Current routines for antibiotic prophylaxis prior to transrectal prostate biopsy: a national survey to all urology clinics in Sweden.

Background: The risk of infection after transrectal ultrasound (TRUS)-guided prostate biopsies is increasing. The aim of the study was to assess the use of antibiotic prophylaxis for prostate biopsy in Sweden. Methods: All public and private urology clinics reporting to the National Prostate Cancer Register of Sweden received a survey on TRUS-biopsy prophylaxis. Results: Of the 84 clinics surveyed, 76 replied (90%). If no risk factors for infection were present, a single dose of ciprofloxacin 750 mg was used by 50 clinics (66%). Multiple doses of ciprofloxacin 500 or 750 mg (n=14; 18%) or a single dose of trimethoprim-sulfamethoxazole 160/800 mg (n=7; 9%) were other common prophylaxes. Most clinics gave the prophylaxes immediately before the biopsy (n=41; 54%). Urine dipstick was used by 30 clinics (39%) and rectal enema by six (8%). In patients with high risk of infection, the survey mirrors a large variety of regiments used. Conclusions: The preference to use a single dose of ciprofloxacin 750 mg is in accordance with the Swedish national guidelines for patients with a low risk of infection. Better compliance to the guideline recommendation to use a urine dipstick would probably increase the number of patients classified as having an increased risk of infection. Being classified as a high-risk patient should lead to an extended duration of antibiotic prophylaxis, however, the variety of regimens used in the high-risk group reflects an inability to treat these patients in a standardized fashion and also highlights a need for more clear-cut guidelines. Pre-biopsy identification of high-risk patients is an important issue to tackle for the urologic clinics in order to reduce the number of infections.

Significance of RNA reference in tumour-related gene expression analyses by cDNA array.

The cDNA array technique is an efficient approach for studying the expression of a large number of genes in a single experiment. The cDNA array analysis indicates the relative level of corresponding gene expression from a specimen and a reference. Our investigation was performed to address the significance of reference RNA on the outcome of the cancer-related gene expression profile obtained from cDNA array analysis. Human head and neck squamous cell carcinoma (HNSCC) biopsies and 5 sources of RNA reference were used for this purpose. In these biopsies, each individual patient expressed a unique set of genes both in normal and tumour tissue. It is important to note that 5 striking patterns of tumour-related gene expression were obtained according to the 5 references used. Significant differences in 60%, 16%, 15% and 15% of the genes expressed were shown when autologous normal matched tissue biopsy references were compared to pooled cell lines, allogenic normal mixed cell types, tumours or allogenic normal matched cell type references, respectively. Thus, theoretically and our study suggested that patient autologous normal cells matching with the tumour type should be the most suitable reference in cDNA array for the identification of individual tumour gene profiles with clinical purpose.