Measurement of capillary refill time with a handheld prototype device: a comparative validation study in healthy volunteers.

Validity and reproducibility of clinical capillary refill time (CRT) measurement depend on many factors in daily routine practice. We conducted a prospective validation study of an automatized handheld prototype device providing standardized CRT assessment (DiCART™) in 20 healthy volunteers. Three different methods of CRT measurement were compared before and during dynamic circulatory changes induced by venous and arterial occlusion tests at both upper and lower limb levels: CRTCLIN corresponding to basic clinical assessment and considered as the reference method; CRTVIDEO corresponding to off-line videos reviewed by investigators recorded by DiCART™; and CRTDiCART corresponding to on-line videos analysed by a built-in proprietary mathematical algorithm included in DiCART™. Five subjects were excluded because of a DiCART™ dysfunction. ROCAUC to detect arterial occlusion test changes at the upper limb level were 1.00 (95%CI 1.00; 1.00), 0.96 (95%CI 0.88; 1.00), and 0.92 (95%CI 0.79; 1.00) for CRTCLIN, CRTVIDEO, and CRTDiCART, respectively. Precision of CRTCLIN and CRTVIDEO were significantly better than CRTDiCART (0.18 and 0.20 vs. 0.28; P < 0.05). Percentages of error were 76% and 87% for CRTVIDEO and CRTDiCART, respectively. DiCART™ had an excellent discrimination to detect major changes in CRT induced by arterial ischemia. However, the perfectible precision, the poor agreement with clinical assessment and numerous device dysfunctions give leads to the development of a further version of the prototype before promoting its use in clinical practice.Trial registration clinicaltrial.gov. Identifier: NCT04538612.

Taxol: a novel investigational antimicrotubule agent.

Microtubules are among the most strategic subcellular targets of anticancer chemotherapeutics. Despite this fact, new antimicrotubule agents that possess unique mechanisms of cytotoxic action and have broader antineoplastic spectra than the vinca alkaloids have not been introduced over the last several decades--until the recent development of taxol. Unlike classical antimicrotubule agents like colchicine and the vinca alkaloids, which induce depolymerization of microtubules, taxol induces tubulin polymerization and forms extremely stable and nonfunctional microtubules. Taxol has demonstrated broad activity in preclinical screening studies, and antineoplastic activity has been observed in several classically refractory tumors. These tumors include cisplatin-resistant ovarian carcinoma in phase II trials and malignant melanoma and non-small cell lung carcinoma in phase I studies. Taxol's structural complexity has hampered the development of feasible processes for synthesis, and its extreme scarcity has limited the use of a conventional, broad-scale screening approach for evaluation of clinical antitumor activity. However, taxol's unique mechanism of action, its spectrum of preclinical antitumor activity, and tumor responses in early clinical trials have generated renewed interest in pursuing its development.

Report of the Cancer Therapy Evaluation Program monitoring plan for secondary acute myeloid leukemia following treatment with epipodophyllotoxins.

BACKGROUND: Recent reports have documented the occurrence of treatment-related acute myeloid leukemia (AML) following therapy with epipodophyllotoxins. These reports have led to growing concern among oncologists, which could lead to premature abandonment of these agents at a time when the relationship between cumulative dose of epipodophyllotoxin and risk of treatment-related AML has not been determined. PURPOSE: Because of the increasingly important role of epipodophyllotoxins in the treatment of several types of adult and pediatric tumors, the Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) has developed a monitoring plan to obtain reliable estimates of the risk of treatment-related AML following epipodophyllotoxin treatment. METHODS: We identified 12 NCI-supported Cooperative Group clinical trials in which patients with solid tumors are being treated with epipodophyllotoxins at different cumulative doses. One trial is using a moderate dose of teniposide (900 mg/m2), and 11 trials are using etoposide at a low dose (< 1500 mg/m2), a moderate dose (1500-3999 mg/m2), or a high dose (> or = 4000 mg/m2). Cases of treatment-related AML and treatment-related myelodysplastic syndrome (MDS) (hereafter referred to as treatment-related AML/MDS) occurring in these trials are reported to CTEP, with initial analysis for each cumulative dose group triggered by the reporting of four cases of treatment-related AML/MDS in that group. For each analysis, total patient follow-up for the group is determined and cumulative 6-year incidence rate is calculated. RESULTS: Three cases of treatment-related AML and one case of treatment-related MDS (with documented monosomy 7) were reported in a group of 207 patients who received etoposide at a low cumulative dose. The calculated 6-year rate of development of treatment-related AML/MDS was 3.2% (95% upper confidence interval bounded by 7.2%). CONCLUSIONS: The 6-year cumulative rate of treatment-related AML/MDS (3.2%) is within the range previously reported for alkylator-based regimens that did not include epipodophyllotoxins. IMPLICATIONS: Previous reports have suggested that higher cumulative doses of alkylators are associated with increased risk of treatment-related AML, and a critical goal of the monitoring plan is to determine whether a similar relationship exists for the epipodophyllotoxins. Estimates will be developed for leukemogenic risk for the moderate- and high-cumulative-dose groups when four cases of treatment-related AML/MDS have been identified within each group.

Phase I study of paclitaxel in combination with a multidrug resistance modulator, PSC 833 (Valspodar), in refractory malignancies.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics of paclitaxel when given with PSC 833 (valspodar) to patients with refractory solid tumors. PATIENTS AND METHODS: Patients were initially treated with paclitaxel 175 mg/m(2) continuous intravenous infusion (CIVI) over 3 hours. Subsequently, 29 hours of treatment with CIVI PSC 833 was started 2 hours before paclitaxel treatment was initiated. In this combination, the starting dose of paclitaxel was 52.5 mg/m(2). Paclitaxel doses were escalated by 17.5 mg/m(2) increments for four subsequent cohorts. Each cohort consisted of three patients with the exception of the last cohort, which consisted of six patients. Data for the pharmacokinetics of paclitaxel with and without concurrent PSC 833 administration were obtained. RESULTS: All 18 patients completed at least one course of concurrent treatment (median, two courses; range, one to six) and were evaluable for toxicity. The MTD for paclitaxel with PSC 833 was 122.5 mg/m(2). Neutropenia was the DLT. All patients had PSC 833 blood concentrations greater than 1, 000 ng/mL before, during, and 24 hours after the paclitaxel infusion. PSC 833 produced small increases in the paclitaxel peak plasma concentrations and areas under the concentration-time curve. However, PSC 833 greatly prolonged the terminal phase of paclitaxel, resulting in plasma paclitaxel concentrations of more than 0.05 micromol/L for much longer than expected. As a result, myelosuppression was comparable to that produced by full-dose paclitaxel given without PSC 833. Of the 16 patients who were assessable for response, one patient experienced a partial response and an additional nine patients experienced disease stabilization after paclitaxel treatment alone. CONCLUSION: Treatment with paclitaxel 122.5 mg/m(2) as a 3-hour CIVI concurrent with a 29-hour CIVI of PSC 833 results in acceptable toxicity. The addition of PSC 833 alters the pharmacokinetics of paclitaxel, which explains the enhanced neutropenia experienced by patients treated with this drug combination.

Clinical development of Taxol.

Taxol is the first of a novel class of anticancer drugs, the taxanes. Taxol's unique effects include its ability to polymerize tubulin into stable microtubules in the absence of cofactors and to induce the formation of stable microtubule bundles. During its development, formidable challenges were overcome: a suitable formulation was developed, an adequate supply was ensured, severe hypersensitivity reactions were diminished in incidence and severity, and clinical efficacy was demonstrated. Phase II evaluation is still underway; to date, clinical efficacy has been demonstrated in ovarian, breast, non-small-cell lung, and head and neck cancer. Response rates were low in early studies in melanoma, prostate, colon, cervix, and renal cancer, but for these tumors, additional evaluation is ongoing with a higher Taxol dose or different schedule. In December 1992, Food and Drug Administration approval was granted for use of Taxol as second-line therapy in ovarian cancer patients. Nevertheless, important questions regarding optimal use of this important new drug remain. These include determination of optimal dose and schedule and development of suitable combination chemotherapy regimens. The clinical development of Taxol and current status of phase I, II, and III clinical trials are reviewed.

Phase II trial of echinomycin in patients with advanced or recurrent colorectal cancer.

Echinomycin is a novel bifunctional intercalating agent derived from Streptomyces echinatus. A phase II clinical trial of echinomycin in patients with advanced, measurable colorectal cancer was initiated to determine the efficacy and toxicities of this agent. Echinomycin, 1.5 mg/m2, was given initially as a 30- to 60-min infusion every 4 weeks. After 4 episodes of anaphylaxis had occurred among the first 14 patients, the schedule was changed to a 24-h infusion, and an additional 16 patients were treated on this schedule. Treatment was given every 3 weeks. A total of 30 patients were eligible and evaluable; there were 3 (10%; 90% confidence interval, 3%-23%) clinical responses lasting 3, 3+, and 12 months, respectively. The most serious toxicity encountered was anaphylaxis, which occurred in 5 patients, although with no serious sequelae. A premedication regimen with dexamethasone, diphenhydramine, and cimetidine and a change of the duration of the infusion to 24 h reduced the incidence of this complication. Grade 2-3 vomiting occurred among earlier patients treated; however, with the 24-h schedule this toxicity was substantially reduced. The sole important case of hematologic toxicity was a single patient with grade 3 thrombocytopenia. Echinomycin employed in this dose and schedule had modest activity against colorectal cancer, comparable with that observed with 5-fluorouracil. Further studies in patients with gastrointestinal malignancies using a 24-h infusion with a dexamethasone premedication regimen similar to that employed prior to administration of taxol may be warranted.

Glutathione S-transferase and drug resistance.

GST isozymes are an important part of the normal cellular defense against toxic xenobiotics and carcinogens. These multifunctional proteins can interact with a broad range of substrates in a variety of ways. In particular, GSTs have been implicated in the detoxication of many antineoplastic agents. Elevated levels of certain GST isozymes have been associated with malignant transformation and with experimental drug resistance. Although the role of GST in antineoplastic drug resistance is unclear, recent studies have shown increased activity of GST in many human tumors relative to normal tissues. These findings raise the possibility that the presence of certain GST isozymes may be a marker for malignant transformation in some human tumors, and that GSTs may play a role in de novo and acquired drug resistance. Identifying the factors which regulate the expression of these drug-metabolizing enzymes as well as agents which inhibit their activities may provide new insights into the therapy of tumors clinically refractory to chemotherapy.

Phase I study of Topotecan, a new topoisomerase I inhibitor, in patients with refractory or relapsed acute leukemia.

The purpose of this study was to define, in a phase I study in leukemia, the maximally tolerated dose (MTD), major toxicities, and possible antitumor activity of Topotecan, a new topoisomerase I (topo I) inhibitor. Topotecan was delivered by a 5-day continuous infusion every 3 to 4 weeks to patients with refractory or relapsed acute leukemia, at doses ranging from 3.5 mg/m2 to 18 mg/m2 per course. Twenty-seven patients were treated, including 17 patients with acute myelogenous or undifferentiated leukemia, 7 with acute lymphocytic leukemia, and 3 with chronic myelogenous leukemia in blastic phase. Severe mucositis was the dose-limiting toxicity occurring in two of five patients treated with Topotecan 11.8 mg/m2 per course; a third patient had prolonged myelosuppression. At the MTD of 10 mg/m2 per course, 1 of 12 patients had severe mucositis and 5 had mild-to-moderate mucositis. Nausea, vomiting, diarrhea, and prolonged myelosuppression were uncommon. Three patients (11%) achieved a complete response, two (7%) had a partial response, and one (4%) had a hematologic improvement. The overall complete plus partial response rate was 19%, and 24% in acute myelogenous or undifferentiated leukemia. A novel in vitro assay that quantifies Topotecan-stabilized topo I-DNA complexes in patient samples was used, which demonstrated heterogeneity in the ability of Topotecan to interact with topo I, the intracellular target of Topotecan. This phase I study defined the MTD of Topotecan to be 10 mg/m2 by continuous infusion over 5 days every 3 to 4 weeks in patients with refractory or relapsed acute leukemia. Severe mucositis was the dose-limiting toxicity. Future studies will define the precise activity of Topotecan in different leukemia subsets, its efficacy in combination with other antileukemic drugs, and correlations between Topotecan-induced topo I-DNA complex formation and individual patient response to Topotecan.

Malignant thoracopulmonary small-cell ("Askin") tumor.

The clinical, radiographic, and pathologic features of 10 patients with documented malignant small-cell tumor of the thoracopulmonary region (Askin tumor) were reviewed. The tumor represents a distinct pathologic entity of neuroectodermal origin. Clinically, it presents as a chest-wall mass with or without pain. Its radiographic appearance is that of a soft-tissue mass with or without pleural or rib involvement, often with metastatic disease--to the skeletal system, bone marrow, thorax, and sympathetic chain. Two patients developed metastases to the adrenal gland and liver, one after autologous bone marrow transplantation. The radiologist should be aware of this entity and its pattern of metastatic spread since metastases are treated aggressively.