Prognostic model for overall survival of head and neck cancer patients in the palliative phase.

BACKGROUND: Patients with head and neck squamous cell carcinoma (HNSCC) enter the palliative phase when cure is no longer possible or when they refuse curative treatment. The mean survival is five months, with a range of days until years. Realistic prognostic counseling enables patients to make well-considered end-of-life choices. However, physicians tend to overestimate survival. The aim of this study was to develop a prognostic model that calculates the overall survival (OS) probability of palliative HNSCC patients. METHODS: Patients diagnosed with incurable HNSCC or patients who refused curative treatment for HNSCC between January 1st 2006 and June 3rd 2019 were included (n = 659). Three patients were lost to follow-up. Patients were considered to have incurable HNSCC due to tumor factors (e.g. inoperability with no other curative treatment options, distant metastasis) or patient factors (e.g. the presence of severe comorbidity and/or poor performance status).Tumor and patients factors accounted for 574 patients. An additional 82 patients refused curative treatment and were also considered palliative. The effect of 17 candidate predictors was estimated in the univariable cox proportional hazard regression model. Using backwards selection with a cut-off P-value < 0.10 resulted in a final multivariable prediction model. The C-statistic was calculated to determine the discriminative performance of the model. The final model was internally validated using bootstrapping techniques. RESULTS: A total of 647 patients (98.6%) died during follow-up. Median OS time was 15.0 weeks (95% CI: 13.5;16.6). Of the 17 candidate predictors, seven were included in the final model: the reason for entering the palliative phase, the number of previous HNSCC, cT, cN, cM, weight loss in the 6 months before diagnosis, and the WHO performance status. The internally validated C-statistic was 0.66 indicating moderate discriminative ability. The model showed some optimism, with a shrinkage factor of 0.89. CONCLUSION: This study enabled the development and internal validation of a prognostic model that predicts the OS probability in HNSCC patients in the palliative phase. This model facilitates personalized prognostic counseling in the palliative phase. External validation and qualitative research are necessary before widespread use in patient counseling and end-of-life care.

Causes and Ways of Death in Patients With Head and Neck Cancer.

Importance: There is limited literature on the exact causes and ways of death in patients with head and neck cancer. To provide optimal care, especially in the palliative phase, more information on this is needed. Objective: To provide insights into the causes and ways of death among patients with head and neck cancer. Design, Setting, and Participants: This retrospective cohort study included a consecutive population of patients who received a diagnosis of primary squamous cell carcinoma of the head and neck between January 2006 and December 2013 who were treated in the Erasmus MC. Patient data were merged with nonpublic microdata from Statistics Netherlands. Follow-up time was specified as the date of diagnosis until death or December 3, 2019, whichever came first. The data were checked and reanalyzed in November 2023. Main outcomes and Measures: Causes (eg, head and neck cancer, other cancer) and ways (eg, natural death, suicide) of death. Results: A total of 1291 patients (59.2%; 342 women [26.5%]) died during follow-up (median [IQR] follow-up, 2.7 [1.2-5.6] years). The main cause of death was head and neck cancer (557 [43.1%]), followed by the competing cause of other cancers (344 [26.6%]). In total, 240 patients (18.6%) received palliative sedation and 70 patients (5.4%) euthanasia. Compared with patients with head and neck cancer as the underlying cause of death, lower odds ratios (ORs) were observed for receiving palliative sedation (OR, 0.32 vs 0.07; 95% CI, 0.22-0.46 vs 0.03-0.12) and euthanasia (OR, 0.22 vs 0.01; 95% CI, 0.11-0.41 vs 0-0.107) in patients with other causes of death. Patients with a middle and high income had higher ORs for receiving palliative sedation (OR, 1.46 vs 1.86; 95% CI, 1.05-2.04 vs 1.22-2.85) or euthanasia (OR, 2.25 vs 3.37; 95% CI, 1.18-4.3, 1.6-7.12) compared with low-income patients. Retired patients had lower ORs for receiving palliative sedation or euthanasia compared with employed patients (OR, 0.56 vs 0.44; 95% CI, 0.39-0.8 vs 0.24-0.82). Conclusion and Relevance: The results of this cohort study suggest that more than half of the patients died of competing causes and palliative sedation and euthanasia were more common in patients with head and neck cancer as the underlying cause of death. Patients with a higher socioeconomic status had higher odds of receiving palliative sedation and euthanasia. These insights may support health care professionals in providing patient-centered care, especially for patients in the palliative phase.

Individualized Dynamic Prediction Model for Patient-Reported Voice Quality in Early-Stage Glottic Cancer.

OBJECTIVE: Early-stage glottic cancer (ESGC) is a malignancy of the head and neck. Besides disease control, preservation and improvement of voice quality are essential. To enable expectation management and well-informed decision-making, patients should be sufficiently counseled with individualized information on expected voice quality. This study aims to develop an individualized dynamic prediction model for patient-reported voice quality. This model should be able to provide individualized predictions at every time point from intake to the end of follow-up. STUDY DESIGN: Longitudinal cohort study. SETTING: Tertiary cancer center. METHODS: Patients treated for ESGC were included in this study (N = 294). The Voice Handicap Index was obtained prospectively. The framework of mixed and joint models was used. The prognostic factors used are treatment, age, gender, comorbidity, performance score, smoking, T-stage, and involvement of the anterior commissure. The overall performance of these models was assessed during an internal cross-validation procedure and presentation of absolute errors using box plots. RESULTS: The mean age in this cohort was 67 years and 81.3% are male. Patients were treated with transoral CO2 laser microsurgery (57.8%), single vocal cord irradiation up to (24.5), or local radiotherapy (17.5%). The mean follow-up was 43.4 months (SD 21.5). Including more measurements during prediction improves predictive performance. Including more clinical and demographic variables did not provide better predictions. Little differences in predictive performance between models were found. CONCLUSION: We developed a dynamic individualized prediction model for patient-reported voice quality. This model has the potential to empower patients and professionals in making well-informed decisions and enables tailor-made counseling.

Unmet supportive care needs among informal caregivers of patients with head and neck cancer in the first 2 years after diagnosis and treatment: a prospective cohort study.

OBJECTIVE: Informal caregivers of head and neck cancer (HNC) patients have a high caregiver burden and often face complex practical caregiving tasks. This may result in unmet supportive care needs, which can impact their quality of life (QoL) and cause psychological distress. In this study, we identify caregivers' unmet needs during long-term follow-up and identify caregivers prone to unmet supportive care needs. METHODS: Data were used from the multicenter prospective cohort study NETherlands QUality of life and Biomedical cohort studies In Cancer (NET-QUBIC). The unmet supportive care needs, psychological distress, caregiver burden, and QoL were measured for 234 informal caregivers and their related patients at baseline, 3, 6, 12, and 24 months after. Mixed effect models for repeated measurements were used. RESULTS: At baseline, most caregivers (70.3%) reported at least one unmet supportive care need, with most of the identified needs in the "healthcare & illness" domain. During the follow-up period, caregivers' unmet needs decreased significantly in all domains. Nevertheless, 2 years after treatment, 28.3% were still reporting at least one unmet need. Financial problems were increasingly associated with unmet needs over time. Furthermore, caring for a patient who themselves had many unmet needs, an advanced tumor stage, or severe comorbidity was associated with significantly more unmet needs in caregivers. CONCLUSIONS: The current study shows the strong likelihood of caregivers of HNC patients facing unmet supportive care needs and the interaction between the needs of patients and caregivers. It is important to optimally support informal caregivers by involving them from the start when counseling patients, by providing them with relevant and understandable information, and by referring vulnerable caregivers for (psychosocial) support.

Longitudinal Patient-Reported Voice Quality in Early-Stage Glottic Cancer.

OBJECTIVE: Patient-reported voice quality is an important outcome during counseling in early-stage glottic cancer. However, there is a paucity of adequate longitudinal studies concerning voice outcomes. This study aimed to investigate longitudinal trajectories for patient-reported voice quality and associated risk factors for treatment modalities such as transoral CO2 laser microsurgery, single vocal cord irradiation, and local radiotherapy. STUDY DESIGN: A longitudinal observational cohort study. SETTING: Tertiary cancer center. METHODS: Patients treated for Tcis-T1b, N0M0 glottic cancer were included in this study (N = 294). The Voice Handicap Index was obtained at baseline and during follow-up (N = 1944). Mixed-effects models were used for investigating the different trajectories for patient-reported voice quality. RESULTS: The mean follow-up duration was 43.4 (SD 21.5) months. Patients received transoral CO2 laser microsurgery (57.8%), single vocal cord irradiation (24.5%), or local radiotherapy (17.5%). A steeper improvement during the first year after treatment for single vocal cord irradiation (-15.7) and local radiotherapy (-12.4) was seen, compared with a more stable trajectory for laser surgery (-6.1). All treatment modalities showed equivalent outcomes during long-term follow-up. Associated risk factors for different longitudinal trajectories were age, tumor stage, and comorbidity. CONCLUSION: Longitudinal patient-reported voice quality after treatment for early-stage glottic cancer is heterogeneous and nonlinear. Most improvement is seen during the first year of follow-up and differs between treatment modalities. No clinically significant differences in long-term trajectories were found. Insight into longitudinal trajectories can enhance individual patient counseling and provide the foundation for an individualized dynamic prediction model.

Self-efficacy and coping style in relation to psychological distress and quality of life in informal caregivers of patients with head and neck cancer: a longitudinal study.

OBJECTIVE: In order to understand how informal caregivers of head and neck cancer (HNC) patients deal with the consequences of the disease, we investigated their self-efficacy and coping style in relation to symptoms of anxiety and depression (distress) and quality of life (QoL) over time. In addition, factors associated with self-efficacy and coping style were investigated. METHODS: A total of 222 informal caregivers and their related HNC patients were prospectively followed as part from the multicenter cohort NETherlands QUality of life and Biomedical cohort studies In Cancer (NET-QUBIC). Self-efficacy and coping style were measured at baseline, and distress and QoL at baseline and 3, 6, 12, and 24 months after treatment. RESULTS: Informal caregivers had a high level of self-efficacy comparable with patients. Caregivers used "seeking social support," "passive reacting," and "expression of emotions" more often than patients. Factors associated with self-efficacy and coping were higher age and lower education. Higher self-efficacy was related with better QoL and "active tackling" was associated with less depression symptoms. "Passive reacting" and "expression of emotions" were associated with higher psychological distress and reduced QoL. CONCLUSION: Among informal caregivers of HNC patients, higher self-efficacy and "active tackling" were associated with better functioning over time, while "passive reacting" and "expression of negative emotions" were associated with worse functioning. Awareness of the differences in self-efficacy skills and coping and their relationship with QoL and psychological distress will help clinicians to identify caregivers that may benefit from additional support that improve self-efficacy and "active tackling" and reduce negative coping styles.

Decisional Conflict in Patients With Head and Neck Cancer.

Importance: Patients who experience less decisional conflict (DC) are more engaged in treatment and less prone to decisional regret, nervousness, and fretting. Objectives: To assess DC among patients with head and neck squamous cell carcinoma (HNSCC) after the treatment decision consultation and the association between DC and quality of life as well as the degree of control patients experience in the decision-making process using the control preference scale and the association with DC. Design, Setting, and Participants: This prospective cohort study with 2 separate cohorts was conducted at a tertiary cancer center and included patients who were eligible for curative treatment of a primary squamous cell carcinoma between January 2014 and August 2018. The 2 cohorts comprised 102 patients with small laryngeal squamous cell carcinoma (SLSCC) and 161 patients with other HNSCC. Main Outcomes and Measures: Decisional Conflict Scale (DCS) score, which was scored within 2 weeks after the treatment decision consultation. Other measures included patient characteristics, tumor characteristics, and Control Preference Scale , EuroQol-5D, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30, Hospital Anxiety and Depression Scale (HADS), Eating Assessment Tool, and Voice Handicap Index (VHI) scores. Results: Of 263 patients, 50 (19%) were women; the mean (SD) age was 66.1 (11.4) years in the SLSCC group and 64.9 (9.8) years in the other HNSCC group. In the SLSCC group, 51 patients (50%) experienced clinically significant DC (total score ≥25) compared with 74 patients (46%) in the other HNSCC group. In the SLSCC group, there was a large difference in the median EuroQol-5D, Global Health status, HADS anxiety, HADS depression, and VHI scores between the patients with a total DCS score of less than 25 and total DCS score of 25 or greater, whereas in the other HNSCC group, this only applied to the VHI. Forty-four patients (43.1%) in the SLSCC group felt their treatment choice was a shared decision, and 39 (38.2%) made the decision themselves. In the other HNSCC group, 62 (38.5%) felt that the physician decided, and 56 (34.8%) felt it was a shared decision. In both groups there was a weak association between control preference scale scores and DC. Conclusions and Relevance: The results of this cohort study found that almost half of patients (48%) experienced clinically significant DC. Several quality-of-life measures associated with clinically significant DC were identified. These results suggest that there is room for improvement in aiming to reduce decision delay and decision-related distress.

Caregiver Burden, Psychological Distress and Quality of Life among Informal Caregivers of Patients with Head and Neck Cancer: A Longitudinal Study.

(1) Background: The aim of this study was to investigate caregiver burden among informal caregivers of head and neck cancer patients, in relation to distress and quality of life (QoL), and the relationship between informal caregivers and patients. (2) Methods: Data of 234 dyads from the multicenter prospective cohort study Netherlands Quality of life and Biomedical Cohort studies in cancer was used. Caregiver burden, psychological distress, global QoL, physical and social functioning were measured from baseline until 24 months after treatment. (4) Conclusions: This prospective cohort study shows the high burden of caring for HNC patients, the impact of this burden and the interaction between caregiver and patient. We suggest that healthcare professionals include caregivers in counseling and support.

Impact of a prognostic model for overall survival on the decision-making process in a head and neck cancer multidisciplinary consultation meeting.

BACKGROUND: Multidisciplinary decision-making in head and neck cancer care is complex and requires a tradeoff between prolonging survival and optimizing quality of life. To support prognostication and decision-making in head and neck cancer care, an individualized prognostic model for overall survival (OncologIQ) is available. METHODS: By quantitative and qualitative research we have studied user value of OncologIQ and its impact on the decision-making process in a multidisciplinary consultation meeting. RESULTS: Healthcare professionals experienced added value upon using prognostic estimates of survival from OncologIQ in half (47.5%) of the measurements. Significant impact on the decision making process was seen when OncologIQ was used for older patients, patients having a WHO performance score ≥ 2, or high tumor stage. CONCLUSIONS: The prognostic model OncologIQ enables patient-centered decision-making in a multidisciplinary consultation meeting and was mostly valued in complex patients.

Key Aspects of Prognostic Model Development and Interpretation From a Clinical Perspective.

Importance: Prognostication is an important aspect of clinical decision-making, but it is often challenging. Previous studies show that both patients and physicians tend to overestimate survival chances. Prediction models may assist in estimating and quantifying prognosis. However, insufficient understanding of the development, possibilities, and limitations of such models can lead to misinterpretations. Although many excellent books and comprehensive methodological articles on prognostic model research are published, they may not be accessible enough for the clinical audience. Our aim is to provide an overview on the main issues regarding prediction research for health care professionals to achieve better interpretation and increase the use of prognostic models in daily clinical practice. Observations: The first steps of model development include coding of predictors, model specification, and estimation. Next, we discuss the assessment of the performance of a prediction model, including discrimination and calibration aspects, followed by approaches to internal and external validation and updating. Finally, model reporting, presentation, and steps toward clinical implementation are presented. Conclusions and Relevance: After thorough consideration of the research question, data inspection, and coding of predictors, one can start with the specification of a prediction model. The number of candidate predictors should be kept limited, in view of the number of events in the data, to prevent overfitting. Calibration and discrimination are 2 aspects of model performance that complement each other and should be assessed preferably at external validation. Model development should be accompanied by qualitative research among patients and physicians to facilitate the development of a valuable tool and maximize possibilities for successful implementation. After model presentation is optimized, impact studies are required to assess the clinical value of a prediction model.

Predicting survival in head and neck cancer: External validation and update of the prognostic model OncologIQ in 2189 patients.

BACKGROUND: Disclosing prognostic information is necessary to enable patients to make well-informed treatment decisions. OncologIQ is a prognostic model that predicts the overall survival (OS) probability in patients with head and neck squamous cell carcinoma (HNSCC). We aimed to externally validate and update the model with new prognostic factors and translate it to a clinically useful tool. METHODS: A consecutive retrospective sample of 2189 patients eligible for curative treatment of a primary HNSCC were selected. Discriminative performance was determined using the C-statistic. RESULTS: External validation showed systematic underestimation of OS in the new population, and reasonable discrimination (C-statistic 0.67). Adding smoking, pack years, BMI, weight loss, WHO performance, socioeconomic status, and p16 positivity to the recalibrated multivariable model, improved the internally validated C-statistic to 0.71. The model showed minor optimism and was translated in an online tool (www.oncologiq.nl). CONCLUSIONS: The updated model enables personalized patient counseling during treatment decision consultations.

Physicians' clinical prediction of survival in head and neck cancer patients in the palliative phase.

BACKGROUND: The prognosis of patients with incurable head and neck cancer (HNC) is a relevant topic. The mean survival of these patients is 5 months but may vary from weeks to more than 3 years. Discussing the prognosis early in the disease trajectory enables patients to make well-considered end-of-life choices, and contributes to a better quality of life and death. However, physicians often are reluctant to discuss prognosis, partly because of the concern to be inaccurate. This study investigated the accuracy of physicians' clinical prediction of survival of palliative HNC patients. METHODS: This study was part of a prospective cohort study in a tertiary cancer center. Patients with incurable HNC diagnosed between 2008 and 2011 (n = 191), and their treating physician were included. Analyses were conducted between July 2018 and February 2019. Patients' survival was clinically predicted by their physician ≤3 weeks after disclosure of the palliative diagnosis. The clinical prediction of survival in weeks (CPS) was based on physicians' clinical assessment of the patient during the outpatient visits. More than 25% difference between the actual survival (AS) and the CPS was regarded as a prediction error. In addition, when the difference between the AS and CPS was 2 weeks or less, this was always considered as correct. RESULTS: In 59% (n = 112) of cases survival was overestimated. These patients lived shorter than predicted by their physician (median AS 6 weeks, median CPS 20 weeks). In 18% (n = 35) of the cases survival was correctly predicted. The remaining 23% was underestimated (median AS 35 weeks, median CPS 20 weeks). Besides the differences in AS and CPS, no other significant differences were found between the three groups. There was worse accuracy when predicting survival closer to death: out of the 66 patients who survived 6 weeks or shorter, survival was correctly predicted in only eight (12%). CONCLUSION: Physicians tend to overestimate the survival of palliative HNC patients. This optimism can result in suboptimal use of palliative and end-of-life care. The future development of a prognostic model that provides more accurate estimates, could help physicians with personalized prognostic counseling.

Head and neck cancer patients' preferences for individualized prognostic information: a focus group study.

BACKGROUND: Head and Neck cancer (HNC) is characterized by significant mortality and morbidity. Treatment is often invasive and interferes with vital functions, resulting in a delicate balance between survival benefit and deterioration in quality of life (QoL). Therefore, including prognostic information during patient counseling can be of great importance. The first aim of this study was to explore HNC patients' preferences for receiving prognostic information: both qualitative (general terms like "curable cancer"), and quantitative information (numbers, percentages). The second aim of this study was to explore patients' views on "OncologIQ", a prognostic model developed to estimate overall survival in newly diagnosed HNC patients. METHODS: We conducted a single center qualitative study by organizing five focus groups with HNC patients (n = 21) and their caregivers (n = 19), categorized in: 1) small laryngeal carcinomas treated with radiotherapy or laser, 2) extensive oral cavity procedures, 3) total laryngectomy, 4) chemoradiation, 5) other treatments. The patients' perspective was the main focus. The interview guide consisted of two main topics: life-expectancy and the prognostic model OncologIQ. All focus groups were recorded, transcribed and coded. Themes were derived using content analysis. RESULTS: While all patients considered it somewhat to very important to receive information about their life-expectancy, only some of them wanted to receive quantitative information. Disclosing qualitative prognostic information like "the cancer is curable" would give enough reassurance for most patients. Overall, patients thought life-expectancy should not be discussed shortly after cancer diagnosis disclosure, as a certain time is needed to process the first shock. They had a stronger preference for receiving prognostic information in case of a poor prognosis. Prognostic information should also include information on the expected QoL. The pie chart was the most preferred chart for discussing survival rates. CONCLUSIONS: The participants found it important to receive information on their life-expectancy. While most patients were enough reassured by qualitative prognostic information, some wanted to receive quantitative information like OncologIQs' estimates. A tailor-made approach is necessary to provide customized prognostic information. A clinical practice guideline was developed to support professionals in sharing prognostic information, aiming to improve shared decision making and patient-centered care.

Communication of prognosis in head and neck cancer patients; a descriptive qualitative analysis.

OBJECTIVES: In shared decision making it is important to adequately, timely and actively involve patients in treatment decisions. Sharing prognostic information can be of key importance. This study describes whether and how prognostic information on life expectancy is included during communication on diagnosis and treatment plans between physicians and head and neck (H&N) oncologic patients in different phases of disease. METHODS: A descriptive, qualitative study was performed of n = 23 audiotaped physician-patient conversations in which both palliative and curative treatment options were discussed and questions on prognosis were expected. Verbatim transcribed consultations were systematically analyzed. A distinction was made between prognostic information that was provided (a) quantitatively: by giving numerical probability estimates, such as percentages or years or (b) qualitatively: through the use of words such as 'most likely' or 'highly improbable'. RESULTS: In all consultations, H&N surgeons provided some prognostic information. In 5.9% of the provided prognostic information, a quantitative method was used. In 94.1% prognostic information was provided qualitatively, using six identified approaches. H&N surgeons possibly affect patients' perception of prognostic content with two identified communication styles: directive (more physician-centered) and affective (more patient-centered). CONCLUSION: This study is first in providing examples of how H&N surgeons communicate with their patients regarding prognosis in all stages of disease. They often exclude specific prognostic information. The study outcomes can be used as a first step in developing a guideline for sharing prognostic information in H&N oncologic patients, in order enable the process of shared decision making.

Outcomes of endoscopic cricopharyngeal myotomy with CO2 laser surgery: A retrospective study of 47 patients.

BACKGROUND: Endoscopic cricopharyngeal myotomy (ECPM) using CO2 laser surgery presents a less invasive treatment technique when compared to transcervical cricopharyngeal myotomy. METHODS: Forty-seven patients who underwent ECPM from 2002 until 2013 were included in this study. Patient characteristics, and preoperative and postoperative outcome and complications were scored by retrospective chart review and by using the Deglutition Handicap Index (DHI). RESULTS: Overall, 40 of 47 patients (85%) experienced relief of symptoms postoperatively. Ten patients (25%) developed recurrent symptoms of dysphagia requiring re-laser surgery. All 40 patients were satisfied at the postoperative visit after an average of 1.3 interventions. DHI scores were better in patients with idiopathic dysfunction and neurologic disease, compared to dysfunction because of prior treatment of head and neck cancer. One patient developed mediastinitis that was successfully treated with antibiotics. There was no mortality. CONCLUSION: ECPM is an effective treatment for cricopharyngeal dysfunction with a low rate of surgical morbidity and complications. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1022-1027, 2016.

Serosal abrasion of bowel ends does not enhance anastomotic healing.

BACKGROUND: Anastomotic leakage rates remain unacceptably high, warranting reconsideration of current anastomotic technique. Anastomotic healing may improve by abrading the serosal surface of bowel ends that are invertedly anastomosed, based on the concept that serosal damage evokes inflammatory adherent processes. It is studied if local abrasion leads to stronger anastomoses and reduces leakage. METHODS: Ninety-eight Wistar rats were allocated to six groups. Either a regular anastomosis (RA) or abraded anastomosis (AA) was constructed in the proximal colon. Animals were sacrificed at day 3 (groups RA3 and AA3, n = 2 × 17) or day 5 (groups RA5 and AA5, n = 2 × 17). Groups RA-Dic and AA-Dic (n = 2 × 15) received diclofenac from day 0 until sacrifice on day 3 to impair anastomotic healing. Outcomes were leakage, bursting pressure, breaking strength, adhesions, and histological appearance. RESULTS: Both in abraded (AA3 and AA5) and control (RA3 and RA5) groups without diclofenac, 1 of 17 anastomoses leaked (6%). Leak rate was 9 of 15 (60%) in group AA-Dic and 8 of 15 (53%) in RA-Dic (P = 1.0). The bursting pressure in group RA3 (127 ± 44 mm Hg) was higher (P = 0.006) compared with group AA3 (82 ± 34 mm Hg), breaking strength was comparable (P = 0.331). Mechanical strength was similar between groups RA5 and AA5. Abrasion did not increase mechanical strength in the diclofenac groups. Adhesion formation was not different between groups. Histology showed dense interserosal scar formation in abraded groups, compared with loose connective tissue in control anastomoses. CONCLUSIONS: Abrasion of serosal edges of large bowel ends invertedly anastomosed does not improve anastomotic strength, neither does it reduce leakage in anastomoses compromised by diclofenac.