[Ultrasound-guided surgery for breast cancer]. / Echogeleid opereren bij mammacarcinoom.

Recent literature shows that perioperative ultrasound guidance of surgery for palpable and nonpalpable breast carcinoma results in improved surgical effectiveness. Ultrasound-guided surgery can easily lead to significant improvement of the number of radical resections and can decrease the need for additional surgery or extra radiotherapy. Ultrasound-guided surgery also contributes to a reduction in the amount of excessive breast tissue removal, which means the final cosmetic result is better. Ultrasound-guided surgery is cost-effective and easy to learn. Implementation of ultrasound-guided surgery has increased in recent years, albeit slowly. Surgeons as well as radiologists should become more aware of the improvement of primary and secondary outcome measures that can be achieved with ultrasound-guided surgery of breast cancer. In addition to radicality, the quantity of excised tissue - tumour tissue and healthy tissue - can be used as a quality indicator, given the impact on cosmetic outcome and quality of life for patients with breast cancer.

Irreversible Electroporation in Hepatopancreaticobiliary Tumours.

Hepatopancreaticobiliary tumours are often diagnosed at an advanced disease stage, in which encasement or invasion of local biliary or vascular structures has already occurred. Irreversible electroporation (IRE) is an image-guided tumour ablation technique that induces cell death by exposing the tumour to high-voltage electrical pulses. The cellular membrane is disrupted, while sparing the extracellular matrix of critical tubular structures. The preservation of tissue integrity makes IRE an attractive treatment option for tumours in the vicinity of vital structures such as splanchnic blood vessels and major bile ducts. This article reviews current data and discusses future trends of IRE for hepatopancreaticobiliary tumours.

Irreversible Electroporation to Treat Malignant Tumor Recurrences Within the Pelvic Cavity: A Case Series.

OBJECTIVE: To describe the initial experience with irreversible electroporation (IRE) to treat pelvic tumor recurrences. METHODS: A retrospective single-center analysis was performed. Adverse events were recorded using Common Terminology Criteria of Adverse Events (CTCAE) 4.0. Clinical outcome was determined using pain- and general- symptom assessment, including Seddon's peripheral nerve injury (PNI) types. Radiological outcome was evaluated by comparing baseline with three-month 18F-FDG PET-CT follow-up. RESULTS: Eight patients (nine tumors [recurrences of primary rectal (n = 4), anal (n = 1), sigmoid (n = 1), cervical (n = 1), and renal cell carcinoma (n = 1)]) underwent percutaneous IRE as salvage therapy. Median longest tumor diameter was 3.7 cm (range 1.2-7.0). One CTCAE grade III adverse event (hemorrhage) and eight CTCAE grade II complications occurred in 6/8 patients: vagino-tumoral fistula (n = 1), lower limb motor loss (n = 3; PNI type II) with partial recovery in one patient, hypotonic bladder (n = 2; PNI types I and II) with complete recovery in one patient, and upper limb motor loss (n = 2; PNI type II) with partial recovery in both patients. No residual tumor tissue was observed at 3-month follow-up. After a median follow-up of 12 months, local progression was observed in 5/9 lesions (4/5 were >3 cm pre-IRE); one lesion was successfully retreated. Debilitating preprocedural pain (n = 3) remained unchanged (n = 1) or improved (n = 2). CONCLUSION: IRE may represent a suitable technique to treat pelvic tumor recurrences, although permanent neural function loss can occur. Complete ablation seems realistic for smaller lesions; for larger lesions symptom control should be the focus.

Intraoperative ultrasound guidance in breast-conserving surgery shows superiority in oncological outcome, long-term cosmetic and patient-reported outcomes: Final outcomes of a randomized controlled trial (COBALT).

BACKGROUND: The multicenter randomized controlled COBALT trial demonstrated that ultrasound-guided breast-conserving surgery (USS) results in a significant reduction of margin involvement (3.1% vs. 13%) and excision volumes compared to palpation-guided surgery (PGS). The aim of the present study was to determine long term oncological and patient-reported outcomes including quality of life (QoL), together with their progress over time. METHODS: 134 patients with T1-T2 breast cancer were randomized to USS (N = 65) or PGS (N = 69). Cosmetic outcomes were assessed with the Breast Cancer Conservative Treatment cosmetic results (BCCT.core) software, panel-evaluation and patient self-evaluation on a 4-point Likert-scale. QoL was measured using the EORTC QLQ-C30/-BR23 questionnaire. RESULTS: No locoregional recurrences were reported after mean follow-up of 41 months. Seven patients (5%) developed distant metastatic disease (USS 6.3%, PGS 4.4%, p = 0.466), of whom six died of disease (95.5% overall survival). USS achieved better cosmetic outcomes compared to PGS, with poor outcomes of 11% and 21% respectively, a result mainly attributable to mastectomies due to involved margins following PGS. There was no difference after 1 and 3 years in cosmetic outcome. Dissatisfied patients included those with larger excision volumes, additional local therapies and worse QoL. Patients with poor/fair cosmetic outcomes scored significantly lower on aspects of QoL, including breast-symptoms, body image and sexual enjoyment. CONCLUSION: By significantly reducing positive margin status and lowering resection volumes, USS improves the rate of good cosmetic outcomes and increases patient-satisfaction. Considering the large impact of cosmetic outcome on QoL, USS has great potential to improve QoL following breast-conserving therapy.

Neoadjuvant chemotherapy in breast-conserving surgery - Consequences on margin status and excision volumes: A nationwide pathology study.

BACKGROUND: Neoadjuvant chemotherapy (NACT) is increasingly used in patients with operable disease due to the potential of converting patients requiring mastectomy to breast conserving surgery (BCS) or lowering resection volumes to improve cosmetic outcome. This nationwide retrospective study aims to determine margin status and specimen volume in patients with invasive breast cancer who underwent BCS after NACT. METHODS: All patients who underwent BCS in 2012-2013 for invasive breast cancer were selected from a nationwide network and registry of histology and cytopathology in the Netherlands (PALGA). RESULTS: Of the 9901 patients, 626 (6.3%) received NACT. After primary surgery 949 (10.2%) patients had tumour-involved margins compared to 152 (24.3%) after NACT. Close margins (≤1 mm) were seen in another 111 (17.7%) patients after NACT. The adjusted odds ratio for involved margins after NACT was 2.94, meaning a three times higher risk of involved margins compared with primary surgery. In patients with lobular carcinoma (54.9%) and no response to NACT (42.1%) higher tumour-involved margins were seen. High resection volumes >60 cc were observed in 224 (36%) patients after NACT of which 37 (16.5%) had tumour involved margins and 32 (14.3%) close margins ≤1 mm. CONCLUSION: The primary goal of the surgeon performing BCS after NACT, to reach tumour-free margins, is not accomplished in one out of four patients. Patients especially at risk are patients with ILC and no pathological tumour response. Excessive resection volumes after NACT do not guarantee tumour-free margins. Further research is necessary to analyze whether we are counterproductive when NACT is given in order to lower resection volumes.

Is ultrasound-guided fine-needle aspiration cytology of adequate value in detecting breast cancer patients with three or more positive axillary lymph nodes?

This study evaluated the accuracy of ultrasound-guided fine-needle aspiration cytology of the sonographically most suspicious axillary lymph node (US/FNAC) to select early breast cancer patients with three or more tumour-positive axillary lymph nodes. Between 2004 and 2014, a total of 2130 patients with histologically proven early breast cancer were evaluated and treated in the Noordwest Clinics Alkmaar. US/FNAC was performed preoperatively in all these patients. We analysed the results of US/FNAC retrospectively. Pathological axillary node status (sentinel node biopsy and/or axillary lymph node dissection) was used as reference standard. A total of 634 (29.8 %) of 2130 patients had axillary lymph node metastases on final histology. 248 node positive patients (11.6 %) had three or more positive lymph nodes. The accuracy of US/FNAC to detect three or more positive lymph nodes was 89.8 %, sensitivity was 44.8 %, specificity was 95.7 %, PPV was 58.1 %, and NPV was 92.9 %. This study shows a more than adequate accuracy of preoperative US/FNAC to detect three or more positive lymph nodes (89.8 %). However, when US/FNAC was chosen as the only axillary staging method, 6.4 % of all patients (false negative group) would have been undertreated and 3.8 % of all patients (false positive group) would have been overtreated according to the ACOSOG Z0011 criteria.

A nationwide pathology study on surgical margins and excision volumes after breast-conserving surgery: There is still much to be gained.

AIM OF THE STUDY: The current study aims to assess margin status in relation to amount of healthy breast tissue resected in breast-conserving surgery (BCS) on a nationwide scale. METHODS: Using PALGA (a nationwide network and registry of histology and cytopathology in the Netherlands), all patients who underwent BCS for primary invasive carcinoma in 2012-13 were selected (10,058 excerpts). 9276 pathology excerpts were analyzed for a range of criteria including oncological margin status and distance to closest margin, specimen weight/volume, greatest tumor diameter, and with or without localization method. Calculated resection ratios (CRR) were assessed to determine excess healthy breast tissue resection. RESULTS: Margins for invasive carcinoma and in situ carcinoma combined were tumor-involved in 498 (5.4%) and focally involved in 1021 cases (11.0%) of cases. Unsatisfactory resections including (focally) involved margins and margins ≤ 1 mm were reported in 33.8% of patients. The median lumpectomy volume was 46 cc (range 1-807 cc; SD 49.18) and median CRR 2.32 (range 0.10-104.17; SD 3.23), indicating the excision of 2.3 the optimal resection volume. CONCLUSION: The unacceptable rate of tumor-involved margins as well as margins ≤ 1 mm in one third of all patients is also achieved at the expense of healthy breast tissue resection, which may carry the drawback of high rates of cosmetic failure. These data clearly suggest the need for improvement in current breast conserving surgical procedures to decrease tumor-involved margin rates while reducing the amount of healthy breast tissue resected.

Anaesthetic management during open and percutaneous irreversible electroporation.

BACKGROUND: Irreversible electroporation (IRE) is a novel tumour ablation technique involving repetitive application of electrical energy around a tumour. The use of pulsed electrical gradients carries a risk of cardiac arrhythmias, severe muscle contractions, and seizures. We aimed to identify IRE-related risks and the appropriate precautions for anaesthetic management. METHODS: All patients who were treated with IRE were prospectively included. Exclusion criteria were arrhythmias, congestive heart failure, active coronary artery disease, and epilepsy. All procedures were performed under general anaesthesia with complete muscle relaxation during ECG-synchronized pulsing. Adverse events, cardiovascular effects, blood samples, cerebral activity, and post-procedural pain were analysed. RESULTS: Twenty-eight patients underwent 30 IRE sessions for tumours in the liver, pancreas, kidney, and lesser pelvis. No major adverse events occurred during IRE. Median systolic and diastolic blood pressure increased by 44 mm Hg (range -7 to 108 mm Hg) and 19 mm Hg (range 1-50 mm Hg), respectively. Two transient minor cardiac arrhythmias without haemodynamic consequences were observed. Muscle contractions were mild and IRE caused no reactive brain activity on a simplified EEG. Pain in the first 24 h after percutaneous IRE was generally mild, but higher pain scores were reported after pancreatic treatment (mean VAS score 3; range 0-9). CONCLUSIONS: Side-effects during IRE on tumours in the liver, pancreas, kidney, and lesser pelvis seem mild and manageable when current recommendations for anaesthesia management, including deep muscle relaxation and ECG synchronized pulsing, are followed. Electrical pulses do not seem to cause reactive cerebral activity and evidence for pre-existing atrial fibrillation as an absolute contra-indication for IRE is questionable.

Ablation of colorectal liver metastases by irreversible electroporation: results of the COLDFIRE-I ablate-and-resect study.

OBJECTIVES: Irreversible electroporation (IRE) is a new ablation technique that relies on high-voltage electrical pulses. This clinical study evaluates the pathological response of colorectal liver metastases (CRLM) treated with IRE and the clinical safety and feasibility. METHODS: Ten patients with resectable CRLM were included. During laparotomy, the metastases were treated with IRE and resected 60 min later. Safety and feasibility were assessed based on adverse events, laboratory values, technical success and intra-operative ultrasound findings. Tissue response was assessed using triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE, complement-3d and caspase-3). RESULTS: Ten lesions with a mean diameter of 2.4 cm were successfully electroporated and resected, on average, 84 min later (range 51-153 min). One minor transient cardiac arrhythmia occurred during IRE. Ultrasound showed a sharply demarcated hypoechoic ablation zone around the tumour. TTC showed avitality of all lesions, covering the complete tumour in 8/10 lesions. Although immunohistochemistry proved heterogeneous and difficult to interpret within the tumours, it confirmed irreversible cell damage in the tumour-free margin of all specimens. CONCLUSIONS: This ablate-and-resect study demonstrated avitality caused by IRE of CRLM in humans. Further characterisation of tissue- and tumour-specific electrical properties is warranted to improve ablation protocols for maximised tissue ablation. KEY POINTS: • Irreversible electroporation induces cell death in colorectal liver metastases within 1 h. • The ablation zone shows a sharp demarcation between avital and vital tissue. • Apoptosis is involved in cell death of colorectal liver metastases after IRE. • Effects of IRE can be monitored real-time using intraoperative ultrasound. • Local electrical heterogeneities of tumour tissue may require tumour-specific ablation protocols.

Aurora kinase A (AURKA) expression in colorectal cancer liver metastasis is associated with poor prognosis.

BACKGROUND: Five-year survival after resection of colorectal cancer liver metastasis (CRLCM) is <30%. We recently found that aurora kinase A (AURKA) drives 20q gain-associated tumour progression and is associated with disease recurrence. This study evaluates the prognostic value of AURKA expression in CRCLM of patients who underwent liver resection. METHODS: Tissue microarrays (TMAs) were generated using formalin-fixed paraffin-embedded CRCLM and matched primary tumour from a multi-institutional cohort of patients with CRCLM who underwent liver resection between 1990 and 2010. Tissue microarrays were stained for AURKA using immunohistochemistry, and a hazard rate ratio (HRR) for the association between overall survival (OS) and nuclear AURKA expression in CRCLM was calculated. Results were validated by 500-fold cross-validation. RESULTS: The expression of AURKA was evaluated in CRCLM of 343 patients. High AURKA expression was associated with poor OS (HRR 1.55, P<0.01), with a cross-validated average HRR of 1.57 (P=0.02). Average HRR was adjusted for the established prognostic clinicopathological variables in a multivariate analysis (average HRR 1.66; P=0.02). The expression of AURKA in CRCLM was correlated to its expression in corresponding primary tumour (P<0.01). CONCLUSION: The expression of AURKA protein is a molecular biomarker with prognostic value for patients with CRCLM, independent of established clinicopathological variables.

Ultrasound-guided surgery for palpable breast cancer is cost-saving: results of a cost-benefit analysis.

Ultrasound-guided surgery (USS) has recently been proven to result in a significant reduction of tumour-involved surgical margins, for patients with palpable invasive breast cancer. The objective of this economic evaluation alongside a randomised trial was to evaluate the costs and benefits of USS compared to palpation-guided surgery (PGS). The hospital perspective was used. On the cost side of the analysis, resource use related to baseline treatment was taken into account and on the benefit side, resource use related to additional treatments was included. On the cost side, the difference in costs per patient was €193 (95% CI €153-€233) with higher costs in the USS group. On the benefit side, the difference in costs per patient was -€349 (95% CI -€591 to -€103) with higher costs in the PGS group. This resulted in a cost decrease of -€154 (95% CI -€388 to €81) in the USS group compared to the PGS group. Intra-operative use of a US system during BCS reduces the rate of tumour-involved margins and thereby the costs of additional treatments.

Resection of liver metastases in patients with breast cancer: survival and prognostic factors.

AIMS: Patients with breast cancer metastasized to the liver have a median survival of 4-33 months and treatment options are usually restricted to palliative systemic therapy. The aim of this observational study was to evaluate the effectiveness and safety of resection of liver metastases from breast cancer and to identify prognostic factors for overall survival. METHODS: Patients were identified using the national registry of histo- and cytopathology in the Netherlands (PALGA). Included were all patients who underwent resection of liver metastases from breast cancer in 11 hospitals in The Netherlands of the last 20 years. Study data were retrospectively collected from patient files. RESULTS: A total of 32 female patients were identified. Intraoperative and postoperative complications occurred in 3 and 11 patients, respectively. There was no postoperative mortality. After a median follow up period of 26 months (range, 0-188), 5-year and median overall survival after partial liver resection was 37% and 55 months, respectively. The 5-year disease-free survival was 19% with a median time to recurrence of 11 months. Solitary metastases were the only independent significant prognostic factor at multivariate analysis. CONCLUSION: Resection of liver metastases from breast cancer is safe and might provide a survival benefit in a selected group of patients. Especially in patients with solitary liver metastasis, the option of surgery in the multimodality management of patients with disseminated breast cancer should be considered.

Optimising surgical accuracy in palpable breast cancer with intra-operative breast ultrasound--feasibility and surgeons' learning curve.

AIMS: To evaluate if intra-operative guidance with ultrasonography (US) could improve surgical accuracy of palpable breast cancer excision, and to evaluate the performance of surgeons during training for US-guided excision. MATERIALS AND METHODS: Thirty female patients undergoing breast-conserving surgery for palpable T1-T2 invasive breast cancer were recruited. Three individual breast surgeons, assisted by US, targeted and excised the tumours. The main objective was to obtain adequate resection margins with optimal resection volumes. The specimen volume, tumour diameter and histological margin status were recorded. The specimen volume was divided by the optimal resection volume, defined as the spherical tumour volume plus a 1.0-cm margin. The resulting calculated resection ratio (CRR) indicated the amount of excess tissue resected. RESULTS: All tumours were correctly identified during surgery, 29 of 30 tumours (96.7%) were removed with adequately negative margins, and one tumour was removed with focally positive margins. The median CRR was 1.0 (range, 0.4-2.8), implying optimal excision volume. For all breast surgeons, CRR improved during the training period. By the 8th procedure, all surgeons showed proficiency in performing intra-operative breast US. CONCLUSION: Surgeons can easily learn the skills needed to perform intra-operative US for palpable breast tumour excision. The technique is non-invasive, simple, safe and effective for obtaining adequate resection margins. Within the first two cases, resections reached optimal volumes, thereby, presumably resulting in improved cosmetic outcomes. In a multicentre, randomised, clinical trial, intra-operative US guidance for palpable breast tumours will be evaluated for oncological and cosmetic outcomes.

A comparison of three methods for nonpalpable breast cancer excision.

AIMS: To evaluate the efficacy of three methods of breast-conserving surgery (BCS) for nonpalpable invasive breast cancer in obtaining adequate resection margins and volumes of resection. MATERIALS AND METHODS: A total of 201 consecutive patients undergoing BCS for nonpalpable invasive breast cancer between January 2006 and 2009 in four affiliated institutions was retrospectively analysed. Patients with pre-operatively diagnosed primary or associated ductal carcinoma in situ (DCIS), multifocal disease, or a history of breast surgery or neo-adjuvant treatment were excluded from the study. The resections were guided by wire localisation (WL), ultrasound (US), or radio-guided occult lesion localisation (ROLL). The pathology reports were reviewed to determine oncological margin status, as well as tumour and surgical specimen sizes. The optimal resection volume (ORV), defined as the spherical tumour volume with an added 1.0-cm margin, and the total resection volume (TRV), defined as the corresponding ellipsoid, were calculated. By dividing the TRV by the ORV, a calculated resection ratio (CRR) was determined to indicate the excess tissue resection. RESULTS: Of all 201 excisions, 117 (58%) were guided by WL, 52 (26%) by US, and 32 (16%) by ROLL. The rate of focally positive and positive margins for invasive carcinoma was significantly lower in the US group (N = 2 (3.7%)) compared to the WL (N = 25 (21.3%)) and ROLL (N = 8 (25%)) groups (p = 0.023). The median CRRs were 3.2 (US), 2.8 (WL) and 3.8 (ROLL) (WL versus ROLL, p < 0.05), representing a median excess tissue resection of 3.1 times the optimal resection volume. CONCLUSION: US-guided BCS for nonpalpable invasive breast cancer was more accurate than WL- and ROLL-guided surgery because it optimised the surgeon's ability to obtain adequate margins. The excision volumes were large in all excision groups, especially in the ROLL group.

4-1BB-mediated expansion affords superior detection of in vivo primed effector memory CD8+ T cells from melanoma sentinel lymph nodes.

We have been studying the re-activation of tumor-associated antigen (TAA)-specific CD8(+) T cells in sentinel lymph nodes (SLN) of melanoma patients upon intradermal administration of the CpG-B oligodeoxynucleotide PF-3512676. To facilitate functional testing of T cells from small SLN samples, high-efficiency polyclonal T cell expansion is required. In this study, SLN cells were expanded via classic methodologies with plate- or bead-bound anti-CD3/CD28 antibodies and with the K562/CD32/4-1BBL artificial APC system (K32/4-1BBL aAPC) and analyzed for responsiveness to common recall or TAA-derived peptides. K32/4-1BBL-expanded T cell populations contained significantly more effector/memory CD8(+) T cells. Moreover, recall and melanoma antigen-specific CD8(+) T cells were more frequently detected in K32/4-1BBL-expanded samples as compared with anti-CD3/CD28-expanded samples. We conclude that K32/4-1BBL aAPC are superior to anti-CD3/CD28 antibodies for the expansion of in vivo-primed specific CD8(+) T cells and that their use facilitates the sensitive monitoring of functional anti-tumor T cell immunity in SLN.

The impact of intraoperative ultrasonography on the surgical treatment of patients with colorectal liver metastases.

INTRODUCTION: Intraoperative ultrasonography (IOUS) has been the standard in surgical decision making in oncologic liver surgery. Preoperative imaging techniques have improved substantially in recent years; therefore, the importance of IOUS might change. The current results of IOUS were compared with preoperative high-resolution helical CT scanning and the impact of IOUS on surgical decision making was evaluated. METHODS: A total of 100 consecutive patients who underwent open surgery for colorectal liver metastases within 4 weeks after preoperative imaging, performed with high-speed helical CT scanners, were included for this study. During surgery, IOUS was performed by a liver specialized radiologist. The findings on preoperative and intraoperative imaging and surgical exploration were compared regarding number, site, and size of the hepatic lesions. The preoperative surgical plan was compared with the final surgical treatment. RESULTS: One hundred patients with CRLM underwent 117 surgical treatments. In 38 patients IOUS differed from preoperative data. In 23 cases IOUS identified more metastatic lesions. In five patients, intraoperative findings identified smaller or less hepatic lesions. Additional information on the localization of the hepatic lesions was gathered by IOUS and changed the surgical treatment in ten cases. IOUS alone altered the surgical strategy 35 times during 117 procedures. In nearly all cases, discrepancy between the preoperative CT scan and IOUS resulted in a change of surgical treatment. CONCLUSIONS: Despite improvement in preoperative imaging technology, the intraoperative use of ultrasonography remains of crucial importance. The detection of preoperatively unknown lesions remains high with great consequence on surgical therapy.

[Breast self-examination also valuable in women participating in a screening programme]. / Borstzelfonderzoek ook van waarde bij vrouwen die participeren in een screeningsprogramma.

OBJECTIVE: To evaluate the different methods of detection of breast cancer in women who at time of diagnosis underwent screening mammographies as participants in the Dutch National Breast Cancer Screening Programme (BOB group), and in women who participated in an intensive screening programme for a familial or genetic predisposition to breast cancer (FAM group). DESIGN: Partly retrospective, partly prospective, descriptive. METHOD: All patients who had surgery for invasive breast cancer at the VU University Medical Center, Amsterdam, the Netherlands, from 1 January 1995 to 30 June 2006 and who were participating in one of the abovementioned screening programmes at the time of diagnosis, were included. Data concerning the palpability of the tumour at time of diagnosis and the diagnostic method that first led to breast cancer being diagnosed, were collected. RESULTS: The BOB group consisted of 397 women with invasive carcinoma of which 57% (227/397) tumours were palpable at the time of diagnosis. The majority (64%; 146/227) of the palpable tumours were discovered by breast self-examination as an interval carcinoma. 31% (71/227) were detected by screening mammography and were also palpable. During the same period, 490 women participated in the high risk screening programme; in this FAM group, 23 invasive tumours were detected. A total of 61% (14/23) of these lesions were found during breast self-examination; 7 lesions (30%) were found by imaging. CONCLUSION: In women who participated in one of the 2 screening programmes, the majority of invasive breast cancers were palpable and more than half were detected by breast self-examination. Performing breast self-examination on a regular basis may contribute to early detection of breast cancer. Therefore, the teaching of breast self-examination to women should be encouraged, even if they are participating in a breast cancer screening programme.

The post-surgical inflammatory response provokes enhanced tumour recurrence: a crucial role for neutrophils.

BACKGROUND/AIMS: Peritoneal trauma activates a cascade of peritoneal defence mechanisms responsible for postoperative intra-abdominal tumour recurrence. After peritoneal trauma, inflammatory cells and soluble factors are present in the abdominal cavity and can be captured in lavage fluids. The present study evaluated which component enhances intra-abdominal tumour recurrence. Furthermore, we evaluated which inflammatory cells are present and studied the influence of anti-neutrophil serum (ANS) on peritoneal tumour recurrence. METHODS: In a peritoneal trauma model in rats, postoperative lavage fluids were collected and separated into cellular and supernatant components. Both components were injected in naïve rats together with CC531s colon carcinoma cells. In a second experiment, rats were treated with one or three doses of ANS. RESULTS: Intraperitoneal injection of naïve recipients with inflammatory cells or supernatant resulted in significant tumour recurrence. Severe peritoneal trauma provoked significant intra-abdominal neutrophil influx which could be prevented by ANS. Treatment with one dose did not affect blood cell counts and significantly reduced tumour recurrence. Treatment with three doses of ANS decreased blood lymphocytes, monocytes, and neutrophils and induced tumour load. CONCLUSIONS: Neutrophils play a crucial role in postoperative adhesion and growth of spilled tumour cells after surgical peritoneal trauma. Prevention of peritoneal neutrophil influx reduces local tumour recurrence.