Skin and soft tissue infections in intercontinental travellers and the import of multi-resistant Staphylococcus aureus to Europe

Staphylococcus aureus is emerging globally. Treatment of infections is complicated by increasing antibiotic resistance. We collected clinical data and swabs of returnees with skin and soft tissue infections (SSTI) at 13 travel-clinics in Europe (www.staphtrav.eu). Sixty-two percent (196/318) SSTI patients had S. aureus-positive lesions, of which almost two-thirds (122/196) were Panton-Valentine leukocidin (PVL) positive. PVL was associated with disease severity, including hospitalization for SSTI (OR 5.2, 95% CI 1.5-18.2). In returnees with SSTI, longer travel and more intense population contact were risk factors for nasal colonization with PVL-positive S. aureus. Imported S. aureus frequently proved resistant to trimethoprim-sulfamethoxazole (21%), erythromycin (21%), tetracycline (20%), ciprofloxacin (13%), methicillin (12%) and clindamycin (8%). Place of exposure was significantly (p < 0.05) associated with predominant resistance phenotypes and spa genotypes: Latin America (methicillin; t008/CC24/304), Africa (tetracycline, trimethoprim-sulfamethoxazole; t084/CC84, t314/singleton, t355/CC355), South Asia (trimethoprim-sulfamethoxazole, ciprofloxacin; t021/CC21/318), South-East Asia (clindamycin; t159/CC272). USA300-like isolates accounted for 30% of all methicillin-resistant S. aureus imported to Europe and were predominantly (71%) acquired in Latin America. Multi-resistance to non-β-lactams were present in 24% of imports and associated with travel to South Asia (ORcrude 5.3, 95% CI 2.4-11.8), even after adjusting for confounding by genotype (ORadjusted 3.8, 95% 1.5-9.5). Choosing randomly from compounds recommended for the empiric treatment of severe S. aureus SSTI, 15% of cases would have received ineffective antimicrobial therapy. These findings call for the development of regionally stratified guidance on the antibiotic management of severe imported S. aureus disease and put the infected and colonized traveller at the centre of interventions against the global spread of multi-resistant S. aureus.

Abstract P2-16-19: Fulvestrant with or without selumetinib (Sel, AZD6244), a mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, in advanced stage breast cancer progressing after aromatase inhibitor (AI): A multicenter randomized placebo-controlled double-blind phase II trial, SAKK21/08

Background:

Mitogen-activated protein kinase (MAPK) pathway is one of the major signaling cascades responsible for resistance to endocrine therapy by promoting estrogen-independent tumor growth. Sel is a potent selective MEK1 and MEK2 inhibitor active in melanoma, ovarian, colorectal and non-small cell lung cancers. Fulvestrant (Fulv) is a pure antagonist and downregulator of nuclear and membranous/cytoplasmic estrogen receptor (ER). The combination of a MEK inhibitor with Fulv may improve the efficacy of endocrine therapy by reversing and/or delaying the development of resistance.

Material and methods:

Postmenopausal patients with advanced stage endocrine-sensitive (ER and/or progesterone receptors ≥10%) breast cancer progressing after aromatase inhibitor were randomized to intramuscular Fulv 500 mg (day 1, 15, 29 then every 28±2 days) combined with either oral Sel 75 mg bid or placebo bid. The primary endpoint was disease control (DC = CR + PR + stable disease ≥ 24 weeks). Sample size was calculated according to Simon's optimal two-stage design. A DC rate of ≤30% in the experimental arm was considered as not interesting and ≥50% as promising. Using a 5% significance level and 80% power, 46 patients were needed, 15 in the first stage and 31 in the second stage. In the control arm a total of 43 patients was needed to estimate the DC rate with a confidence interval width of ≤30%. An interim efficacy analysis was planned according to Herndon's modification of Simon's optimal two-stage design.

Results:

Forty-six patients were included (23 per arm). Seventy percent of the patients in the experimental arm had measurable disease and 57% had visceral metastases. Patients had received AI in the metastatic (61%) or adjuvant (39%) setting (65% had also prior tamoxifen). Five of 23 patients (22%) reached DC in the experimental arm. DC rate being inferior to the statistical hypothesis the study was terminated following the planned interim efficacy analysis. Most frequently reported adverse events (AEs) were rash and other skin disorders, fatigue, diarrhea, hypertension, edema, nausea/vomiting, anorexia, musculoskeletal symptoms, dry mouth and paresthesia. AEs were mainly grade 1 and 2 (NCI-CTCAE v4.0), but they often precluded treatment continuation. Most of the first patients exposed to Sel 75 mg bid stopped treatment before disease progression. Seven of the 23 patients (30%) were exposed to Sel for only 1 cycle or less. After an amendment facilitating early dose-reduction, patients decreasing to 75 mg qd had much better tolerance and improved treatment duration with Sel. Four out of the 5 patients reaching DC had Sel dose reduction.

Conclusion:

The combination of Sel with fulvestrant did not reach the prespecified disease control rate. The toxicity of Sel 75 mg bid led to frequent treatment interruptions/dose reductions and poor exposure to the drug.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-19.

Hepatitis B e antigen-suppressing mutations enhance the replication efficiency of adefovir-resistant hepatitis B virus strains

Hepatitis B e antigen (HBeAg) negative hepatitis B virus (HBV) infections caused by precore (PC) or basal core promoter (BCP) mutations are associated with disease progression and complications. PC or BCP mutations may enhance the replication capacity of distinct drug-resistance-associated polymerase mutations, but their effect on adefovir-resistant HBV mutants is unclear. Importantly, BCP mutations were an independent risk factor for virological breakthrough in lamivudine-resistant patients treated with adefovir. We aimed at addressing the functional consequences of PC and BCP mutations on the replication and drug susceptibility of adefovir-resistant HBV mutants. Therefore, HBV constructs with wild type (WT) or adefovir-resistant rtN236T, rtA181V and rtA181T mutations, with or without concomitant PC or BCP mutations, were analysed in vitro using molecular assays. The adefovir-resistant polymerase mutations rtN236T, rtA181V and rtA181T showed a drastically reduced viral replication compared with WT. Interestingly, additional PC or BCP mutations enhanced the reduced replication efficacy of adefovir-resistant constructs and restored HBV replication to WT level. HBV rtA181T mutants displayed abolished hepatitis B surface antigen (HBsAg) secretion, owing to a sW172* stop codon in the overlapping envelope gene. All rtN236T- or rtA181V/T-containing constructs, regardless of concomitant PC or BCP mutations, were resistant to adefovir, but remained susceptible to telbivudine, entecavir and tenofovir. In conclusion, adefovir drug resistance mutations reduced viral replication, which can be significantly increased by additional HBeAg-suppressing PC or BCP mutations. Because increased HBV replication in HBeAg-negative patients has been associated with an unfavourable clinical course, close monitoring appears indispensable during adefovir treatment in HBeAg-negative patients.

Parotidectomy and submandibulectomy for benign diseases in Thuringia, Germany: a population-based study on epidemiology and outcome

Although salivary gland surgery for benign diseases is an integral part of clinical routine of head and neck surgeons, there is not many population-based data published on incidence and efficiency of this surgery. Parotidectomy was performed in 180 patients and submandibulectomy in 97 patients for benign diseases in eight otorhinolaryngology and two maxillofacial surgery departments in Thuringia, Germany, in 2005. All patients were analysed regarding patients' characteristics, therapy, complications and further course of disease. Predominant indications were epithelial tumours for parotidectomy (79 %) and sialolithiasis for submandibulectomy (50 %). The most frequent tumour types were pleomorphic adenoma (46 %) and Warthin tumours (29 %). Pleomorphic adenoma was significantly more frequent in female patients and Warthin tumours in male patients and smokers. The incidence of parotidectomy, i.e. the surgical rate, was 7.8/100,000 habitants and of submandibulectomy 4.1/100,000 habitants. One hundred and seventy-eight tumours including 154 epithelial tumours resulted in an incidence of 7.6/100,000 habitants for all treated tumours and of 6.6/100,000 for epithelial tumours, respectively. The majority of parotid cases were treated by lateral parotidectomy (79 %). Relevant complications were observed in 22 % of patients. After parotidectomy and submandibulectomy a postoperative facial palsy was observed in 28 and 2 % of cases, respectively. Only 1 % was permanent. During a mean follow-up time of 9.6 months, 3 % of parotidectomy patients developed a Frey's syndrome needing treatment and 0.8 % developed a tumour recurrence. This population-based analysis shows that salivary gland surgery is performed in higher incidence than expected, effectively and with low-risk in daily routine of head and neck surgeons.