFS patients in this pilot data. This is contrary to other MFS data, which did not account for the CD44 isoforms but is confirmed by data from other cancer types. Further investigation is needed to confirm CD44 isoform expression data as a relevant survival biomarker and whether it could be used to inform clinical decisions such as adjuvant therapy.
    European journal of medical research. 02/2014; 19(1):6.
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    ABSTRACT: To investigate the reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) in assessing tumor response early in the course of neoadjuvant chemoradiotherapy in patients with operable esophageal cancer. Eleven male patients (mean age 54.8 years) with newly diagnosed esophageal cancer underwent DW-MRI before and 10 days after start of chemoradiotherapy. Reproducibility of apparent diffusion coefficient (ADC) measurements by manual (freehand) and semi-automated volumetric methods was assessed. Interobserver reproducibility for the assessment of mean tumor ADC by the manual measurement method was good, with an ICC of 0.69 (95% CI, 0.36 to 0.85; P = 0.001). Interobserver reproducibility for the assessment of mean tumor ADC by the semi-automated volumetric measurement method was very good, with an ICC of 0.96 (95% CI, 0.91 to 0.98; P<0.001). Semi-automated volumetric ADC measurements have higher reproducibility than manual ADC measurements in assessing tumor response to chemoradiotherapy in patients with esophageal adenocarcinoma.
    PLoS ONE 01/2014; 9(4):e92211. · 3.73 Impact Factor
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    ABSTRACT: Purpose/objective Chemoradiation (CRT) has been shown to lead to downsizing of an important portion of rectal cancers. In order to tailor treatment at an earlier stage during treatment, predictive models are being developed. Adding blood biomarkers may be attractive for prediction, as they can be collected very easily and determined with excellent reproducibility in clinical practice. The hypothesis of this study was that blood biomarkers related to tumor load, hypoxia and inflammation can help to predict response to CRT in rectal cancer. Material/methods 295 patients with locally advanced rectal cancer who were planned to undergo CRT were prospectively entered into a biobank protocol (NCT01067872). Blood samples were drawn before start of CRT. Nine biomarkers were selected, based on a previously defined hypothesis, and measured in a standardized way by a certified lab: CEA, CA19-9, LDH, CRP, IL-6, IL-8, CA IX, osteopontin and 25-OH-vitamin D. Outcome was analyzed in two ways: pCR vs. non-pCR and responders (defined as ypT0-2N0) vs. non-responders (all other ypTN stages). Results 276 patients could be analyzed. 20.7% developed a pCR and 47.1% were classified as responders. In univariate analysis CEA (p = 0.001) and osteopontin (p = 0.012) were significant predictors for pCR. Taking response as outcome CEA (p < 0.001), IL-8 (p < 0.001) and osteopontin (p = 0.004) were significant predictors. In multivariate analysis CEA was the strongest predictor for pCR (OR 0.92, p = 0.019) and CEA and IL-8 predicted for response (OR 0.97, p = 0.029 and OR 0.94, p = 0.036). The model based on biomarkers only had an AUC of 0.65 for pCR and 0.68 for response; the strongest model included clinical data, PET-data and biomarkers and had an AUC of 0.81 for pCR and 0.78 for response. Conclusion CEA and IL-8 were identified as predictive biomarkers for tumor response and PCR after CRT in rectal cancer. Incorporation of these blood biomarkers leads to an additional accuracy of earlier developed prediction models using clinical variables and PET-information. The new model could help to an early adaptation of treatment in rectal cancer patients.
    Radiotherapy and Oncology. 01/2014;
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    ABSTRACT: A previous study showed promising results for gadofosveset-trisodium as a lymph node magnetic resonance imaging (MRI) contrast agent in rectal cancer. The aim of this study was to prospectively confirm the diagnostic performance of gadofosveset MRI for nodal (re)staging in rectal cancer in a second patient cohort. Seventy-one rectal cancer patients were prospectively included, of whom 13 (group I) underwent a primary staging gadofosveset MRI (1.5-T) followed by surgery (± preoperative 5 × 5 Gy) and 58 (group II) underwent both primary staging and restaging gadofosveset MRI after a long course of chemoradiotherapy followed by surgery. Nodal status was scored as (y)cN0 or (y)cN+ by two independent readers (R1, R2) with different experience levels. Results were correlated with histology on a node-by-node basis. Sensitivity, specificity and area under the receiver operating characteristics curve (AUC) were 94 %, 79 % and 0.89 for the more experienced R1 and 50 %, 83 % and 0.74 for the non-experienced R2. R2's performance improved considerably after a learning curve, to an AUC of 0.83. Misinterpretations mainly occurred in nodes located in the superior mesorectum, nodes located in between vessels and nodes containing micrometastases. This prospective study confirms the good diagnostic performance of gadofosveset MRI for nodal (re)staging in rectal cancer. • Gadofosveset-enhanced MRI shows high performance for nodal (re)staging in rectal cancer. • Gadofosveset MRI may facilitate better selection of patients for personalised treatment. • Results can be reproduced by non-expert readers. • Experience of 50-60 cases is required to achieve required expertise level. • Main pitfalls are nodes located between vessels and nodes containing micrometastases.
    European Radiology 09/2013; · 3.55 Impact Factor
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    ABSTRACT: PURPOSE: Neoadjuvant chemoradiotherapy is increasingly used in oesophageal cancer patients. In general, small tumours are associated with a survival benefit compared to large tumours. Little is known, however, about the relationship between initial tumour volume and response to chemoradiotherapy. Therefore, the aim of this study was to determine whether the pretherapy metabolic tumour volume (MTV) on diagnostic PET/CT in oesophageal cancer patients is correlated with response to chemoradiotherapy in the resection specimen. METHODS: A consecutive series of patients underwent diagnostic PET/CT scanning prior to chemoradiotherapy and oesophagectomy. MTVs were determined on PET/CT and an automated tumour contour was generated using specified standard uptake value thresholds. Response to chemoradiotherapy was determined in the resection specimen according to the scoring system developed by Mandard et al. Patients were divided into different groups according to response to chemoradiotherapy. RESULTS: Between January 2008 and May 2011 a total of 115 patients underwent an oesophagectomy. The MTV determined on diagnostic PET/CT scans was available in 79 patients. Of these 79 patients, 30 (38 %) showed no residual tumour cells at the location of the primary tumour. Three of these patients presented with residual tumour cells in the lymph nodes; 27 patients (34 %) had a complete pathological response. There was a trend towards a better response in patients with a smaller MTV (p = 0.084). CONCLUSION: This study demonstrated a trend towards a correlation between response to chemoradiotherapy in oesophageal cancer patients and smaller MTVs as determined on diagnostic PET/CT prior to neoadjuvant chemoradiotherapy. However, tumour volumes overlapped between groups, indicating the need for multifactorial parameters as predictors. In addition, a complete local tumour response may be accompanied by residual disease in the regional lymph nodes.
    European Journal of Nuclear Medicine 06/2013; · 4.53 Impact Factor
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    ABSTRACT: BACKGROUND: Long-term survival can be obtained with local treatment of lung metastases from colorectal cancer. However, it is unclear as to what the optimal local therapy is: surgery, radiofrequency ablation (RFA) or stereotactic radiotherapy (SBRT). METHODS: A systematic review included 27 studies matching with the a priori selection criteria, the most important being ⩾50 patients and a follow-up period of ⩾24months. No SBRT studies were eligible. The review was therefore conducted on 4 RFA and 23 surgical series. RESULTS: Four of the surgical studies were prospective, all others were retrospective. No randomized trial was found. The reporting of data differed between the studies, which led to difficulties in the analyses. Treatment-related mortality rates for RFA and surgery were 0% and 1.4-2.4%, respectively, whereas morbidity rates were reported inconsistently but seemed the lowest for surgery. CONCLUSION: Due to the lack of phase III trials, no firm conclusions can be drawn, although most evidence supports surgery as the most effective treatment option. High-quality trials comparing currently used treatment modalities such as SBRT, RFA and surgery are needed to inform treatment decisions.
    Cancer Treatment Reviews 06/2013; · 6.02 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE: Rectal bleeding can occur following radiotherapy for prostate cancer and negatively impacts quality of life for cancer survivors. Treatment and clinical factors do not fully predict rectal bleeding, and genetic factors may be important. MATERIALS AND METHODS: A genome-wide association study (GWAS) was performed to identify SNPs associated with the development of late rectal bleeding following radiotherapy for prostate cancer. Logistic regression was used to test the association between 614,453 SNPs and rectal bleeding in a discovery cohort (79 cases, 289 controls), and top-ranking SNPs were tested in a replication cohort (108 cases, 673 controls) from four independent sites. RESULTS: rs7120482 and rs17630638, which tag a single locus on chromosome 11q14.3, reached genome-wide significance for association with rectal bleeding (combined p-values 5.4×10(-8) and 6.9×10(-7) respectively). Several other SNPs had p-values trending toward genome-wide significance, and a polygenic risk score including these SNPs shows a strong rank-correlation with rectal bleeding (Sommers' d=5.0×10(-12) in the replication cohort). CONCLUSIONS: This GWAS identified novel genetic markers of rectal bleeding following prostate radiotherapy. These findings could lead to the development of a predictive assay to identify patients at risk for this adverse treatment outcome so that dose or treatment modality could be modified.
    Radiotherapy and Oncology 05/2013; · 4.52 Impact Factor
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    ABSTRACT: PURPOSE: To investigate the toxicity of nelfinavir, administered during preoperative chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. MATERIAL AND METHODS: Twelve patients were treated with chemoradiotherapy to 50.4Gy combined with capecitabine 825mg/m(2) BID. Three dose levels (DL) of nelfinavir were tested: 750mg BID (DL1), 1250mg BID (DL2) and an intermediate level of 1000mg BID (DL3). Surgery was performed between 8 and 10weeks after completion of CRT. Primary endpoint was dose-limiting toxicity (DLT), defined as any grade 3 or higher non-hematological or grade 4 or higher hematological toxicity. RESULTS: Eleven patients could be analyzed: 5 were treated in DL1, 3 in DL2 and 3 in DL3. The first 3 patients in DL1 did not develop a DLT. In DL2 one patient developed gr 3 diarrhea, 1 patient had gr 3 transaminase elevation and 1 patient had a gr 3 cholangitis with unknown cause. An intermediate dose level was tested in DL3. In this group 2 patients developed gr 3 diarrhea and 1 patient gr 3 transaminase elevation and gr 4 post-operative wound complication. Three patients achieved a pathological complete response (pCR). CONCLUSIONS: Nelfinavir 750mg BID was defined as the recommended phase II dose in combination with capecitabine and 50.4Gy pre-operative radiotherapy in rectal cancer. First tumor response evaluations are promising, but a further phase II study is needed to get more information about efficacy of this treatment regimen.
    Radiotherapy and Oncology 05/2013; · 4.52 Impact Factor
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    ABSTRACT: PURPOSE: Accurate tumor positioning in stereotactic body radiation therapy (SBRT) of liver lesions is often hampered by motion and setup errors. We combined 3-dimensional ultrasound imaging (3DUS) and active breathing control (ABC) as an image guidance tool. METHODS AND MATERIALS: We tested 3DUS image guidance in the SBRT treatment of liver lesions for 11 patients with 88 treatment fractions. In 5 patients, 3DUS imaging was combined with ABC. The uncertainties of US scanning and US image segmentation in liver lesions were determined with and without ABC. RESULTS: In free breathing, the intraobserver variations were 1.4 mm in left-right (L-R), 1.6 mm in superior-inferior (S-I), and 1.3 mm anterior-posterior (A-P). and the interobserver variations were 1.6 mm (L-R), 2.8 mm (S-I), and 1.2 mm (A-P). The combined uncertainty of US scanning and matching (inter- and intraobserver) was 4 mm (1 SD). The combined uncertainty when ABC was used reduced by 1.7 mm in the S-I direction. For the L-R and A-P directions, no significant difference was observed. CONCLUSION: 3DUS imaging for IGRT of liver lesions is feasible, although using anatomic surrogates in the close vicinity of the lesion may be needed. ABC-based breath-hold in midventilation during 3DUS imaging can reduce the uncertainty of US-based 3D table shift correction.
    International journal of radiation oncology, biology, physics 10/2012; · 4.59 Impact Factor
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    ABSTRACT: PURPOSE: To identify single nucleotide polymorphisms (SNPs) associated with development of erectile dysfunction (ED) among prostate cancer patients treated with radiation therapy. METHODS AND MATERIALS: A 2-stage genome-wide association study was performed. Patients were split randomly into a stage I discovery cohort (132 cases, 103 controls) and a stage II replication cohort (128 cases, 102 controls). The discovery cohort was genotyped using Affymetrix 6.0 genome-wide arrays. The 940 top ranking SNPs selected from the discovery cohort were genotyped in the replication cohort using Illumina iSelect custom SNP arrays. RESULTS: Twelve SNPs identified in the discovery cohort and validated in the replication cohort were associated with development of ED following radiation therapy (Fisher combined P values 2.1 × 10(-5) to 6.2 × 10(-4)). Notably, these 12 SNPs lie in or near genes involved in erectile function or other normal cellular functions (adhesion and signaling) rather than DNA damage repair. In a multivariable model including nongenetic risk factors, the odds ratios for these SNPs ranged from 1.6 to 5.6 in the pooled cohort. There was a striking relationship between the cumulative number of SNP risk alleles an individual possessed and ED status (Sommers' D P value = 1.7 × 10(-29)). A 1-allele increase in cumulative SNP score increased the odds for developing ED by a factor of 2.2 (P value = 2.1 × 10(-19)). The cumulative SNP score model had a sensitivity of 84% and specificity of 75% for prediction of developing ED at the radiation therapy planning stage. CONCLUSIONS: This genome-wide association study identified a set of SNPs that are associated with development of ED following radiation therapy. These candidate genetic predictors warrant more definitive validation in an independent cohort.
    International journal of radiation oncology, biology, physics 09/2012; · 4.59 Impact Factor
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    ABSTRACT: Background. The objectives of this study were to investigate the predictive value of sequential (18)F-FDG PET scans for pathological tumor response grade (TRG) after preoperative chemoradiotherapy (PCRT) in locally advanced rectal cancer (LARC) and the impact of partial volume effects correction (PVC). Methods. Twenty-eight LARC patients were included. Responders and non-responders status were determined in histopathology. PET indices [SUV max and mean, volume and total lesion glycolysis (TLG)] at baseline and their evolution after one and two weeks of PCRT were extracted by delineation of the PET images, with or without PVC. Their predictive value was investigated using Mann-Whitney-U tests and ROC analysis. Results. Within baseline parameters, only SUV(mean) was correlated with response. No evolution after one week was predictive of the response, whereas after two weeks all the parameters except volume were, the best prediction being obtained with TLG (AUC 0.79, sensitivity 63%, specificity 92%). PVC had no significant impact on these results. Conclusion. Several PET indices at baseline and their evolution after two weeks of PCRT are good predictors of response in LARC, with or without PVC, whereas results after one week are suboptimal. Best predictor was TLG reduction after two weeks, although baseline SUV(mean) had smaller but similar predictive power.
    Acta oncologica (Stockholm, Sweden) 08/2012; · 2.27 Impact Factor
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    ABSTRACT: Previously, we showed a good correlation between pathology and an automatically generated PET-contour in rectal cancer. This study analyzed the effect of the use of PET-CT scan on the interobserver variation in GTV definition in rectal cancer and the influence of PET-CT on treatment volumes. Forty two patients diagnosed with rectal cancer underwent an FDG-PET-CT for radiotherapy planning. An automatic contour was created on PET-scan using the source-to-background ratio. The GTV was delineated by 5 observers in 3 rounds: using CT and MRI, using CT, MRI and PET and using CT, MRI and PET auto-contour. GTV volumes were compared and concordance indices (CI) were calculated. Since the GTV is only a small portion of the treatment volume in rectal cancer, a separate analysis was performed to evaluate the influence of PET on the definition of the CTV used in daily clinical practice and the caudal extension of the treatment volumes. GTV volumes based on PET were significantly smaller. CIs increased significantly using PET and the best interobserver agreement was observed using PET auto-contours. Furthermore, we found that in up to 29% of patients the CTV based on PET extended outside the CTV used in clinical practice. The caudal border of the treatment volume can be tailored using PET-scan in low seated tumors. Influence of PET on the position of the caudal border was most pronounced in high seated tumors. PET-CT increases the interobserver agreement in the GTV definition in rectal cancer, helps to avoid geographical misses and allows tailoring the caudal border of the treatment volume.
    Radiotherapy and Oncology 03/2012; 102(3):371-6. · 4.52 Impact Factor
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    ABSTRACT: The CARTS study is a multicenter feasibility study, investigating the role of rectum saving surgery for distal rectal cancer. Patients with a clinical T1-3 N0 M0 rectal adenocarcinoma below 10 cm from the anal verge will receive neoadjuvant chemoradiation therapy (25 fractions of 2 Gy with concurrent capecitabine). Transanal Endoscopic Microsurgery (TEM) will be performed 8 - 10 weeks after the end of the preoperative treatment depending on the clinical response.Primary objective is to determine the number of patients with a (near) complete pathological response after chemoradiation therapy and TEM. Secondary objectives are the local recurrence rate and quality of life after this combined therapeutic modality. A three-step analysis will be performed after 20, 33 and 55 patients to ensure the feasibility of this treatment protocol. The CARTS-study is one of the first prospective multicentre trials to investigate the role of a rectum saving treatment modality using chemoradiation therapy and local excision. The CARTS study is registered at clinicaltrials.gov (NCT01273051).
    BMC Surgery 12/2011; 11:34. · 1.97 Impact Factor
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    ABSTRACT: The "wait-and-see" policy instead of standard surgery for patients with rectal cancer who undergo a complete tumor regression after chemoradiation treatment is highly controversial. It is not clear yet how patients should be monitored once they are managed nonoperatively and whether follow-up by MRI has any potential role. This study aimed to describe the rectal wall MRI morphology during short-term and long-term follow-up in patients with a clinical complete tumor response undergoing a wait-and-see policy without surgical treatment. As part of an observational study in our center, a cohort of 19 carefully selected patients with a clinical complete response after chemoradiation was managed with a wait-and-see policy and followed regularly (every 3-6 mo) by clinical examination, endoscopy with biopsies, and a rectal MRI. The MR morphology of the tumor bed was studied on the consecutive MRI examinations. The primary outcome measured was the morphology of the tumor bed on the consecutive MRI examinations performed during short-term (≤6 mo) and long-term (>6 mo) follow-up. Patients with a complete tumor response after chemoradiation presented with either a normalized rectal wall (26%) or fibrosis (74%). In the latter group, 3 patterns of fibrosis were observed (full-thickness, minimal, or spicular fibrosis). The morphology patterns of a normalized rectal wall or fibrosis remained consistent during long-term follow-up in 18 of 19 patients. One patient developed a small, endoluminal recurrence, which was salvaged with transanal endoscopic microsurgery. In 26% of patients, an edematous wall thickening was observed in the first months after chemoradiation, which gradually decreased during long-term follow-up. Median follow-up was 22 months (range, 12-60). This was a small observational study, and had no histological validation. Four MR patterns of a persistent complete response of rectal cancer after chemoradiation were identified. These MR features can serve as a reference for the follow-up in a wait-and-see policy.
    Diseases of the Colon & Rectum 12/2011; 54(12):1521-8. · 3.34 Impact Factor
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    ABSTRACT: Neoadjuvant chemoradiotherapy for rectal cancer can result in complete disappearance of tumor and involved nodes. In patients without residual tumor on imaging and endoscopy (clinical complete response [cCR]) a wait-and-see-policy (omission of surgery with follow-up) might be considered instead of surgery. The purpose of this prospective cohort study was to evaluate feasibility and safety of a wait-and-see policy with strict selection criteria and follow-up. Patients with a cCR after chemoradiotherapy were prospectively selected for the wait-and-see policy with magnetic resonance imaging (MRI) and endoscopy plus biopsies. Follow-up was performed 3 to 6 monthly and consisted of MRI, endoscopy, and computed tomography scans. A control group of patients with a pathologic complete response (pCR) after surgery was identified from a prospective cohort study. Functional outcome was measured with the Memorial Sloan-Kettering Cancer Center (MSKCC) bowel function questionnaire and Wexner incontinence score. Long-term outcome was estimated by using Kaplan-Meier curves. Twenty-one patients with cCR were included in the wait-and-see policy group. Mean follow-up was 25 ± 19 months. One patient developed a local recurrence and had surgery as salvage treatment. The other 20 patients are alive without disease. The control group consisted of 20 patients with a pCR after surgery who had a mean follow-up of 35 ± 23 months. For these patients with a pCR, cumulative probabilities of 2-year disease-free survival and overall survival were 93% and 91%, respectively. A wait-and-see policy with strict selection criteria, up-to-date imaging techniques, and follow-up is feasible and results in promising outcome at least as good as that of patients with a pCR after surgery. The proposed selection criteria and follow-up could form the basis for future randomized studies.
    Journal of Clinical Oncology 11/2011; 29(35):4633-40. · 18.04 Impact Factor
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    ABSTRACT: Hemangiosarcomas of the breast represent a rare disease of the breast mainly occurring as secondary neoplasias with a latency of 5-10 years after primary treatment of breast cancer and are associated with an unfavourable prognosis. Radiation therapy, which is integrated within the concept of breast conserving therapy ranks as the main risk factor. In this report we describe the clinical course of 4 patients including their molecular genetic pattern and give a summary of the actual literature. Hemangiosarcomas occur as a secondary neoplasm with a latency of 5-10 years after primary treatment of breast cancer and have an unfavorable prognosis. A genetic predisposition is assumed, but we could not find a significant role of tumor suppressor genes BRCA1, BRCA2 or p53 in our patients. Due to limited data available for these tumors, recommendations for therapy include radical tumor resection achieving wide free margins and inconsistent regimens of chemo- and/or immunetherapy modalities. In the majority these are based on systemic therapy regimens for other cutaneous sarcomas, such as Kaposi's sarcoma. Efforts should be taken for a nation-wide systematic registration of all cases of post-irradiation hemangiosarcomas.
    Strahlentherapie und Onkologie 08/2011; 187(10):656-64. · 4.16 Impact Factor
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    ABSTRACT: The purpose of this study was to develop accurate models and nomograms to predict local recurrence, distant metastases, and survival for patients with locally advanced rectal cancer treated with long-course chemoradiotherapy (CRT) followed by surgery and to allow for a selection of patients who may benefit most from postoperative adjuvant chemotherapy and close follow-up. All data (N = 2,795) from five major European clinical trials for rectal cancer were pooled and used to perform an extensive survival analysis and to develop multivariate nomograms based on Cox regression. Data from one trial was used as an external validation set. The variables used in the analysis were sex, age, clinical tumor stage stage, tumor location, radiotherapy dose, concurrent and adjuvant chemotherapy, surgery procedure, and pTNM stage. Model performance was evaluated by the concordance index (c-index). Risk group stratification was proposed for the nomograms. The nomograms are able to predict events with a c-index for external validation of local recurrence (LR; 0.68), distant metastases (DM; 0.73), and overall survival (OS; 0.70). Pathologic staging is essential for accurate prediction of long-term outcome. Both preoperative CRT and adjuvant chemotherapy have an added value when predicting LR, DM, and OS rates. The stratification in risk groups allows significant distinction between Kaplan-Meier curves for outcome. The easy-to-use nomograms can predict LR, DM, and OS over a 5-year period after surgery. They may be used as decision support tools in future trials by using the three defined risk groups to select patients for postoperative chemotherapy and close follow-up (http://www.predictcancer.org).
    Journal of Clinical Oncology 08/2011; 29(23):3163-72. · 18.04 Impact Factor
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    ABSTRACT: To determine diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging for assessment of complete tumor response (CR) after combined radiation therapy with chemotherapy (CRT) in patients with locally advanced rectal cancer (LARC) by means of volumetric signal intensity measurements and apparent diffusion coefficient (ADC) measurements and to compare the performance of DW imaging with that of T2-weighted MR volumetry. A retrospective analysis of 50 patients with LARC, for whom clinical and imaging data were retrieved from a previous imaging study approved by the local institutional ethical committee and for which all patients provided informed consent, was conducted. Patients underwent pre- and post-CRT standard T2-weighted MR and DW MR. Two independent readers placed free-hand regions of interest (ROIs) in each tumor-containing section on both data sets to determine pre- and post-CRT tumor volumes and tumor volume reduction rates (volume). ROIs were copied to an ADC map to calculate tumor ADCs. Histopathologic findings were the standard of reference. Receiver operating characteristic (ROC) curves were generated to compare performance of T2-weighted and DW MR volumetry and ADC. The intraclass correlation coefficient (ICC) was used to evaluate interobserver variability and the correlation between T2-weighted and DW MR volumetry. Areas under the ROC curve (AUCs) for identification of a CR that was based on pre-CRT volume, post-CRT volume, and volume, respectively, were 0.57, 0.70, and 0.84 for T2-weighted MR versus 0.63, 0.93, and 0.92 for DW MR volumetry (P = .15, .02, .42). Pre- and post-CRT ADC and ADC AUCs were 0.55, 0.54, and 0.51, respectively. Interobserver agreement was excellent for all pre-CRT measurements (ICC, 0.91-0.96) versus good (ICC, 0.61-0.79) for post-CRT measurements. ICC between T2-weighted and DW MR volumetry was excellent (0.97) for pre-CRT measurements versus fair (0.25) for post-CRT measurements. Post-CRT DW MR volumetry provided high diagnostic performance in assessing CR and was significantly more accurate than T2-weighted MR volumetry. Post-CRT DW MR was equally as accurate as volume measurements of both T2-weighted and DW MR. Pre-CRT volumetry and ADC were not reliable.
    Radiology 06/2011; 260(3):734-43. · 6.34 Impact Factor
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    ABSTRACT: Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction. We hypothesized that signals from the tumor microenvironment such as growth factors and tumor oxygenation collaborate to promote EMT and thereby contribute to radioresistance. Gene expression changes under hypoxia were analyzed using microarray and validated by qRT-PCR. Conversion of epithelial phenotype upon hypoxic exposure, TGFβ addition or oncogene activation was investigated by Western blot and immunofluorescence. Cell survival following ionizing radiation was assayed using clonogenic survival. Upon hypoxia, TGFβ addition or EGFRvIII expression, MCF7, A549 and NMuMG epithelial cells acquired a spindle shape and lost cell-cell contacts. Expression of epithelial markers such as E-cadherin decreased, whereas mesenchymal markers such as vimentin and N-cadherin increased. Combining hypoxia with TGFβ or EGFRvIII expression, lead to more rapid and pronounced EMT-like phenotype. Interestingly, E-cadherin expression and the mesenchymal appearance were reversible upon reoxygenation. Mesenchymal conversion and E-cadherin loss were associated with radioresistance. Our findings describe a mechanism by which the tumor microenvironment may contribute to tumor radioresistance via E-cadherin loss and EMT.
    Radiotherapy and Oncology 06/2011; 99(3):392-7. · 4.52 Impact Factor

Publication Stats

1k Citations
396.59 Total Impact Points

Institutions

  • 2008–2014
    • Maastricht Universitair Medisch Centrum
      Maestricht, Limburg, Netherlands
  • 2009–2013
    • Maastro Clinic
      Maestricht, Limburg, Netherlands
  • 2011
    • Catholic University of the Sacred Heart
      Milano, Lombardy, Italy
    • Universitätsklinikum Düsseldorf
      Düsseldorf, North Rhine-Westphalia, Germany
    • University of Coimbra
      Coímbra, Coimbra, Portugal
  • 2005–2011
    • Maastricht University
      • • Radiologie
      • • GROW School for Oncology & Developmental Biology
      Maastricht, Provincie Limburg, Netherlands
  • 2003–2011
    • Heinrich-Heine-Universität Düsseldorf
      Düsseldorf, North Rhine-Westphalia, Germany
  • 2000–2003
    • Virginia Commonwealth University
      • Department of Radiation Oncology
      Richmond, VA, United States
  • 1999
    • Universitätsklinikum Tübingen
      Tübingen, Baden-Württemberg, Germany