Rob L. Jansen
Maastricht University
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Journal of Clinical Oncology | 2011
Monique Maas; Regina G. H. Beets-Tan; Doenja M. J. Lambregts; Guido Lammering; Patty J. Nelemans; Sanne M. E. Engelen; Ronald M. van Dam; Rob L. Jansen; M. N. Sosef; Jeroen W. A. Leijtens; Karel W.E. Hulsewé; Jeroen Buijsen; Geerard L. Beets
PURPOSE 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 AND METHODS 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. RESULTS 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. CONCLUSION 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.
Lancet Oncology | 2014
Walter Taal; Hendrika M Oosterkamp; Annemiek M.E. Walenkamp; Hendrikus J. Dubbink; Laurens V. Beerepoot; M. Hanse; Jan Buter; Ah Honkoop; Dolf Boerman; Filip de Vos; Winand N. M. Dinjens; Roelien H. Enting; Martin J. B. Taphoorn; Franchette W P J van den Berkmortel; Rob L. Jansen; Dieta Brandsma; Jacoline E. C. Bromberg; Irene van Heuvel; Rene Vernhout; Bronno van der Holt; Martin J. van den Bent
BACKGROUND Treatment options for recurrent glioblastoma are scarce, with second-line chemotherapy showing only modest activity against the tumour. Despite the absence of well controlled trials, bevacizumab is widely used in the treatment of recurrent glioblastoma. Nonetheless, whether the high response rates reported after treatment with this drug translate into an overall survival benefit remains unclear. We report the results of the first randomised controlled phase 2 trial of bevacizumab in recurrent glioblastoma. METHODS The BELOB trial was an open-label, three-group, multicentre phase 2 study undertaken in 14 hospitals in the Netherlands. Adult patients (≥18 years of age) with a first recurrence of a glioblastoma after temozolomide chemoradiotherapy were randomly allocated by a web-based program to treatment with oral lomustine 110 mg/m(2) once every 6 weeks, intravenous bevacizumab 10 mg/kg once every 2 weeks, or combination treatment with lomustine 110 mg/m(2) every 6 weeks and bevacizumab 10 mg/kg every 2 weeks. Randomisation of patients was stratified with a minimisation procedure, in which the stratification factors were centre, Eastern Cooperative Oncology Group performance status, and age. The primary outcome was overall survival at 9 months, analysed by intention to treat. A safety analysis was planned after the first ten patients completed two cycles of 6 weeks in the combination treatment group. This trial is registered with the Nederlands Trial Register (www.trialregister.nl, number NTR1929). FINDINGS Between Dec 11, 2009, and Nov 10, 2011, 153 patients were enrolled. The preplanned safety analysis was done after eight patients had been treated, because of haematological adverse events (three patients had grade 3 thrombocytopenia and two had grade 4 thrombocytopenia) which reduced bevacizumab dose intensity; the lomustine dose in the combination treatment group was thereafter reduced to 90 mg/m(2). Thus, in addition to the eight patients who were randomly assigned to receive bevacizumab plus lomustine 110 mg/m(2), 51 patients were assigned to receive bevacizumab alone, 47 to receive lomustine alone, and 47 to receive bevacizumab plus lomustine 90 mg/m(2). Of these patients, 50 in the bevacizumab alone group, 46 in the lomustine alone group, and 44 in the bevacizumab and lomustine 90 mg/m(2) group were eligible for analyses. 9-month overall survival was 43% (95% CI 29-57) in the lomustine group, 38% (25-51) in the bevacizumab group, 59% (43-72) in the bevacizumab and lomustine 90 mg/m(2) group, 87% (39-98) in the bevacizumab and lomustine 110 mg/m(2) group, and 63% (49-75) for the combined bevacizumab and lomustine groups. After the reduction in lomustine dose in the combination group, the combined treatment was well tolerated. The most frequent grade 3 or worse toxicities were hypertension (13 [26%] of 50 patients in the bevacizumab group, three [7%] of 46 in the lomustine group, and 11 [25%] of 44 in the bevacizumab and lomustine 90 mg/m(2) group), fatigue (two [4%], four [9%], and eight [18%]), and infections (three [6%], two [4%], and five [11%]). At the time of this analysis, 144/148 (97%) of patients had died and three (2%) were still on treatment. INTERPRETATION The combination of bevacizumab and lomustine met prespecified criteria for assessment of this treatment in further phase 3 studies. However, the results in the bevacizumab alone group do not justify further studies of this treatment. FUNDING Roche Nederland and KWF Kankerbestrijding.
The Lancet | 2015
Lieke H. J. Simkens; Harm van Tinteren; Anne May; Albert J. ten Tije; Geert-Jan Creemers; Olaf Loosveld; Felix E. de Jongh; Frans Erdkamp; Zoran Erjavec; Adelheid Me van der Torren; Jolien Tol; Hans J Braun; Peter Nieboer; Jacobus J. M. van der Hoeven; Janny G. Haasjes; Rob L. Jansen; Jaap Wals; Annemieke Cats; Veerle A. Derleyn; Aafk e H Honkoop; Linda Mol; Cornelis J. A. Punt; Miriam Koopman
BACKGROUND The optimum duration of first-line treatment with chemotherapy in combination with bevacizumab in patients with metastatic colorectal cancer is unknown. The CAIRO3 study was designed to determine the efficacy of maintenance treatment with capecitabine plus bevacizumab versus observation. METHODS In this open-label, phase 3, randomised controlled trial, we recruited patients in 64 hospitals in the Netherlands. We included patients older than 18 years with previously untreated metastatic colorectal cancer, with stable disease or better after induction treatment with six 3-weekly cycles of capecitabine, oxaliplatin, and bevacizumab (CAPOX-B), WHO performance status of 0 or 1, and adequate bone marrow, liver, and renal function. Patients were randomly assigned (1:1) to either maintenance treatment with capecitabine and bevacizumab (maintenance group) or observation (observation group). Randomisation was done centrally by minimisation, with stratification according to previous adjuvant chemotherapy, response to induction treatment, WHO performance status, serum lactate dehydrogenase concentration, and treatment centre. Both patients and investigators were aware of treatment assignment. We assessed disease status every 9 weeks. On first progression (defined as PFS1), patients in both groups were to receive the induction regimen of CAPOX-B until second progression (PFS2), which was the studys primary endpoint. All endpoints were calculated from the time of randomisation. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00442637. FINDINGS Between May 30, 2007, and Oct 15, 2012, we randomly assigned 558 patients to either the maintenance group (n=279) or the observation group (n=279). Median follow-up was 48 months (IQR 36-57). The primary endpoint of median PFS2 was significantly improved in patients on maintenance treatment, and was 8·5 months in the observation group and 11·7 months in the maintenance group (HR 0·67, 95% CI 0·56-0·81, p<0·0001). This difference remained significant when any treatment after PFS1 was considered. Maintenance treatment was well tolerated, although the incidence of hand-foot syndrome was increased (64 [23%] patients with hand-foot skin reaction during maintenance). The global quality of life did not deteriorate during maintenance treatment and was clinically not different between treatment groups. INTERPRETATION Maintenance treatment with capecitabine plus bevacizumab after six cycles of CAPOX-B in patients with metastatic colorectal cancer is effective and does not compromise quality of life. FUNDING Dutch Colorectal Cancer Group (DCCG). The DCCG received financial support for the study from the Commissie Klinische Studies (CKS) of the Dutch Cancer Foundation (KWF), Roche, and Sanofi-Aventis.
Journal of Clinical Oncology | 2007
Manfred P. Lutz; Hansjochen Wilke; D.J. Theo Wagener; Udo Vanhoefer; Krzysztof Jeziorski; S. Hegewisch-Becker; Leopold Balleisen; Eric Joossens; Rob L. Jansen; Muriel Debois; Ullrich Bethe; Michel Praet; Jacques Wils; Eric Van Cutsem
PURPOSE This multicentric, randomized, two-stage phase II trial evaluated three simplified weekly infusional regimens of fluorouracil (FU) or FU plus folinic acid (FA) and cisplatin (Cis) with the aim to select a regimen for future phase III trials. PATIENTS AND METHODS A total of 145 patients with advanced gastric cancer where randomly assigned to weekly FU 3,000 mg/m2/24 hours (HD-FU), FU 2,600 mg/m2/24 hours plus dl-FA 500 mg/m2 or l-FA 250 mg/m2 (HD-FU/FA), or FU 2000 mg/m2/24 hours plus FA plus biweekly Cis 50 mg/m2, each administered for 6 weeks with a 1-week rest. The primary end point was the response rate. RESULTS Confirmed responses were observed in 6.1% (two of 33) of the eligible patients treated with HD-FU, in 25% (12 of 48, including one complete remission [CR]) with HD-FU/FA, and in 45.7% (21 of 46, including four CRs) with HD-FU/FA/Cis. The HD-FU arm was closed after stage 1 because the required minimum number of responses was not met. The median progression-free survival of all patients in the HD-FU, HD-FU/FA, and HD-FU/FA/Cis arm was 1.9, 4.0, and 6.1 months, respectively. The median overall survival was 7.1, 8.9, and 9.7 months, and the survival rate at 1 year was 24.3%, 30.3%, and 45.3%, respectively. Grade 4 toxicities were rare. The most relevant grade 3/4 toxicities were neutropenia in 1.9%, 5.4%, and 19.6%, and diarrhea in 2.7%, 1.9%, and 3.9% of the cycles in the HD-FU, HD-FU/FA, and HD-/FU/Cis arms, respectively. CONCLUSION Weekly infusional FU/FA plus biweekly Cis is effective and safe in patients with gastric cancer.
European Journal of Cancer | 2013
Sanne M. E. Engelen; Monique Maas; M. Lahaye; Jeroen W. A. Leijtens; C.L.H. van Berlo; Rob L. Jansen; S.O. Breukink; C.H.C. Dejong; C.J.H. van de Velde; Regina G. H. Beets-Tan; Geerard L. Beets
AIM The purpose of this multicenter cohort study was to evaluate whether a differentiated treatment of primary rectal cancer based on magnetic resonance imaging (MRI) can reduce the number of incomplete resections and local recurrences and improve recurrence-free and overall survival. METHODS From February 2003 until January 2008, 296 patients with rectal cancer underwent preoperative MRI using a lymph node specific contrast agent to predict circumferential resection margin (CRM), T- and N-stage. Based on expert reading of the MRI, patients were stratified in: (a) low risk for local recurrence (CRM>2mm and N0 status), (b) intermediate risk and (c) high risk (close/involved CRM, N2 status or distal tumours). Mainly based on this MRI risk assessment patients were treated with (a) surgery only (TME or local excision), (b) preoperative 5 × 5 Gy+TME and (c) a long course of chemoradiation therapy followed by surgery after a 6-8 week interval. RESULTS Overall 228 patients underwent treatment with curative intent: 49 with surgery only, 86 with 5 × 5 Gy and surgery and 93 with chemoradiation and surgery. The number of complete resections (margin>1mm) was 218 (95.6%). At a median follow-up of 41 months the three-year local recurrence rate, disease-free survival rate and overall survival rate is 2.2%, 80% and 84.5%, respectively. CONCLUSION With a differentiated multimodality treatment based on dedicated preoperative MR imaging, local recurrence is no longer the main problem in rectal cancer treatment. The new challenges are early diagnosis and treatment, reducing morbidity of treatment and preferably prevention of metastatic disease.
Acta Oncologica | 2013
Sander Kelderman; Monique K. van der Kooij; Alfons J.M. van den Eertwegh; Patricia Soetekouw; Rob L. Jansen; Rob R. H. van den Brom; Geke A.P. Hospers; John B. A. G. Haanen; Ellen Kapiteijn; Christian U. Blank
predict changes in psychological distress among oesophageal cancer survivors? J Health Psychol 2011 ; 16 : 500 – 9 . Linden W , Vodermaier A , Mackenzie R , Mackenzie R , [22] Greig D . Anxiety and depression after cancer diagnosis: Prevalence rates by cancer type, gender, and age . J Affect Disord 2012 ; 141 : 343 – 51 . Hinz A , Krauss O , Hauss JP , H ö ckel M , Kortmann RD , [23] Stolzenburg JU , et al . Anxiety and depression in cancer patients compared with the general population . Eur J Can Care 2010 ; 19 : 522 – 9 . Leventhal H , Meyer D , Nerenz DR . The common sense resp[24] resentation of illness danger. In: Rachman S, editor. Contributions to medical psychology, Vol 2. New York: Pergamon Press; 2012. p 17 – 30. Dempster M , McCorry NK , Brennan E , Donnelly M , [25] Murray L , Johnston BT . Illness perceptions among carersurvivor dyads are related to psychological distress among oesophageal cancer survivors . J Psychosom Res 2011 ; 70 : 432 – 9 . Dempster M , McCorry NK , Brennan E , Donnelly M , [26] Murray L , Johnston BT . Psychological distress among family carers of oesophageal cancer survivors: The role of illness cognitions and coping . Psycho-Oncology 2011 ; 20 : 698 – 705 . Vodermaier A , Millman RD . Accuracy of the Hospital [27] Anxiety and Depression Scale as a screening tool in cancer patients: A systematic review and meta-analysis . Support Care Cancer 2011 ; 19 : 1899 – 908 .
Lancet Oncology | 2018
Annemieke Cats; Edwin P.M. Jansen; Nicole C.T. van Grieken; Karolina Sikorska; Pehr Lind; Marianne Nordsmark; Elma Meershoek-Klein Kranenbarg; Henk Boot; Anouk Kirsten Trip; Ha Maurits Swellengrebel; Hanneke W. M. van Laarhoven; Hein Putter; Johanna W. van Sandick; Mark I. van Berge Henegouwen; Henk H. Hartgrink; Harm van Tinteren; Cornelis J. H. van de Velde; Marcel Verheij; Frits van Coevorden; Steven Vanhoutvin; Maarten C. C. M. Hulshof; Olaf Jl Loosveld; A (Bert) Jan Ten Tije; Frans Erdkamp; Fabiënne A. R. M. Warmerdam; Donald L Van der Peet; Henk M.W. Verheul; Djamila Boerma; Maartje Los; Annerie Slot
BACKGROUND Both perioperative chemotherapy and postoperative chemoradiotherapy improve survival in patients with resectable gastric cancer from Europe and North America. To our knowledge, these treatment strategies have not been investigated in a head to head comparison. We aimed to compare perioperative chemotherapy with preoperative chemotherapy and postoperative chemoradiotherapy in patients with resectable gastric adenocarcinoma. METHODS In this investigator-initiated, open-label, randomised phase 3 trial, we enrolled patients aged 18 years or older who had stage IB- IVA resectable gastric or gastro-oesophageal adenocarcinoma (as defined by the American Joint Committee on Cancer, sixth edition), with a WHO performance status of 0 or 1, and adequate cardiac, bone marrow, liver, and kidney function. Patients were enrolled from 56 hospitals in the Netherlands, Sweden, and Denmark, and were randomly assigned (1:1) with a computerised minimisation programme with a random element to either perioperative chemotherapy (chemotherapy group) or preoperative chemotherapy with postoperative chemoradiotherapy (chemoradiotherapy group). Randomisation was done before patients were given any preoperative chemotherapy treatment and was stratified by histological subtype, tumour localisation, and hospital. Patients and investigators were not masked to treatment allocation. Surgery consisted of a radical resection of the primary tumour and at least a D1+ lymph node dissection. Postoperative treatment started within 4-12 weeks after surgery. Chemotherapy consisted of three preoperative 21-day cycles and three postoperative cycles of intravenous epirubicin (50 mg/m2 on day 1), cisplatin (60 mg/m2 on day 1) or oxaliplatin (130 mg/m2 on day 1), and capecitabine (1000 mg/m2 orally as tablets twice daily for 14 days in combination with epirubicin and cisplatin, or 625 mg/m2 orally as tablets twice daily for 21 days in combination with epirubicin and oxaliplatin), received once every three weeks. Chemoradiotherapy consisted of 45 Gy in 25 fractions of 1·8 Gy, for 5 weeks, five daily fractions per week, combined with capecitabine (575 mg/m2 orally twice daily on radiotherapy days) and cisplatin (20 mg/m2 intravenously on day 1 of each 5 weeks of radiation treatment). The primary endpoint was overall survival, analysed by intention-to-treat. The CRITICS trial is registered at ClinicalTrials.gov, number NCT00407186; EudraCT, number 2006-004130-32; and CKTO, 2006-02. FINDINGS Between Jan 11, 2007, and April 17, 2015, 788 patients were enrolled and randomly assigned to chemotherapy (n=393) or chemoradiotherapy (n=395). After preoperative chemotherapy, 372 (95%) of 393 patients in the chemotherapy group and 369 (93%) of 395 patients in the chemoradiotherapy group proceeded to surgery, with a potentially curative resection done in 310 (79%) of 393 patients in the chemotherapy group and 326 (83%) of 395 in the chemoradiotherapy group. Postoperatively, 233 (59%) of 393 patients started chemotherapy and 245 (62%) of 395 started chemoradiotherapy. At a median follow-up of 61·4 months (IQR 43·3-82·8), median overall survival was 43 months (95% CI 31-57) in the chemotherapy group and 37 months (30-48) in the chemoradiotherapy group (hazard ratio from stratified analysis 1·01 (95% CI 0·84-1·22; p=0·90). After preoperative chemotherapy, in the total safety population of 781 patients (assessed together), there were 368 (47%) grade 3 adverse events; 130 (17%) grade 4 adverse events, and 13 (2%) deaths. Causes of death during preoperative treatment were diarrhoea (n=2), dihydropyrimidine deficiency (n=1), sudden death (n=1), cardiovascular events (n=8), and functional bowel obstruction (n=1). During postoperative treatment, grade 3 and 4 adverse events occurred in 113 (48%) and 22 (9%) of 233 patients in the chemotherapy group, respectively, and in 101 (41%) and ten (4%) of 245 patients in the chemoradiotherapy group, respectively. Non-febrile neutropenia occurred more frequently during postoperative chemotherapy (79 [34%] of 233) than during postoperative chemoradiotherapy (11 [4%] of 245). No deaths were observed during postoperative treatment. INTERPRETATION Postoperative chemoradiotherapy did not improve overall survival compared with postoperative chemotherapy in patients with resectable gastric cancer treated with adequate preoperative chemotherapy and surgery. In view of the poor postoperative patient compliance in both treatment groups, future studies should focus on optimising preoperative treatment strategies. FUNDING Dutch Cancer Society, Dutch Colorectal Cancer Group, and Hoffmann-La Roche.
BMC Cancer | 2015
Ninos Ayez; Eric P. van der Stok; Hans de Wilt; Sandra A. Radema; Richard van Hillegersberg; Rudi M. H. Roumen; Gerard Vreugdenhil; Pieter J. Tanis; Cornelis J. A. Punt; Cornelis H.C. Dejong; Rob L. Jansen; Henk M.W. Verheul; Koert P. de Jong; Geke A.P. Hospers; Joost M. Klaase; Marie-Cecile Legdeur; Esther van Meerten; Ferry A.L.M. Eskens; Nelly van der Meer; Bruno van der Holt; Cornelis Verhoef; Dirk J. Grünhagen
BackgroundEfforts to improve the outcome of liver surgery by combining curative resection with chemotherapy have failed to demonstrate definite overall survival benefit. This may partly be due to the fact that these studies often involve strict inclusion criteria. Consequently, patients with a high risk profile as characterized by Fong’s Clinical Risk Score (CRS) are often underrepresented in these studies. Conceptually, this group of patients might benefit the most from chemotherapy. The present study evaluates the impact of neo-adjuvant chemotherapy in high-risk patients with primary resectable colorectal liver metastases, without extrahepatic disease. Our hypothesis is that adding neo-adjuvant chemotherapy to surgery will provide an improvement in overall survival (OS) in patients with a high-risk profile.Methods/DesignCHARISMA is a multicenter, randomized, phase III clinical trial. Patients will be randomized to either surgery alone (standard treatment, arm A) or to 6 cycles of neo-adjuvant oxaliplatin-based chemotherapy, followed by surgery (arm B). Patients must be ≥ 18 years of age with liver metastases of histologically confirmed primary colorectal carcinoma. Patients with extrahepatic metastases are excluded. Liver metastases must be deemed primarily resectable. Only patients with a CRS of 3–5 are eligible. The primary study endpoint is OS. Secondary endpoints are progression free survival (PFS), quality of life, morbidity of resection, treatment response on neo-adjuvant chemotherapy, and whether CEA levels can predict treatment response.DiscussionCHARISMA is a multicenter, randomized, phase III clinical trial that will provide an answer to the question if adding neo-adjuvant chemotherapy to surgery will improve OS in a well-defined high-risk patient group with colorectal liver metastases.Trial registrationThe CHARISMA is registered at European Union Clinical Trials Register (EudraCT), number: 2013-004952-39, and in the “Netherlands national Trial Register (NTR), number: 4893.
European Journal of Cancer | 1998
M. J. van den Bent; J. H. M. Schellens; Ch.J. Vecht; P.A.E Sillevis Smit; O.J.L Loosveld; J. Ma; Cees C. Tijssen; Rob L. Jansen; J.M Kros; J. Verweij
27 patients with recurrent high grade glioma following surgery and radiation therapy were treated with 100 mg/m2 cisplatin and 6 g/m2 ifosfamide per cycle, administered on days 1-3 in 4 week cycles, for a maximum of six cycles. Toxicity was assessed after every cycle. Response was assessed following every second cycle, and a 50% decrease of the largest cross-sectional tumour area on contrast enhanced magnetic resonance imaging or computed tomography scan was considered a partial response (PR). A total of 95 cycles was administered; 26 patients were evaluable for response. In 5 patients (19%), a PR was obtained (median time to progression (TTP): 34 weeks). Stable disease was observed in 6 patients (23%, median TTP: 22 weeks). The most frequent toxicity was haematological: 37% of cycles were complicated by a grade 3 or 4 leucopenia. 1 patients died, probably as a consequence of increased cerebral oedema induced by the cisplatin hydration schedule. Determination of the cisplatin concentration in this patient showed a 10-fold increase in the tumour concentration as compared with that in normal brain tissue, demonstrating the absence of a blood-brain barrier in the tumour. In conclusion, generally this schedule was well tolerated, but it is of moderate activity for recurrent glioma.
Biochimica et Biophysica Acta | 2017
André B.P. van Kuilenburg; Judith Meijer; Dirk Maurer; Doreen Dobritzsch; Rutger Meinsma; Maartje Los; Lia Knegt; Lida Zoetekouw; Rob L. Jansen; V. O. Dezentje; Lieke H. van Huis-Tanja; Roel J.W. van Kampen; Jens Michael Hertz; Raoul C. M. Hennekam
Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the catabolism of 5-fluorouracil (5FU). Genetic variations in DPD have emerged as predictive risk factors for severe fluoropyrimidine toxicity. Here, we report novel and rare genetic variants underlying DPD deficiency in 9 cancer patients presenting with severe fluoropyrimidine-associated toxicity. All patients possessed a strongly reduced DPD activity, ranging from 9 to 53% of controls. Analysis of the DPD gene (DPYD) showed the presence of 21 variable sites including 4 novel and 4 very rare aberrations: 3 missense mutations, 2 splice-site mutations, 1 intronic mutation, a deletion of 21 nucleotides and a genomic amplification of exons 9-12. Two novel/rare variants (c.2843T>C, c.321+1G>A) were present in multiple, unrelated patients. Functional analysis of recombinantly-expressed DPD mutants carrying the p.I948T and p.G284V mutation showed residual DPD activities of 30% and 0.5%, respectively. Analysis of a DPD homology model indicated that the p.I948T and p.G284V mutations may affect electron transfer and the binding of FAD, respectively. cDNA analysis showed that the c.321+1G>A mutation in DPYD leads to skipping of exon 4 immediately upstream of the mutated splice-donor site in the process of DPD pre-mRNA splicing. A lethal toxicity in two DPD patients suggests that fluoropyrimidines combined with other therapies such as radiotherapy might be particularly toxic for DPD deficient patients. Our study advocates a more comprehensive genotyping approach combined with phenotyping strategies for upfront screening for DPD deficiency to ensure the safe administration of fluoropyrimidines.