Advances in Conceptual and Methodological Issues in Symptom Cluster Research: A 20-Year Perspective.

Two conceptual approaches are used to evaluate symptom clusters: "clustering" symptoms (ie, variable-centered analytic approach) and "clustering" patients (ie, person-centered analytic approach). However, these methods are not used consistently and conceptual clarity is needed. Given the emergence of novel methods to evaluate symptom clusters, a review of the conceptual basis for older and newer analytic methods is warranted. Therefore, this article will review the conceptual basis for symptom cluster research; compare and contrast the conceptual basis for using variable-centered versus patient-centered analytic approaches in symptom cluster research; review their strengths and weaknesses; and compare their applications in symptom cluster research.

A randomized clinical trial of granulocyte macrophage colony stimulating factor mouthwash for oral mucositis in head and neck cancer.

PURPOSE: Oral mucositis (OM) is a significant problem for patients with head and neck cancer (HNC). The purpose of this double-blind, randomized clinical trial (RCT) was to evaluate the effectiveness of the granulocyte macrophage colony stimulating factor (GM-CSF) mouthwash compared to Salt and Soda mouthwash for both the prevention (prior to onset of OM) and treatment (beginning at the onset of OM to its healing) of radiation therapy (RT)-induced OM. METHODS: A total of 91 patients with HNC were randomized to receive: GM-CSF throughout both the prevention and treatment phases (GG group); Salt and Soda throughout both phases (SS group) or Salt and Soda during the prevention phase followed by GM-CSF at the onset of OM (SG group). Three groups were compared on the occurrence and grades of OM, functional status, pain, chewing, and swallowing during and after RT. RESULTS: No significant differences were found in the occurrence and grades of OM in the patients who used GM-CSF vs. Salt and Soda in the prevention phase. In addition, no differences were seen among the three groups in functional status, pain, chewing, and swallowing during and after RT. CONCLUSION: Given that GM-CSF was no more effective than Salt and Soda mouthwash for the prevention or treatment of OM, the readily available and cheaper mouthwash can be used at considerable cost savings.

Research Agenda of the Oncology Nursing Society: 2019-2022.

PROBLEM STATEMENT: To define the Oncology Nursing Society Research Agenda for 2019-2022. DESIGN: Multimethod, consensus-building approach by members of the Research Agenda Project Team. DATA SOURCES: Expert opinion, literature review, surveys, interviews, focus groups, town hall, and review of research priorities from other cancer care organizations and funding agencies. ANALYSIS: Content analysis and descriptive statistics were used to synthesize research priority themes that emerged. FINDINGS: Three priority areas for scientific development were identified. IMPLICATIONS FOR NURSING: The Research Agenda can be used to focus oncology nurses' research, scholarship, leadership, and health policy efforts to advance quality cancer care, inform research funding priorities, and align initiatives and resources across the ONS enterprise.

Symptom Cluster Trajectories During Chemotherapy in Breast Cancer Outpatients.

CONTEXT: Breast cancer patients often experience multiple symptoms and substantial discomfort. Some symptoms may occur simultaneously and throughout the duration of chemotherapy treatment. OBJECTIVES: The aim of this study was to investigate symptom severity and symptom cluster trajectories during chemotherapy in outpatients with breast cancer in Taiwan. METHODS: This prospective, longitudinal, repeated measures study administered a standardized questionnaire (M. D. Anderson Symptom Inventory Taiwan version) to 103 breast cancer patients during each day of the third 21-day cycle of chemotherapy. Latent class growth analysis was performed to examine symptom cluster trajectories. RESULTS: Three symptom clusters were identified within the first 14 days of the 21-day chemotherapy cycle: the neurocognition cluster (pain, shortness of breath, vomiting, memory problems, and numbness/tingling) with a trajectory of Y = 2.09 - 0.11 (days), the emotion-nausea cluster (nausea, disturbed sleep, distress/upset, drowsiness, and sadness) with a trajectory ofY = 3.57 - 0.20 (days), and the fatigue-anorexia cluster (fatigue, lack of appetite, and dry mouth) with a trajectory of Y = 4.22 - 0.21 (days). The "fatigue-anorexia cluster" and "emotion-nausea cluster" peaked at moderate levels on chemotherapy days 3-5, and then gradually decreased to mild levels within the first 14 days of the 21-day chemotherapy cycle. CONCLUSION: Distinct symptom clusters were observed during the third cycle of chemotherapy. Systematic and ongoing evaluation of symptom cluster trajectories during cancer treatment is essential. Healthcare providers can use these findings to enhance communication with their breast cancer patients and to prioritize symptoms that require attention and intervention.

Variations in potassium channel genes are associated with distinct trajectories of persistent breast pain after breast cancer surgery.

Persistent pain after breast cancer surgery is a common clinical problem. Given the role of potassium channels in modulating neuronal excitability, coupled with recently published genetic associations with preoperative breast pain, we hypothesized that variations in potassium channel genes will be associated with persistent postsurgical breast pain. In this study, associations between 10 potassium channel genes and persistent breast pain were evaluated. Using growth mixture modeling (GMM), 4 distinct latent classes of patients, who were assessed before and monthly for 6 months after breast cancer surgery, were identified previously (ie, No Pain, Mild Pain, Moderate Pain, Severe Pain). Genotyping was done using a custom array. Using logistic regression analyses, significant differences in a number of genotype or haplotype frequencies were found between: Mild Pain vs No Pain and Severe Pain vs No Pain classes. Seven single-nucleotide polymorphisms (SNPs) across 5 genes (ie, potassium voltage-gated channel, subfamily A, member 1 [KCNA1], potassium voltage-gated channel, subfamily D, member 2 [KCND2], potassium inwardly rectifying channel, subfamily J, members 3 and 6 (KCNJ3 and KCNJ6), potassium channel, subfamily K, member 9 [KCNK9]) were associated with membership in the Mild Pain class. In addition, 3 SNPs and 1 haplotype across 4 genes (ie, KCND2, KCNJ3, KCNJ6, KCNK9) were associated with membership in the Severe Pain class. These findings suggest that variations in potassium channel genes are associated with both mild and severe persistent breast pain after breast cancer surgery. Although findings from this study warrant replication, they provide intriguing preliminary information on potential therapeutic targets.

Healthy Lifestyle Behaviors of Breast Cancer Survivors.

The purpose of this secondary analysis was to describe the extent to which women with breast cancer, who participated in a randomized control trial on exercise, adopted American Cancer Society (ACS) guidelines for healthy lifestyle behaviors. Women in the study exercised during cancer treatment and for 6 months after completion of treatment. The sample included 106 women, average age 50.7 years (SD = 9.6). Adherence to guidelines for 5 servings of fruits and vegetables ranged from 36% (n = 28) to 39% (n = 36). Adherence with alcohol consumption guidelines was 71% (n = 28) to 83% (n = 30). Adherence with meeting a healthy weight ranged from 52% (n = 33) to 61% (n = 31). Adherence with physical activity guidelines ranged from 13% (n = 30) to 31% (n = 35). Alcohol and healthy weight guidelines were followed by more than half of the participants, but physical activity and dietary guidelines were followed by far fewer women. Further prospective clinical studies are indicated to determine whether interventions are effective in producing a healthy lifestyle in cancer survivors.

Cytokine gene associations with self-report ratings of morning and evening fatigue in oncology patients and their family caregivers.

The purpose of this study was to evaluate for differences in variations in pro- and anti-inflammatory cytokine genes between participants who were classified as having low and high levels of morning and evening fatigue and to evaluate for differences in phenotypic characteristics between these two groups. In a sample of 167 oncology outpatients with breast, prostate, lung, or brain cancer and 85 of their family caregivers, growth mixture modeling was used to identify latent classes of individuals based on ratings of morning and evening fatigue obtained prior to, during, and for 4 months following completion of radiation therapy. Differences in single nucleotide polymorphisms and haplotypes in 15 cytokine genes were evaluated between the latent classes. Multiple logistic regression was used to assess the effect of phenotypic and genotypic characteristics on morning and evening fatigue class membership. Associations were found between morning fatigue and number of comorbidities as well as variations in tumor necrosis factor alpha (TNFA) rs1800629 and rs3093662. Evening fatigue was associated with caring for children at home and variations in interleukin 4 (IL4) rs2243248 and TNFA rs2229094. Younger age and lower performance status were associated with both morning and evening fatigue. These findings suggest that inflammatory mediators are associated with the development of morning and evening fatigue. However, because different phenotypic characteristics and genomic markers are associated with diurnal variations in fatigue, morning and evening fatigue may be distinct but related symptoms.

Preoperative Breast Pain Predicts Persistent Breast Pain and Disability After Breast Cancer Surgery.

CONTEXT: Approximately 30% of the women report pain in the affected breast before breast cancer surgery. OBJECTIVES: The purpose of this secondary analysis of our prospective study was to determine how women who experienced both preoperative and persistent postsurgical breast pain (n=107) differed from women who did not report preoperative breast pain and did (n=158) or did not (n=122) experience persistent postsurgical breast pain. METHODS: Differences in demographic and clinical characteristics were evaluated. Linear mixed effects (LME) modeling was used to evaluate for group differences in symptom severity, function, sensation, and quality of life (QOL) over time. RESULTS: Between-group differences in demographic and clinical characteristics as well as trajectories of shoulder function and QOL were identified. Women with both preoperative and persistent postsurgical breast pain were younger; were more likely to report swelling, strange sensations, hardness, and numbness in the affected breast before surgery; and were more likely to have reconstruction at the time of surgery. Women with both preoperative and persistent postsurgical breast pain had more biopsies in the prior year, more lymph nodes removed, and reported more severe acute postsurgical pain than women without preoperative breast pain. The LME modeling revealed significant group effects for most outcomes evaluated. Over the six months of the study, women with both preoperative and persistent postsurgical pain had persistently poorer shoulder flexion and physical well-being than women without preoperative breast pain. CONCLUSION: Investigations of the etiology and molecular mechanisms of preoperative breast pain, as well as interventions for this high-risk group, are needed.

Trajectories of Depressive Symptoms in Women Prior to and for Six Months After Breast Cancer Surgery.

Depressive symptoms are common in women with breast cancer. This study evaluated how ratings of depressive symptoms changed from the time of the preoperative assessment to 6 months after surgery and investigated whether specific demographic, clinical, and symptom characteristics predicted preoperative levels of and/or characteristics of the trajectories of depressive symptoms. Characteristics that predicted higher preoperative levels of depressive symptoms included being married/partnered; receipt of adjuvant chemotherapy; more fear of metastasis; higher levels of trait anxiety, state anxiety, sleep disturbance, problems with changes in appetite; more hours per day in pain; and lower levels of attentional function. Future studies need to evaluate associations between anxiety, fears of recurrence, and uncertainty, as well as personality characteristics and depressive symptoms.

Upper extremity bioimpedance before and after treadmill testing in women post breast cancer treatment.

Research on the effect of cardiorespiratory (CR) exercise on upper extremity (UE) limb volume is limited in women with breast cancer-related lymphedema (BCRL). The aim of this study was to compare changes in UE volume immediately following a symptom-limited CR treadmill test in women with and without BCRL. As part of a cross-sectional study, 133 women post unilateral BC treatment completed symptom-limited treadmill testing. Bioimpedance spectroscopy (BIS) was used to measure UE resistance before and immediately following treadmill testing. Resistance ratios >1 (unaffected side/affected side) indicate greater volume in the affected limb. T-tests and repeated measures ANOVA were performed to evaluate differences between and within groups. Mean age was 56.2 years (SD 9.4); BMI was 26.13 kg m(-2) (SD 5.04). For women with previously diagnosed BCRL (n = 63), the resistance ratio was 1.116 (SD 0.160) pre-treadmill and 1.108 (SD 0.155) post-treadmill. For women without BCRL (n = 70), the resistance ratio was 0.990 (SD 0.041) pre-treadmill and 1.001 (SD 0.044) post-treadmill. Resistance ratios for women with BCRL were higher than those for women without BCRL at both time points (main effect of group: p < 0.001). No main effects were found for time (p = 0.695). A statistically significant effect was found for the time-by-group interaction (p = 0.002). 78% of the women with BCRL wore a compression garment during testing. Following testing, the women with BCRL demonstrated a non-statistically significant decrease in the resistance ratio, suggesting an immediate decrease in interlimb volume difference. The women without BCRL demonstrated an increase in the resistance ratio.

Pain medication management processes used by oncology outpatients and family caregivers part II: home and lifestyle contexts.

CONTEXT: Despite the increasing complexity of medication regimens for persistent cancer pain, little is known about how oncology outpatients and their family caregivers manage pain medications at home. OBJECTIVES: To describe the day-to-day management of pain medications from the perspectives of oncology outpatients and their family caregivers who participated in a randomized clinical trial of a psychoeducational intervention called the Pro-Self(©) Plus Pain Control Program. In this article, we focus on pain medication management in the context of highly individualized home environments and lifestyles. METHODS: This qualitative study was conducted as part of a randomized clinical trial, in which an embedded mixed methods research design was used. Audio-recorded dialogue among patients, family caregivers, and intervention nurses was analyzed using qualitative research methods. RESULTS: Home and lifestyle contexts for managing pain medications included highly individualized home environments, work and recreational activities, personal routines, and family characteristics. Pain medication management processes particularly relevant in these contexts included understanding, organizing, storing, scheduling, remembering, and taking the medications. With the exception of their interactions with the intervention nurses, most study participants had little involvement with clinicians as they worked through these processes. CONCLUSION: Pain medication management is an ongoing multidimensional process, each step of which has to be mastered by patients and their family caregivers when cancer treatment and supportive care are provided on an outpatient basis. Realistic patient- and family-centered skill-building interventions are needed to achieve effective and safe pain medication management in the contexts of individual home environments and lifestyles.

Pain medication management processes used by oncology outpatients and family caregivers part I: health systems contexts.

CONTEXT: Oncology patients with persistent pain treated in outpatient settings and their family caregivers have significant responsibility for managing pain medications. However, little is known about their practical day-to-day experiences with pain medication management. OBJECTIVES: The aim was to describe day-to-day pain medication management from the perspectives of oncology outpatients and their family caregivers who participated in a randomized clinical trial of a psychoeducational intervention called the Pro-Self(©) Plus Pain Control Program. In this article, we focus on pain medication management by patients and family caregivers in the context of multiple complex health systems. METHODS: We qualitatively analyzed audio-recorded intervention sessions that included extensive dialogue between patients, family caregivers, and nurses about pain medication management during the 10-week intervention. RESULTS: The health systems context for pain medication management included multiple complex systems for clinical care, reimbursement, and regulation of analgesic prescriptions. Pain medication management processes particularly relevant to this context were getting prescriptions and obtaining medications. Responsibilities that fell primarily to patients and family caregivers included facilitating communication and coordination among multiple clinicians, overcoming barriers to access, and serving as a final safety checkpoint. Significant effort was required of patients and family caregivers to insure safe and effective pain medication management. CONCLUSION: Health systems issues related to access to needed analgesics, medication safety in outpatient settings, and the effort expended by oncology patients and their family caregivers require more attention in future research and health-care reform initiatives.

Effects of an educational intervention for managing fatigue in women with early stage breast cancer.

PURPOSE: This randomized controlled trial of outpatients with breast cancer (stage I or II) evaluated the effects of a 3-week educational intervention on patient levels of fatigue. METHODS: Norwegian outpatients were randomized into an intervention group (n = 79) and a control group (n = 81). Women with fatigue (>2.5 on a 0-10 numeric rating scale, NRS) completed the Fatigue Questionnaire (FQ) and the Lee Fatigue Scale (LFS) at baseline (after treatment) (T1), immediately after intervention (T2) and 3 months after intervention (T3). RESULTS: The mean fatigue score (NRS) at study entry was 6.1 (SD 1.7) and 36% (n = 57) had a score ≥7. There were no statistically significant differences between the fatigue measures of women in the intervention and control group at T2 or T3 in the overall sample after the intervention. Using an NRS cut-off of 5, there was a borderline difference for women who scored <5 for chronic fatigue on FQ (p = 0.062) and a significant difference for energy on LFS (p = 0.042) where the women in the intervention group had less fatigue. Using an NRS cut-off score of 6, there was a borderline difference for women who scored <6 for fatigue on FQ (p = 0.062) and a significant difference for energy on LFS (p = 0.021) where women in the intervention group had more energy than those in the control group. CONCLUSIONS: Further research is needed to identify psycho-educational interventions to reduce levels of fatigue and to tailor an intervention based on the level of fatigue. Fatigue measurements should be chosen more carefully.

Predictors of initial levels and trajectories of anxiety in women before and for 6 months after breast cancer surgery.

BACKGROUND: The diagnosis of breast cancer, in combination with the anticipation of surgery, evokes fear, uncertainty, and anxiety in most women. OBJECTIVE: Study purposes were to examine in patients who underwent breast cancer surgery how ratings of state anxiety changed from the time of the preoperative assessment to 6 months after surgery and to investigate whether specific demographic, clinical, symptom, and psychosocial adjustment characteristics predicted the preoperative levels of state anxiety and/or characteristics of the trajectories of state anxiety. INTERVENTIONS/METHODS: Patients (n = 396) were enrolled preoperatively and completed the Spielberger State Anxiety inventory monthly for 6 months. Using hierarchical linear modeling, demographic, clinical, symptom, and psychosocial adjustment characteristics were evaluated as predictors of initial levels and trajectories of state anxiety. RESULTS: Patients experienced moderate levels of anxiety before surgery. Higher levels of depressive symptoms and uncertainty about the future, as well as lower levels of life satisfaction, less sense of control, and greater difficulty coping, predicted higher preoperative levels of state anxiety. Higher preoperative state anxiety, poorer physical health, decreased sense of control, and more feelings of isolation predicted higher state anxiety scores over time. CONCLUSIONS: Moderate levels of anxiety persist in women for 6 months after breast cancer surgery. IMPLICATIONS FOR PRACTICE: Clinicians need to implement systematic assessments of anxiety to identify high-risk women who warrant more targeted interventions. In addition, ongoing follow-up is needed to prevent adverse postoperative outcomes and to support women to return to their preoperative levels of function.

Association between an interleukin 1 receptor, type I promoter polymorphism and self-reported attentional function in women with breast cancer.

Subgroups of patients with breast cancer may be at greater risk for cytokine-induced changes in cognitive function after diagnosis and during treatment. The purposes of this study were to identify subgroups of patients with distinct trajectories of attentional function and evaluate for phenotypic and genotypic (i.e., cytokine gene polymorphisms) predictors of subgroup membership. Self-reported attentional function was evaluated in 397 patients with breast cancer using the Attentional Function Index before surgery and for six months after surgery (i.e., seven time points). Using growth mixture modeling, three attentional function latent classes were identified: High (41.6%), Moderate (25.4%), and Low-moderate (33.0%). Patients in the Low-moderate class were significantly younger than those in the High class, with more comorbidities and lower functional status than the other two classes. No differences were found among the classes in years of education, race/ethnicity, or other clinical characteristics. DNA was recovered from 302 patients' samples. Eighty-two single nucleotide polymorphisms among 15 candidate genes were included in the genetic association analyses. After controlling for age, comorbidities, functional status, and population stratification due to race/ethnicity, IL1R1 rs949963 remained a significant genotypic predictor of class membership in the multivariable model. Carrying the rare "A" allele (i.e., GA+AA) was associated with a twofold increase in the odds of belonging to a lower attentional function class (OR: 1.98; 95% CI: 1.18, 3.30; p=.009). Findings provide evidence of subgroups of women with breast cancer who report distinct trajectories of attentional function and of a genetic association between subgroup membership and an IL1R1 promoter polymorphism.

Mechanosensitivity in the upper extremity following breast cancer treatment.

STUDY DESIGN: Descriptive, cross-sectional. INTRODUCTION: Breast cancer (BC) treatments place the nervous system at risk, which may contribute to upper extremity (UE) mechanosensitivity. PURPOSE OF THE STUDY: To evaluate elbow extension range of motion (EE-ROM) during upper limb neurodynamic testing (ULNT) post-BC treatment. METHODS: ULNT EE-ROM was measured for 145 women post-BC treatment. Women were sub-grouped by presence/absence of pain and lymphedema. RESULTS: Mean EE-ROM during ULNT1 was -22.3° (SD 11.9°) on the unaffected limb and -25.99° (SD 13.1°) on the affected limb. The women with pain and lymphedema had the greatest limitation in EE-ROM during ULNT1 testing, particularly of their affected limb (-33.8°, SD 12.9). Symptoms were reported more frequently in the affected chest, shoulder, arm, elbow, and hand. The intensity of symptoms was greater at the affected chest (p = 0.046), shoulder (p = 0.033) and arm (p = 0.039). CONCLUSIONS: Women with lymphedema and pain after BC treatment may present with altered neural mechanosensitivity. LEVEL OF EVIDENCE: 3a.

Differences in morning and evening fatigue in oncology patients and their family caregivers.

PURPOSE OF THE RESEARCH: To identify distinct latent classes of individuals based on ratings of morning and evening fatigue; evaluate for differences in phenotypic characteristics, as well as symptom and quality of life scores, among these latent classes; and evaluate for an overlap in morning and evening fatigue class membership. PATIENTS AND METHODS: In a sample of 167 oncology outpatients and 85 of their FCs, growth mixture modeling was used to identify distinct latent classes based on ratings of morning and evening fatigue obtained before, during, and after radiation therapy. Analyses of variance and Chi Square analyses were used to evaluate for differences among the morning and evening fatigue latent classes. RESULTS: Three distinct latent classes for morning fatigue were identified. Participants in the High Morning Fatigue class (47%) were younger and had lower functional status. Three distinct latent classes for evening fatigue were identified. Participants in the High Evening Fatigue class (61%) were younger, more likely to be female, more likely to have children at home, and more likely to be a FC. Only 10.3% of participants were classified in both the Very Low Morning and Low Evening Fatigue classes and 41.3% were classified in both the High Morning and High Evening Fatigue classes. CONCLUSIONS: Different characteristics were associated with morning and evening fatigue, which suggests that morning and evening fatigue may be distinct but related symptoms. Additional research is needed to elucidate the mechanisms that may underlie diurnal variability in fatigue.

Lymphatic and angiogenic candidate genes predict the development of secondary lymphedema following breast cancer surgery.

The purposes of this study were to evaluate for differences in phenotypic and genotypic characteristics in women who did and did not develop lymphedema (LE) following breast cancer treatment. Breast cancer patients completed a number of self-report questionnaires. LE was evaluated using bioimpedance spectroscopy. Genotyping was done using a custom genotyping array. No differences were found between patients with (n = 155) and without LE (n = 387) for the majority of the demographic and clinical characteristics. Patients with LE had a significantly higher body mass index, more advanced disease and a higher number of lymph nodes removed. Genetic associations were identified for four genes (i.e., lymphocyte cytosolic protein 2 (rs315721), neuropilin-2 (rs849530), protein tyrosine kinase (rs158689), vascular cell adhesion molecule 1 (rs3176861)) and three haplotypes (i.e., Forkhead box protein C2 (haplotype A03), neuropilin-2 (haplotype F03), vascular endothelial growth factor-C (haplotype B03)) involved in lymphangiogensis and angiogenesis. These genetic associations suggest a role for a number of lymphatic and angiogenic genes in the development of LE following breast cancer treatment.

Trajectories of sleep disturbance and daytime sleepiness in women before and after surgery for breast cancer.

CONTEXT: Sleep disturbance is a problem for oncology patients. OBJECTIVES: To evaluate how sleep disturbance and daytime sleepiness (DS) changed from before to six months following surgery and whether certain characteristics predicted initial levels and/or the trajectories of these parameters. METHODS: Patients (n=396) were enrolled prior to surgery and completed monthly assessments for six months following surgery. The General Sleep Disturbance Scale was used to assess sleep disturbance and DS. Using hierarchical linear modeling, demographic, clinical, symptom, and psychosocial adjustment characteristics were evaluated as predictors of initial levels and trajectories of sleep disturbance and DS. RESULTS: All seven General Sleep Disturbance Scale scores were above the cutoff for clinically meaningful levels of sleep disturbance. Lower performance status; higher comorbidity, attentional fatigue, and physical fatigue; and more severe hot flashes predicted higher preoperative levels of sleep disturbance. Higher levels of education predicted higher sleep disturbance scores over time. Higher levels of depressive symptoms predicted higher preoperative levels of sleep disturbance, which declined over time. Lower performance status; higher body mass index; higher fear of future diagnostic tests; not having had sentinel lymph node biopsy; having had an axillary lymph node dissection; and higher depression, physical fatigue, and attentional fatigue predicted higher DS prior to surgery. Higher levels of education, not working for pay, and not having undergone neo-adjuvant chemotherapy predicted higher DS scores over time. CONCLUSION: Sleep disturbance is a persistent problem for patients with breast cancer. The effects of interventions that can address modifiable risk factors need to be evaluated.

Cytokine gene variation is associated with depressive symptom trajectories in oncology patients and family caregivers.

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.