Multicentre Investigation of Prognostic Factors Incorporating p16 and Tumour Infiltrating Lymphocytes for Anal Cancer After Chemoradiotherapy.

AIMS: Anal squamous cell carcinomas (ASCC) are strongly associated with human papillomaviruses. Standard of care is chemoradiotherapy at uniform doses with no treatment stratification. Immunohistochemical staining for p16INK4A (p16), a surrogate for human papillomaviruses, is prognostic for outcomes. We investigated this alongside clinical-pathological factors, including tumour infiltrating lymphocyte (TIL) scores. MATERIALS AND METHODS: Using an independent, multicentre cohort of 257 ASCC treated with chemoradiotherapy, pretreatment biopsies were stained and scored for p16 and TIL. Kaplan-Meier curves were derived for outcomes (disease-free survival [DFS], overall survival and cancer-specific survival), by stage, p16 and TIL scores and Log-rank tests were carried out to investigate prognostic effect. A multivariate analysis was carried out using Cox regression. RESULTS: Stage, sex, p16 and TILs were independently prognostic. Hazard ratios for death (overall survival) were 2.51 (95% confidence interval 1.36-4.63) for p16 negative versus p16 positive, 2.17 (1.34-3.5) for T3/4 versus T1/2, 2.42 (1.52-3.8) for males versus females and 3.30 (1.52-7.14) for TIL1 versus TIL3 (all P < 0.05). CONCLUSIONS: We have refined prognostic factors in ASCC. p16 adds to stratification by stage with respect to DFS in early disease and overall survival/DFS in locally advanced cancers. Our data support the role of the host immune response in mediating outcomes. These factors will be prospectively evaluated in PLATO (ISRCTN88455282).

Experimental comparison of mesenteric vessel sealing and thermal damage between one bipolar and two ultrasonic shears devices.

BACKGROUND: Several instruments are available for open and laparoscopic dissection, including electrothermal bipolar vessel sealers and ultrasonically coagulating shears. The vessel sealing ability of three devices in colorectal specimens was compared in an experimental study. METHODS: Surgical specimens from patients scheduled for elective open or laparoscopic colorectal resection were allocated to one of the three devices. After removal of the surgical specimen, up to eight mesenteric vessels were dissected ex vivo and sealed using the allocated instrument. The vessel seal was tested for the maximum pressure at which it leaked and then assessed by a pathologist for depth of thermal tissue damage. RESULTS: A total of 93 vessels from 18 patients were assessed ex vivo (LOTUS™ n = 33; Harmonic Ace® n = 30; LigaSure™ n = 30), a median of 6 (range 1-8) vessels per surgical specimen with a mean(s.d.) diameter of 1·06(0·70) mm and wall thickness of 0·29(0·19) mm. Mean(s.d.) bursting pressures were 1170(440), 1470(670) and 1510(740) mmHg with LOTUS(™) , Harmonic Ace® and LigaSure™ respectively. ANCOVA showed no difference in bursting pressure between the instruments (P = 0·058). The depth of thermal damage was significantly greater with LigaSure™ (3·37(1·44) mm) than with LOTUS(™) (2·18(0·99) mm; P < 0·001) or Harmonic Ace® (1·95(0·92) mm; P < 0·001). CONCLUSION: All three instruments were equally good at sealing blood vessels, with bursting pressures well above physiological blood pressure levels. REGISTRATION NUMBER: NCT01121614 (http://www.clinicaltrials.gov).

Double-blind, randomized study of the effects of influenza vaccination on the specific antibody response and clinical course of patients with chronic fatigue syndrome.

OBJECTIVE: To determine whether influenza immunization is associated with early side effects, a deleterious impact on the illness course and depressed antibody response in patients with chronic fatigue syndrome (CFS). DESIGN: Prospective, randomized, double-blind, placebo controlled trial. CFS patients and healthy volunteers filled out a questionnaire on immunization side effects and had hemagglutination-inhibiting (HI) antibody titres measured pre- and three weeks after immunization. CFS patients completed symptom and function questionnaires before and during the six-week, postimmunization period. SETTING: Ambulatory care. POPULATION STUDIED: Convenience sample of 40 CFS patients fulfilling the Centers for Disease Control and Prevention criteria and 21 demographically matched healthy volunteers. INTERVENTIONS: CFS patients were randomly selected to receive commercially available whole virus influenza vaccine (n=19) or an injection of saline placebo (n=21). Healthy volunteers received vaccine only. MAIN RESULTS: As a group, immunized CFS patients had lower geometric mean HI antibody rises than healthy volunteers (P<0.001). However, there was no difference in the rates of fourfold titre rises, and immunization did achieve a probably protective titre (1:32 or greater) in most CFS patients. No difference could be detected between immunized and placebo CFS patients in immunization side effects, although CFS patients as a group reported four times as many side effects as healthy volunteers. Further, in the six weeks following immunization, placebo and immunized CFS patients did not demonstrate any differences in terms of functioning, symptom severity and sleep disturbance. CONCLUSIONS: In patients with CFS, influenza immunization is safe, not associated with any excess early reactions, and stimulates an immunizing response comparable with that of healthy volunteers.

Cost-minimization analysis of piperacillin/tazobactam versus imipenem/cilastatin for the treatment of serious infections: a Canadian hospital perspective.

BACKGROUND: In 1998 we reported the first Canadian double-blind, randomized, clinical trial involving a comparison of piperacillin/tazobactam (P/T) with imipenem/cilastatin (I/C). The present study was conducted to determine the feasibility of replacing I/C at our institution. OBJECTIVE: To describe the outcome of a pharmacoeconomic analysis of the clinical trial from the perspective of a tertiary acute-care institution. METHODS: A total of 150 consenting adults originally prescribed I/C were randomly assigned to receive either P/T 4.5 g i.v. (n = 75) or I/C 500 mg i.v. (n = 75) every six hours. Actual direct medical resources used in relation to the treatment of bacterial infections were prospectively assessed during a clinical trial; these included cost of study and ancillary antibiotics, hospitalization, diagnostic testing (radiology, laboratory assessments), and labor, as well as treatment of adverse drug reactions, antibiotic failures, and superinfections. RESULTS: While costs for successful treatment courses were similar across treatment arms, hospitalization costs for treatment course failures were higher for P/T recipients. Direct medical costs for treatment courses associated with a superinfection were also higher in the P/T arm. Overall costs for treatment failures with either study drug were at least twofold those observed for successful treatment courses. Mean total management cost per patient in the P/T group was $15,211 ($ CDN throughout) (95% CI $11,429 to $18,993), compared with $14,232 (95% CI $11,421 to $17,043) in the I/C group (p = 0.32), resulting in a mean cost difference of $979. Sensitivity analyses revealed that the superiority of I/C over P/T for successful treatment of serious infections was sensitive to changes in the cost of hospitalization and drug efficacy for either drug. CONCLUSIONS: Based on the results of the clinical trial, P/T and I/C offer similar clinical, microbiologic, and toxicity outcomes in hospitalized patients with serious infections. Under base-case conditions, our pharmacoeconomic analysis showed that I/C was a cost-effective alternative to P/T at the dosage regimens studied. However, this finding was sensitive to plausible changes in both clinical and economic parameters.

Piperacillin/tazobactam versus imipenem: a double-blind, randomized formulary feasibility study at a major teaching hospital.

With the introduction of piperacillin/tazobactam to the North American market, hospitals have been faced with the task of making a decision regarding its formulary role. In view of its broad spectrum of activity, piperacillin/tazobactam could be considered as a formulary alternative to imipenem. To evaluate the formulary feasibility of substituting piperacillin/tazobactam for imipenem, a comparative assessment of these agents in the empiric treatment of serious bacterial infections was undertaken at this tertiary care hospital. This trial was conducted as a randomized, double-blind, single-center study. Consenting adult patients (>16 years of age) who were prescribed imipenem were randomized to receive either 4 g of i.v. piperacillin/tazobactam or imipenem 500 mg of i.v. Q6H with or without concurrent antibiotics. Doses were adjusted according to renal function. There were no restrictions regarding the use of nonstudy antibiotics before and during the study period. Patients with beta-lactam allergies or meningitis or who had received greater than 72 h of previous imipenem therapy were excluded. Patients were evaluated at the end of treatment, at discharge, and at 30 days postdischarge. Endpoints included both clinical and microbiologic efficacy as well as drug toxicity. Over the 433-day study period, 360 imipenem treatment courses were initiated. Of these, 150 treatment courses (75 piperacillin/tazobactam courses and 75 imipenem courses) met study criteria and were subsequently randomized. The distribution of prescriber services for enrolled patients was similar to that for all patients receiving imipenem during the study period (p = 0.15). Also, there were no statistically significant differences in demographic parameters between enrolled and excluded patients. For those patients enrolled in the study, demographic characteristics, treatment course indication(s), and accompanying antibiotics were similar across treatment arms. The mean duration of study drug therapy was 7.7 days (SD, 6.2) for imipenem and 7.5 days (SD, 6.7)for piperacillin/tazobactam (p = 0.84). In the majority of cases, treatment discontinuation occurred as a result of a favorable treatment course outcome, stepdown to a narrower spectrum parenteral agent, or stepdown to an oral agent and did not differ between study drugs (p = 0.73). Clinical and microbiologic treatment course outcomes were also similar across treatment arms. Clinical outcome was deemed successful or improved for 68% of imipenem and 70% of the piperacillin/tazobactam treatment courses (p = 0.54). Fifty-three percent of treatment courses were microbiologically confirmed. Of the 58 courses that were assessed for microbiological outcome, 93% demonstrated successful eradication of the causative pathogens. There was no difference between study drugs (96% imipenem; 90% piperacillin/tazobactam; p = 0.61). The proportion of treatment courses with at least one adverse event was similar between the study drugs (p = 1.0). Nausea and/or vomiting were/was observed more commonly in the imipenem arm (p = 0.03). Discontinuation of therapy due to drug toxicity occurred in 16% of imipenem and 5% of piperacillin/tazobactam treatment courses (p = 0.06). There was no statistically significant difference between the mean treatment course cost for imipenem ($762; range, $55-$3192) versus piperacillin/tazobactam ($696; range, $79-$2967; p = 0.59). In summary, piperacillin/tazobactam seems to represent a suitable alternative to imipenem for several clinical indications including intraabdominal infections, pneumonia, febrile neutropenia, and skin/soft tissue infections in which the causative pathogens are susceptible. However, in view of the prevalence of multiresistant Gram-negative aerobic pathogens at this institution, we do not believe that imipenem can be removed from the drug formulary. In addition, at the currently studied dosing regimen, there seems to be no evidence of a direct cost advantage associated with

A double-blind, randomized study of three antimicrobial regimens in the prevention of infections after elective colorectal surgery.

The objective of this study was to assess the prophylactic efficacy of cefoxitin, ceftizoxime, and metronidazole-gentamicin in colorectal surgery. A double-blind, randomized prospective clinical trial design was used in a Canadian tertiary care teaching hospital. Patients were randomized to one of three treatment groups and received three doses of a study drug (30 min preoperative and 2 postoperative doses at 12 and 24 h). Cefoxitin and ceftizoxime were given as 1000-mg doses. Metronidazole-gentamicin was given as 500 mg of metronidazole plus 120 mg of gentamicin in a minibag. High-risk patients (bowel ischemia, diabetic, current steroid use, etc.) received 10 postoperative doses. Patients with infections, prior antibiotics, or study drug allergies were excluded. Over 30 months, 153 patients were enrolled. Thirty-one patients were excluded for protocol violations. Of the 122 evaluable patients (38 ceftizoxime, 45 metronidazole-gentamicin, 39 cefoxitin), there was no difference across groups regarding sex, age, weight, preoperative Apache II score, and prior history of bowel surgery. Groups were equivalent regarding surgeon, nursing unit, high-risk status (six ceftizoxime, seven metronidazole-gentamicin, seven cefoxitin), bowel preparation, and procedure (including blood loss, drains, organ injury, intraoperative complications). Clinically significant infection requiring systemic antibiotics (7-day hospital and 30-day follow-up) was identified in 0% of ceftizoxime, 15% of metronidazole-gentamicin, and 26% of cefoxitin receiving patients (p = 0.005). Mean ASEPSIS scores for each group were 2.3 (range 0-15) for ceftizoxime, 9.2 (range 0-45) for metronidazole-gentamicin, and 10.4 (range 0-75) for cefoxitin (p = 0.01). Ceftizoxime patients tended to have a shorter total hospital stay (12.2 days versus 19.7 days for cefoxitin versus 13.9 days for metronidazole-gentamicin; p = 0.04), although the procedure to discharge interval was not significantly different (p = 0.09). There was no difference in clinical outcome according to risk status. Anaerobic bacteria were observed more commonly in the ceftizoxime and cefoxitin groups, whereas enteric Gram-negative aerobes were observed most often in the metronidazole-gentamicin group. The study regimens were generally well tolerated. Drug costs were equivalent between ceftizoxime and cefoxitin and lowest with the metronidazole-gentamicin regimen. Ceftizoxime appears to be more effective for the prevention of infection in colorectal surgery than either cefoxitin or metronidazole-gentamicin in the dosage regimens studied.

Double-blind comparison of cefazolin and ceftizoxime for prophylaxis against infections following elective biliary tract surgery.

Antibiotics have been shown to reduce the incidence of wound infections after elective biliary tract procedures. Cefazolin and cefoxitin are among the agents most commonly promoted for this purpose. Cefoxitin has been substituted with ceftizoxime in many institutions; however, the role of ceftizoxime as a prophylactic agent in this setting has not been determined. To assess the comparative prophylactic efficacies of cefazolin and ceftizoxime in biliary tract surgery, we conducted a double-blind, randomized prospective clinical trial in a tertiary-care teaching hospital. Adult patients were randomized to one of two treatment groups and received a 30-min preoperative dose of study drug and as many as two postoperative doses at 12 and 24 h, depending on hospitalization status. Cefazolin and ceftizoxime were given as 1,000-mg doses. Patients with infections, those receiving prior antibiotics, or those with beta-lactam allergies were excluded. Over the 19-month study tenure, 167 patients were enrolled. Seventeen patients were excluded from analysis because of protocol violations. Of the 150 evaluable patients (72 and 78 receiving cefazolin and ceftizoxime doses, respectively), there was no significant difference among groups regarding sex, age, weight, preoperative Apache II score, baseline chemistry, and hematological parameters. Groups were also equivalent regarding the surgeon, type of procedure, characteristics (blood loss, drains, organ injury, and complications), and duration of hospital stay (mean, 5.6 versus 4.3 days [P = 0.31]). No clinical evidence of infection (7-day hospital stay and 30-day follow-up) was identified in 93% of cefazolin and 92% of ceftizoxime patients (P = 1.0). Microbiological confirmation was found in only 18% of primary-site infections. In conclusion, cefazolin and ceftizoxime appear to be equivalent for the prevention of infection in biliary tract surgery with the dosage regimens studied.