Measurement of chronic pain in companion animals: Priorities for future research and development based on discussions from the Pain in Animals Workshop (PAW) 2017.

The estimation of long-standing pain in companion animals through the measurement of different dimensions impacted by pain is a fundamental requirement if pain management, and pain therapeutic development, are to advance. Although pain management in veterinary medicine has advanced considerably in the last 20 years, there is much critical work to do in the area of measurement of chronic pain. To date, most work has centered on musculoskeletal pain, and has been focused around the measurement of limb use and the development of owner-completed questionnaires, or clinical metrology instruments (CMI). Recent areas of research have extended to developing measures of activity, sensory function (quantitative sensory testing; nociceptive withdrawal reflexes), and quality of life (QoL). Across all these areas, more data on validity are needed, and studies should be extended to other painful disease states. By necessity, assessing measurement tools requires testing in field studies, which incur considerable time and expense. Facilitating these studies could be optimized with a collaborative (industry, academia and private practice) approach, and the utility of the information produced from all field studies would be enhanced by full and transparent reporting and data sharing, including data already generated by industry in the form of studies submitted to the regulatory authorities.

Measurement of chronic pain in companion animals: Discussions from the Pain in Animals Workshop (PAW) 2017.

In the face of increasing recognition and interest in treating chronic pain in companion animals, we struggle with a lack of therapeutic options. A significant barrier to the development of new therapeutics, or the critical evaluation of current therapies, is our inability to accurately measure chronic pain and its impact on companion animals. Over the last 20 years, much progress has been made in developing methods to measure chronic pain via subjective and objective methods - particularly in owner assessment tools and measurements of limb use and activity. Most work has been focused on chronic joint pain conditions, but there has been relatively little work in other areas of chronic pain, such as neuropathic and cancer pain. Although progress has been made, there is a considerable interest in improving our assessment of chronic pain, as evidenced by the multiple disciplines across industry, academia, and clinical practice from the veterinary and human medical fields that participated in the Pain in Animals Workshop held at the National Institutes of Health in 2017. This review is one product of that meeting and summarizes the current state of knowledge surrounding the measurement of chronic pain (musculoskeletal, cancer, neuropathic), and its impact, in cats and dogs.

Outcome following treatment of feline gastrointestinal mast cell tumours.

Prognosis of feline gastrointestinal mast cell tumours (FGIMCT), based on limited available literature, is described as guarded to poor, which may influence treatment recommendations and patient outcome. The purpose of this study is to describe the clinical findings, treatment response, and outcome of FGIMCT. Medical records of 31 cats diagnosed with and treated for FGIMCT were retrospectively reviewed. Data collected included signalment, method of diagnosis, tumour location (including metastatic sites), treatment type, cause of death and survival time. Mean age was 12.9 y. Diagnosis was made via cytology (n = 15), histopathology (n = 13) or both (n = 3). Metastatic sites included abdominal lymph node (n = 10), abdominal viscera (n = 4) and both (n = 2). Therapeutic approaches included chemotherapy alone (n = 15), surgery and chemotherapy (n = 7), glucocorticoid only (n = 6) and surgery and glucocorticoid (n = 3). Lomustine (n = 15) and chlorambucil (n = 12) were the most commonly used chemotherapy drugs. Overall median survival time was 531 d (95% confidence interval 334, 982). Gastrointestinal location, diagnosis of additional cancers, and treatment type did not significantly affect survival time. Cause of death was tumour-related or unknown (n = 12) and unrelated (n = 8) in the 20 cats dead at the time of analysis. The prognosis for cats with FGIMCT may be better than previously reported, with 26% of cats deceased from an unrelated cause. Surgical and medical treatments (including prednisolone alone) were both associated with prolonged survival times. Treatment other than prednisolone may not be necessary in some cats. Continued research into prognostic factors and most effective treatment strategies are needed.

Cholangitis and Cholangiohepatitis in Dogs: A Descriptive Study of 54 Cases Based on Histopathologic Diagnosis (2004-2014).

BACKGROUND: Cholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete. OBJECTIVE: To describe a population of dogs with cholangitis or cholangiohepatitis. ANIMALS: Fifty-four client-owned dogs with cholangitis or cholangiohepatitis. METHODS: Medical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer-based search and retrospectively reviewed. RESULTS: Clinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114-1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0-4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9-13.2) compared to younger dogs. CONCLUSIONS AND CLINICAL SIGNIFICANCE: Chronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.

Spontaneous painful disease in companion animals can facilitate the development of chronic pain therapies for humans.

OBJECTIVE: To outline the role that spontaneous osteoarthritis (OA) in companion animals can play in translational research and therapeutic pharmacological development. OUTLINE: Narrative review summarizing the opportunities and limitations of naturally occurring, spontaneous OA as models of human OA pain, with a focus on companion animal pets. The background leading to considering inserting spontaneous disease models in the translational paradigm is provided. The utility of this model is discussed in terms of outcome measures that have been validated as being related to pain, and in terms of the potential for target discovery is outlined. The limitations to using companion animal pets as models of human disease are discussed. CONCLUSIONS: Although many steps along the translational drug development pathway have been identified as needing improvement, spontaneous painful OA in companion animals offers translational potential. Such 'models' may better reflect the complex genetic, environmental, temporal and physiological influences present in humans and current data suggests the predictive validity of the models are good. The opportunity for target discovery exists but is, as yet, unproven.

The Use of Darbepoetin to Stimulate Erythropoiesis in the Treatment of Anemia of Chronic Kidney Disease in Dogs.

BACKGROUND: Darbepoetin alfa (darbepoetin) is an erythropoiesis-stimulating agent used for the treatment of anemia secondary to chronic kidney disease (CKD) in dogs, but reports describing response are lacking. HYPOTHESIS/OBJECTIVES: To evaluate the effectiveness of darbepoetin in dogs with anemia secondary to CKD, dosing protocols, and adverse events. ANIMALS: Thirty-three client-owned dogs with naturally occurring CKD, including 26 with comorbidities. METHODS: Multi-institutional retrospective study. RESULTS: The median starting dosage and highest dosage of darbepoetin administered were 0.5 and 0.8 µg/kg SC once weekly, respectively. Response to treatment was defined as achieving a packed cell volume (PCV) ≥30% or an increase in PCV ≥10%. Twenty-eight of 33 dogs (85%) achieved a PCV ≥30% and 22 of 33 (67%) dogs achieved an increase in PCV ≥10%. Median time to achieve a PCV ≥30% was 29 days. A higher starting dosage was associated with achieving an increase in PCV ≥10% (P = .01). No dog sustained a response at a dosing interval >q21d. Potential adverse events included increased blood pressure requiring treatment (n = 12), seizures (n = 5), vomiting (n = 3), diarrhea (n = 3), and possible pure red cell aplasia (PRCA) (n = 2). CONCLUSIONS AND CLINICAL IMPORTANCE: Darbepoetin, when combined with treatment of comorbidities, is an effective treatment for anemia secondary to CKD in dogs. A dosing interval >q21d was ineffective at maintaining a response to treatment. PRCA was a possible adverse event in 2 of 33 dogs (6%).

Electrolyte solution structure and its effect on the properties of electric double layers with surface charge regulation.

The physical origin of charged interfaces involving electrolyte solutions is in the thermodynamic equilibrium between the surface reactive groups and certain dissolved ionic species in the bulk. This equilibrium is very strongly dependent on the precise local density of these species, also known as potential determining ions in the solution. The latter, however, is determined by the overall solution structure, which is dominated by the large number of solvent molecules relative to all solutes. Hence, the solvent contribution to the molecular structure is a crucial factor that determines the properties of electric double layers. Models that explicitly account for the solvent structure are often referred to as "civilized" as opposed to the "primitive" ones that consider the solvent as a structureless continuum. In the present paper, we demonstrate that for a physically correct description of charged interfaces that involve electrolyte solutions (electric double layers), the full solution structure needs to be taken into account in conjunction with the precise surface chemistry governed by the thermodynamic equilibrium. The analysis shows how the surface charge depends on various experimentally relevant parameters, many of which are outside the realm of simple electrostatics. We present results on the effects of solvent molecular dimensions, ionic solvation, surface chemistry, solvophilicity and solvophobicity.

Evaluation of histological grade and histologically tumour-free margins as predictors of local recurrence in completely excised canine mast cell tumours.

Completeness of mast cell tumour (MCT) excision is determined by assessment of histologically tumour-free margins (HTFM). The HTFM width necessary to prevent local recurrence (LR), recognized as histologic safety margin (HSM) in human oncology, has not been defined. We hypothesized that HTFM width would correlate with risk for LR and high-grade tumours would require wider HTFM than low-grade tumours. Records of dogs with completely excised MCTs were included. Signalment, two-tier tumour grade, tumour size, HTFM width, recurrence and therapy data was collected. High-grade (n = 39) tumours were more likely to recur than low-grade (n = 51) tumours (35.9% versus 3.9%), P < 0.0001, with no association between HTFM width and LR. Twenty-nine percent of low-grade tumours had HTFM less than 3 mm; none recurred. Narrow (≤3 mm) histologic margins are likely adequate to prevent LR of low-grade tumours. High-grade tumours have significant risk of LR regardless of HTFM width.

Effect of duration of packed red blood cell storage on morbidity and mortality in dogs after transfusion: 3,095 cases (2001-2010).

BACKGROUND: Accumulating evidence suggests that transfusion of packed red blood cells (PRBCs) stored for >14 days is associated with increased rates of sepsis, multiple organ dysfunction, and mortality in human patients. OBJECTIVE: To determine if duration of PRBC storage has an effect on morbidity and mortality in dogs after transfusion. ANIMALS: Dogs admitted to the Matthew J Ryan Veterinary Hospital of the University of Pennsylvania. METHODS: A retrospective case review of dogs identified through blood bank logbooks that received PRBC transfusions (minimum, 5 mL/kg) between 2001 and 2010. Dogs were categorized according to major cause of anemia (eg, hemorrhage, hemolysis, ineffective erythropoiesis) for analysis. RESULTS: A total of 3,095 dogs received 5,412 PRBC units. Longer duration of PRBC storage was associated with development of new or progressive coagulation failure (P = .001) and thromboembolic disease (P = .005). There was no association between duration of PRBC storage and survival for all dogs overall. However, a logistic regression model indicated that for dogs with hemolysis, 90% of which had immune-mediated hemolytic anemia, longer duration of PRBC storage was a negative risk factor for survival. For every 7 day increase in storage, there was a 0.79 lesser odds of 30 day survival (95% CI, 0.64-0.97; P = .024). CONCLUSIONS AND CLINICAL IMPORTANCE: Duration of PRBC storage does not appear to be a major contributing factor to mortality in the overall canine population. However, longer duration of PRBC storage may negatively impact outcome in dogs with immune-mediated hemolytic anemia, thus warranting further investigation with prospective studies.

Accuracy of non-operative identification of the sentinel lymph node using combined gamma and ultrasound scanning.

AIM: To assess how accurately the sentinel lymph node (SLN) can be identified percutaneously, using gamma probe and ultrasound technology. MATERIALS AND METHODS: Women with breast cancer, scheduled for wide local excision or mastectomy with SLN biopsy (SLNB), were included. Peri-areolar intradermal injection of technetium-99 nanocolloid was performed on the morning of surgery and 1-2 ml of blue dye was injected in the peri-areolar region once the patient was anaesthetized. Prior to surgery, a gamma probe was used over the skin to identify any hot spot that could represent a SLN. Ultrasound, guided by the hot spot, was then used to visualize potential SLNs and guide the insertion of a localizing wire. The accuracy in localizing the SLN by preoperative gamma-probe guided ultrasonography was assessed by comparison to SLNB. RESULTS: A SLN was correctly identified and marked using gamma-probe guided ultrasonography in 44 of 59 cases (75%; 95% CI: 63-86%). CONCLUSION: This study supports the case for investigating percutaneous gamma probe and ultrasound guided interventions in the axilla in women with breast cancer, as a potential alternative to surgical SLNB.

Comparison of mammographic findings after intraoperative radiotherapy or external beam whole breast radiotherapy.

BACKGROUND: The TARGIT (TARGeted Intraoperative Radiotherapy) trial was designed to compare local recurrence and complication rates in breast cancer patients, prospectively randomised to either EBRT (external beam whole breast radiotherapy) or a single dose of IORT (intraoperative radiotherapy). The aim of our study was to compare follow-up mammographic findings, ultrasound and biopsy rates in each group. METHODS: Follow-up imaging and breast biopsies of women from one centre participating in the TARGIT-A trial were independently reviewed by two radiologists blinded to the radiotherapy treatment received. RESULTS: The cohort consisted of 141 patients (EBRT n = 80/IORT n = 61). There was no significant difference in the patient or disease characteristics of the two groups. The number of follow-up mammograms and length of follow-up was similar (EBRT/IORT n = 2.0/2.4; 4.3yr/5.1yr; p = 0.386 χ(2) test). There were no significant differences in mammographic scar or calcification appearances of the post-operative site. Generalised increase in breast density and skin thickening were more common in the EBRT compared to the IORT group (p = 0.002; p = 0.030, χ(2) test respectively). A trend towards additional ultrasound at follow-up was observed in the IORT group (15 of 61 [24.6%] versus 11 of 80 [13.8%]), however this was not statistically significant (p = 0.100 χ(2) test). No disease recurrence was demonstrated on any of the breast biopsies taken. Only one biopsy was reported as fat necrosis in the IORT group. CONCLUSIONS: Mammographic changes were more common following EBRT, although more additional follow-up ultrasounds were performed in the IORT group. IORT is not detrimental to subsequent radiological follow up.

Treatment of aldosterone-secreting adrenocortical tumors in cats by unilateral adrenalectomy: 10 cases (2002-2012).

BACKGROUND: Primary hyperaldosteronism (PHA) in cats occurs as a consequence of excessive hormone production by an adrenocortical tumor. Median survival time, association between tumor type and prognosis, and the likelihood that cats require continued medical therapy after surgery have not been systematically evaluated. OBJECTIVES: To determine the median survival time of cats with PHA treated by unilateral adrenalectomy. To examine if tumor type, anesthesia time, or tumor location (left or right side) affect survival and if affected cats require continued postoperative treatment for persistent hypertension or hypokalemia. ANIMALS: Ten client-owned cats. METHODS: Retrospective study. Cats were diagnosed with PHA based on clinical signs, increased plasma aldosterone concentration, and advanced imaging. Cats underwent unilateral adrenalectomy. Survival time (days alive after surgery) was determined for each cat. Factors affecting median survival time were investigated, including histopathology, anesthesia time, and location (side) of the tumor. RESULTS: Eight of 10 cats survived to discharge from the hospital post adrenalectomy. Overall median survival was 1,297 days (range 2-1,582 days). The only significant factor affecting median survival time was anesthesia time >4 hours. Tumor type and location (side) did not significantly affect median survival time. No cats required continued medical treatment for PHA. CONCLUSIONS AND CLINICAL IMPORTANCE: Although PHA in cats is still considered an uncommon condition, it should be considered in middle to older aged cats with hypokalemic polymyopathy and systemic hypertension. Surgical correction by unilateral adrenalectomy is a viable approach to definitive treatment of PHA with no need for continued medical management.

Can additional histopathological examination of ultrasound-guided axillary lymph node core biopsies improve preoperative diagnosis of primary breast cancer nodal metastasis?

AIM: To assess whether an additional histopathological examination of ultrasound-guided core biopsy (USCB)/fine-needle aspiration (FNA) of abnormal axillary lymph nodes (ALN) can improve the preoperative diagnosis of axillary nodal metastasis. MATERIALS AND METHODS: Women with suspected invasive breast cancer and abnormal axillary ultrasound (AUS), but negative USCB on standard histopathological assessment were included. From the core biopsies six additional levels were sectioned for haematoxylin and eosin examination, and two levels were sectioned for immunohistochemistry with AE1/3. The presence of metastatic disease was noted. RESULTS: The USCB of 102 patients were submitted for additional histopathological examination, of whom 58 had screen-detected lesions and 44 had symptomatic lesions. Eighty underwent axillary surgery for invasive carcinoma (n = 74) or for ductal carcinoma in situ (DCIS) requiring mastectomy (n = 6). Twelve patients were found to have nodal disease with a mean of two nodes involved. The additional histopathological assessment of the nodal USCBs revealed tumour not seen at the standard examination in only three cases, which consisted of isolated tumour cells (n = 2) and micrometastasis (n = 1). All three patients underwent subsequent axillary node clearance; however, no upgrade of axillary disease was found at final histopathology. CONCLUSION: Additional histopathological examination of USCBs of radiologically abnormal ALN does not improve the preoperative diagnosis of axillary nodal metastasis in primary breast cancer and may lead to unnecessary axillary clearance.

Comparison of force plate gait analysis and owner assessment of pain using the Canine Brief Pain Inventory in dogs with osteoarthritis.

BACKGROUND: Lameness assessment using force plate gait analysis (FPGA) and owner assessment of chronic pain using the Canine Brief Pain Inventory (CBPI) are valid and reliable methods of evaluating canine osteoarthritis. There are no studies comparing these 2 outcome measures. OBJECTIVE: Evaluate the relationship between CBPI pain severity (PS) and interference (PI) scores with the vertical forces of FPGA as efficacy measures in canine osteoarthritis. ANIMALS: Sixty-eight client-owned dogs with osteoarthritis (50 hind limb and 18 forelimb). METHODS: Double-blind, randomized. Owners completed the CBPI, and dogs underwent FPGA on days 0 and 14. Dogs received carprofen or placebo on days 1 through 14. The change in PS and PI scores from day 0 to 14 were compared to the change in peak vertical force (PVF) and vertical impulse (VI). RESULTS: PS and PI scores significantly decreased in carprofen- compared with placebo-treated dogs (P = .002 and P = .03, respectively). PVF and VI significantly increased in carprofen- compared with placebo-treated dogs (P = .006 and P = .02, respectively). There was no correlation or concordance between the PS or PI score changes and change in PVF or VI. CONCLUSIONS AND CLINICAL IMPORTANCE: In these dogs with hind limb or forelimb osteoarthritis, owner assessment of chronic pain using the CBPI and assessment of lameness using FPGA detected significant improvement in dogs treated with carprofen. The lack of correlation or concordance between the change in owner scores and vertical forces suggests that owners were focused on behaviors other than lameness when making efficacy evaluations in their dogs.

Evaluation of clinical and histopathologic prognostic factors for survival in canine osteosarcoma of the extracranial flat and irregular bones.

Osteosarcoma is the most common bone tumor in dogs. However, current literature focuses primarily on appendicular osteosarcoma. This study examined the prognostic value of histological and clinical factors in flat and irregular bone osteosarcomas and hypothesized that clinical factors would have a significant association with survival time while histological factors would not. All osteosarcoma biopsy samples of the vertebra, rib, sternum, scapula, or pelvis were reviewed while survival information and clinical data were obtained from medical records, veterinarians, and owners. Forty-six dogs were included in the analysis of histopathological variables and 27 dogs with complete clinical data were included in the analysis of clinical variables. In the histopathologic cox regression model, there was no significant association between any histologic feature of osteosarcoma, including grade, and survival time. In the clinical cox regression model, there was a significant association between the location of the tumor and survival time as well as between the percent elevation of alkaline phosphatase (ALP) above normal and survival time. Controlling for ALP elevation, dogs with osteosarcoma located in the scapula had a significantly greater hazard for death (2.8) compared to dogs with tumors in other locations. Controlling for tumor location, every 100% increase in ALP from normal increased the hazard for death by 1.7. For canine osteosarcomas of the flat and irregular bones, histopathological features, including grade do not appear to be rigorous predictors of survival. Clinical variables such as increased ALP levels and tumor location in the scapula were associated with decreased survival times.

Sentinel node biopsy in breast cancer has a greater node positivity rate than axillary node sample: results from a retrospective analysis.

BACKGROUND: Sentinel node biopsy as a surgical method of axillary staging for early breast cancer has been widely accepted as an alternative to traditional four-node axillary node sampling, and is the recommended technique by the Association of Breast Surgery in the United Kingdom. In selected units axillary sampling has been compared with either radioisotope sentinel node or blue dye only techniques with comparable node positivity rates. There are no studies directly comparing combined method sentinel node biopsy (SNB) with conventional axillary (four) node sampling (ANS). METHODS: Data for all patients undergoing axillary staging by axillary node sample or sentinel node biopsy were collected, including those proceeding to axillary clearance as a second procedure, but excluding those undergoing axillary clearance as a first procedure. RESULTS: From January 2005 to January 2011, 641 axillary staging procedures were performed (SNB n=231 (36.0%), ANS n=410 (64.0%)). Baseline tumour characteristics were similar for the two groups except for a higher frequency of breast conservation in the SNB group (95.6 vs. 75.6%; p<0.0001). The proportion of cases with positive nodes was higher in the SNB group (20.8 vs. 14.4%; p=0.042). In patients who had presented with symptomatic disease, there was a significantly higher node positivity rate with SNB (30.9%) than with ANS (15.5%; p=0.002), despite similar baseline characteristics in both groups. CONCLUSION: Combined method sentinel node biopsy is more sensitive at detecting low volume axillary disease than traditional four-node sample.

Urine specific gravity values in clinically healthy young pet ferrets (Mustela furo).

OBJECTIVES: To determine urine specific gravity values in clinically healthy pet ferrets and explore possible associations with sex, sampling techniques, hydration status and urine analytes. METHODS: Sixty-nine entire ferrets of both sexes, under one year of age, were included in this study. Physical examination, complete blood count, blood biochemistry, urine microscopy, urine dipstick and urine specific gravity were performed on all ferrets. Urine specific gravity was determined using a handheld urine refractometer. Statistical analysis was performed to determine urine specific gravity value intervals and to test for associations with sex, sample collection method, packed cell volume, plasma total protein concentrations and urine analytes. RESULTS: Urine specific gravity differed by sex in ferrets as females exhibited a lower urine specific gravity (P<0·001). There was no significant correlation between urine specific gravity, sampling method, packed cell volume/total protein and urine dipstick analytes. Mean urine specific gravity reported in this study was 1·051 for entire males (sd ±9; range 1·034 to 1·070) and 1·042 for entire females (sd ±8; range 1·026 to 1·060). CLINICAL SIGNIFICANCE: Results of this study may allow clinicians to have a more accurate evaluation of the ability of those animals to concentrate urine by comparing their urine specific gravity results to those obtained from this cohort of clinically healthy animals.

Involved anterior margins after breast conserving surgery: is re-excision required?

BACKGROUND: Complete tumour excision in breast conserving surgery (BCS) is critical for successful outcome; involved circumferential resection margins are associated with increased disease recurrence. However, the importance of an involved anterior margin (IAM) is less clear. The purpose of this study was to review an aggressive approach to IAM and hence assess whether anterior margin re-excision (RE) yields clinical benefit. METHODS: A review of prospectively collected clinical and pathology data was performed for all patients who underwent BCS between 2006 and 2010 through a single cancer centre. An involved margin was defined as < 1 mm clearance of invasive or in-situ breast cancer. RESULTS: 1667 patients underwent BCS for invasive and/or in-situ disease, of whom 114 underwent RE. A total of 170 involved margins were identified: most commonly the anterior (52 margins) followed by the posterior (39 margins) and inferior (31 margins) margin. Patients with IAM were more likely to have grade 3 invasive disease (p = 0.0323) but less likely to have residual disease found at re-excision (2/49 vs. 32/101 margins, p = 0.0033); there were no differences when in-situ characteristics were compared. CONCLUSIONS: RE of IAM after BCS rarely yields further disease; multi-disciplinary teams should consider whether further therapy for an IAM is required on a patient by patient basis.

Association between article citation rate and level of evidence in the companion animal literature.

BACKGROUND: Level of evidence (LOE) hierarchies rank scientific articles according to the use of study design features intended to limit bias. Citation analysis of medical articles has shown that studies with high LOE ranking are preferentially cited. OBJECTIVES: To determine whether clinical companion animal articles reporting study designs classified as high LOE are more frequently cited than those with designs classified as low LOE and to characterize other factors associated with 5-year citation rate. METHODS: Literature survey of all original clinical articles published in 2004 in 5 peer-reviewed clinical veterinary journals. For each eligible article, details of scientific and nonscientific characteristics were collected, an LOE classification was assigned, and the 5-year citation rate following publication was determined. Linear regression was used to identify factors associated with citation rate. RESULTS: Overall LOE was low with 188 of 209 eligible articles describing a study design classified as low LOE. An association was not identified between 5-year citation frequency and LOE classification or any specific feature of study methodology. Articles pertaining to infectious disease or published in the Journal of Veterinary Internal Medicine were associated with significantly greater subsequent citations. CONCLUSIONS AND CLINICAL IMPORTANCE: Reports of veterinary studies designed to limit the influence of bias are not more widely referenced than articles reporting data obtained through less stringent methodologies. Medical subspecialty and publishing journal prestige can influence an article's subsequent citation rate.

Axillary lymph node core biopsy for breast cancer metastases -- how many needle passes are enough?

AIM: To determine the diagnostic yield of each of three core passes when sampling abnormal lymph nodes in patients presenting with breast cancer. MATERIALS AND METHODS: All patients suspected of having breast cancer had axillary ultrasound as part of initial assessment. Radiologically abnormal nodes (cortical thickness >2.3mm or round shape) were biopsied with three passes of a 22 mm throw 14 G core biopsy needle and sent for histopathology in separate numbered pots. Data were collected prospectively, and analysis performed on the data of 55 consecutive patients who had positive nodes on at least one core biopsy needle pass. RESULTS: Of 55 patients with a positive node on core biopsy, tumour was noted in all three cores taken in 39 (70.9%). Lymph node metastasis was detected in 45 (81.8%) first core biopsies. With the first two cores taken, positive results were detected in 53 of 55 cases (96.4%). In both cases where tumour was only found on a third core biopsy pass, no lymph node tissue was present in the first two biopsy passes. CONCLUSION: Two well-directed 14 G core biopsy samples from an abnormal axillary node are adequate for diagnosis of breast cancer metastasis.