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Open Access Publications from the University of California

Scholarly Works (31 results)

  • Thesis
  • Peer Reviewed
UC San Francisco Electronic Theses and Dissertations (2013)

Subgroups of individuals may be at greater risk for changes in attentional function before, during, and after cancer treatment. Proposed mechanisms for these changes may include genetic predisposition to cytokine and neurotransmitter dysregulation. The purposes of this dissertation research were to identify subgroups of individuals with distinct trajectories of attentional function and to evaluate for phenotypic and genotypic (i.e., variations in cytokine and neurotransmission genes) differences among these subgroups. Self-reported attentional function was evaluated in two independent samples using the Attentional Function Index. In the first sample of 167 oncology patients receiving radiation therapy and their 85 family caregivers, three latent classes were identified using growth mixture modeling: high (15.5%), moderate-to-high (48.0%), and moderate (36.5%) attentional function. Participants in the moderate class were younger, with more comorbidities and lower functional status. Multivariable models controlled for phenotypic differences among classes, population stratification due to race/ethnicity, and other genetic variations in the same gene. A cytokine gene variation (i.e., IL6 rs1800795) remained a significant genotypic predictor of latent class membership in multivariable models. In addition, two catecholaminergic gene variations (i.e., ADRA1D rs4815675, SLC6A3 rs37022), a gamma-aminobutyric acid (GABA)-ergic gene variation (i.e., SLC6A1 rs2697138), and two serotonergic gene variations (i.e., HTR2A rs2296972, rs9534496) remained significant predictors of latent class membership. In the second sample of 397 patients with breast cancer, three latent classes were identified: high (41.6%), moderate (25.4%), and low-moderate (33.0%) attentional function. Patients in the low-moderate class were younger than those in the high class, with more comorbidities and lower functional status than the other two classes. Controlling for phenotypic differences among classes, population stratification due to race/ethnicity, and other genetic variations in the same gene, a cytokine gene variation (i.e., IL1R1 rs949963) remained a significant genotypic predictor of latent class membership. Findings provide evidence of subgroups of individuals with distinct trajectories of attentional function and of genetic associations with subgroup membership. These findings suggest that variations in genes that encode for inflammatory cytokines and for three distinct but related neurotransmission systems are involved in attentional function.

    Cover page: Identification of Genetic Markers Associated With Self-Reported Attentional Function
    • Thesis
    • Peer Reviewed
    UC San Francisco Electronic Theses and Dissertations (2009)

    This study of breast cancer patients who underwent radiation therapy (RT) examined how attentional fatigue changed from the time of simulation to four months after the completion of RT and investigated whether specific variables predicted initial levels of attentional fatigue and characteristics of the trajectories of attentional fatigue. Seventy-three women completed a number of measures (i.e., Attentional Function Index, General Sleep Disturbance Scale, Center for Epidemiologic Studies-Depression scale, Spielberger State-Trait Anxiety Inventories, Brief Pain Inventory) over six months. Descriptive statistics and hierarchical linear modeling were used for data analysis. Large amounts of inter-individual variability were found in the trajectories of attentional fatigue. At baseline, higher levels of attentional fatigue were associated with younger age, not working, a higher number of comorbidities, and higher levels of trait anxiety. The trajectory of attentional fatigue improved over time for women with a higher body mass index at baseline. This study is the first to identify predictors of inter-individual variability in attentional fatigue in women with breast cancer undergoing RT. The various predictors should be considered in the design of future correlational and interventional studies in this population.

      Cover page: Predictors of the Trajectories of Self-Reported Attentional Fatigue in Women With Breast Cancer Undergoing Radiation Therapy
      • Article
      • Peer Reviewed
      UC San Francisco Previously Published Works (2015)

      Purpose/objectives

      To evaluate gender differences in quality of life (QOL), demographic, clinical, and symptom characteristics.


      Design

      Prospective, observational.


      Setting

      Two radiation oncology departments in northern California.


      Sample

      185 patients before initiation of radiation therapy (RT).


      Methods

      At their RT simulation visit, patients completed a demographic questionnaire, a measure of QOL, and symptom-specific scales. Backward elimination regression analyses were conducted to determine the significant predictors of QOL
.

      Main research variables

      QOL, gender, and 20 potential predictors
.

      Findings

      In women, depressive symptoms, functional status, age, and having children at home explained 64% of the variance in QOL. In men, depressive symptoms, state anxiety, number of comorbidities, being a member of a racial or ethnic minority, and age explained 70% of the variance in QOL
.

      Conclusions

      Predictors of QOL differed by gender. Depressive symptom score was the greatest contributor to QOL in both genders.
.

      Implications for nursing

      Nurses need to assess for QOL and depression at the initiation of RT. Knowledge of the different predictors of QOL may be useful in the design of gender-specific interventions to improve QOL.
        Cover page: Gender Differences in Predictors of Quality of Life at the Initiation of Radiation Therapy.
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2013)

        Objectives

        To review the proposed mechanisms of cognitive changes associated with non-central nervous system cancers and cancer treatment.

        Data sources

        Review and synthesis of databased publications and review articles.

        Conclusion

        Proposed mechanisms include cytokine upregulation, hormonal changes, neurotransmitter dysregulation, attentional fatigue, genetic predisposition, and comorbid symptoms.

        Implications for nursing practice

        Oncology nurses need to understand the multiple mechanisms that may contribute to the development of cancer- and treatment-related cognitive changes so that they can identify patients at high risk and help patients understand why these changes occur.
          Cover page: Proposed mechanisms for cancer- and treatment-related cognitive changes.
          • Article
          • Peer Reviewed
          UC San Francisco Previously Published Works (2015)

          Purpose of the research

          Evaluate for associations between variations in genes involved in catecholaminergic, gamma-aminobutyric acid (GABA)-ergic, and serotonergic mechanisms of neurotransmission and attentional function latent classes.

          Patients and methods

          This descriptive, longitudinal study was conducted at two radiation therapy departments. The sample included three latent classes of individuals with distinct trajectories of self-reported attentional function during radiation therapy, who were previously identified using growth mixture modeling among 167 oncology patients and 85 of their family caregivers. Multivariable models were used to evaluate for genotypic associations of neurotransmission genes with attentional function latent class membership, after controlling for covariates.

          Results

          Variations in catecholaminergic (i.e., ADRA1D rs4815675, SLC6A3 rs37022), GABAergic (i.e., SLC6A1 rs2697138), and serotonergic (i.e., HTR2A rs2296972, rs9534496) neurotransmission genes were significant predictors of latent class membership in multivariable models.

          Conclusions

          Findings suggest that variations in genes that encode for three distinct but related neurotransmission systems are involved in alterations in attentional function. Knowledge of both phenotypic and genetic markers associated with alterations in attentional function can be used by clinicians to identify patients and family caregivers who are at higher risk for this symptom. Increased understanding of the genetic markers associated with alterations in attentional function may provide insights into the underlying mechanisms for this significant clinical problem.
            Cover page: Associations between catecholaminergic, GABAergic, and serotonergic genes and self-reported attentional function in oncology patients and their family caregivers.
            • Article
            • Peer Reviewed
            UC San Francisco Previously Published Works (2013)
            Abstract Background Mortality rates for cancer are decreasing in patients under 60 and increasing in those over 60 years of age. The reasons for these differences in mortality rates remain poorly understood. One explanation may be that older patients received substandard treatment because of concerns about adverse effects. Given the paucity of research on the multiple dimensions of the symptom experience in older oncology patients, the purpose of this study was to evaluate for differences in ratings of symptom occurrence, severity, frequency, and distress between younger (< 60 years) and older ( ≥ 60 years) adults undergoing cancer treatment. We hypothesized that older patients would have significantly lower ratings on four symptom dimensions. Methods Data from two studies in the United States and one study in Australia were combined to conduct this analysis. All three studies used the MSAS to evaluate the occurrence, severity, frequency, and distress of 32 symptoms. Results Data from 593 oncology outpatients receiving active treatment for their cancer (i.e., 44.4% were < 60 years and 55.6% were ≥ 60 years of age) were evaluated. Of the 32 MSAS symptoms, after controlling for significant covariates, older patients reported significantly lower occurrence rates for 15 (46.9%) symptoms, lower severity ratings for 6 (18.9%) symptoms, lower frequency ratings for 4 (12.5%) symptoms, and lower distress ratings for 14 (43.8%) symptoms. Conclusions This study is the first to evaluate for differences in multiple dimensions of symptom experience in older oncology patients. For almost 50% of the MSAS symptoms, older patients reported significantly lower occurrence rates. While fewer age-related differences were found in ratings of symptom severity, frequency, and distress, a similar pattern was found across all three dimensions. Future research needs to focus on a detailed evaluation of patient and clinical characteristics (i.e., type and dose of treatment) that explain the differences in symptom experience identified in this study.
              Cover page: Differences in the symptom experience of older versus younger oncology outpatients: a cross-sectional study
              • Article
              • Peer Reviewed
              UC San Francisco Previously Published Works (2014)

              Context

              The relatively low number of older patients in cancer trials limits knowledge of how older adults experience symptoms associated with cancer and its treatment.

              Objectives

              This study evaluated for differences in the symptom experience across four older age groups (60-64, 65-69, 70-74, ≥75 years).

              Methods

              Demographic, clinical, and symptom data from 330 patients aged >60 years who participated in one Australian and two U.S. studies were evaluated. The Memorial Symptom Assessment Scale was used to evaluate the occurrence, severity, frequency, and distress of 32 symptoms commonly associated with cancer and its treatment.

              Results

              On average, regardless of the age group, patients reported 10 concurrent symptoms. The most prevalent symptoms were physical in nature. Worrying was the most common psychological symptom. For 28 (87.5%) of the 32 Memorial Symptom Assessment Scale symptoms, no age-related differences were found in symptom occurrence rates. For symptom severity ratings, an age-related trend was found for difficulty swallowing. As age increased, severity of difficulty swallowing decreased. For symptom frequency, age-related trends were found for feeling irritable and diarrhea, with both decreasing in frequency as age increased. For symptom distress, age-related trends were found for lack of energy, shortness of breath, feeling bloated, and difficulty swallowing. As age increased, these symptoms received lower average distress ratings.

              Conclusion

              Additional research is warranted to examine how age differences in symptom experience are influenced by treatment differences, aging-related changes in biological or psychological processes, or age-related response shift.
                • Article
                • Peer Reviewed
                UC San Francisco Previously Published Works (2014)
                CONTEXT: The relatively low number of older patients in cancer trials limits knowledge of how older adults experience symptoms associated with cancer and its treatment. OBJECTIVES: This study evaluated for differences in the symptom experience across four older age groups (60-64, 65-69, 70-74, ≥75 years). METHODS: Demographic, clinical, and symptom data from 330 patients aged >60 years who participated in one Australian and two U.S. studies were evaluated. The Memorial Symptom Assessment Scale was used to evaluate the occurrence, severity, frequency, and distress of 32 symptoms commonly associated with cancer and its treatment. RESULTS: On average, regardless of the age group, patients reported 10 concurrent symptoms. The most prevalent symptoms were physical in nature. Worrying was the most common psychological symptom. For 28 (87.5%) of the 32 Memorial Symptom Assessment Scale symptoms, no age-related differences were found in symptom occurrence rates. For symptom severity ratings, an age-related trend was found for difficulty swallowing. As age increased, severity of difficulty swallowing decreased. For symptom frequency, age-related trends were found for feeling irritable and diarrhea, with both decreasing in frequency as age increased. For symptom distress, age-related trends were found for lack of energy, shortness of breath, feeling bloated, and difficulty swallowing. As age increased, these symptoms received lower average distress ratings. CONCLUSION: Additional research is warranted to examine how age differences in symptom experience are influenced by treatment differences, aging-related changes in biological or psychological processes, or age-related response shift.
                  Cover page: Differences in the symptom experience of older oncology outpatients.
                  • Article
                  • Peer Reviewed
                  UC San Francisco Previously Published Works (2014)
                  Subgroups of individuals may be at greater risk of cytokine-induced changes in attentional function. The purposes of this study were to identify subgroups of individuals with distinct trajectories of attentional function and evaluate for phenotypic and genotypic (i.e., cytokine gene polymorphisms) differences among these subgroups. Self-reported attentional function was evaluated in 252 participants (167 oncology patients and 85 family caregivers) using the Attentional Function Index before radiation therapy and at six additional assessments over 6 months. Three latent classes of attentional function were identified using growth mixture modeling: moderate (36.5%), moderate-to-high (48.0%), and high (15.5%) attentional function. Participants in the moderate class were significantly younger, with more comorbidities and lower functional status, than those in the other two classes. However, only functional status remained significant in multivariable models. Included in the genetic association analyses were 92 single nucleotide polymorphisms (SNPs) among 15 candidate genes. Additive, dominant, and recessive genetic models were assessed for each SNP. Controlling for functional status, only Interleukin 6 (IL6) rs1800795 remained a significant genotypic predictor of class membership in multivariable models. Each additional copy of the rare G allele was associated with a 4-fold increase in the odds of belonging to the lower attentional function class (95% confidence interval: [1.78, 8.92]; p = .001). Findings provide preliminary evidence of subgroups of individuals with distinct trajectories of attentional function and of a genetic association with an IL6 promoter polymorphism.
                    Cover page: Preliminary evidence of an association between an interleukin 6 promoter polymorphism and self-reported attentional function in oncology patients and their family caregivers.
                    • Article
                    • Peer Reviewed
                    UC San Francisco Previously Published Works (2013)
                    PURPOSE: Depressive symptoms are common in cancer patients and their family caregivers (FCs). While these symptoms are characterized by substantial interindividual variability, the factors that predict this variability remain largely unknown. This study sought to confirm latent classes of oncology patients and FCs with distinct depressive symptom trajectories and to examine differences in phenotypic and genotypic characteristics among these classes. METHOD: Among 167 oncology outpatients with breast, prostate, lung, or brain cancer and 85 of their FCs, growth mixture modeling (GMM) was used to identify latent classes of individuals based on Center for Epidemiological Studies-Depression (CES-D) scores obtained prior to, during, and for four months following completion of radiation therapy. One hundred four single nucleotide polymorphisms (SNPs) and haplotypes in 15 candidate cytokine genes were interrogated for differences between the two largest latent classes. Multivariate logistic regression analyses assessed effects of phenotypic and genotypic characteristics on class membership. RESULTS: Four latent classes were confirmed: Resilient (56.3%), Subsyndromal (32.5%), Delayed (5.2%), and Peak (6.0%). Participants who were younger, female, non-white, and who reported higher baseline trait and state anxiety were more likely to be in the Subsyndromal, Delayed, or Peak groups. Variation in three cytokine genes (i.e., interleukin 1 receptor 2 [IL1R2], IL10, tumor necrosis factor alpha [TNFA]), age, and performance status predicted membership in the Resilient versus Subsyndromal classes. CONCLUSIONS: Findings confirm the four latent classes of depressive symptom trajectories previously identified in a sample of breast cancer patients. Variations in cytokine genes may influence variability in depressive symptom trajectories.
                      Cover page: Cytokine gene variation is associated with depressive symptom trajectories in oncology patients and family caregivers.
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