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Biomedical subjects

E F Smit

Publications and source records attributed to E F Smit.

89 records · Page 5Linked to original sources
PubMed1991

A feasibility study of testing new drugs for small-cell lung cancer in patients with a poor performance status.

Testing of new drugs in small-cell lung cancer is definitely necessary for the development of agents that might be effective against this tumor. However, testing such drugs in previously untreated patients with a good performance status (PS) may give rise to ethical problems. When previously treated patients are used in testing, potentially effective agents could well elude discovery. Patients who are not eligible for "standard" combination chemotherapy, e.g. untreated patients with a poor PS, may be suitable for testing of new drugs. To evaluate the potential usefulness of such patients in the testing of new agents, we evaluated an effective drug (etoposide) at a relatively nontoxic dose in a group of 14 patients with a PS of 4 (WHO). Oral etoposide resulted in a response in only 3 cases, whereas 5 subjects died of therapy-related toxicity. We conclude that previously untreated patients with a poor PS are not suitable candidates for the testing of new drugs.

Adult↗
PubMed1991

Continuous infusion carboplatin on a 21-day schedule: a phase I and pharmacokinetic study.

A phase I study with continuous infusion carboplatin for 21 days every 6 weeks using a venous access port and portable pump was performed over a dose range of 12 to 32 mg/m2/d, with increments of 2 mg/m2/d. Forty-four patients received 107 courses (median, two; range, one to nine). World Health Organization (WHO) grade III/IV leukopenia and thrombocytopenia occurred in one of seven patients at 30 mg/m2/d, and in two of six and four of six patients at 32 mg/m2/d. Cumulative platelet depression was found at dose levels of 28 mg/m2/d or more. Median glomerular filtration rate (GFR) and effective renal plasma flow, monitored by radioisotope clearances at doses greater than or equal to 20 mg/m2/d, decreased 8.2% (P less than .05) and 10.9% (P less than .01) after two courses. There was a relationship (r = .50, P less than .0002) between the percentage of platelet depression and GFR. No other toxicity was observed. Of the 17 patients who were evaluable, one complete response and four partial responses were observed. In addition, six patients had stable disease. Pharmacokinetic analysis of total and ultrafiltrable platinum (UFPt) was performed by atomic absorption spectrophotometry. Steady-state plasma levels for UFPt were reached after 8 hours. These levels could be detected from the 20 mg/m2/d dose. During steady state, carboplatin dose and UFPt plasma levels were not correlated, but steady-state UFPt and GFR (r = -.27, P less than .05) were. Twenty-four percent of total platinum (Pt) was present as UFPt during steady state (x = 160 +/- 10 micrograms/L). Total body clearance of UFPt exceeded GFR 2.2 times. Mean area under the curve (AUC) for UFPt during continuous infusion was 4,921.8 +/- 301.72 mg.min/L. For total Pt, steady-state plasma levels were not reached; total Pt plasma levels increased between day 7 and day 21 (P less than .0001). There was a significant relation between total Pt serum levels day 7, 14, and 21 and the drug dose administered. Immunohistochemical analysis of DNA-bound Pt in leukocytes showed a linear increase from day 7 to day 14 to day 21 (r = .97) between DNA-bound Pt and duration of infusion in individual patients. The maximum-tolerable dose of carboplatin is 30 mg/m2/d for 21 days (total dose 630 mg/m2) and is recommended for phase II studies.

Adult↗
PubMed1991

Limitations of the fast green assay for chemosensitivity testing in human lung cancer.

Selection of patients with lung cancer who are most likely to benefit from chemotherapeutic treatment would be a substantial step forward. Therefore, a prospective study in predictive chemosensitivity testing in vitro using the fast green assay (FGA) as developed by Weisenthal et al was carried out. Sixty-six pretreatment tumor specimens were obtained, the majority by means of bronchoscopy (n = 42). Due to an initially insufficient yield of tumor cells (n = 19), dead cells in control samples after four-day culture (n = 15), contamination (n = 7), and laboratory failure (n = 2), only 23 (34.8 percent) samples were successfully tested. In 14 of 36 patients, a comparison between in vitro and in vivo response was possible. Taking into account the number of failures, this number of successful assays does not allow for any conclusion regarding accuracy of the FGA. We conclude that the FGA has limited usefulness for in vitro chemosensitivity testing in patients with disseminated lung cancer in whom biopsy specimens were taken without major surgical investigations. Future directions for predictive testing in vitro are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Single-agent oral etoposide for elderly small cell lung cancer patients.

Among new patients with small cell lung cancer (SCLC), 20% to 25% are over 70 years of age and account for 8,000 cases annually in the United States. For such patients, intensive, aggressive, cytotoxic, combination chemotherapy is not often used because of its association with unacceptable morbidity and mortality rates. However, treatment of these patients is often indicated, if not demanded. Etoposide is among the most active agents for the treatment of SCLC; both oral (PO) and intravenous preparations are available. The bioavailability of etoposide PO ranges from 15% to 75%. We carried out a phase II trial of etoposide PO in elderly patients (greater than or equal to 70 years of age) with a confirmed histologic diagnosis of SCLC. Patients were treated with etoposide capsules 800 mg/m2, with the total dose divided over 5 consecutive days. Cycles were repeated every 3 to 4 weeks for a total of six cycles. All treatment was administered on an outpatient basis. Staging procedures were confined to physical examination, chest x-ray, and laboratory investigations. Further staging procedures were carried out only if clinically indicated. In September 1985, 53 patients (35 male, 18 female) with a median age of 73 years (range, 70 to 95) were treated. After staging, 24 patients (45%) had limited disease (LD); the remaining 29 patients had extensive disease (ED). Overall response was 79% (complete response [CR], 17%; partial response, 62%). CRs were seen in 8 of 24 patients (33%) with LD and in 1 of 29 patients (3%) with ED. Median survival of all patients was 9.5 months (range, 1 to 22+) with 20 patients still alive; the toxicity rate was acceptable. Total alopecia developed in all patients, whereas significant neutropenia (8%) and thrombocytopenia (6%) were rare. There were no treatment-related deaths or hospital admissions. In this study, we showed activity of etoposide PO in patients with SCLC; these results were comparable with those reported for more intensive combination regimens. For elderly patients, etoposide PO provides excellent palliative treatment, with a high response rate and significant prolongation of survival. In addition, therapy is associated with minimal toxicity and can be administered entirely on an outpatient basis.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1989

A phase II study of carboplatin and vincristine in previously treated patients with small-cell lung cancer.

A total of 28 previously treated patients with small-cell lung cancer were treated at relapse with 400 mg/m2 carboplatin and 2 mg vincristine on days 1 and 8, every 4 weeks. Ten partial responses (PRs) (37%) but no complete responses (CRs) were seen. Median survival after the start of second-line treatment was 120 days (range, 39-503 days). Toxicity of this regimen was moderate, including WHO grade 3/4 myelosuppression in 26% of courses (n = 66). Eight PRs were seen in a subgroup of 22 patients who relapsed less than 3 months after first-line treatment. The responses seen in this group of patients may be due to the absence of cross-resistance between the regimens used.

Aged↗
PubMed1989

Acute and cumulative effects of carboplatin on renal function.

Carboplatin, a cisplatinum analogue, has no reported nephrotoxicity in phase I/II studies, assessed by creatinine clearance. We prospectively determined renal function in 10 untreated lung cancer patients with normal baseline renal function, treated with carboplatin 400 mg m-2 day 1 and vincristine 2 mg day 1 and 8 every 4 weeks (max. five cycles) by means of clearance studies with 125I-sodium thalamate and 131I-hippurate to determine GFR and ERPF respectively. Tubular damage was monitored by excretion of tubular enzymes and relative beta 2-microglobulin clearance. During the first course no changes in renal function were seen. After the second course a significant fall in GFR and ERPF started, ultimately leading to a median decrease in GFR of 19.0% (range 6.8-38.7%) and in ERPF of 14% (range 0-38.9%). No increases in the excretion of tubular enzymes or changes in the relative beta 2-microglobulin clearances were seen. We conclude from our data that carboplatin causes considerable loss of renal function. Monitoring renal function in patients treated with multiple courses of carboplatin is warranted.

Aged↗
PubMed1989

A phase II study of oral etoposide in elderly patients with small cell lung cancer.

Thirty five previously untreated patients with small cell lung cancer older than 70 years were treated with oral etoposide (800 mg/m2 over five consecutive days) every four weeks. Twenty two patients had extensive disease and 13 limited disease. The overall response rate was 71%. The median survival for patients with limited diseases was 16 (range 6-32) months and for patients with extensive disease nine (range 4-17) months. There was mild haematological toxicity and alopecia but no major toxicity. It is concluded that etoposide in this dose regimen is an effective and well tolerated treatment for elderly patients with small cell lung cancer.

Administration, Oral↗
PubMedDate not supplied

Combination of gemcitabine and cisplatin for advanced non-small cell lung cancer: a phase II study with emphasis on scheduling.

BACKGROUND: Many regimens of gemcitabine-cisplatin chemotherapy have proven activity in patients with advanced non-small cell lung cancer (NSCLC). However, the optimal dose and schedule still have to be established. PATIENTS AND METHODS: We conducted a phase II study with administration of cisplatin 50 mg/m(2) on days 1 and 8 and gemcitabine 800 mg/m(2) on days 2, 9 and 15. This schedule was selected to optimise the synergism between the two drugs and reduce toxicity due to high dose cisplatin. RESULTS: Thirty-six chemo-naive patients with stage IIIA, IIIB or IV NSCLC entered the study (26 men, 10 women; median age 58 years, range 29-74). Twenty patients achieved a partial response: 7 out of 10 stage IIIA patients, 7 out of 13 stage IIIB patients and 6 out of 13 stage IV patients. On intent-to-treat basis, the overall response rate (RR) was 58% (95% confidence interval, 42-74%). Ninety percent of stage IIIA patients and 46% of stage IIIB patients received adjuvant surgery or radiotherapy. Overall median duration of response was 28 weeks (range 6-147 weeks). For stage IIIA, IIIB and IV patients, these numbers were 91, 13 and 23 weeks, respectively. One-year survival was 49% with 90%, 23% and 42% for stage IIIA, IIIB and IV patients, respectively. The main toxicity was myelosuppression. WHO grades 3 and 4 leukopenia occurred in 67% of patients, whereas 61% experienced grade 3 or 4 thrombocytopenia. Although hematological toxicity was clinically tolerable, it frequently led to omission of gemcitabine administration on day 15. The incidence of non-hematological toxicity was very low. CONCLUSION: This regimen of cisplatin on days 1 and 8 and gemcitabine on days 2, 9 and 15 induced a high RR in patients with advanced NCSLC. Frequent omission of gemcitabine day 15 is a limitation of this schedule. This should be an important factor in a practical approach to decide on the most optimal schedule of the cisplatin plus gemcitabine combination.

Adolescent↗
PubMedDate not supplied

Molecular pathology of non-small-cell lung cancer.

The molecular basis of lung carcinogenesis must be understood more fully and exploited to enhance survival rates of patients suffering from lung cancer. In this review we will discuss the major molecular alterations that occur in lung cancer. Emphasis is placed on alterations that occur early during carcinogenesis since they might be relevant for future screening programs. Finally we will shortly review new approaches that are used to study the molecular pathology of lung cancer and how they can be applied in a clinical setting.

Apoptosis↗
PubMedDate not supplied

A PCR-aided transcript titration assay (PATTY) to measure topoisomerase I gene expression in human tumor specimens.

UNLABELLED: Topoisomerase I (topo I) inhibitors are promising anticancer agents with demonstrated activity against a wide range of solid tumors. Quantitative information on topol mRNA levels in tumor biopsies may predict response to topo I inhibitors. MATERIALS AND METHODS: A polymerase chain reaction aided transcript titration assay (PATTY) was developed to allow quantitation of topol mRNA in small samples. Concentrations of topol mRNA in total RNA samples were estimated by RT-PCR analysis in a human small cell lung cancer (SCLC) cell line (GLC,) and its topotecan (GL2C/SK and F) and camptothecin (GL2C/Campt) resistant sublines, human non-small cell lung cancer (NSCLC) and ovarian carcinoma samples. RESULTS: Topol PATTY showed a decreased topo I mRNA level in GLC2/SK and F (4.5 pg/100 ng total RNA) and GLC,/Campt (2.2 pg/100 ng total RNA), respectively, compared to the parent cell line GLC2 (5.4 pg/100 ng total RNA). Topol protein levels as measured by Western blotting were compatible with topol mRNA levels. Median (range) topol mRNA levels were 3.23 (2.33-5.10) pg/100 ng total RNA in resected NSCLC specimen (n = 6), and 2.03 (0.54-0.95) pg/100 ng total RNA in resected ovarian cancer specimen (n = 6). CONCLUSION: We conclude that topol PATTY is a new assay that quantitates topol mRNA levels in cell lines and small tumor samples.

Blotting, Northern↗
PubMedDate not supplied

99mTc-Sestamibi scanning with SDZ PSC 833 as a functional detection method for resistance modulation in patients with solid tumours.

BACKGROUND: Our aim was to determine the value of 99mTc-Sestamibi scanning as functional detection method of P-glycoprotein (Pgp) blockade by PSC 833 in solid tumour patients. PATIENTS AND METHODS: Day 1 and day 4 after 2,200 mg orally administered PSC 833 the tumour area was scanned after intravenous (i.v.) administration of 400 MBq 99mTc-Sestamibi. In tumours with net 99mTc-Sestamibi uptake and in the hepatic region K-efflux was determined. Whole blood was analyzed for 99mTc-Sestamibi, and PSC 833 levels. RESULTS: Fourteen patients were included. In the only Pgp-positive tumour with positive 99mTc-Sestamibi scanning K-efflux of 99mTc-Sestamibi decreased significantly after PSC 833 intake. A net inhibition of liver efflux of Sestamibi after PSC 833 intake was observed in all evaluable patients. PSC 833 blood levels were all above 2 mg/L during scanning; 99mTc-Sestamibi blood levels post versus pre PSC 833 were unchanged. CONCLUSIONS: PSC 833 induced modulation of K-efflux of 99mTc-Sestamibi in a Pgp positive tumour and in all patients in the liver.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Validation of a polymerase chain reaction aided transcript titration assay (PATTY) for topoisomerase II in lung cancer samples.

This report describes the validation of a polymerase chain reaction aided transcript titration assay (PATTY) for tumor samples. The results obtained with the PATTY were compared to those of RNase protection in a set of 7 human lung cancer cell lines and in 23 non-small cell lung cancer samples derived from resected patients. Whereas between PATTY and RNase protection assay a good correlation was observed in the cell lines (r = 0.74, p = 0.057), no correlation was observed within the tumor samples (r = 0.06, p = 0.78). This was also the case when only tumors with a high percentage of tumor cells (> 90%) were selected. Although PATTY is a valuable tool to measure mRNA expression in cell lines, our results caution the use of PATTY in human tumor samples without proper validation. The possible causes of these results are discussed.

Antigens, Neoplasm↗