Biomedical subjects

Kathleen J Yost

Publications and source records attributed to Kathleen J Yost.

10 recordsLinked to original sources

PubMed2006

Phase II trial of PN401, 5-FU, and leucovorin in unresectable or metastatic adenocarcinoma of the stomach: a Southwest Oncology Group study.

From February, 2001 to September, 2002, the Southwest Oncology Group (SWOG) accrued 65 patients with advanced gastric adenocarcinoma to a phase II trial of weekly 5-FU, leucovorin, and the orally-administered uridine analog PN401. Of these 65 patients, 57 were assessable for survival and toxicity, which were the endpoints for the study. Treatment consisted of the administration of 1200 mg/m(2) of 5-FU, 500 mg/m(2) of leucovorin, and 6 grams of PN401 every 8 h, beginning 8 h after the completion of the 5-FU infusion, and continuing for a total of 8 doses (48 grams) during each weekly chemotherapy session. Therapy was delivered for six weeks out of every 8-week treatment cycle. The gastrointestinal toxicity of this regimen was mild with 2 patients experiencing grade 3 stomatitis, and 6 patients having grade 3 diarrhea; and the hematologic toxicity was acceptable with 6 of 57 patients found to have had grade 3 or 4 leukopenia, and 14 of 57 patients experiencing grade 3 or 4 neutropenia. There were two deaths judged possibly related to treatment; one in a patient who experienced a variety of Grade 2 gastrointestinal toxicities and died at home with an unknown cause of death; and a second patient who also died at home, and for whom treatment-related sepsis could not be ruled out. The overall median survival was 7.2 months. The ability to safely deliver twice the usual dose of 5-FU with leucovorin on a weekly schedule suggests that oral uridine analog supplementation with PN401 may enhance the therapeutic index of the fluoropyrimidines.

Acetates↗

PubMed2006

Application of robust statistical methods for sensitivity analysis of health-related quality of life outcomes.

BACKGROUND: Researchers often use conventional parametric procedures to test hypotheses of health-related quality of life (HRQL) mean equality across patient groups. However, these techniques are sensitive to the presence of skewed distributions and unequal group variances, which may characterize many HRQL measures. PURPOSE: To conduct a sensitivity analysis of conventional and robust approaches to test hypotheses of mean equality on HRQL measures for hematopoietic stem cell transplantation survivors and a healthy comparison group. METHODS: The methods applied were the conventional parametric procedure of least-squares analysis of variance applied to the raw scores, the conventional parametric procedure applied to transformed data, and a robust approximate degrees of freedom parametric procedure utilizing trimmed means and Winsorized variances. RESULTS: The choice of analysis method affected the conclusions about the null hypothesis of mean equality. More commonly observed, however, was a substantial difference in the value of the F-statistic and standard errors which was particularly evident in the measures with greater degrees of skewness and heterogeneity of variances. CONCLUSIONS: Robust statistical tests should be incorporated into sensitivity analyses when analyzing HRQL data.

Adult↗

PubMed2006

Phase II trial of gemcitabine plus irinotecan in patients with esophageal cancer: a Southwest Oncology Group (SWOG) trial.

OBJECTIVES: Metastatic esophageal carcinoma is an incurable disease with median survival duration of 6 to 8 months. Based on preclinical data suggesting a dose-dependent synergy between gemcitabine and irinotecan we have conducted a phase II trial in patients with advanced or metastatic esophageal carcinoma. METHODS: Patient eligibility included a diagnosis of squamous cell or adenocarcinoma of the esophagus/gastroesophageal (GE) junction, metastatic or recurrent disease, no CNS metastasis, no prior chemotherapy, prior adjuvant/neoadjuvant chemotherapy was allowed, no prior gemcitabine or irinotecan, performance status of 0 to 2 and adequate organ function. Patients received gemcitabine 1000 mg/m2 and irinotecan 100 mg/m2 given day 1 and day 8, every 3 weeks. The primary end point was the 6-month survival rate. The secondary end point was to assess qualitative and quantitative toxicities. RESULTS: Fifty-seven eligible patients were accrued. There were 4 treatment-related deaths. The primary grade 3 to 4 toxic events were diarrhea, dehydration, neutropenia, thrombocytopenia, anemia, and anorexia; and 4 episodes of grade 3 to 5 febrile neutropenia, 1 fatal. The study was designed to detect a difference between the null hypothesis of 30% 6-month survival and the alternative hypothesis of 50% 6-month survival. The Kaplan-Meier estimate of 6-month survival is 56% (95% CI: 43-69%), with a median of 6.3 months. The median time to progression was 3.7 months. The 6-month progression-free survival estimate is 25% (95% CI: 13-36%). CONCLUSIONS: The length of survival suggests that this combination has benefit similar to platinum containing regimens, however, the toxicity is substantial and is unlikely to prove superior to platinum containing regimens.

Adenocarcinoma↗

PubMed2006

Future trends in patient-reported outcomes assessment for patients with advanced-stage lung cancer receiving targeted therapy.

Recent advances in cancer cell biology have led to the development of therapeutic agents that target pathways critical to the development and progression of disease. These so-called "targeted therapies" might offer patients a more tolerable alternative to traditional systemic chemotherapy that often achieves therapeutic benefit at the cost of debilitating side effects. Several targeted agents have been recently tested in clinical trials of advanced-stage lung cancer. As interest in these therapies grows, an understanding of their impact on the patient's well-being will be important. Patient-reported outcome measures such as formal assessments of health-related quality of life and disease symptoms provide a useful means for addressing the impact of therapy from the perspective of the patient. We summarize the most commonly used measures of health-related quality of life in clinical trials of advanced-stage lung cancer. Although existing measurement systems do provide adequate coverage of many important patient-related outcome issues, the advent of targeted therapies in advanced-stage lung cancer does expose several measurement gaps. We highlight some of these gaps by reviewing a representative sample of recently conducted clinical trials of targeted lung cancer therapy and offer insight as to how these gaps can be filled. We also briefly discuss a set of issues unique to patients receiving targeted therapy (eg, perceptions of treatment efficacy, treatment compliance, patient satisfaction, and treatment convenience) and consider a few methodologic concerns unique to patients with advanced cancer.

Clinical Trials as Topic↗

PubMed2005

Patients' perceptions of quality of care for colorectal cancer by race, ethnicity, and language.

PURPOSE: To identify opportunities for improving care, we evaluated patients' perceptions of the quality of their cancer care by race, ethnicity, and language. PATIENTS AND METHODS: We surveyed a population-based cohort of 1,067 patients with colorectal cancer in northern California approximately 9 months after diagnosis. Adjusting for clinical and demographic factors, mean problem scores were analyzed on a 100-point scale for six domains of care. RESULTS: Mean problem scores were highest for health information (47.8), followed by treatment information (32.3), psychosocial care (31.7), coordination of care (21.3), confidence in providers (13.1), and access to cancer care (12.7). In adjusted comparisons with white patients, African American patients reported more problems with coordination of care (difference, 9.8; P < .001), psychosocial care (difference, 7.2; P = .03), access to care (difference, 6.6; P = .03), and health information (difference, 12.5; P < .001). Asian/Pacific Islander patients reported more problems than did white patients with coordination of care (difference, 13.2; P < .001), access to care (difference, 15.5; P < .001), and health information (difference, 12.6; P = .004). Hispanic patients tended to report more problems with coordination of care (difference, 4.4; P = .06), access to care (difference, 5.8; P = .08), and treatment information (difference, 7.0; P = .06). Non-English-speaking white patients reported more problems than other white patients with coordination of care (difference, 21.9; P < .001), psychosocial care (difference, 16.1; P = .009), access to care (difference, 19.8; P = .003), and treatment information (difference, 17.8; P = .002). Non-English-speaking Hispanic patients reported more problems than other Hispanic patients with confidence in providers (difference, 16.9; P = .01). CONCLUSION: Efforts to improve patients' experiences with cancer care should address disparities by race, ethnicity, and language, particularly in coordination of care, access to care, and the provision of relevant information.

Adult↗

PubMed2005

Validation of the Functional Assessment of Cancer Therapy-Breast Symptom Index (FBSI).

We assessed the reliability, validity, and responsiveness to change of the 6-item Functional Assessment of Cancer Therapy-Breast Symptom Index (FBSI) in a sample of 615 metastatic breast cancer patients. The FBSI is a brief, clinically relevant, and psychometrically sound instrument that can be used to measure symptoms in patients with breast cancer.

Breast Neoplasms↗

PubMed2005

Comparing SF-36 scores across three groups of women with different health profiles.

BACKGROUND: The widespread use of the Medical Outcomes Study (MOS) 36-item Short-Form Health Survey (SF-36) facilitates the comparison of health-related quality of life (HRQL) across independent studies. OBJECTIVES: To compare the scores of eight scales and two summary scales of the SF-36 across participants in the Women's Healthy Eating and Living (WHEL) trial, the Women's Health Initiative-Dietary Modification trial (WHI-DM), and the MOS, and to illustrate the use of effect sizes for interpreting the importance of group differences. METHODS: WHEL and WHI-DM are both multi-center dietary interventions; only data from the UC Davis sites were used in our study. WHEL participants had a recent history of breast cancer, WHI-DM participants were healthy, postmenopausal women, and women in the MOS had a history of hypertension, diabetes, heart disease, or depression. General linear models were used to identify statistically significant differences in scale scores. Meaningful differences were determined by effect sizes computed using a common within-group standard deviation (SD) and SDs from normative data. RESULTS: After adjusting for age and marital status, SF-36 scores for the WHI-DM and WHEL samples were similar and both had statistically significantly higher scores than the MOS sample. Relative to the WHEL or WHI-DM studies, MOS scores for scales related to the physical domain were clearly meaningfully lower whereas scale scores related to the mental health domain were potentially meaningfully lower. CONCLUSIONS: The HRQL of breast cancer survivors is comparable to that of healthy women and better than that of women with chronic health conditions, particularly with respect to physical health. This study illustrated the use of ranges of effects sizes for aiding the interpretation of SF-36 scores differences across independent studies.

Activities of Daily Living↗

PubMed2005

Combining distribution- and anchor-based approaches to determine minimally important differences: the FACIT experience.

Health-related quality of life (HRQOL) is an important endpoint in cancer clinical trials and in cancer treatment in general; however, the meaningfulness of HRQOL scores may not be apparent to clinicians or researchers. Minimally important differences (MIDs) can enhance the interpretability of HRQOL scores by identifying differences likely to be meaningful to patients and clinicians. This article's objective is to describe and provide examples of approaches we have used to identify MIDs for instruments in the Functional Assessment of Chronic Illness Therapy (FACIT) measurement system. Distribution- and anchor-based approaches are described and illustrated. We also discuss the importance of assessing the appropriateness of anchors, and we provide suggestions for combining results into a single range of plausible MIDs. MIDs for FACIT instruments established to date are summarized, and general guidelines that can be used to estimate MIDs for other FACIT instruments are provided. Applications of MIDs in research are illustrated.

Cross-Sectional Studies↗

PubMed2004

A combination of distribution- and anchor-based approaches determined minimally important differences (MIDs) for four endpoints in a breast cancer scale.

OBJECTIVE: To determine distribution- and anchor-based minimal important difference (MID) estimates for four scores from the Functional Assessment of Cancer Therapy-Breast (FACT-B): the breast cancer subscale (BCS), Trial Outcome Index (TOI), FACT-G (the general version), and FACT-B. STUDY DESIGN AND SETTING: We used data from a Phase III clinical trial in metastatic breast cancer (ECOG study 1193; n=739) and a prospective observational study of pain in metastatic breast cancer (n=129). One third and one half of the standard deviation and 1 standard error of measurement were used as distribution-based criteria. Clinical indicators used to determine anchor-based differences included ECOG performance status, current pain, and response to treatment. RESULTS: FACT-B scores were responsive to performance status and pain anchors, but not to treatment response. By combining the results of distribution- and anchor-based methods, MID estimates were obtained: BCS=2-3 points, TOI=5-6 points, FACT-G=5-6 points, and FACT-B=7-8 points. CONCLUSION: Distribution- and anchor-based estimates of the MID do show convergence. These estimates can be used in combination with other measures of efficacy to determine meaningful benefit and provide a basis for sample size estimation in clinical trials.

Adult↗

PubMedDate not supplied

Using multiple anchor- and distribution-based estimates to evaluate clinically meaningful change on the Functional Assessment of Cancer Therapy-Biologic Response Modifiers (FACT-BRM) instrument.

OBJECTIVE: The interpretation of health-related quality of life (HRQL) data from clinical trials can be enhanced by understanding the degree of change in HRQL scores that is considered meaningful. Our objectives were to combine distribution-based and two anchor-based approaches to identify minimally important differences (MIDs) for the 27-item Trial Outcome Index (TOI), the seven-item Social Well-Being (SWB) subscale, and the six-item Emotional Well-being (EWB) subscale from the Functional Assessment of Cancer Therapy-Biological Response Modifiers (FACT-BRM) instrument. METHODS: Distribution-based MIDs were based on the standard error of measurement. Anchor-based approaches utilized patient-reported global rating of change (GRC) and change in physician-reported performance status rating (PSR). Correlations and weighted kappa statistics were used to assess association and agreement between the two anchors. FACT-BRM changes were evaluated for three time periods: baseline to month 1, month 2 to month 3, and month 5 to month 6. RESULTS: Association between GRC and change in PSR was poor. Correlation between the anchors and HRQL change scores was largest at month 1 and decreased through month 6. Combining results from all approaches, the MIDs identified were 5-8 points for the TOI, 2 points for the SWB subscale, and 2-3 points for the EWB subscale. CONCLUSIONS: We combined patient-reported estimates, physician-reported estimates, and distribution-based estimates to derive MIDs for HRQL outcomes from the FACT-BRM. These results will enable interpretation of treatment group effects in a clinical trial setting, and they can be used to estimate sample size or power when designing future studies.

Adolescent↗