Examining temporal trends in psychological distress and the co-occurrence of common substance use in a population-based sample of grade 7-12 students from 2013 to 2019.

PURPOSE: Characterizing trends and correlates of adolescent psychological distress is important due to observed global increases over the last 20 years. Substance use is a commonly discussed correlate, though we lack an understanding about how co-occurrence of these concerns has been changing over time. METHODS: Data came from repeated, representative, cross-sectional surveys of grade 7-12 students across Ontario, Canada conducted biennially from 2013 to 2019. Poisson regression with robust standard errors was used to examine changes in the joint association between psychological distress (operationalized as Kessler-6 [K6] scores ≥ 13) and substance use over time. Weighted prevalence ratios (PR) and their 99% confidence intervals were estimated, where p < 0.01 denotes statistical significance. RESULTS: The prevalence of psychological distress doubled between 2013 and 2019, with adjusted increases of about 1.2 times each survey year. This biennial increase did not differ based on sex, perceived social standing, school level, or any substance use. Students using substances consistently reported a higher prevalence of psychological distress (between 1.2 times and 2.7 times higher). There were similarly no differential temporal trends based on substance use for very high distress (K6 ≥ 19) or K6 items explored individually. CONCLUSION: Psychological distress steeply increased among adolescents and substance use remains important to assess and address alongside distress. However, the magnitude of temporal increases appears to be similar for adolescents reporting and not reporting substance use.

Assessing distress in the community: psychometric properties and crosswalk comparison of eight measures of psychological distress.

BACKGROUND: Many measures are available for measuring psychological distress in the community. Limited research has compared these scales to identify the best performing tools. A common metric for distress measures would enable researchers and clinicians to equate scores across different measures. The current study evaluated eight psychological distress scales and developed crosswalks (tables/figures presenting multiple scales on a common metric) to enable scores on these scales to be equated. METHODS: An Australian online adult sample (N = 3620, 80% female) was administered eight psychological distress measures: Patient Health Questionnaire-4, Kessler-10/Kessler-6, Distress Questionnaire-5 (DQ5), Mental Health Inventory-5, Hopkins Symptom Checklist-25 (HSCL-25), Self-Report Questionnaire-20 (SRQ-20) and Distress Thermometer. The performance of each measure in identifying DSM-5 criteria for a range of mental disorders was tested. Scale fit to a unidimensional latent construct was assessed using Confirmatory Factor Analysis (CFA). Finally, crosswalks were developed using Item Response Theory. RESULTS: The DQ5 had optimal performance in identifying individuals meeting DSM-5 criteria, with adequate fit to a unidimensional construct. The HSCL-25 and SRQ-20 also had adequate fit but poorer specificity and/or sensitivity than the DQ5 in identifying caseness. The unidimensional CFA of the combined item bank for the eight scales showed acceptable fit, enabling the creation of crosswalk tables. CONCLUSIONS: The DQ5 had optimal performance in identifying risk of mental health problems. The crosswalk tables developed in this study will enable rapid conversion between distress measures, providing more efficient means of data aggregation and a resource to facilitate interpretation of scores from multiple distress scales.

Validity of the PROMIS depression and anxiety common metrics in an online sample of Australian adults.

PURPOSE: Recent US-based studies have utilised item response theory (IRT) to equate several self-report scales for depression and anxiety using the PROMIS depression and anxiety common metrics. The current study reports on the validity of the US-based equating procedures for the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7) and Kessler 6 psychological distress scale (K6) to equate scores in a large online sample of Australian adults. METHODS: Data comprised 3175 Australians recruited online. Each participant provided responses to the PROMIS depression and anxiety item banks, the PHQ-9, the GAD-7 and the K6. Two scoring methods were used to convert the scores on the PHQ-9, GAD-7 and K6 to the PROMIS depression and anxiety metrics. The converted scores were compared to the PROMIS depression and anxiety scores using intraclass correlations, mean difference, mean of absolute differences and Bland-Altman limits of agreement. RESULTS: Statistically significant mean differences were identified in five out of eight equated scores, albeit the effect sizes were small (Cohen's dz ≤ 0.25). The correlations were uniformly high (ICC ≥ 0.86). The mean of absolute differences between observed and equated scores for each metric and across scoring methods ranged between 4.23 and 5.33. CONCLUSIONS: The results demonstrate the validity of generating PROMIS depression and anxiety scores from the PHQ-9, GAD-7 and K6 in an independent sample of Australians. The agreement between equated scores provides some assurance that researchers and clinicians can utilise the converted PHQ-9, GAD-7 and K6 scores on the PROMIS metrics without a substantial decrease in accuracy and precision at the group level.

Perceived needs for mental health care and barriers to treatment across age groups.

PURPOSE: This study aimed to assess responses to a structured measure of perceived need for treatment to understand whether differences in treatment uptake across age groups are related to differences in: (1) perceived need for mental health care; (2) perceptions of treatment needs being met; and/or (3) perceived attitudinal and structural treatment barriers. METHODS: Data from a nationally representative sample of the Australian population (2007 National Survey of Mental Health and Wellbeing) were analysed using logistic and multinomial regression. All participants potentially benefiting from mental health services were included in analyses; including those reporting symptoms of mental disorders, using mental health services, or self-reporting significant mental health problems in the past 12 months (n = 5733). All regression analyses were adjusted for gender, the presence of chronic physical health conditions, disorder type, and disorder severity. RESULTS: Older adults were the least likely to report any perceived need for mental health care, and specifically reported lower needs for psychotherapy, information about available services, and support improving their ability to work. Older adults perceiving a need for mental health care were also the most likely to report having these needs met. There were no differences in attitudinal and structural barriers to treatment across age groups. CONCLUSIONS: These results highlight that age needs to be considered in strategies for improving engagement and efficacy of mental health services, as well as the need for further research to understand what drives age differences in perceived need for mental health care.

The structure of adolescent psychopathology: a symptom-level analysis.

BACKGROUND: Most empirical studies into the covariance structure of psychopathology have been confined to adults. This work is not developmentally informed as the meaning, age-of-onset, persistence and expression of disorders differ across the lifespan. This study investigates the underlying structure of adolescent psychopathology and associations between the psychopathological dimensions and sex and personality risk profiles for substance misuse and mental health problems. METHOD: This study analyzed data from 2175 adolescents aged 13.3 years. Five dimensional models were tested using confirmatory factor analysis and the external validity was examined using a multiple-indicators multiple-causes model. RESULTS: A modified bifactor model, with three correlated specific factors (internalizing, externalizing, thought disorder) and one general psychopathology factor, provided the best fit to the data. Females reported higher mean levels of internalizing, and males reported higher mean levels of externalizing. No significant sex differences emerged in liability to thought disorder or general psychopathology. Liability to internalizing, externalizing, thought disorder and general psychopathology was characterized by a number of differences in personality profiles. CONCLUSIONS: This study is the first to identify a bifactor model including a specific thought disorder factor. The findings highlight the utility of transdiagnostic treatment approaches and the importance of restructuring psychopathology in an empirically based manner.

Examining the shared and unique relationships among substance use and mental disorders.

BACKGROUND: Co-morbidity among use of different substances can be explained by a shared underlying dimensional factor. What remains unknown is whether the relationship between substance use and various co-morbid mental disorders can be explained solely by the general factor or whether there remain unique contributions of specific substances. METHOD: Data were from the 2007 Australian National Survey of Mental Health and Wellbeing (NSMHWB). A unidimensional latent factor was constructed that represented general substance use. The shared and specific relationships between lifetime substance use indicators and internalizing disorders, suicidality and psychotic-like experiences (PLEs) were examined using Multiple Indicators Multiple Causes (MIMIC) models in the total sample. Additional analyses then examined the shared and specific relationships associated with substance dependence diagnoses as indicators of the latent trait focusing on a subsample of substance users. RESULTS: General levels of latent substance use were significantly and positively related to internalizing disorders, suicidality and psychotic-like experiences. Similar results were found when examining general levels of latent substance dependence in a sample of substance users. There were several direct effects between specific substance use/dependence indicators and the mental health correlates that significantly improved the overall model fit but they were small in magnitude and had relatively little impact on the general relationship. CONCLUSIONS: The majority of pairwise co-morbid relationships between substance use/dependence and mental health correlates can be explained through a general latent factor. Researchers should focus on investigating the commonalities across all substance use and dependence indicators when studying mental health co-morbidity.

An examination of generalized anxiety disorder and dysthymic disorder by latent class analysis.

BACKGROUND: The nosological status of generalized anxiety disorder (GAD) versus dysthymic disorder (DD) has been questioned. The aim of this study was to examine qualitative differences within (co-morbid) GAD and DD symptomatology. METHOD: Latent class analysis was applied to anxious and depressive symptomatology of respondents from three population-based studies (2007 Australian National Survey of Mental Health and Wellbeing; National Comorbidity Survey Replication; and Netherlands Mental Health Survey and Incidence Study-2; together known as the Triple study) and respondents from a multi-site naturalistic cohort [Netherlands Study of Depression and Anxiety (NESDA)]. Sociodemographics and clinical characteristics of each class were examined. RESULTS: A three-class (Triple study) and two-class (NESDA) model best fitted the data, reflecting mainly different levels of severity of symptoms. In the Triple study, no division into a predominantly GAD or DD co-morbidity subtype emerged. Likewise, in spite of the presence of pure GAD and DD cases in the NESDA sample, latent class analysis did not identify specific anxiety or depressive profiles in the NESDA study. Next, sociodemographics and clinical characteristics of each class were examined. Classes only differed in levels of severity. CONCLUSIONS: The absence of qualitative differences in anxious or depressive symptomatology in empirically derived classes questions the differentiation between GAD and DD.

Playing for more than winning: Exploring sports participation, physical activity, and belongingness and their relationship with patterns of adolescent substance use and mental health.

BACKGROUND: Promoting adolescent sports participation and physical activity may be effective low-barrier prevention strategies for co-occurring adolescent substance use (SU) and mental health symptoms (MH). The objectives of this study were to: 1) explore associations between profiles of SU/MH and sports participation; and 2) determine whether physical activity and belongingness account for these associations. METHODS: Data came from a representative sample of 11,994 grade 9-12 Ontarian students (ages ~14-18) previously grouped into five SU/MH profiles based on patterns of use and symptoms. A series of multinomial logistic regressions, adjusted for socio-demographics and school clustering, were used to predict the risks of students belonging to SU/MH profiles based on: 1) school sports participation (>=weekly), 2) sports and physical activity (>=60minutes; 0-7 days), and 3) sports, physical activity, and school belongingness. RESULTS: Greater school sports participation, physical activity, and belongingness were each associated with reduced risks of belonging to most profiles with elevations in SU and/or MH symptoms relative to the low SU/MH profile (Relative Risk Ratios: sports=0.62-0.87, physical activity=0.78-0.98, belonging=0.75-0.83). Frequency of physical activity accounted for ~32-60% of the associations between sports and SU/MH profiles, while school belongingness accounted for the remaining associations. Physical activity and belongingness remained independently associated with SU/MH profiles. CONCLUSIONS: Findings suggest possible indirect associations between school sports participation and SU/MH profiles through physical activity and school belongingness, which may be promising prevention targets that have independent associations over and above sports. School sports participation may be one of a number of ways to achieve these goals.

Unmet needs, quality of life and psychological distress: insights regarding head and neck cancer patients in a rural setting.

OBJECTIVE: This study aimed to evaluate the perceived quality of life, unmet needs and psychological distress in patients with head and neck cancer in a rural setting in New Zealand. METHOD: Patients presenting with head and neck cancer in Northland, New Zealand, were asked to complete questionnaires on quality of life, unmet needs, and anxiety or depression together with a free-text option. RESULTS: About one quarter of respondents (27 per cent) scored high in the anxiety and depression scale, with corresponding diminished quality of life scores and increased needs. Over half of respondents (54 per cent) found it challenging to travel for treatment. Financial difficulties were encountered more frequently with indigenous patients. Rurality alone does not lead to significant differences in quality of life or needs. CONCLUSION: After treatment for head and neck cancer, it is important to monitor and manage patients' psychological distress and ease of access to health services to improve quality of life.

Psychotic-like experiences in a community sample of 8000 children aged 9 to 11 years: an item response theory analysis.

BACKGROUND: Psychotic-like experiences (PLEs) in the general population are common, particularly in childhood, and may constitute part of a spectrum of normative development. Nevertheless, these experiences confer increased risk for later psychotic disorder, and are associated with poorer health and quality of life. METHOD: This study used factor analytic methods to determine the latent structure underlying PLEs, problem behaviours and personal competencies in the general child population, and used item response theory (IRT) to assess the psychometric properties of nine PLE items to determine which items best represented a latent psychotic-like construct (PSY). A total of 7966 children aged 9-11 years, constituting 95% of eligible children, completed self-report questionnaires. RESULTS: Almost two-thirds of the children endorsed at least one PLE item. Structural analyses identified a unidimensional construct representing psychotic-like severity in the population, the full range of which was well sampled by the nine items. This construct was discriminable from (though correlated with) latent dimensions representing internalizing and externalizing problems. Items assessing visual and auditory hallucination-like experiences provided the most information about PSY; delusion-like experiences identified children at more severe levels of the construct. CONCLUSIONS: Assessing PLEs during middle childhood is feasible and supplements information concerning internalizing and externalizing problems presented by children. The hallucination-like experiences constitute appropriate items to screen the population to identify children who may require further clinical assessment or monitoring. Longitudinal follow-up of the children is required to determine sensitivity and specificity of the PLE items for later psychotic illness.

Investigating differential symptom profiles in major depressive episode with and without generalized anxiety disorder: true co-morbidity or symptom similarity?

BACKGROUND: Large community-based epidemiological surveys have consistently identified high co-morbidity between major depressive episode (MDE) and generalized anxiety disorder (GAD). Some have suggested that this co-morbidity may be artificial and the product of the current diagnostic system. Because of the added direct and indirect costs associated with co-morbidity, it is important to investigate whether methods of diagnostic classification are artificially increasing the level of observed co-morbidity. METHOD: The item response theory (IRT) log-likelihood ratio procedure was used to test for differential item functioning (DIF) of MDE symptoms between respondents with and without a diagnosis of GAD in the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC). RESULTS: The presence of GAD significantly increased the chances of reporting any symptom of MDE, with odds ratios ranging from 2.54 to 5.36. However, there was no indication of significant DIF of MDE symptoms in respondents with and without GAD. CONCLUSIONS: The lack of any significant DIF indicates that cases with GAD do not present with a distinct MDE symptom profile, one that is consistent with the endorsement of symptoms that are conceptually similar in nature between the two disorders, compared to cases without GAD. This does not support the hypothesis that co-morbidity between MDE and GAD is artificially inflated because of the similar symptom criteria required by the current diagnostic system. Instead, MDE and GAD may be thought of as two distinct diagnostic entities that frequently co-occur because of a shared underlying trait.

Neurocognitive disorders: cluster 1 of the proposed meta-structure for DSM-V and ICD-11.

BACKGROUND: In an effort to group mental disorders on the basis of aetiology, five clusters have been proposed. In this paper, we consider the validity of the first cluster, neurocognitive disorders, within this proposal. These disorders are categorized as 'Dementia, Delirium, and Amnestic and Other Cognitive Disorders' in DSM-IV and 'Organic, including Symptomatic Mental Disorders' in ICD-10. METHOD: We reviewed the literature in relation to 11 validating criteria proposed by a Study Group of the DSM-V Task Force as applied to the cluster of neurocognitive disorders. RESULTS: 'Neurocognitive' replaces the previous terms 'cognitive' and 'organic' used in DSM-IV and ICD-10 respectively as the descriptor for disorders in this cluster. Although cognitive/organic problems are present in other disorders, this cluster distinguishes itself by the demonstrable neural substrate abnormalities and the salience of cognitive symptoms and deficits. Shared biomarkers, co-morbidity and course offer less persuasive evidence for a valid cluster of neurocognitive disorders. The occurrence of these disorders subsequent to normal brain development sets this cluster apart from neurodevelopmental disorders. The aetiology of the disorders is varied, but the neurobiological underpinnings are better understood than for mental disorders in any other cluster. CONCLUSIONS: Neurocognitive disorders meet some of the salient criteria proposed by the Study Group of the DSM-V Task Force to suggest a classification cluster. Further developments in the aetiopathogenesis of these disorders will enhance the clinical utility of this cluster.

Neurodevelopmental disorders: cluster 2 of the proposed meta-structure for DSM-V and ICD-11.

BACKGROUND: DSM-IV and ICD-10 are atheoretical and largely descriptive. Although this achieves good reliability, the validity of diagnoses can be increased by an understanding of risk factors and other clinical features. In an effort to group mental disorders on this basis, five clusters have been proposed. We now consider the second cluster, namely neurodevelopmental disorders. METHOD: We reviewed the literature in relation to 11 validating criteria proposed by a DSM-V Task Force Study Group. RESULTS: This cluster reflects disorders of neurodevelopment rather than a 'childhood' disorders cluster. It comprises disorders subcategorized in DSM-IV and ICD-10 as Mental Retardation; Learning, Motor, and Communication Disorders; and Pervasive Developmental Disorders. Although these disorders seem to be heterogeneous, they share similarities on some risk and clinical factors. There is evidence of a neurodevelopmental genetic phenotype, the disorders have an early emerging and continuing course, and all have salient cognitive symptoms. Within-cluster co-morbidity also supports grouping these disorders together. Other childhood disorders currently listed in DSM-IV share similarities with the Externalizing and Emotional clusters. These include Conduct Disorder, Attention Deficit Hyperactivity Disorder and Separation Anxiety Disorder. The Tic, Eating/Feeding and Elimination disorders, and Selective Mutisms were allocated to the 'Not Yet Assigned' group. CONCLUSION: Neurodevelopmental disorders meet some of the salient criteria proposed by the American Psychiatric Association (APA) to suggest a classification cluster.

Pharmacokinetics of continuous infusion of methotrexate and teniposide in pediatric cancer patients.

Laboratory studies have demonstrated the ability of teniposide to markedly enhance the intracellular accumulation of methotrexate suggesting that combination therapy with these agents may produce clinical benefit. Studies of methotrexate and teniposide were conducted in 19 children with relapsed acute lymphocytic leukemia to evaluate the pharmacokinetics of this previously untested combination of agents given alone or in combination and to demonstrate the feasibility of a Bayesian dose optimization strategy. Patients were randomly assigned to receive intermediate dose methotrexate as a 24-h continuous infusion, administered either simultaneously with continuous infusion teniposide or sequentially with the teniposide infusion beginning 12 h after the end of the methotrexate infusion. Plasma samples were obtained during and after infusions at appropriate times for a comprehensive pharmacokinetic study of each drug. Two measured drug concentrations obtained during the infusion were used to adjust each patient's dose rate to achieve target values of 10 microM for methotrexate and 15 microM for teniposide. Pharmacokinetic parameters for teniposide were not different for patients given simultaneous methotrexate from parameters estimated for patients receiving teniposide 12 h after the end of the methotrexate infusion. Despite similar end of infusion methotrexate concentrations, 24-h postinfusion methotrexate concentrations were lower (0.137 versus 0.235 microM; P less than 0.05) in the patients receiving simultaneous infusions. The patient specific dose regimens yielded acceptably precise, minimally biased steady state drug concentrations. These pharmacokinetic results provide the basis for further clinical studies with this combination of antileukemic agents.

Tamoxifen in premenopausal patients with metastatic breast cancer: a review.

The antiestrogen tamoxifen is the most widely used hormonal therapy for breast cancer. The drug exerts its antiproliferative effects primarily through estrogen receptor (ER)-mediated mechanisms, although other cellular actions may augment tumor inhibition. Clinically, tamoxifen has been less well studied in premenopausal than in postmenopausal patients. The drug has complex endocrine effects that are dependent on the treatment duration and dose, menopausal status, and target organ. In postmenopausal women receiving tamoxifen, serum estrogen levels remain low, and the normally elevated gonadotropin levels decrease. In contrast, serum estrogen levels are strikingly elevated in many premenopausal women, and gonadotropin concentrations are either unchanged or slightly increased. Large systematic trials in metastatic breast cancer have established tamoxifen as the recommended hormonal therapy for postmenopausal women with ER-positive tumors. Tamoxifen is also an active agent for premenopausal metastatic disease, and response rates are comparable to those reported for oophorectomy. Clinical experience with tamoxifen in this younger age group, however, is more limited. Few premenopausal women (less than 400) have been included in phase II and phase III trials. Two randomized trials (total of 160 patients) comparing oophorectomy with tamoxifen do not definitively establish therapeutic equivalence, and a survival advantage for either treatment cannot be excluded. Many questions remain concerning the appropriate role for tamoxifen in premenopausal patients. Still, tamoxifen has an attractive toxicity profile, and it offers a favorable therapeutic alternative for premenopausal women with ER-positive metastatic breast cancer who wish to avoid surgical or radiation castration.

Escalating teniposide systemic exposure to increase dose intensity for pediatric cancer patients.

PURPOSE: The primary objective for this study was to determine whether controlling pharmacokinetic variability, by designing patient-specific dosage regimens for teniposide using a Bayesian estimation control strategy, would permit an increase in dose intensity without increased toxicity. PATIENTS AND METHODS: Twenty patients with relapsed acute lymphocytic leukemia were given teniposide as part of their induction and maintenance therapy. Before beginning reinduction therapy, an intensive pharmacokinetic study was performed based on 12 measured teniposide plasma concentrations. Doses were determined to achieve a targeted systemic exposure defined by an area under the plasma concentration time curve (AUC) beginning at an AUC consistent with that predicted for a patient with average pharmacokinetic parameters receiving the currently accepted maximal-tolerated dose. The targeted systemic exposure was then escalated in increments of 25% in cohorts of at least three patients until unacceptable toxicity occurred. In 36 follow-up studies, when teniposide was administered during maintenance therapy, a Bayesian strategy based on only three or five measured drug concentrations was evaluated for precision and bias for achieving the targeted systemic exposure against the full pharmacokinetic study. RESULTS: Teniposide clearance varied over a fivefold range (3.7 to 21.6 mL/min/m2). With the use of the patient-specific dosage regimens, the intensity of systemic exposure was increased 50% (1,656 mumol.h v 1,060 mumol/L.h) over that previously possible with standard fixed doses, with no increase in acute, nonhematologic toxicity. Teniposide concentrations (n = 265) were well predicted (R2 = .82) with as few as three measured values from the initial study. CONCLUSION: Targeting systemic exposure is clinically feasible, precise, and allows increased dose intensity for teniposide without increased risk of acute, nonhematologic toxicity, when compared with fixed-dose regimens.

Randomized phase III trial of treatment with high-dose interleukin-2 either alone or in combination with interferon alfa-2a in patients with advanced melanoma.

PURPOSE: To compare the response rate, survival, and toxicity of treatment with high-dose intravenous (IV) bolus interleukin-2 (IL-2) plus interferon alfa-2a (IFN-alpha) with high-dose IL-2 alone in patients with advanced melanoma in a randomized phase III trial design. PATIENTS AND METHODS: Eighty-five patients with advanced melanoma were randomly assigned to receive IL-2 6 X 10(6) U/m2 per dose every 8 hours as tolerated for a maximum of 14 doses on days 1 through 5 and 15 through 19, or IL-2 4.5 X 10(6) U/m2 per dose, plus IFN-alpha 3 X 10(6) U/m2 using an identical schedule. A planned interim analysis was performed after 85 patients were entered, which forms the basis for this report. RESULTS: Partial response (PR) occurred in two of 44 patients (5%; 95% confidence interval, 1% to 15%) receiving IL-2 alone, compared with four of 41 patients (10%; 95% confidence interval, 3% to 23%) receiving IL-2/IFN-alpha (P = .30). There were no complete responses (CRs). The median duration of response was 11.5 months (range, 2.0 to 15.7+). There was no significant difference in the median survival duration for patients receiving IL-2 alone (10.2 months) compared with patients receiving IL-2/IFN-alpha (9.7 months). The median and mean number of doses of IL-2 were equivalent in both groups, as was toxicity. There were three treatment-related deaths, two in the IL-2-alone arm and one in the IL-2/IFN-alpha arm. The trial was terminated after the first interim analysis based on predefined early-stopping rules, which included termination if the response rate in the IL-2/IFN-alpha arm was less than 25%. CONCLUSION: Using the preparation, dose, and schedule of IL-2 in our trial, IFN-alpha failed to enhance significantly the response rate to high-dose IL-2 in the treatment of patients with advanced melanoma.

Phase I/II trial of continuous infusion vinorelbine for advanced breast cancer.

PURPOSE: A phase I/II trial of vinorelbine (VRL) administered by continuous infusion (CIV) was conducted in advanced breast carcinoma (ABC) patients to determine the maximum-tolerated dose (MTD) and to evaluate the toxicity pattern and antitumor activity of this alternative administration schedule to the currently recommended weekly short intravenous (IV) administration. PATIENTS AND METHODS: Between February 1990 and July 1991, 64 consecutive, eligible patients with ABC were treated; 33 had received one or two previous palliative chemotherapy combinations and 31 had not received chemotherapy for metastatic disease. VRL was administered, after an initial IV bolus of 8 mg/m2 on day 1, by a 4-day CIV at five different 24-hour dose levels (DLs) to be repeated every 21 or 28 days: DL1, 5.5 mg/m2; DL2, 7 mg/m2; DL3, 8 mg/m2, DL4, 9 mg/m2; and DL5, 10 mg/m2. RESULTS: The limiting noncumulative toxicity was neutropenia, with the MTD established at 8 mg/m2 bolus plus 10 mg/m2/d for 4 days (total dose per cycle, 48 mg/m2). At DL3 and DL4, we observed mucositis (14% of patients; five percent of cycles > grade 2), alopecia, and asthenia. By contrast, neurotoxicity was minor. The toxicity was otherwise predictable and manageable. Pharmacokinetic data obtained at DL1 and DL3 showed a mean VRL plasma concentration of 967 +/- 331 ng/mL after the initial 8 mg/m2 IV bolus dose, which declined rapidly thereafter to reach mean steady-state levels of 12 ng/mL (n = 5) for the 30-mg/m2 dose and 8 ng/mL (n = 2) for the 40-mg/m2 dose. These levels were maintained over the 96-hour CIV. The mean residence time (MRT) was 29 +/- 7 hours (terminal half-life [t1/2], 23 hours), the total-body clearance (CL) was 24 +/- 11 L/hr/m2, and the volume of distribution at steady-state (Vss) was high at 1,832 +/- 359 L/m2. Two patients achieved a complete response (CR) and 21 a partial response (PR), for an objective response rate of 36% (95% confidence interval [Cl], 23 to 49). The median duration of response was 6 months. The median survival duration was 24 months (range, 3 to 37). A relationship between given dose-intensity and objective response rate was found, with an overall response (OR) rate of 13.3% (two of 15) for 8 to 10 mg/m2/wk, 35.4% (11 of 31) for 10 to 12 mg/m2/wk, and 55.5% (10 of 18) for 12 to 14.5 mg/m2/wk. CONCLUSION: This trial, while confirming VRL activity in ABC, shows the feasability of a CIV administration schedule. A decrease of the administrated total dose per 3- to 4-week cycle to less than the weekly schedule with the same therapeutic activity suggests a better therapeutic index. The data are also suggestive of a dose-response relationship and a dose-intensity/activity correlation.

Hormones and breast cancer.

The study of steroid hormone receptors in human breast cancer provides insight into tumor biology and forms the rationale for many therapeutic modalities. Clinical assays for estrogen and progesterone receptors improve the selection of patients who may benefit from hormonal therapy. In addition, receptor content in breast cancer tissue is useful for determining prognosis. Together with other new prognostic factors, hormone receptors help to distinguish among patients with primary breast cancer who are at risk for early recurrence.

The pharmacokinetics of high-dose carboplatin in pediatric patients with cancer.

Carboplatin disposition was studied in 18 pediatric patients with cancer over a dosage range of 400 to 700 mg/m2 given on an alternate-day schedule (total doses of 1200 to 2100 mg/m2) with high-dose etoposide. Median age was 7.7 years, hepatic functions were normal, and serum creatinine levels were less than or equal to 1.0 mg/dl. Carboplatin pharmacokinetics were determined by atomic absorption spectroscopy. Median pharmacokinetic parameters for ultrafilterable platinum were as follows: clearance 45.8 ml/min/m2 (range, 25.5 to 65.3 ml/min/m2) and a terminal half-life of 3.6 hours (range, 2.1 to 14.2 hours). Carboplatin clearance (CL) values and volume of distribution (VC) were highly correlated to body size (CL = 55 x Body surface area in [BSA, in square meters] - 6.7, r2 = 0.73; VC = 5 x BSA [in square meters] + 0.26, r2 = 0.69). However, carboplatin doses normalized to BSA still resulted in twofold to threefold variability in area under the concentration-time curve. Carboplatin CL was significantly lower in those subjects (n = 9) who had previously received cumulative cisplatin doses of greater than or equal to 960 mg/m2 (p less than 0.05) but was not influenced by age, gender, or diagnosis.