Paclitaxel, carboplatin, and extended-schedule etoposide in the treatment of small-cell lung cancer: comparison of sequential phase II trials using different dose-intensities

PURPOSE: In two sequential phase II studies, we evaluate the feasibility and efficacy of adding paclitaxel to a standard platinum/etoposide regimen in the first-line treatment of small-cell lung cancer. PATIENTS AND METHODS: One hundred seventeen patients with small-cell lung cancer were treated between June 1993 and July 1996. The first 38 patients received a lower-dose regimen: paclitaxel 135 mg/m2 by 1-hour infusion, carboplatin at an area under the concentration-time curve (AUC) of 5.0, and etoposide 50 mg alternating with 100 mg orally on days 1 to 10. When only mild myelosuppression was observed, doses of paclitaxel and carboplatin were increased in the subsequent 79 patients (paclitaxel 200 mg/m2 by 1-hour infusion and carboplatin at an AUC of 6.0). All patients received four courses of treatment, administered at 21-day intervals. Patients with limited-stage small-cell lung cancer also received thoracic radiation therapy (1.8 Gy/d; total dose, 45 Gy) administered concurrently with courses 3 and 4 of chemotherapy. RESULTS: Seventy-two of 79 patients (91%) who receive the higher-dose regimen had major responses. Thirty-two of 38 (84%) with extensive-stage disease responded (21% complete response rate); median survival was 10 months for this group. With limited-stage disease, the overall response rate was 98%, with 71% complete responses; the median survival time has not been reached at 16 months. Median survival in extensive-stage patients was longer in patients who received the higher-dose regimen (10 months) than in the previous group treated with lower doses (7 months; P = .008). The higher-dose regimen was well tolerated, with myelosuppression being the major toxicity. Compared with the lower-dose regimen, grade 3/4 neutropenia increased from 8% to 38% of courses, but the incidence of hospitalization for neutropenia and fever did not increase. Other nonhematologic toxicities were uncommon, and did not increase substantially with the higher-dose regimen. CONCLUSION: Paclitaxel can be added at full dose (200 mg/m2) to a carboplatin/etoposide combination while maintaining a tolerable toxicity profile. Median survival times in both extensive- and limited-stage patients compare favorably with other reported regimens. This regimen merits further investigation, and a randomized trial to compare this regimen with a standard carboplatin/etoposide combination is underway.     

Detection of mutant K-ras DNA in plasma or serum of patients with colorectal cancer

Increased understanding of the molecular basis of colorectal cancer and recognition that extracellular DNA circulates in the plasma and serum of cancer patients enables new approaches to detection and monitoring. We used a polymerase chain reaction (PCR) assay to demonstrate mutant K-ras DNA in the plasma or serum of patients with colorectal cancer. Plasma or serum was fractionated from the blood of 31 patients with metastatic or unresected colorectal cancer and from 28 normal volunteers. DNA was extracted using either a sodium chloride or a gelatin precipitation method and then amplified in a two-stage PCR assay using selective restriction enzyme digestion to enrich for mutant K-ras DNA. Mutant K-ras DNA was detected in the plasma or serum of 12 (39%) patients, all confirmed by sequencing, but was not detected in any of the normal volunteers. K-ras mutations were detected in plasma or serum regardless of sex, primary tumour location, principal site of metastasis or proximity of chemotherapy and surgery to blood sampling. Tumour specimens available for 19 of the patients were additionally assayed for ras mutations and compared with blood specimens. Our results indicate mutant K-ras DNA is readily detectable by PCR in the plasma or serum of patients with advanced colorectal cancer. Thus, plasma- or serum-based nucleic acid amplification assays may provide a valuable method of monitoring and potentially detecting colorectal cancer.     

Removal of erythrocyte membrane iron in vivo ameliorates the pathobiology of murine thalassemia

Abnormal deposits of free iron are found on the cytoplasmic surface of red blood cell (RBC) membranes in beta-thalassemia. To test the hypothesis that this is of importance to RBC pathobiology, we administered the iron chelator deferiprone (L1) intraperitoneally to beta-thalassemic mice for 4 wk and then studied RBC survival and membrane characteristics. L1 therapy decreased membrane free iron by 50% (P = 0.04) and concomitantly improved oxidation of membrane proteins (P = 0.007), the proportion of RBC gilded with immunoglobulin (P = 0.001), RBC potassium content (P < 0.001), and mean corpuscular volume (P < 0.001). Osmotic gradient ektacytometry confirmed a trend toward improvement of RBC hydration status. As determined by clearance of RBC biotinylated in vivo, RBC survival also was significantly improved in L1-treated mice compared with controls (P = 0.007). Thus, in vivo therapy with L1 removes pathologic free iron deposits from RBC membranes in murine thalassemia, and causes improvement in membrane function and RBC survival. This result provides in vivo confirmation that abnormal membrane free iron deposits contribute to the pathobiology of thalassemic RBC.     

Childhood injuries in an urban area of Ghana a hospital-based study of 677 cases

Eleven cancer patients colonized with vancomycin-resistant enterococci (VRE) were followed as outpatients. Environmental cultures were obtained from clinic rooms before and after patients care. Environmental contamination occurred in 29% of encounters. Superficial disinfection did not eradicate contamination, although more thorough cleaning did. We conclude that environmental VRE contamination occurs in the outpatient setting. Infection control practices, similar to those used in the inpatient setting, may be necessary for outpatient clinics.     

HIV type 1 resistance in Kenyan sex workers is not associated with altered cellular susceptibility to HIV type 1 infection or enhanced beta-chemokine production

A small group of women (n = 80) within the Nairobi-based Pumwani Sex Workers Cohort demonstrates epidemiologic resistance to HIV-1 infection. Chemokine receptor polymorphisms and beta-chemokine overproduction have been among the mechanisms suggested to be responsible for resistance to HIV-1 infection. This study attempts to determine if any of those mechanisms are protecting the HIV-1-resistant women. Genetic analysis of CCR5 and CCR3 from the resistant women demonstrated no polymorphisms associated with resistance. Expression levels of CCR5 among the resistant women were shown to be equivalent to that found in low-risk seronegative (negative) controls, while CXCR4 expression was greater among some of the resistant women. In vitro infection experiments showed that phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) from resistant women were as susceptible to infection to T cell- and macrophage-tropic North American and Kenyan HIV-1 isolates as were the PBMCs from negative controls. No significant difference in circulating plasma levels of MIP-1alpha and MIP-1beta were found between the resistant women and negative or HIV-1-infected controls. In vitro cultures of media and PHA-stimulated PBMCs indicated that the resistant women produced significantly less MIP-1alpha and MIP-1beta than did negative controls and no significant difference in RANTES levels were observed. In contrast to studies in Caucasian cohorts, these data indicate that CCR5 polymorphisms, altered CCR5 and CXCR4 expression levels, cellular resistance to in vitro HIV-1 infection, and increased levels of beta-chemokine production do not account for the resistance to HIV-1 infection observed among the women of the Pumwani Sex Workers Cohort.     

Central venous cannulation: how to do it

Central venous cannulation is an important clinical tool for the hospital doctor. A sound knowledge of applied anatomy, relative contraindications and possible complications is required to decrease morbidity and mortality. This article seeks to provide the working knowledge required to perform and use central venous cannulation safely.     

Lung cancer practice guidelines: lessons learned and issues addressed by the Ontario Lung Cancer Disease Site Group

PURPOSE: The primary objective was to identify the lessons learned and issues addressed by the Disease Site Group (DSG) developing guidelines on lung cancer for practitioners in the province of Ontario. METHODS: The minutes of the Ontario Lung Cancer Disease Site Group (LCDSG) and the meeting notes of a medical sociologist who attended all LCDSG meetings were reviewed to identify the disease-specific and generic issues addressed by the LCDSG during guideline development. RESULTS AND CONCLUSION: The Ontario LCDSG has completed three practice guidelines and has five evidence-based recommendations (EBRs) in production. Topics for guideline development were selected on the basis of known practice variability (eg, advanced-stage non-small-cell lung cancer [NSCLC]); the size of the patient population that could potentially be affected by the guideline; results of phase II trials of new and potentially expensive agents (vinorelbine, paclitaxel, and docetaxel); and randomized controlled clinical trials that support new practice standards (combined modality therapy for unresectable stage III NSCLC). The wording of each EBR reflects the strength and quality of the evidence in support of the treatment option, the primary outcome(s), and the individual physician and discipline values concerning treatment outcomes in the absence of known patient values.     

Reference values of common blood chemistry analytes in healthy population of Rawalpindi-Islamabad area

The reference values of common blood chemistry analytes in healthy population, aged newborn to 80 years, of Rawalpindi Islamabad area were determined at AFIP, Rawalpindi. A total of 2115 healthy subjects, 1206 males and 909 females, were included in the study. Plasma glucose was analysed by GOD/POD, serum cholesterol by CHOD/PAP, triglycerides by GPO/PAP, urea by urease/GLDH, creatinine by Jaffe' rate reaction, uric acid by uricase, total bilirubin by Jendrassik and Grof, total protein by biuret, alanine transaminase (ALT) by optimized IFCC and alkaline phosphatase (AP) by optimized DGKC method. The between batch CVs of all the parameters were within acceptable quality goals. The reference values were calculated using 2.5 and 97.5 percentiles as lower and upper limits (95% CI). In healthy adult males the reference values were: fasting plasma glucose, 3.6-6.0 mmol/l; serum cholesterol; 3.2-6.6 mmol/l; triglycerides, 0.6-2.3 mmol/l; urea, 2.8-6.4 mmol/l; creatinine, 65-132 umol/l; uric acid, 164-430 umol/l; total bilirubin, 5-18 umol/l; total protein, 57-83 g/l; ALT, 15-45 U/l and AP, 185-620 U/l. The values in adult females, children and elderly subjects were slightly different than adult males. The reference values of our population show mild to moderate differences from the other Asian, European and American populations. It is recommended that reference values of different biochemical investigations should be established in various areas of Pakistan to make appropriate use of such investigations.