Walter R. Marti

The timing of surgical antimicrobial prophylaxis.

Objective:To obtain precise information on the optimal time window for surgical antimicrobial prophylaxis. Summary Background Data:Although perioperative antimicrobial prophylaxis is a well-established strategy for reducing the risk of surgical site infections (SSI), the optimal timing for this procedure has yet to be precisely determined. Under todays recommendations, antibiotics may be administered within the final 2 hours before skin incision, ideally as close to incision time as possible. Methods:In this prospective observational cohort study at Basel University Hospital we analyzed the incidence of SSI by the timing of antimicrobial prophylaxis in a consecutive series of 3836 surgical procedures. Surgical wounds and resulting infections were assessed to Centers for Disease Control and Prevention standards. Antimicrobial prophylaxis consisted in single-shot administration of 1.5 g of cefuroxime (plus 500 mg of metronidazole in colorectal surgery). Results:The overall SSI rate was 4.7% (180 of 3836). In 49% of all procedures antimicrobial prophylaxis was administered within the final half hour. Multivariable logistic regression analyses showed a significant increase in the odds of SSI when antimicrobial prophylaxis was administered less than 30 minutes (crude odds ratio = 2.01; adjusted odds ratio = 1.95; 95% confidence interval, 1.4–2.8; P < 0.001) and 120 to 60 minutes (crude odds ratio = 1.75; adjusted odds ratio = 1.74; 95% confidence interval, 1.0–2.9; P = 0.035) as compared with the reference interval of 59 to 30 minutes before incision. Conclusions:When cefuroxime is used as a prophylactic antibiotic, administration 59 to 30 minutes before incision is more effective than administration during the last half hour.

Axillary recurrence rate in breast cancer patients with negative sentinel lymph node (SLN) or SLN micrometastases: prospective analysis of 150 patients after SLN biopsy.

Objective:To assess the axillary recurrence rate in breast cancer patients with negative sentinel lymph node (SLN) or SLN micrometastases (>0.2 mm to ≤2.0 mm) after breast surgery and SLN procedure without formal axillary lymph node dissection (ALND). Summary Background Data:Under controlled study conditions, the SLN procedure proved to be a reliable method for the evaluation of the axillary nodal status in patients with early-stage invasive breast cancer. Axillary dissection of levels I and II can thus be omitted if the SLN is free of macrometastases. The prognostic value and potential therapeutic consequences of SLN micrometastases, however, remain a matter of great debate. We present the follow-up data of our prospective SLN study, particularly focusing on the axillary recurrence rate in patients with negative SLN and SLN micrometastases. Methods:In this prospective study, 236 SLN procedures were performed in 234 patients with early-stage breast cancer between April 1998 and September 2002. The SLN were marked and identified with 99m technetium-labeled colloid and blue dye (Isosulfanblue 1%). The excised SLNs were examined by step sectioning and stained with hematoxylin and eosin and immunohistochemistry (cytokeratin antibodies Lu-5 or CK 22). Only patients with SLN macrometastases received formal ALND of levels I and II, while patients with negative SLN or SLN micrometastases did not undergo further axillary surgery. Results:The SLN identification rate was 95% (224/236). SLN macrometastases were found in 33% (74/224) and micrometastases (>0.2 mm to ≤2 mm) in 12% (27/224) of patients. Adjuvant therapy did not differ between the group of SLN-negative patients and those with SLN micrometastases. After a median follow-up of 42 months (range 12–64 months), 99% (222/224) of evaluable patients were reassessed. While 1 patient with a negative SLN developed axillary recurrence (0.7%, 1/122), all 27 patients with SLN micrometastases were disease-free at the last follow-up control. Conclusions:Axillary recurrences in patients with negative SLN or SLN micrometastases did not occur more frequently after SLN biopsy alone compared with results from the recent literature regarding breast cancer patients undergoing formal ALND. Based on a median follow-up of 42 months—one of the longest so far in the literature—the present investigation does not provide evidence that the presence of SLN micrometastases leads to axillary recurrence or distant disease and supports the theory that formal ALND may be omitted in these patients.

Surgical Glove Perforation and the Risk of Surgical Site Infection

HYPOTHESIS Clinically apparent surgical glove perforation increases the risk of surgical site infection (SSI). DESIGN Prospective observational cohort study. SETTING University Hospital Basel, with an average of 28,000 surgical interventions per year. PARTICIPANTS Consecutive series of 4147 surgical procedures performed in the Visceral Surgery, Vascular Surgery, and Traumatology divisions of the Department of General Surgery. MAIN OUTCOME MEASURES The outcome of interest was SSI occurrence as assessed pursuant to the Centers of Disease Control and Prevention standards. The primary predictor variable was compromised asepsis due to glove perforation. RESULTS The overall SSI rate was 4.5% (188 of 4147 procedures). Univariate logistic regression analysis showed a higher likelihood of SSI in procedures in which gloves were perforated compared with interventions with maintained asepsis (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.4-2.8; P < .001). However, multivariate logistic regression analyses showed that the increase in SSI risk with perforated gloves was different for procedures with vs those without surgical antimicrobial prophylaxis (test for effect modification, P = .005). Without antimicrobial prophylaxis, glove perforation entailed significantly higher odds of SSI compared with the reference group with no breach of asepsis (adjusted OR, 4.2; 95% CI, 1.7-10.8; P = .003). On the contrary, when surgical antimicrobial prophylaxis was applied, the likelihood of SSI was not significantly higher for operations in which gloves were punctured (adjusted OR, 1.3; 95% CI, 0.9-1.9; P = .26). CONCLUSION Without surgical antimicrobial prophylaxis, glove perforation increases the risk of SSI.

Phase I/II clinical trial of a nonreplicative vaccinia virus expressing multiple HLA-A0201-restricted tumor-associated epitopes and costimulatory molecules in metastatic melanoma patients.

We performed a phase I/II clinical trial in metastatic melanoma patients with an ultraviolet (UV)-inactivated nonreplicating recombinant vaccinia virus enabling the expression, from a single construct, of endoplasmic reticulum-targeted HLA-A0201-restricted Melan-A/MART-1(27-35), gp100(280-288), and tyrosinase(1-9) epitopes, together with CD80 and CD86 costimulatory proteins. Corresponding soluble peptides were used to boost responses and granulocyte-macrophage colony-stimulating factor was used as systemic adjuvant. Safety and immunogenicity, as monitored with in vitro-restimulated peripheral blood mononuclear cells by cytotoxic T lymphocyte precursor (CTLp) frequency analysis and tetramer staining, were specifically addressed. Of 20 patients entering the protocol, 2 had to withdraw because of rapidly progressing disease. Immune responses were evaluated in 18 patients (stage III, n = 5; stage IV, n = 13) and increases in specific CTLp frequencies were observed in 15. In 16 patients responsiveness against all 3 antigens could be analyzed: 7 (43%), including all stage III cases, showed evidence of induction of CTLs specific for the three epitopes, and 2 (12%) and 4 (25%), respectively, showed reactivity against two or one tumor-associated antigen. In three stage IV patients no specific CTL reactivity could be induced. Increases in CTLp frequency were detected mostly after viral vaccine injections. However, in a majority of patients final CTLp levels were comparable to initial levels. Tetramer characterization of Melan-A/MART-1(27-35)-specific CTLs during the protocol also suggested preferential expansion after recombinant virus administration. Vector-specific humoral responses, frequently undetectable in stage IV patients, did not appear to prevent tumor-associated antigen-specific CTL induction. Aside from a single occurrence of transient grade 3 leukopenia, no major clinical toxicity was reported. Seventeen of 18 patients completed the 3-month trial (one patient died before the last delayed-type hypersensitivity test). Three displayed regression of individual metastases, seven had stable disease, and progressive disease was observed in seven patients. This is the first report on the administration of a UV-inactivated recombinant vaccinia virus coexpressing five transgenes in cancer patients. The results described here, in terms of safety and immunogenicity, support the use of this reagent in active specific immunotherapy.

Selective axillary surgery in breast cancer patients based on positron emission tomography with 18F-fluoro-2-deoxy-D-glucose: not yet!

We prospectively evaluated 31 patients with invasive breast cancer. Preoperative positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (18F-FDG) for detection of axillary lymph node metastases was compared with the histopathologic status of the sentinel lymph node (SLN). Sensitivity of PET imaging was 43%, specificity and negative predictive value were 94 and 67%, respectively. The smallest metastasis detected by PET measured 3 mm in diameter. The results of this study suggest that detection of small axillary lymph node metastases is limited by the currently achievable spatial resolution of PET imaging. Selective axillary surgery in breast cancer patients based on 18F-FDG PET is yet not possible.

Perioperative detection of disseminated tumour cells is an independent prognostic factor in patients with colorectal cancer

The objective of the present investigation was to assess the prognostic significance of disseminated tumour cells in peritoneal lavage, and peripheral and mesenteric venous blood in patients undergoing curative resection of colorectal cancer.

Identification of Sentinel Lymph Nodes in Colon Cancer Depends on the Amount of Dye Injected Relative to Tumor Size

Recent studies have shown that the sentinel lymph node (SLN) procedure might improve staging in colon cancer. However, low SLN identification and high false negative rates have also been reported. In a two-institution study, the SLN procedure with isosulfan blue 1% was performed according to a standardized protocol in 31 patients with open resections for colon cancer. Data were collected prospectively. The database was analyzed retrospectively to determine factors contributing to a low identification rate. The SLN identification rate was 87% and the false negative rate was 50%. Successful SLN identification was significantly associated with application of higher volumes of dye relative to the tumor diameter (p = 0.04) and more frequent tumor localization in the sigmoid colon (p = 0.04) as compared to missing SLN identification. The tumor diameter was not significantly different in the two groups. Sentinel lymph node identification in colon cancer depends on the amount of dye injected relative to the tumor size. Application of only 1 ml of dye—the amount generally recommended in the literature—is not sufficient in large tumors.

Rapid induction of specific cytotoxic T lymphocytes against melanoma-associated antigens by a recombinant vaccinia virus vector expressing multiple immunodominant epitopes and costimulatory molecules in vivo.

A specific cellular immune response directed against a panel of three defined tumor-associated antigen (TAA) epitopes was induced in metastatic melanoma patients by a prime-boost strategy taking advantage of an innovative recombinant vaccinia virus as evaluated by quantitative assessment of cytotoxic T lymphocytes (CTLs) with corresponding specificity. The immunization protocol consisted of the administration of psoralen-UV-treated and replication-incompetent recombinant vaccinia virus encoding the three immunodominant HLA-A*0201-restricted epitopes Melan-A(27-35), gp100(280-288), and tyrosinase(1-9) together with two costimulatory molecules, B7.1 and B7.2, in the context of systemic granulocyte-macrophage colony-stimulating factor (GM-CSF) treatment. Boosts were subsequently applied with corresponding synthetic nonapeptides and GM-CSF. Specific CTL induction was assessed by tetramer staining and CTL precursor (CTLp) frequency evaluation. Within 12 days of injection of the recombinant vector, cytotoxic T cell responses specific for engineered epitopes were detectable in three of three patients. During the vaccination treatment, antigen-specific CTLp frequencies exceeding 1:10,000 peripheral CD8(+) T cells could be observed. Tetramer staining also revealed significant increases in specific CD8(+) T cell numbers. We conclude that active specific antitumor vaccination can raise a concurrent and specific cellular immune response against a panel of molecularly defined antigens, thereby increasing the chance of an immune hit against neoplastic cells with heterogeneous antigen expression. Data from this study emphasize the potency of a recombinant vaccinia virus vector encoding multiple minigenes and costimulatory molecules in the context of exogenously administered GM-CSF. Clinical effectiveness of this immunologically active protocol should therefore be explored in appropriately selected groups of patients.

The association of preoperative anemia and perioperative allogeneic blood transfusion with the risk of surgical site infection

BACKGROUND: The purpose of the study was to investigate allogeneic blood transfusion (ABT) and preoperative anemia as risk factors for surgical site infection (SSI).

Intranodal immunization with a vaccinia virus encoding multiple antigenic epitopes and costimulatory molecules in metastatic melanoma.

Recombinant vaccinia virus (rVV) encoding tumor-associated antigens (TAAs) and adhesion or costimulatory molecules may represent important immunogenic reagents for cancer immunotherapy. Recently, intranodal (IN) antigen administration was suggested to be more immunogenic than intradermal (ID) vaccination. However, IN rVV administration has not been attempted so far. We used a rVV encoding gp100(280-288), Melan-A/MART-1(27-35) and tyrosinase(1-9) HLA-A0201 restricted epitopes and CD80 and CD86 costimulatory molecules in stage III and IV melanoma patients in a phase 1/2 trial. Of 15 patients initiating treatment, including two cycles of IN immunization, each comprising one rVV administration and three recall injections of the corresponding peptides, accompanied by subcutaneous granulocyte macrophage-colony stimulating factor supplementation, five withdrew due to progressing disease. Of 10 remaining patients seven showed evidence of induction of cytotoxic T lymphocytes (CTLs) directed against at least one epitope under investigation, as detectable by limiting dilution analysis (LDA) of specific precursors and multimer staining. Adverse reactions were mild (National Cancer Institute (NCI) grade 1-2) and mainly represented by fever, skin rashes, and pruritus. These data indicate that IN administration of rVV encoding melanoma-associated epitopes and costimulatory molecules is safe and immunogenic.