Higher Dosing of Rifamycins Does Not Increase Activity against Mycobacterium tuberculosis in the Hollow-Fiber Infection Model.

Improvements in the translational value of preclinical models can allow more-successful and more-focused research on shortening the duration of tuberculosis treatment. Although the hollow-fiber infection model (HFIM) is considered a valuable addition to the drug development pipeline, its exact role has not been fully determined yet. Since the strategy of increasing the dose of rifamycins is being evaluated for its treatment-shortening potential, additional in vitro modeling is important. Therefore, we assessed increased dosing of rifampin and rifapentine in our HFIM in order to gain more insight into the place of the HFIM in the drug development pipeline. Total and free-fraction concentrations corresponding to daily dosing of 2.7, 10, and 50 mg of rifampin/kg of body weight, as well as 600 mg and 1,500 mg rifapentine, were assessed in our HFIM using the Mycobacterium tuberculosis H37Rv strain. Drug activity and the emergence of drug resistance were assessed by CFU counting and subsequent mathematical modeling over 14 days, and pharmacokinetic exposures were checked. We found that increasing rifampin exposure above what is expected with the standard dose did not result in higher antimycobacterial activity. For rifapentine, only the highest concentration showed increased activity, but the clinical relevance of this observation is questionable. Moreover, for both drugs, the emergence of resistance was unrelated to exposure. In conclusion, in the simplest experimental setup, the results of the HFIM did not fully correspond to preexisting clinical data. The inclusion of additional parameters and readouts in this preclinical model could be of interest for proper assessment of the translational value of the HFIM.

Optimal treatment for intermediate- and high-risk, nonmuscle-invasive bladder cancer.

According to clinical and pathological factors the prognosis of a patient with non-muscle invasive bladder tumors can be assessed. The prognosis is determined by the likelihood of recurrence (30-70%) and/or progression to muscle invasive bladder cancer (1-15%).Trans urethral resection of bladder tumors remains the initial therapy but adjuvant intravesical instillations are necessary. All patients benefit from a single immediate post operative instillation with a chemotherapeutic agent and for low risk tumors this is the optimal therapy. Patients with intermediate and high risk tumors need more intravesical chemo-or immunotherapy. Chemotherapy reduces recurrences but not progression. Intravesical immunotherapy(BCG) prevents or delays progression. Patients at high risk for progression may need upfront cystectomy.

Image cytometry determination of ploidy level, proliferative activity, and nuclear size in a series of 314 transitional bladder cell carcinomas.

Image cytometry was carried out on 281 superficial (Ta and T1) and 33 invasive (T2 to T4) bladder cancers. The parameters used to characterize these bladder tumors were: (1) histopathological grading, (2) clinical staging, (3) tumor size, (4) deoxyribonucleic acid (DNA) index (DI), (5) DNA histogram type (DHT), (6) percentage of euploid (diploid plus tetraploid) cells, (7) percentage of polyploid cells (> 5C DNA content), (8) proliferative activity (S phase fraction value), and (9) nuclear area (NA). The proliferative activity of the tumors was not related to either histopathological grade or to clinical stage, but it was related to the DHT parameter, which made it possible to identify diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic tumors. The hypertriploid tumors exhibited a significantly lower proliferative activity than the nonhypertriploid ones. Although both the DI and the NA values correlated significantly with histopathological grading, only the NA values correlated significantly with clinical staging. We further observed that some grade III bladder tumors were definitely diploid, whereas some grade I tumors were highly aneuploid. We thus hypothesize that the ploidy level of a given tumor reflects its age directly and its aggressiveness only very indirectly. In our opinion aneuploidy is only an indirect marker of aggressiveness because it reflects the fact that a malignant tumor is old, ie, has been present in a patient over a long period of time and has had ample time to express its malignancy at the clinical level. A significant relationship was accordingly obtained between tumor size and ploidy level with the highest proportion of aneuploid tumors and the highest percentage of polyploid cell nuclei being observed among the largest bladder tumors.

Treatment schedule of intravesical chemotherapy with mitomycin C in superficial bladder cancer: short-term courses or maintenance therapy.

Intravesical chemotherapy using mitomycin C in patients with superficial bladder cancer after transurethral resection (TUR) has proved to be highly effective in preventing tumor recurrences and/or progression. No consensus has been reached on the appropriate dose and treatment schedule. This and other variable factors such as different criteria for entry and follow-up in the reported studies so far make it impossible to compare the results. There are indications that long-term mitomycin C instillation therapy improves recurrence rate, progression rate, and survival. Considering prognostic factors in patients with superficial bladder tumors, it is justified and necessary to investigate this regimen in future protocols.

BCG (RIVM) versus mitomycin intravesical therapy in superficial bladder cancer. First results of randomized prospective trial.

This study presents the preliminary results of a randomized prospective two-arm study in which bacillus Calmette-Guérin (BCG) RIVM, a Dutch BCG preparation, is compared with mitomycin C (MMC) in patients with primary or recurrent superficial bladder tumors, including carcinoma in situ (CIS). Therapeutic regimens were as follows: after complete transurethral resection of all visible tumors, BCG RIVM (1 x 10(9) bacilli in 50 mL saline) was instilled once a week for six consecutive weeks, and mitomycin C (30 mg in 50 mL saline) was administered once a week for one month (weeks 1 to 4) and thereafter once a month for a total of six months. Reported are the incidence of side effects in 165 patients and the recurrence rate of tumors in 308 patients after a follow-up period of twelve months. Drug-induced, or chemical cystitis was observed in 13 (16.7%) of 78 BCG-treated patients and in 12 (13.8%) of 87 MMC-treated patients. In the same groups bacterial cystitis occurred in 17 (21.8%) patients and in 16 (18.4%) patients, respectively. In the BCG-treated group (N = 148), 44 (29.8%) had recurrent tumors, while in the MMC-treated group (N = 160), 40 (25.0%) had a recurrence. The recurrence rate for BCG-treated patients was 0.33; the recurrence rate for MMC-treated patients was 0.29 (P = 0.560, not significant). These preliminary data demonstrated no statistically significant difference between the two arms with regard to toxicity and recurrence of tumors.

Intravesical therapy with adriamycin and 4-epirubicin for superficial bladder cancer: the experience of the EORTC GU Group.

The anthracycline derivatives Adriamycin and 4-epirubicin are used to prevent recurrent tumors after transurethral resection of superficial bladder tumors. Both drugs are instilled intravesically. The present report describes the results of two multicenter, prospective, randomized phase III studies carried out by the EORTC GU Group. In protocol 30,790, after a mean follow-up period of 26.6 months, the recurrence rate for 165 patients treated with Adriamycin was 0.29 and the tumor rate was 0.74. For 156 patients treated with Epodyl, the recurrence rate was 0.29 and the tumor rate was 0.57. This difference was not statistically significant. For 70 patients who received transurethral resection alone, the recurrence rate was 0.65 and the tumor rate, 2.04. In protocol 30,763, patients with good prognostic factors were treated with one single instillation of 4-epirubicin versus sterile water. After a mean follow-up period of 16 months, in 190 patients treated with 4-epirubicin the recurrence rate was 0.20 and the tumor rate was 0.35; in 196 patients treated with sterile water, the recurrence rate was 0.37 and the tumor rate was 0.65 (P = 0.0001). Adriamycin and 4-epirubicin were efficacious, and severe side effects were not encountered. The superiority of Adriamycin over Epodyl could not be proven.

Intravesical Bacillus Calmette-Guérin treatment for superficial bladder cancer: results after 15 years of experience.

Superficial bladder cancer has a high recurrence rate and considerable progression rate. The treatment currently consists of resection and adjuvant intravesical chemotherapy or immunotherapy. Intravesical instillation of Bacillus Calmette-Guérin (B.C.G.) is considered to be one of the most successful immunotherapies in man. Durable response rates of 60-70% are achieved. Toxicity is more pronounced in comparison with intravesical chemotherapy. In this article we describe the experience with B.C.G. during the last 15 years. No consensus has been reached yet about the ideal treatment scheme, appropriate strain and optimal dosage. The mechanisms of action are complicated and still not completely understood.

Management of carcinoma of the bladder.

Carcinoma of the bladder (CaB) is a common tumor of the genitourinary tract. In the United States in 1997, CaB was second in frequency of occurrence and third in mortality among genitourinary tumors. This tumor has a well-documented history of environmental and industrial causative factors. The strongest etiologic risk factors include the use of tobacco, which is thought to be responsible for half of the CaB diagnosed in men in the United States, and some arylamines. In the past 30 years, there has been major improvement in the survival of patients with this disease. Multiple factors were responsible for this accomplishment and they include: 1) better understanding of the natural history of CaB, 2) development of immunohistochemical analysis helpful in defining prognostic factors, 3) improved imaging and nonimaging diagnostic modalities helpful in making earlier diagnosis and better defining the true anatomical extent of the tumor, 4) development of more effective therapy for carcinoma in situ, 5) major improvement in surgical techniques resulting in better treatment outcomes, and 6) the wide use of adjuvant chemotherapy. Major stress has been placed on the quality of life of patients treated for CaB. Quality of life was improved by optimizing surgical, radiation, and medical treatment techniques. The two most important factors producing this quality-of-life improvement include: 1) the use of organ-preserving therapy in properly selected patients that involves the use of a multimodality therapeutic approach with transurethral resection, radiation therapy, and chemotherapy; and 2) the ability to treat selected men and women with radical cystectomy followed by orthotopic reconstruction that allows patients nearly physiologic voiding. Current research efforts are directed toward better patient selection for appropriate therapy which is expected to increase patient survival and improve quality of life. Of particular importance in the selection of this optimal therapy in patients with CaB is a wide application in the clinical practice of important recent advances in molecular genetics.

Non specific immunotherapy with B.C.G. in superficial bladder cancer: an overview.

In the seventies non specific immunotherapy with B.C.G. was used for a number of malignancies in man. After initial successful reports on leukaemia and melanoma, results could not always be confirmed and the use of B.C.G. seemed to be limited. In 1976 B.C.G. was used for the first time intravesically in patients with superficial bladder cancer. At present non specific immunotherapy with B.C.G. for superficial bladder cancer is considered the most efficacious treatment modality. It is probably the most widely used and most successful immunotherapy in man. A number of issues on this treatment are still unclear. No consensus has been reached about the treatment schedule, optimal dose and appropriate BCG strain while toxicity is more pronounced than in intravesical chemotherapy. Improvement of the treatment as well as basic research are necessary and will determine the exact place of B.C.G. in the coming years.

Leukocytes and cytokines in the urine of superficial bladder cancer patients after intravesical immunotherapy with bacillus Calmette-Guerin.

The urine of superficial bladder cancer patients treated intravesically with BCG was examined for the presence of leukocytes and cytokines. The number of leukocytes was markedly increased 24h and 48h after five or more BCG instillations. Flow cytofluorometric analysis revealed that, in addition to large numbers of granulocytes, monocytes/macrophages and T-lymphocytes were clearly detectable. The T cells were predominantly CD4+ and probably activated, since they expressed IL2 receptors and HLA-DR. The cytokines IL1, IL2, IL6 and TNF alpha were also increased after BCG instillations. These cytokines and leukocytes may play a role in the antitumor activity of BCG.

Deep intraspecific divergences in the medically relevant fat-tailed scorpions (Androctonus, Scorpiones).

The genus Androctonus, commonly known as fat-tailed scorpions, contains 22 species distributed from Togo and Mauritania in the west, North Africa, through the Middle East and to as far east as India. With 13 species, a substantial amount of this genus' diversity occurs in North Africa, which is a major hotspot of scorpion sting incidents. Androctonus are among the most medically relevant animals in North Africa. Since venom composition within species is known to vary regionally, the improvement of therapeutic management depends on a correct assessment of the existing regional specific and sub-specific variation. In this study, we assessed the phylogeographical patterns in six species of Androctonus scorpions from North Africa using mitochondrial DNA markers. We sequenced COX1, 12S, 16S and ND1 genes from 110 individuals. Despite lacking basal resolution in the tree, we found taxonomical and geographically coherent clades. We discovered deep intraspecific variation in the widespread Androctonus amoreuxi and Androctonus australis, which consisted of several well-supported clades. Genetic distances between some of these clades are as high as those found between species. North African A. australis have a deep split in Tunisia around the Chott el-Djerid salt-lake. A novel split between A. amoreuxi scorpions was found in Morocco. We also found deep divergences in Androctonus mauritanicus, corresponding to areas attributed to invalidated subspecies. In addition we uncovered a clade of specimens from coastal south Morocco, which could not be ascribed to any know species using morphological characters. Based on these findings we recommend a reassessment of venom potency and anti-venom efficacy between these deep intraspecific divergent clades.

Practical approaches to the prevention and treatment of adverse reactions to BCG.

Compared to intravesical chemotherapy, instillations with bacillus Calmette-Guérin (BCG) may provoke more frequently local and systemic reactions. As well as irritative bladder symptoms, BCG therapy may cause systemic side-effects, such as mild malaise, fever and, less commonly, life-threatening sepsis. It is important that risk factors for these adverse events are recognized, and that traumatic catheterization and instillations in inflamed or damaged bladders are avoided. Once recognized, virtually all side-effects can be treated successfully. Treatment options may include delaying or withholding BCG instillations, or using antipyretics and analgesics for reducing bladder symptoms. Treatment with tuberculostatic drugs for up to 6 months may be necessary in cases of severe systemic or local toxicity. In vitro, BCG is very susceptible to most antibiotics and tuberculostatic agents. Clinical trials are currently investigating whether the prophylactic use of tuberculostatic agents, such as isoniazid, or dose reduction in BCG can prevent adverse effects without impairing the antitumour efficacy of BCG.

Practical aspects of clinical trials on chemoprevention of prostate cancer.

In addition to the normal aspects of organizing clinical trials, the launch of a chemoprevention trial on prostate cancer needs extra effort. The sample size and duration of follow-up is so extensive that such a trial should be organized as an intergroup study, preferably worldwide. For that a central data center and data management is mandatory. Because healthy individuals are involved, refusal, loss to follow-up and inadequate adherence may be substantial. The choice of the study endpoint presence of prostate cancer or death due to prostate cancer will lead to completely different sample sizes and length of follow-up. Of criteria leading to the diagnosis of prostate cancer (PSA, DRE and transrectal ultrasound), at least two are rather subjective. The drug involved might affect the criteria for diagnosis. Because of the high incidence of clinically nonsignificant prostate cancer of men over 55, a large number of nonrelevant prostate cancers will be detected in both arms. Due to the long follow-up and alterations in the state of the art of detection and therapy of prostate cancer, the completion of such a study might be hampered. If the average price per patient involved in a clinical trial is currently between USD 1, 000 and 2,000, one may calculate that for 30,000 men, USD 20-40 million are needed, not including the hospital visits, examinations and biopsies. Economic considerations thus play a major role in organizing trials on the chemoprevention of prostate cancer.

The role and impact of pathology review on stage and grade assessment of stages Ta and T1 bladder tumors: a combined analysis of 5 European Organization for Research and Treatment of Cancer Trials.

PURPOSE: Pathological interpretations are largely subject to interpathologist and intrapathologist variation. Differences in tumor stage and grade exist in local and review pathological findings in patients with stage Ta-T1 bladder tumors who are entered in randomized trials of adjuvant treatment after transurethral resection. Because they are diagnosed and treated based on local pathological results, it is important to determine the reliability of local pathological evaluations and the extent to which pathology review may change the treatment decision process. MATERIALS AND METHODS: We assessed local and review pathology results in 1,400 patients treated in 5 European Organization for Research and Treatment of Cancer randomized phase III trials comparing various adjuvant prophylactic treatment strategies for primary or recurrent stage Ta-T1 transitional cell bladder cancer. RESULTS: We noted large variations in T category and grade. Pathology review down staged T category to stage Ta in 53% of cases originally classified as stage T1. There was agreement in only 57% and 50% of stage Ta grade 1 and stage T1 grade 3 cases, of which 10% were reclassified as muscle invasive disease greater than stage T1. While T category and grade have prognostic importance, differences in the prognosis based on local and review pathological studies were slight. CONCLUSIONS: Pathology review is not mandatory in low and intermediate risk cases since it has little impact on the prognosis and treatment decision making. In high risk cases of stage T1 grade 3 disease stage or grade is often changed, so that review remains essential in this subgroup.