A phase II study of cisplatin, etoposide and gemcitabine in an unfavourable group of patients with carcinoma of unknown primary site

BACKGROUND

The aim of this phase II study was to determine toxicity, response rate, time to progression, and overall survival of cisplatin, etoposide and gemcitabine in patients with carcinoma of unknown primary tumour site.

PATIENTS AND METHODS

Thirty patients with no previous chemotherapy and not belonging to a treatable group were treated with cisplatin 70 mg/m(2) on day 1, etoposide 70 mg/m(2) on days 1 and 2, and gemcitabine 700 mg m(2) on days 1 and 8, administered every 3 weeks. Stable or responding patients received a maximum of eight cycles. Twenty patients (67%) had more than three affected sites, and 25 patients (84%) had adenocarcinomas.

RESULTS

Overall response rate was 36.6% (11 patients), including four complete responses (13.3%) and seven partial responses (23.3%), with a 95% confidence interval of 19.9-56. Median survival was 7.21 months and eight patients remained alive for >1 year. Myelosuppression was the most important toxicity, with grade 3-4 neutropenia in 18 patients (60%) in 32% of the cycles: eight patients had neutropenic fever and 10 patients had thrombopenia in 11% of cycles. No non-haematological grade 4 toxicity occurred.

CONCLUSIONS

Cisplatin, etoposide and gemcitabine is an active combination, inducing objective responses in a subset of heavily advanced disease patients with carcinoma of unknown primary site. The role of adding gemcitabine to cisplatin and etoposide remains to be resolved as to the best schedule to diminish toxicity for the three-drug combination.

Chromosomal imbalance maps of human 5FU-resistant colorectal cancer cell lines: implications in the analysis of 5FU-acquired resistance mechanisms

Thymidylate synthase (TS), a critical enzyme in the de novo synthesis of thymidylate, is an important target for fluoropyrimidines and folate-based TS inhibitors. Overexpression of TS has been correlated to 5-fluorouracil (5FU)-resistance. Because 5FU still remains a basic component of the treatment of colorectal cancer, circumvention of resistance is of vital importance. A panel of sensitive (HT29 and LoVo) and 5FU-resistant colorectal cancer cell lines (HT29-5FUR and LoVo-5FUR) were subjected to comparative genomic hybridization (CGH) analysis to identify possible amplified/deleted regions associated with 5FU-resistance in colon tumours. We have identified chromosomal gains at 5p, 6, 7p, 7q and 8q and one loss at 3q in 5FU-resistant cells as compared to corresponding sensitive cell lines. Neither chromosomal gains at 18p nor gene amplification of TS were observed in our resistant cell lines although an overexpression of TS gene exists (at mRNA level) in these cell lines as compared with corresponding parental cells. Most of the chromosomal gains identified in this study occur frequently in sporadic colorectal tumours and has been associated to a poor prognosis and a greater progression of the tumour and could be related to a worse chemotherapy response. The chromosomal imbalance profile detected in 5FU-resistant cell lines should provide a basis for interpreting mechanisms of 5FU-resistance in colorectal cancer and also possibly in other tumours treated with this agent. This study also identified new genes potentially implicated in 5FU-resistance and suggests new targets that could be useful for the chemotherapy treatment of colorectal cancer.

Irinotecan (CPT-11) in metastatic colorectal cancer patients resistant to 5-fluorouracil (5-FU): A phase II study

The efficacy and toxicity of irinotecan (CPT-11) 350 mg/m(2) i.v. once every 3 weeks was assessed in 60 patients with advanced colorectal cancer (CRC) showing failure to 5-fluorouracil (5-FU) treatment. The overall objective response rate was 13.6% (1 complete response and 4 partial responses) and 25 patients (42.4%) showed stable disease; the median time to disease progression was 4.4 months and the median survival was 10.5 months. The main non-hematological toxicities were alopecia (80.3% of patients), diarrhea (75.0%), and nausea/vomiting (71.7%); neutropenia was the main hematological toxicity. Grade 3 or 4 diarrhea appeared in 21 of 131 cycles (16.1%), whereas grade 3 or 4 neutropenia appeared in 78 cycles (25.0%). In conclusion, the present phase II study confirms that CPT-11 350 mg/m(2) every 3 weeks is active and well tolerated as second-line chemotherapy for CRC in 5-FU resistant patients.

Improving nitrogen removal in predenitrification-nitrification biofilters

The effect on NH4-N removal rates in nitrification biofilters of filtered biodegradable COD and particulate COD leaving predenitrification biofilters was studied in a lab scale plant configured with the separated system of biofilters for secondary nitrogen removal from urban wastewaters. Applying a typical COD load of 11 kg/m3 x day to the predenitrification biofilter and maximizing its COD removal by adding nitrates or by operating an improved control of the internal recycle, only 60% removal of filtered biodegradable COD was found. This value corresponds to the complete removal of the readily biodegradable substrate (30% of influent filtered COD) and 36% of filtered slowly biodegradable substrate (50% of influent COD). The remaining 64% of the latter entered the nitrification biofilter, causing competition between heterotrophs and nitrifiers for dissolved oxygen in the inner layers of the biofilm. Consequently the nitrification rate had relatively low values (0.5 kgN/m3 x d) at 14 degrees C despite using dissolved oxygen levels of 6 mg/l. This behaviour may explain the lower nitrification rates obtained in some cases of nitrification biofilters compared to those in tertiary nitrification after activated sludge processes. The particulate COD entering the nitrification biofilter is associated with the suspended solids leaving the denitrification biofilter which are adsorbed by the external layers of the biofilm, increasing its thickness. The activity of the nitrifiers was affected because of a lack of oxygen when the thickness was left to grow considerably. Therefore no significant particulate COD effect is expected to occur as long as backwashing is carried out with the appropriate frequency.

Phase I study of weekly CPT-11 (irinotecan)/docetaxel in patients with advanced solid tumors

Based on the synergistic cytotoxicity demonstrated in vitro by topoisomerase I inhibitors followed by docetaxel and the feasibility of giving both drugs on a weekly schedule avoiding overlapping toxicities, we designed a phase I trial of weekly CPT-11 (irinotecan)/docetaxel to determine the dose-limiting toxicities (DLT) and the maximum-tolerated dose (MTD) of this combination. Eighteen patients with advanced solid tumors treated with at least one prior chemotherapy regimen were included in this trial. CPT-11 was administered as a 90-min (intravenous) IV infusion followed immediately by docetaxel as a 30-min IV infusion. Both drugs were given on days 1, 8 and 15 in 4-week cycles. Four escalating dose levels of CPT-11/docetaxel (level I: 60/20 mg/m(2), level II: 60/25 mg/m(2), level III: 70/25 mg/m(2), and level IV: 70/30 mg/m(2)) were studied. Forty-seven cycles were administered (range, 1-5 courses) with a median number of 2.6 cycles per patient. Grade 4 leukopenia was the DLT reached at dose-level IV (CPT-11/docetaxel 70/30 mg/m(2)). Four patients had grade 3 anemia at dose levels III (two patients) and IV (two patients), while grade 3/4 thrombocytopenia was not seen. Grade 3/4 non-hematologic toxicities included grade 3 diarrhea in two patients (dose levels II and IV), grade 3 asthenia in one patient (dose level II) and grade 3 stomatitis in one patient (dose level I). The recommended dose of this weekly schedule is CPT-11 70 mg/m(2) and docetaxel 25 mg/m(2). DLT of this regimen is leukopenia, although toxicity is manageable at the recommended dose level. The activity of this regimen is being evaluated in a phase II study in previously treated patients with advanced non-small cell lung cancer.

[Massive hemoptysis secondary to cardiac insufficiency in a context of dilated myocardiopathy]

Massive hemoptysis is a life-threatening emergency that rarely occurs in association with heart failure and is even less frequent when the underlying cause is dilated myocardiopathy. We report the case of a 69-year-old man with undiagnosed heart disease who presented with severe hemoptysis. Images showed evident cardiac insufficiency. The unusualness of the case obliged us to rule out other diseases through differential diagnosis before starting to treat the underlying condition.

Validation of a monoclonal enzyme immunoassay for the determination of carbofuran in fruits and vegetables

The N-methylcarbamate pesticide carbofuran is a very important insecticide used worldwide. In the present work, the validation of a monoclonal antibody-based enzyme immunoassay (ELISA) to determine this compound in fruits and vegetables is described. The immunoassay is a competitive heterologous ELISA in the antibody-coated format, with an I(50) value for standards in buffer of 740 ng/L and with a dynamic range between 200 and 3100 ng/L. For recovery studies, peppers, cucumbers, strawberries, tomatoes, potatoes, oranges, and apples were spiked with carbofuran at 10, 50, and 200 ppb. After liquid extraction, analyses were performed by ELISA on extracts purified on solid-phase extraction (SPE) columns and crude, nonpurified extracts. Depending on the crop, mean recoveries in the 43.9--90.7% range were obtained for purified samples and in the 90.1--121.6% range for crude extracts. The carbofuran immunoassay performance was further validated with respect to high-performance liquid chromatography (HPLC) with postcolumn derivatization and fluorescence detection (EPA Method 531.1). Samples were spiked with carbofuran at several concentrations and analyzed as blind samples by ELISA and HPLC after SPE cleanup. The correlation between methods was very good (y = 0.90x + 2.66, r(2)() = 0.958, n = 25), with HPLC being more precise than ELISA (mean coefficients of variation of 4.1 and 11.5%, respectively). The immunoassay was then applied to the analysis of nonpurified extracts of the same samples. Results also compared very well with those obtained by HPLC on purified samples (y = 1.02x + 10.44, r(2)() = 0.933, n = 29). Therefore, the developed immunoassay is a suitable method for the quantitative and reliable determination of carbofuran in fruits and vegetables even without sample cleanup, which saves time and money and considerably increases the sample throughput.

Prognostic value of K-ras mutations and allelic imbalance on chromosome 18q in patients with resected colorectal cancer

PURPOSE

We designed this study to assess the frequency of K-ras mutations in patients with resected colorectal tumors and their association with survival. A second objective was to analyze the prognostic value of different K-ras genotypes. In a subgroup of patients we also investigated the presence of allelic imbalance on chromosome 18q and its relationship to clinical outcome.

METHODS

One hundred fourteen colorectal tumors resected between 1983 and 1986 were analyzed to detect K-ras point mutations at codons 12, 13, and 61 by polymerase chain reaction followed by allele specific oligonucleotide hybridization. A subgroup of 77 tumors was further screened to detect loss of heterozygosity on chromosome 18q using three polymorphic microsatellite markers (D18S67, D18S474 and D18S58).

RESULTS

K-ras mutations were detected in 29 percent (33/114) of patients. K-ras mutations correlated with age and preoperative carcinoembryonic antigen levels, and there was some indication that they may be linked to poor survival, especially in Stage II tumors, where a subgroup of patients with aspartic and serine mutations showed significantly reduced survival (P = 0.03) compared with K-ras-negative patients. 18q loss of heterozygosity was present in 39 percent (25/63) of tumors. A multivariate analysis of Stage II tumors showed that 18q loss of heterozygosity was significantly associated with a worse prognosis (P = 0.006). A significant decrease in survival was identified in ten patients harboring both genetic alterations (K-i mutations and 18q loss of heterozygosity; P = 0.02).

CONCLUSIONS

In colorectal tumors, K-ras mutations and 18q loss of heterozygosity are two genetic markers which may identify patients with more aggressive behavior, mainly in Stage II tumors. These findings warrant further research, because they can be useful in customizing adjuvant chemotherapy.

Monoclonal enzyme immunoassay for the analysis of carbaryl in fruits and vegetables without sample cleanup

The N-methylcarbamate pesticide carbaryl is one of the most important insecticides used worldwide. In the present work, the validation of a monoclonal antibody-based enzyme immunoassay (ELISA) for the determination of this compound in fruits and vegetables is described. The immunoassay is a competitive heterologous ELISA in the antibody-coated format, with an I(50) value for standards in buffer of 101.0 +/- 26.9 ng/L and with a dynamic range between 31.6 and 364.0 ng/L. For recovery studies, peppers, cucumbers, strawberries, tomatoes, potatoes, oranges, and apples were spiked with carbaryl at 10, 50, and 200 ppb. After liquid extraction, analyses were performed by ELISA on both extracts purified on solid-phase extraction (SPE) columns and crude, nonpurified extracts. Depending on the crop and the fortification level, recoveries in the 59.0--120.0% range were obtained for purified samples and in the 70.0--137.7% range for crude extracts. The carbaryl immunoassay performance was further validated with respect to high-performance liquid chromatography (HPLC) with postcolumn derivatization and fluorescence detection (EPA Method 531.1). Samples were spiked with carbaryl at several concentrations and analyzed as blind samples by ELISA and HPLC after SPE cleanup. The correlation between methods was excellent (y = 1.04x + 0.71, r(2) = 0.992, n = 33), with HPLC being more precise than ELISA (mean coefficients of variation of 5.2 and 12.0%, respectively). The immunoassay was then applied to the analysis of nonpurified extracts of the same samples. Results also compared very well with those obtained by HPLC on purified samples (y = 1.28x - 0.59, r(2) = 0.987, n = 33) while maintaining similar precision. Therefore, the developed immunoassay is a suitable method for the quantitative and reliable determination of carbaryl in fruits and vegetables even without sample cleanup, which saves time and money and considerably increases sample throughput.

Determination of thiabendazole in fruit juices by a new monoclonal enzyme immunoassay

A competitive, indirect enzyme-linked immunosorbent assay (ELISA) for thiabendazole has been developed and applied to the analysis of fruit juices spiked with this fungicide. The immunoassay is based on a new monoclonal antibody derived from a hapten functionalized at the nitrogen atom in the 1-position of the thiabendazole structure. To our knowledge, such a structure has not been previously used to obtain antibodies to thiabendazole. The I50 value and the detection limit of the ELISA for standards were 0.2 and 0.05 ng/mL, respectively. Fruit juices were analyzed by diluting samples in assay buffer, without extraction or cleanup. Samples were not even centrifuged or filtered to remove fruit pulp. Under these conditions, the immunoassay was able to accurately determine thiabendazole down to 1 ng/mL in orange and grapefruit juices, down to 5 ng/mL in banana juice, and down to 20 ng/mL in apple and pear juices. Sensitivity differences of the ELISA were caused by the minimum dilution required by each juice to minimize matrix effects: 1/10 for orange and grapefruit juices, 1/50 for banana juice, and 1/100 for apple and pear juices. In an attempt to further increase the sensitivity of the immunoassay for matrixes showing the strongest interferences, apple and pear juices spiked with thiabendazole at low levels (1-20 ng/mL) were extracted with ethyl acetate before analysis. This simple procedure entailed a significant reduction of matrix effects, which in fact allowed us to determine accurately as low as 5 ng/mL thiabendazole in apple and pear juices. Irrespective of whether samples were analyzed by the direct dilution method or after extraction, the simplicity, sensitivity, and sample throughput of this monoclonal immunoassay makes it a very convenient method for the routine monitoring of thiabendazole residues in fruit juices.

Production of monoclonal antibodies to the N-methylcarbamate pesticide propoxur

Monoclonal antibodies (MAbs) to the pesticide propoxur were produced from haptens with carboxylic spacer arms of different lengths introduced at the carbamate group of the analyte structure. MAbs were subsequently characterized in the conjugate-coated format using these immunizing haptens and newly synthesized compounds as homologous and heterologous assay conjugates, respectively. Appropriate combinations of immunoreagents resulted in competitive enzyme immunoassays (ELISA) with I(50) values in the low nanomolar range (6.5-17.9 nM). A modification of the conjugate-coated format consisting of the simultaneous incubation of the MAb and the peroxidase-labeled secondary antibody in the presence of the analyte resulted in an assay with an I(50) value of 4.4 nM. This one-step conjugate-coated ELISA format is as simple and fast as the antibody-coated format but without the need of synthesizing enzyme-hapten conjugates. Major N-methylcarbamate pesticides were not recognized by the MAb. This immunoassay should reasonably allow the rapid, low-cost, and sensitive determination of propoxur in food, soils, and the environment at levels of regulatory and practical importance.

Scoring system has better discriminative value than Helicobacter pylori testing in patients with dyspepsia in a setting with high prevalence of infection

OBJECTIVE

To prospectively assess the accuracy of a scoring system to predict organic diseases in dyspeptic patients in an area of South Europe, and to compare it with that of Helicobacter pylori testing in patients with dyspepsia in an environment with high prevalence of H. pylori infection.

METHODS

Symptoms and demographic data were recorded in 501 consecutive dyspeptic patients referred to an outpatient gastroenterology clinic. A simple scoring system was constructed from the predictive factors obtained in a multi-variate logistic regression analysis. Overall predictive accuracy was assessed with the c statistic. The model was validated using bootstrap techniques. The accuracy of clinical judgement and H. pylori testing to predict endoscopic diagnosis was also assessed.

RESULTS

Organic dyspepsia (peptic ulcer, oesophagitis or malignancies) was diagnosed in 45% of the patients. The test for H. pylori was positive in 68%, and 29% of infected patients had an ulcer. The organic dyspepsia predictive model had an accuracy of 0.79, which decreased to 0.77 after validation adjustment. The predictive accuracies for clinical judgement and H. pylori testing were 0.69 and 0.61, respectively. The addition of H. pylori testing to the scoring system resulted in a minor improvement of the predictive accuracy.

CONCLUSION

In an environment with a high rate of H. pylori infection and a low prevalence of peptic ulcer among infected patients, a scoring system has higher predictive accuracy for the diagnosis of organic disease than H. pylori testing. Moreover, in this setting, H. pylori testing adds a minimum value to the predictive capability of the scoring system.