De-escalation of axillary surgery in breast cancer patients treated in the neoadjuvant setting: a Dutch population-based study.

PURPOSE: An overall trend is observed towards de-escalation of axillary surgery in patients with breast cancer. The objective of this study was to evaluate this trend in patients treated with neoadjuvant systemic therapy (NST). METHODS: Patients with cT1-4N0-3 breast cancer treated with NST (2006-2016) were selected from the Netherlands Cancer Registry. Patients were classified by clinical node status (cN) and type of axillary surgery. Uni- and multivariable logistic regression analyses were performed to determine the clinicopathological factors associated with performing ALND in cN+ patients. RESULTS: A total of 12,461 patients treated with NST were identified [5830 cN0 patients (46.8%), 6631 cN+ patients (53.2%)]. In cN0 patients, an overall increase in sentinel lymph node biopsy (SLNB) only (not followed by ALND) was seen from 11% in 2006 to 94% in 2016 (p < 0.001). SLNB performed post-NST increased from 33 to 62% (p < 0.001). In cN+ patients, an overall decrease in ALND was seen from 99% in 2006 to 53% in 2016 (p < 0.001). Age (OR 1.01, CI 1.00-1.02), year of diagnosis (OR 0.47, CI 0.44-0.50), HER2-positive disease (OR 0.62, CI 0.52-0.75), clinical tumor stage (T2 vs. T1 OR 1.32, CI 1.06-1.65, T3 vs. T1 OR 2.04, CI 1.58-2.63, T4 vs. T1 OR 6.37, CI 4.26-9.50), and clinical nodal stage (N3 vs. N1 OR 1.65, CI 1.28-2.12) were correlated with performing ALND in cN+ patients. CONCLUSIONS: ALND decreased substantially over the past decade in patients treated with NST. Assessment of long-term prognosis of patients in whom ALND is omitted after NST is urgently needed.

Excision of both pretreatment marked positive nodes and sentinel nodes improves axillary staging after neoadjuvant systemic therapy in breast cancer.

BACKGROUND: Marking the axilla with radioactive iodine seed and sentinel lymph node (SLN) biopsy have been proposed for axillary staging after neoadjuvant systemic therapy in clinically node-positive breast cancer. This study evaluated the identification rate and detection of residual disease with combined excision of pretreatment-positive marked lymph nodes (MLNs) together with SLNs. METHODS: This was a multicentre retrospective analysis of patients with clinically node-positive breast cancer undergoing neoadjuvant systemic therapy and the combination procedure (with or without axillary lymph node dissection). The identification rate and detection of axillary residual disease were calculated for the combination procedure, and for MLNs and SLNs separately. RESULTS: At least one MLN and/or SLN(s) were identified by the combination procedure in 138 of 139 patients (identification rate 99·3 per cent). The identification rate was 92·8 per cent for MLNs alone and 87·8 per cent for SLNs alone. In 88 of 139 patients (63·3 per cent) residual axillary disease was detected by the combination procedure. Residual disease was shown only in the MLN in 20 of 88 patients (23 per cent) and only in the SLN in ten of 88 (11 per cent), whereas both the MLN and SLN contained residual disease in the remainder (58 of 88, 66 per cent). CONCLUSION: Excision of the pretreatment-positive MLN together with SLNs after neoadjuvant systemic therapy in patients with clinically node-positive disease resulted in a higher identification rate and improved detection of residual axillary disease.

ANTECEDENTES: En el cáncer de mama con ganglios positivos clínicamente tras el tratamiento neoadyuvante sistémico, se ha propuesto la utilización de iodo radioactivo (Marking Axilla with Radioactive Iodine, MARI) y de la biopsia de ganglio linfático centinela para la estadificación axilar. En este estudio se evaluó la tasa de identificación y detección de enfermedad residual cuando se combinó la exéresis de los ganglios linfáticos marcados antes del tratamiento (marked lymph nodes, MLN) junto con los ganglios centinela (sentinel lymph nodes, SLN). MÉTODOS: Se realizó un análisis retrospectivo multicéntrico de pacientes con cáncer de mama con ganglios positivos clínicamente que se sometieron a tratamiento neoadyuvante sistémico y en las que se combinaron ambas técnicas (con o sin disección axilar). Se calcularon las tasas de identificación y detección de enfermedad residual axilar para MLN y SLN por separado y en conjunto. RESULTADOS: En 138/139 pacientes se identificaron ≥ 1 MLN y/o SLN combinando ambas técnicas (tasa de identificación del 99,3%). La tasa de identificación fue de 92,8% para MLN y del 87,8% para SLN. Combinando ambas técnicas se detectó enfermedad axilar residual en 88/139 (63,3%) pacientes. Se detectó enfermedad residual en 20/88 (22,7%) pacientes utilizando únicamente MLN, en 10/88 (11,4%) pacientes utilizando únicamente SLN y en 58/88 (65,9%) combinando ambas técnicas. CONCLUSIÓN: La exéresis conjunta de los ganglios marcados con iodo radioactivo antes del tratamiento neoadyuvante sistémico y de los ganglios centinela después del tratamiento en pacientes con cN+ logró una tasa de identificación más alta y una mejor detección de la enfermedad axilar residual.

Honorary Authorships in Surgical Literature.

INTRODUCTION: Honorary authorship (HA) is defined as an enlisted co-author who did not make sufficient contributions to merit being included as a co-author according to the ICMJE guidelines on authorship. It is unknown if HA is present in the surgical literature. METHODS: We analysed studies published in 2016 in five journals with the highest impact factor in general surgery. All original articles, reviews and clinical trials with more than one author were included. Corresponding authors of these manuscripts received an online survey by email. The survey consisted of three parts focussing on demographics, knowledge and application of the ICMJE guidelines, and deciding authorship. RESULTS: In total, 320 of the 1037 surveys were completed (30.9%). Two hundred and seventy-two (88.6%) of the corresponding authors were aware of the ICMJE authorship guidelines, and 203 (66.3%) were aware of the general issue of honorary authorship. One hundred and thirty-five (44.0%) responders reported at least one co-author who only performed tasks which should not merit actual authorship according to the ICMJE guidelines. Furthermore, only 46 (15.0%) of the responders believed that a co-author listed for their article did not make sufficient contribution to merit being included as co-author. No significant differences were found between the journals investigated. CONCLUSION: Despite ICMJE guidelines to reduce HA, the prevalence may still exist to a higher level than preferable. The authors plead for more transparent authorship systems in which journal editors and senior department members take more responsibility into enforcement of the ICMJE guidelines.

Prognosis of residual axillary disease after neoadjuvant chemotherapy in clinically node-positive breast cancer patients: isolated tumor cells and micrometastases carry a better prognosis than macrometastases.

PURPOSE: The aim of this study was to compare disease-free survival (DFS) and overall survival (OS) between clinically node-positive breast cancer patients, treated with neoadjuvant chemotherapy (NAC), with axillary pathologic complete response (ypN0), residual axillary isolated tumor cells or micrometastases (ypNitc/mi), and residual axillary macrometastases (ypN1-3). METHODS: All patients diagnosed with clinically node-positive primary invasive breast cancer treated with NAC and subsequent axillary lymph node dissection between 2005 and 2008 were retrospectively analyzed. Data were obtained from the Netherlands Cancer Registry. Patients were stratified by final pathological axillary status: ypN0, ypNitc/mi, or ypN1-3. The main outcome measures DFS and OS were analyzed using Kaplan-Meier survival analysis. Uni- and multivariable cox regression analyses were used to determine independent predictors for DFS and OS. RESULTS: A total of 1347 patients were included. Pathologic nodal status was ypN0 in 22.2%, ypNitc/mi in 3.8%, and ypN1-3 in 74.0% of patients. Overall, 5-year DFS was 57.8% and mean OS was 7.4 years. DFS and OS were comparable between ypN0 and ypNitc/mi (HR 1.38 (0.40-4.79, p = 0.613) and HR 0.92 (0.27-3.09, p = 0.889), respectively), but significantly different between ypN0 and ypN1-3 (HR 1.78 (1.06-3.00, p = 0.031) and HR 1.70 (1.07-2.71, p = 0.026), respectively). CONCLUSIONS: Clinically node-positive patients, treated with NAC, with axillary nodal status ypN0 or ypNitc/mi carry similar prognosis regarding DFS and OS. Axillary nodal status ypN1-3 is associated with a less favorable prognosis. Future studies should consider ypN0 and ypNitc/mi as one entity.

Repeat sentinel node biopsy should be considered in patients with locally recurrent breast cancer.

Most patients with locally recurrent breast cancer undergo axillary lymph node dissection (ALND). However, repeat sentinel node biopsy (SNB) could provide regional nodal staging and obviate the need for standard ALND. The Sentinel Node and Recurrent Breast Cancer (SNARB) study is a Dutch nationwide registration study conducted to determine feasibility, aberrant drainage rates, and clinical consequences of repeat SNB. A total of 536 patients with locally recurrent non-metastatic breast cancer underwent lymphatic mapping and repeat SNB in 29 Dutch hospitals. A repeat sentinel node (SN) was identified in 333 of 536 patients (62.1 %) and surgically harvested in 287 patients (53.5 %). Aberrant lymph drainage was observed in 180 (54.1 %) of the 333 patients, more often after previous ALND (81.9 %) than SNB (28.4 %; P < 0.001). In 230 patients (80.1 %), the retrieved SN was tumor negative; 17 SNs (5.9 %) contained a micrometastasis and 29 (10.1 %) a macrometastasis. Confirmation ALND in 31 repeat SN-negative patients revealed a macrometastasis in two patients (6.5 %). The negative predictive value (NPV) of repeat SNB was 93.6 %, and ALND was omitted in 109 of the 248 patients (44.0 %) with a negative repeat SN. In 29 of the 44 patients (63.0 %) with a positive SN, adjuvant treatment plans were altered based on the repeat SNB. Repeat SNB is a feasible procedure with a high NPV, leading to a change in management in a substantial proportion of patients. Therefore, repeat SNB should replace routine ALND and serve as the standard of care in recurrent breast cancer.

Improving the Success Rate of Repeat Sentinel Node Biopsy in Recurrent Breast Cancer.

PURPOSE: Repeat sentinel node biopsy (SNB) is an alternative to axillary lymph node dissection (ALND) for axillary staging in recurrent breast cancer. This study was conducted to determine factors associated with technical success of repeat SNB. METHODS: A total of 536 patients with locally recurrent nonmetastatic breast cancer underwent lymphatic mapping (LM) and repeat SNB in 29 Dutch hospitals. RESULTS: A total of 179 patients previously underwent breast-conserving surgery (BCS) with SNB, 262 patients BCS with ALND and 61 patients mastectomy, 35 with SNB and 26 with ALND. Another 34 patients underwent breast surgery without axillary interventions. A repeat sentinel node (SN) was identified in 333 patients (62.1 %) and was successfully removed in 235 (53.5 %). The overall repeat SN identification rate was 62.1 %, varying from 35 to 100 % in the participating hospitals. Previous radiotherapy of the breast [odds ratio (OR) 0.16; 95 % confidence interval (CI) 0.03-0.84], subareolar tracer injection (OR 0.34; 95 % CI 0.16-0.73), and a 2-day LM protocol (OR 0.57; 95 % CI 0.33-0.97) after previous BCS were independently associated with failure of SN identification. Injection of a larger amount of tracer (>180 MBq) led to a higher identification rate (OR 4.40; 95 % CI 1.45-13.32). CONCLUSIONS: Repeat SNB is a technically feasible procedure for axillary staging in recurrent breast cancer patients. Previous radiotherapy appears to be associated with failure of SN identification. Injection with a larger amount of tracer (>180 MBq) leads to a higher identification rate; subareolar injection and a 2-day LM protocol after previous BCS appear to be less adequate.

Iodine seed- versus wire-guided localization in breast-conserving surgery for non-palpable ductal carcinoma in situ.

BACKGROUND: Breast-conserving surgery for isolated non-palpable ductal carcinoma in situ (DCIS) is associated with high rates of incomplete surgical resection in comparison with unifocal invasive breast cancer. Therefore, accurate preoperative localization of the lesion is very important to facilitate adequate resection. Wire-guided localization (WGL) remains the standard for localization of DCIS. Recently, iodine-125 seed-guided localization (I-125 GL) was introduced as an alternative localization technique. The aim of this study was to compare the efficacy of these localization techniques in the resection of DCIS by breast-conserving surgery. METHODS: Between March 2006 and June 2013, 169 patients with non-palpable DCIS were treated with breast-conserving surgery. Only patients with pure DCIS on both preoperative core biopsy and definitive pathology were included. RESULTS: WGL was performed in 78 patients and I-125 GL in 91 patients. The groups did not differ with respect to age, size of DCIS or type of imaging used. Patients in the I-125 GL group had a significantly lower risk of extensively involved resection margins than those in the WGL group (4 versus 13 per cent respectively; P = 0·048). CONCLUSION: In patients treated with breast-conserving surgery for non-palpable DCIS, localization with iodine-125 seeds is superior to the WGL technique in reducing the risk of extensively involved resection margins.

Two decades of axillary management in breast cancer.

BACKGROUND: Axillary lymph node dissection (ALND) in patients with breast cancer provides prognostic information. For many years, positive nodes were the most important indication for adjuvant systemic therapy. It was also believed that regional control could not be achieved without axillary clearance in a positive axilla. However, during the past 20 years the treatment and staging of the axilla has undergone many changes. This large population-based study was conducted in the south-east of the Netherlands to evaluate the changing patterns of care regarding the axilla, including the introduction of sentinel lymph node biopsy (SLNB) in the late 1990s, implementation of the results of the American College of Surgeons Oncology Group Z0011 study, and the initial effects of the European Organization for Research and Treatment of Cancer AMAROS study. METHODS: Data from the population-based Eindhoven Cancer Registry of all women diagnosed with invasive breast cancer in the south of the Netherlands between January 1993 and July 2014 were used. RESULTS: The proportion of 34,037 women staged by SLNB without completion ALND increased from 0 per cent in 1993-1994 to 69·0 per cent in 2013-2014. In the same period the proportion undergoing ALND decreased from 88·8 to 18·7 per cent. Among women with one to three positive lymph nodes, the proportion undergoing SLNB alone increased from 10·6 per cent in 2011-2012 to 37·6 per cent in 2013-2014. CONCLUSION: This population-based study demonstrated the radical transformation in management of the axilla since the introduction of SLNB and following the recent publication of trials on management of the axilla with a low metastatic burden.

The role of radioactive iodine-125 seed localization in breast-conserving therapy following neoadjuvant chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy (NAC) is increasingly used in the framework of breast-conserving therapy (BCT). Localization of the initial tumor is essential to guide surgical resection after NAC. This study describes the results obtained with I-125 seed localization in BCT including NAC. PATIENTS AND METHODS: Between January 2009 and December 2010, 85 patients treated with NAC and BCT after I-125 seed localization were included. Radiological and pathological response and resection margins were retrospectively evaluated. RESULTS: BCT was carried out in 85 patients without secondary local excisions. Nineteen patients with unifocal tumors and seven patients with multifocal tumors showed a complete pathological response (P = 0.18). Tumor-free resection margins were obtained in 78 patients (50 patients with unifocal and 28 patients with multifocal tumors, P = 0.27). Focally involved margins were found in four patients (two patients with a unifocal and two patients with a multifocal tumor, P = 0.27). A subsequent mastectomy was carried out in three patients (two patients with multifocal tumors, P = 0.29). CONCLUSIONS: BCT after NAC can be carried out successfully after initial localization with I-125 seeds in both unifocal and multifocal breast tumors with complete resection rates of >90%.

Patterns of axillary staging and management in clinically node positive breast cancer patients treated with neoadjuvant systemic therapy: Results of a survey amongst breast cancer specialists.

INTRODUCTION: Various options for axillary staging after neoadjuvant systemic therapy (NST) are available for breast cancer patients with a clinically positive axillary node (cN+). This survey assessed current practices amongst breast cancer specialists. MATERIALS AND METHODS: A survey was performed amongst members of the European Society of Surgical Oncology and two UK-based Associations: the Association of Breast Surgery and the British Association of Surgical Oncology. The survey included 3 parts: 1. general information, 2. diagnostic work-up and 3. axillary staging after NST. RESULTS: A total of 310 responses were collected: parts 1, 2 and 3 were fully completed by 282 (91%), 270 (87.1%) and 225 (72.6%) respondents respectively. After NST, 153/267 (57.3%) respondents currently perform ALND routinely and 114 (42.7%) respondents perform less invasive restaging of the axilla with possible omission of ALND. In the latter group, 85% does and 15% does not use nodal response seen on imaging to guide the axillary restaging procedure. Regarding respondents that do use imaging: 95% would perform a less invasive staging procedure in case of complete nodal response on imaging (63% sentinel lymph node biopsy (SLNB), excision of a previously marked positive node with SLNB (21%) and without SLNB (11%)). In case of no nodal response on imaging 77% would perform ALND. CONCLUSION: Current axillary staging and management practices in cN + patients after NST vary widely. To determine optimal axillary staging and management in terms of quality of life and oncologic safety, breast specialists are encouraged to include patients in clinical trials/prospective registries.

Outcome of surgical treatment of pancreatic, peri-ampullary and ampullary cancer diagnosed in the south of The Netherlands: a cancer registry based study.

AIMS: To gain insight into the quality of pancreatic cancer surgery in 10 low-volume (median sized) hospitals, each serving 150,000-250,000 people, in the Comprehensive Cancer Centre South (CCCS) area and of referred patients to academic centres to determine the need for further regionalization. METHOD: The population-based Eindhoven Cancer Registry was used to select all patients in the CCCS area with pancreatic, peri-ampullary and ampullary cancer diagnosed between January 1, 1995 and April 30, 2000 (N = 1130). Of those, 124 patients (11%) underwent surgical resection (of which 40 were treated in university hospitals outside the region). RESULTS: For all pancreatic carcinoma resections, the 3-month survival rate was 82%, varying from 95% for referred patients to 76% for patients treated within the region (p = 0.014). One- and two-year survival rates showed no difference between both groups (p = 0.36 and p = 0.55, respectively). Surgically treated patients who were referred to university hospitals outside the CCCS area were younger, more often male, more often diagnosed with pTNM stage III, exhibited less comorbidity and had a higher socio-economic status than patients surgically treated within the region. CONCLUSION: Although the results are based on small numbers and patient selection probably influenced these outcomes, these data seem to support further hospital specialisation, to which the surgeons of the CCCS area have committed themselves.

Clinical impact of breast MRI with regard to axillary reverse mapping in clinically node positive breast cancer patients following neo-adjuvant chemotherapy.

BACKGROUND: Axillary reverse mapping (ARM) is a technique that discerns axillary lymphatic drainage of the arm from the breast. In the current study, we retrospectively evaluated the incidence of metastatic axillary lymph node involvement, including ARM lymph nodes, in clinically node positive breast cancer patients (cN+ patients) in whom neo-adjuvant chemotherapy (NAC) was administered followed by primary ALND using breast MRI. PATIENTS AND METHODS: Data from 98 cN+ breast cancer patients were analysed retrospectively. Patients without residual axillary disease at breast MRI following NAC (RAD-, n = 64) were compared with patients with residual axillary disease (RAD+, n = 34). Presence of suspect axillary lymph nodes on pre-NAC and post-NAC breast MRI was determined by experienced breast radiologists and was correlated to histopathological findings. RESULTS: In the RAD-group residual axillary disease on pathological analysis following NAC was found in 25 patients (39.1%), as compared to 24 patients (70.6%) in the RAD + group (p = 0.003). Metastatic involvement of ARM lymph nodes following NAC was demonstrated in 5 patients (7.8%) in the RAD-group as compared to 10 patients (29.4%) in the RAD + group (p = 0.005). CONCLUSION: Breast MRI following NAC is not suitable to detect residual metastatic disease of the axilla. However, breast MRI post-NAC may be of use to identify cN+ patients with a low risk of ARM lymph node metastases. This may help to select a subgroup of cN+ patients in whom sparing of ARM lymph nodes during axillary lymph node dissection can be considered.

Axillary reverse mapping (ARM) in clinically node positive breast cancer patients.

BACKGROUND: Axillary reverse mapping (ARM) is a technique to map and preserve upper extremity lymphatic drainage during axillary lymph node dissection (ALND) in breast cancer patients. We prospectively evaluated the metastatic involvement of ARM-nodes in patients who underwent an ALND for clinically node positive disease following (neo)adjuvant chemotherapy (NAC) in comparison to patients in whom primary ALND was performed without NAC. PATIENTS AND METHODS: Patients with clinically node positive invasive breast cancer, confirmed by fine needle aspiration cytology and scheduled for primary ALND were enrolled in the study. Patients were separated into two groups: one group treated with NAC (NAC+ group) and one group not treated with NAC (NAC- group). ARM was performed in all patients by injecting blue dye into the ipsilateral upper extremity. During ALND, ARM-nodes were first identified and removed separately, followed by a standard ALND. RESULTS: 91 patients were included in the NAC+ and 21 patients in the NAC- group. There was no difference in the ARM visualization rate between the two groups (86.8% for NAC+ group versus 90.5% for NAC- group, P = 0.647). In the NAC+ group 16.5% of the patients had metastatic involvement of the ARM-nodes versus 36.8% of the patients in the NAC- group (P = 0.048). CONCLUSION: The risk of metastatic involvement of ARM-nodes in clinically node positive breast cancer patients is significantly lower in patients who have received NAC.

The influence of simultaneous integrated boost, hypofractionation and oncoplastic surgery on cosmetic outcome and PROMs after breast conserving therapy.

INTRODUCTION: We retrospectively investigated the possible influence of a simultaneous integrated boost (SIB), hypofractionation and oncoplastic surgery on cosmetic outcome in 125 patients with stage I-II breast cancer treated with breast conserving therapy (BCT). PATIENTS AND METHODS: The boost was given sequentially (55%) or by SIB (45%); fractionation was conventional (83%) or hypofractionated (17%); the surgical technique was a conventional lumpectomy (74%) or an oncoplastic technique (26%). We compared cosmetic results subjectively using a questionnaire independently completed by the patient and by the physician and objectively with the BCCT.core software. Independent-samples T-tests were used to compare outcome in different groups. Patients also completed the EORTC QLQ C30 and BR23. RESULTS: Univariate analyses indicated no significant differences of the cosmetic results (P ≤ 0.05) for the type of boost or fractionation. However, the conventional lumpectomy group scored significantly better than the oncoplastic group in the BCCT.core evaluation, without a significant difference in the subjective cosmetic evaluation. Quality of life outcome was in favour of SIB, hypofractionation and conventional surgery. CONCLUSION: Our study indicates that the current RT techniques seem to be safe for cosmetic outcome and quality of life. Further investigation is needed to verify the possible negative influence of oncoplastic surgery on the cosmetic outcome and the quality of life as this technique is especially indicated for patients with an unfavourable tumour/breast volume ratio.

ARM: axillary reverse mapping - the need for selection of patients.

BACKGROUND: Axillary reverse mapping (ARM) is a technique that discerns axillary lymphatic drainage of the arm from the breast. This study was performed to evaluate both the feasibility of this technique and the proportion of metastatic involvement of ARM-nodes. PATIENTS AND METHODS: Patients with invasive breast cancer and an indication for axillary lymph node dissection (ALND) were enrolled in the study: patients with a tumor-positive sentinel lymph node (SLN(+)-group) and patients who had axillary metastases proven by preoperative cytology (CP-N(+)-group) were distinguished. ARM was performed in all patients by injecting blue dye. During surgery ARM-nodes were identified and removed first, followed by ALND. RESULTS: Between October 2009 and June 2011 93 patients underwent ARM. There were 43 patients in the SLN(+)-group and 50 patients in the CP-N(+)-group. No significant differences in visualization rate of ARM-nodes between the groups (86 vs 94% respectively, P = 0.196) were identified. In the SLN(+)-group none of the ARM-nodes contained metastases versus 11 patients (22%) in the CP-N(+)-group (P = 0.001). Patients receiving neoadjuvant systemic therapy had a significantly lower risk of additional axillary lymph node metastases (24.6 vs 44.4%, P = 0.046). DISCUSSION: The ARM procedure is technically feasible with a high visualization rate. The proportion of patients with metastases in the ARM-nodes was significantly higher in patients with proven axillary metastases than in patients with a positive SLN. Patients with SLN metastases appear to be good candidates for the ARM technique and possibly also patients with proven axillary metastases receiving neoadjuvant chemotherapy.

Reduction of in-hospital mortality following regionalisation of pancreatic surgery in the south-east of the Netherlands.

BACKGROUND: In the late nineties of the former century, surgery for pancreatic and peri-ampullary cancer in the southern part of The Netherlands was performed mainly in low-volume hospitals (<5 resections/year). Results reported by the Comprehensive Cancer Center South (CCCS) in 2005 revealed the clearly disappointing results of this practice. The former stimulated the regionalisation of pancreatic surgery by 3 collaborating surgical units into one non-academic teaching hospital in the eastern part of the CCCS-region starting from July 2005. METHODS: All of the 76 patients in this regional cohort group in whom a resection of a (peri-)pancreatic tumour was performed with curative intent have been followed up prospectively. The results of surgical morbidity and in-hospital mortality were compared with the results of the CCCS cohort group which were reported previously. RESULTS: Ever since the regionalisation the annual number of patients undergoing resection of a pancreatic tumour increased from 10 to 33, resulting in a total number of 76 patients. Post-operative complications, reoperation rate and in-hospital mortality decreased significantly to 34.2%, 18.4% and 2.6% respectively, as compared to 71.9%, 37.8 and 24.4% in the time period before regionalisation (p < 0.01). CONCLUSION: These unique comparative prospective data derived from daily practice in a collaborative surgical region in The Netherlands (CCCS) support the need for centralisation of pancreatic surgery in order to improve standard of care in pancreatic surgery. This can be achieved by collaboration in a large regional hospital.