Psychological symptoms and disease-free and overall survival in women with stage II breast cancer. Cancer and Leukemia Group B

The link between psychological distress and survival in solid tumor patients: A systematic review

PURPOSE

Research has demonstrated that solid tumor patients experience high levels of psychological distress at the time of diagnosis. While distress has been associated with many adverse clinical outcomes, little is known about how this symptom may influence the disease trajectory for cancer patients, affecting outcomes such as progression, recurrence, and survival. The purpose of this systematic review was to explore the literature linking distress with survival in solid tumor patients, which may guide future work exploring clinical outcomes as a function of distress.

METHODS

A systematic search of PubMed, Embase, and Web of Science was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines with predefined eligibility criteria. Thirteen studies met the inclusion criteria and were selected for review.

RESULTS

Findings from this review demonstrated a weak-to-moderate relationship between cancer patients' experience of distress and overall survival, with most included studies (11/13) finding at least one predictive analysis to be significant when controlling for confounders. However, significant heterogeneity in the literature, particularly with study sample characteristics and varying methodologies, made direct comparisons across studies challenging.

CONCLUSION

Findings from this review suggest that psychological distress may have an impact on disease-related outcomes, including (but not limited to) survival. Future work should consider performing disease-specific analyses controlling for key prognostic factors to better understand the nuanced relationship between distress and clinical outcomes, which may allow further understanding of the biological underpinnings of this relationship and enable the development of targeted interventions for improving distress.

Modulation of anti-tumor immunity by the brain's reward system

Regulating immunity is a leading target for cancer therapy. Here, we show that the anti-tumor immune response can be modulated by the brain's reward system, a key circuitry in emotional processes. Activation of the reward system in tumor-bearing mice (Lewis lung carcinoma (LLC) and B16 melanoma) using chemogenetics (DREADDs), resulted in reduced tumor weight. This effect was mediated via the sympathetic nervous system (SNS), manifested by an attenuated noradrenergic input to a major immunological site, the bone marrow. Myeloid derived suppressor cells (MDSCs), which develop in the bone marrow, became less immunosuppressive following reward system activation. By depleting or adoptively transferring the MDSCs, we demonstrated that these cells are both necessary and sufficient to mediate reward system effects on tumor growth. Given the central role of the reward system in positive emotions, these findings introduce a physiological mechanism whereby the patient's psychological state can impact anti-tumor immunity and cancer progression.

Mortality, cancer incidence, and survival in parents after bereavement

PURPOSE

The study objective was to investigate whether child loss is related to mortality, cancer incidence, and cancer survival in parents.

METHODS

We used a population-based birth cohort (1964-1976) in Jerusalem and ascertained mortality (average follow-up of 39.1 years) and any cancer (average follow-up of 35.6 years) among parents who lost a child (2838 mothers and 2532 fathers) and among nonbereaved parents (38,212 mothers and 36,433 fathers). We also assessed mortality among parents with cancer. Time-dependent Cox models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Overall mortality rates among bereaved parents were modestly increased when compared with nonbereaved parents (HR = 1.18, 95% CI: 1.05-1.32 in mothers; HR = 1.10, 95% CI: 1.01-1.20 in fathers). Hazard models indicated a significant relationship between bereavement and deaths from coronary heart disease in mothers (HR = 1.90, 95% CI: 1.23-2.95) and circulatory causes in both parents (HR = 1.69; 95% CI: 1.22-2.34 in mothers and HR = 1.25; 95% CI: 1.02-1.54 in fathers). Bereavement was not associated with parental risk of cancer disease and with survival from cancer. The association between bereavement and parental overall mortality was similar in the different parental sociodemographic characteristics. We observed a decrease in HRs for parental mortality associated with bereavement, with increasing time since the death of the child (HRs = 9-10, 0-3 years; HRs = 0.9-1.0, 9+ years; P(heterogeneity) ≤ 3 × 10(-32)). A similar decrease in HRs was observed for parental survival from cancer (HRs = 6.7-8.7, 0-3 years; HRs = 0.9-1.0, 9+ years).

CONCLUSIONS

Our study suggests that child loss was associated with slightly increased risk of all-cause and circulatory mortality in parents but not with incidence of cancer and cancer survival. The considerable increased parental mortality during a short period after child loss support the involvement of pathways related to psychological stress.

The Prognostic Value of Patient-Reported Outcome Data in Patients With Colorectal Hepatic Metastases Who Underwent Surgery

INTRODUCTION

Patient-reported outcomes (PROs) are critical to evaluate clinically effective treatments and evidence suggests that PROs might predict survival. The prognostic value of PROs in patients with isolated liver metastases from colorectal cancer (CRC) who undergo surgery is unclear. In this study we investigated whether baseline PROs are prognostic in this patient group.

PATIENTS AND METHODS

From April 2004 to May 2007, consecutive patients who underwent curative resection of CRC liver metastases completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ)-C30 and QLQ-LMC21 questionnaires before surgery. Patients were followed until death or data were censored on April 9, 2012. Cox proportional hazards models were used to assess the effect of PROs on survival controlling for predefined clinical covariates. Models were simplified using a backwards stepwise approach and model utility appraised using the Harrell C and Somers D statistics and bootstrap methods.

RESULTS

Two hundred thirty-two patients underwent liver resection and 101 (43.5%) survived 5 years. Multivariate analysis controlling for relevant clinical covariates showed that a 10-point improvement in baseline global quality of life scores was associated with a 54% improvement in survival (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.33-0.63; P < .001), and a clinically significant weight loss was associated with 75% worse survival (HR, 1.75; 95% CI, 1.20-2.55; P = .004). Smaller effects were noted for worsening abdominal pain, taste problems, and fatigue (30%-38% poorer survival). Results of bootstrap resampling suggested that global health and weight loss most reliably predicted survival.

CONCLUSION

Results of this study demonstrated that patients who reported worse baseline global quality of life and increased weight loss before liver resection for CRC liver metastases had significantly poorer survival. These findings if externally validated might be used to inform patients, and could also influence treatment planning and advise follow-up strategies and supportive care.

Depression and Anxiety Disorders among Hospitalized Women with Breast Cancer

PURPOSE

To document the prevalence of depression and anxiety disorders, and their associations with mortality among hospitalized breast cancer patients.

METHODS

We examined the associations between breast cancer diagnosis and the diagnoses of anxiety or depression among 4,164 hospitalized breast cancer cases matched with 4,164 non-breast cancer controls using 2006-2009 inpatient data obtained from the Nationwide Inpatient Sample database. Conditional logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CI) for the associations between breast cancer diagnosis and diagnoses of anxiety or depression. We also used binary logistic regression models to examine the association between diagnoses of depression or anxiety, and in-hospital mortality among breast cancer patients.

RESULTS

We observed that breast cancer cases were less likely to have a diagnosis of depression (OR=0.63, 95% CI: 0.52-0.77), and less likely to have a diagnosis of anxiety (OR=0.68, 95% CI: 0.52-0.90) compared with controls. This association remained after controlling for race/ethnicity, residential income, insurance and residential region. Breast cancer patients with a depression diagnosis also had lower mortality (OR=0.69, 95% CI: 0.52-0.89) compared with those without a depression diagnosis, but there was no significant difference in mortality among those with and without anxiety diagnoses.

CONCLUSION

Diagnoses of depression and anxiety in breast cancer patients were less prevalent than expected based on our analysis of hospitalized breast cancer patients and matched non-breast cancer controls identified in the NIS dataset using ICD-9 diagnostic codes. Results suggest that under-diagnosis of mental health problems may be common among hospitalized women with a primary diagnosis of breast cancer. Future work may fruitfully explore reasons for, and consequences of, inappropriate identification of the mental health needs of breast cancer patients.

Perioperative comprehensive supportive care interventions for chinese patients with esophageal carcinoma: a prospective study

OBJECTIVE

To assess the effects of perioperative comprehensive supportive care interventions on outcome of Chinese esophageal cancer patients in a prospective study.

METHODS

60 patients with primary esophageal carcinoma were randomized into an intervention group (IG, n=31) and a control group (CG, n=29). The Chinese version of symptom checklist-90 (SCL-90) was adopted to assess their psychological status. The interventions, including health education, psychological support, stress management, coping strategies and behavior training, were carried out in 3 phases (preoperative, postoperative I and postoperative II), and psychological effects were thereafter evaluated accordingly before surgery, and 1 week, 4 weeks and 24 weeks post-surgery. Medical costs were estimated at discharge. Survival of patients was estimated each year post-surgery. General health status and satisfaction-with-hospital were surveyed by a follow-up questionnaire 4 years post-surgery.

RESULTS

All the subjects demonstrated higher scores in the preoperative phase than the normal range of Chinese population concerning 7 psychological domains including somatization, obsessive-compulsive, depression, anxiety, hostility, phobic anxiety and paranoid ideation. Although no significant difference was observed between the two groups at admission, the scores of IG, which tended to decrease at a faster rate, were generally lower than those of CG at weeks 1, 4 and 24 post-surgery. The length of hospital stay and medical costs of IG were significantly less than those of CG and satisfaction-with-hospital was better. However, there was no significant difference in 4-year survival or health status between two groups.

CONCLUSIONS

Appropriate perioperative comprehensive supportive care interventions help to improve the psychological state of Chinese patients with esophageal carcinoma, to reduce health care costs and to promote satisfaction of patients and their families with hospital.

Psychiatric and psychosocial challenges in patients undergoing haematopoietic stem cell transplants

Haematological malignancies are often treated with haematopoietic stem cell transplants (HSCT). The disease and its treatment are challenging and life threatening, as they not only affect the recipients, but also their families. This review highlights the available data on the psychological, psychiatric and social impact of these illnesses and their treatment on recipients and families. There are robust data that correlate HSCT with emotional distress, as emotional and physical functioning significantly affect quality of life. Psychiatric co-morbidity including anxiety, depression, adjustment and post-traumatic stress disorder, delirium and cognitive deficits have been reported at different stages in the transplant process. This review will highlight the psychosocial and clinical research findings relevant to HSCT patients and will summarize recommendations for future psychosocial research in this population.

Prospective associations of depression with survival: a population-based cohort study in patients with newly diagnosed breast cancer

Psychological factors may influence survival in breast cancer patients but results of previous research are inconclusive. This prospective population-based study tested whether depression predicts mortality in breast cancer patients. Routinely collected depression screening data were merged with electronically archived provincial cancer registry data and censored data from British Columbia Vital Statistics (extracted in December 2012). Cox proportional-hazards regression analyses were conducted to predict all-cause and breast cancer-specific mortality as a function of depression after controlling for biomedical confounders. Of 1,646 patients, 1,604 had breast cancer stages I-III and 42 had stage IV breast cancer. 176 (11.0 %) versus 28 (66.7 %) were deceased after a median follow-up of 76 months. In patients with curable breast cancer, depression predicted all-cause (HR = 1.54 (95 % CI 1.06-2.25); p = 0.024), but not breast cancer-specific mortality (HR = 1.51 (95 % CI 0.95-2.41); p = 0.084). No association was shown for metastatic disease. Stage-specific analyses demonstrated a 2-2.5-fold increase in breast cancer-specific and all-cause mortality in patients with stage I and II disease, but not in patients with stage III or IV breast cancer. In stage I breast cancer patients, age moderated effects of depression such that depressed younger patients diagnosed at age 45 (i.e., mean age -1SD) showed a ninefold (HR = 9.82 (95 % CI 2.26-42.68); p = 0.002) increase in all-cause mortality and depressed patients at 57 a 3.7-fold (HR = 3.69 (95 % CI 1.44-9.48); p = 0.007) increase, while no association was evident in older patients at age 69 (mean age +1SD). Depression is strongly associated with mortality in younger patients with early stage breast cancer.

Does the Brief Symptom Inventory-18 case rule apply in adult survivors of childhood cancer? Comparison with the Symptom Checklist-90

OBJECTIVE

Screening for psychological distress is an important tool for improving survivors' access to psychosocial care. The Brief Symptom Inventory-18 (BSI-18) has been widely used to identify psychological distress in cancer survivors, but few studies have reported on its validity. This study evaluated validity of the BSI-18 by comparing it to the Symptom Checklist-90 (SCL-90).

METHODS

Concordance of cases identified by the BSI-18 and SCL-90 was examined in a sample of 193 adult survivors of childhood cancer.

RESULTS

Receiver operating characteristics analysis showed strong diagnostic utility of the BSI-18 (area under curve = 0.922). However, the standard BSI-18 case-rule demonstrated low sensitivity (45.2%) against the SCL-90. An alternative case-rule showed better results; sensitivity (87.10%), specificity (83.33%).

CONCLUSIONS

The BSI-18 is a useful measure for evaluating distress in adult survivors of childhood cancers; however, the standard BSI-18 case-rule has not been validated for this population, and an alternative case rule should be considered.

Depression and mortality in end-stage renal disease

End-stage renal disease is growing in prevalence and incidence. With technical advancements, patients are living longer on hemodialysis. Depression is the most prevalent comorbid psychiatric condition, estimated at about 25% of end-stage renal disease samples. The identification and assessment of depression are confounded by the overlap between depression symptomatology and uremia. Several recent studies have employed time-varying models and identified a significant association between depression and mortality. Due to the high prevalence of depression and the potential impact on survival, well-constructed investigations are warranted.

Decrease in depression symptoms is associated with longer survival in patients with metastatic breast cancer: a secondary analysis

PURPOSE

Numerous studies have examined the comorbidity of depression with cancer, and some have indicated that depression may be associated with cancer progression or survival. However, few studies have assessed whether changes in depression symptoms are associated with survival.

METHODS

In a secondary analysis of a randomized trial of supportive-expressive group therapy, 125 women with metastatic breast cancer (MBC) completed a depression symptom measure (Center for Epidemiologic Studies-Depression Scale [CES-D]) at baseline and were randomly assigned to a treatment group or to a control group that received educational materials. At baseline and three follow-up points, 101 of 125 women completed a depression symptom measure. We used these data in a Cox proportional hazards analysis to examine whether decreasing depression symptoms over the first year of the study (the length of the intervention) would be associated with longer survival.

RESULTS

Median survival time was 53.6 months for women with decreasing CES-D scores over 1 year and 25.1 months for women with increasing CES-D scores. There was a significant effect of change in CES-D over the first year on survival out to 14 years (P = .007) but no significant interaction between treatment condition and CES-D change on survival. Neither demographic nor medical variables explained this association.

CONCLUSION

Decreasing depression symptoms over the first year were associated with longer subsequent survival for women with MBC in this sample. Further research is necessary to confirm this hypothesis in other samples, and causation cannot be assumed based on this analysis.

Added value of health-related quality of life measurement in cancer clinical trials: the experience of the NCIC CTG

Health-related quality-of-life (HRQoL) data are often included in Phase III clinical trials. We evaluate and classify the value added to Phase III trials by HRQoL outcomes, through a review of the National Cancer Institute of Canada Clinical Trials Group clinical trials experience within various cancer patient populations. HRQoL may add value in a variety of ways, including the provision of data that may contrast with or may support the primary study outcome; or that assess a unique perspective or subgroup, not addressed by the primary outcome. Thus, HRQoL data may change the study's interpretation. Even in situations where HRQoL measurement does not alter the clinical interpretation of a trial, important methodologic advances can be made. A classification of the added value of HRQoL information is provided, which may assist in choosing trials for which measurement of HRQoL outcomes will be beneficial.

Health-related quality of life assessment in prospective trials of systemic cytotoxic chemotherapy for metastatic castration-resistant prostate cancer: which instrument we need?

Knowledge about psychological health of men with prostate cancer is still limited. HRQoL assessment adds value in symptom management by allowing a broader understanding of the impact of symptom management beyond the targeted symptom, on functioning, and on overall QoL. In this paper, the results of the commonly used HRQoL questionnaires in phase III randomized clinical trials of chemotherapy in metastatic castration-resistant prostate cancer has been discussed. An overview about symptom burden, treatments and HRQoL domains, a description of available HRQoL instruments used for patients with metastatic castration-resistant prostate cancer were reported. Finally, the characteristics of most commonly used HRQoL instruments were identified and compared. To provide better empirical justification for the selection of HRQoL instruments, head-to-head comparisons of them within the same studies are needed. Estimating a minimal important difference could be significant when interpreting trial results. The impact of HRQoL scores in clinical practice remains unclear; poor communication of clinical significance of the results and limited training of clinicians are the most important barriers to a widespread use of HRQoL questionnaires.

Quality of life data as prognostic indicators of survival in cancer patients: an overview of the literature from 1982 to 2008

BACKGROUND

Health-related quality of life and survival are two important outcome measures in cancer research and practice. The aim of this paper is to examine the relationship between quality of life data and survival time in cancer patients.

METHODS

A review was undertaken of all the full publications in the English language biomedical journals between 1982 and 2008. The search was limited to cancer, and included the combination of keywords 'quality of life', 'patient reported-outcomes' 'prognostic', 'predictor', 'predictive' and 'survival' that appeared in the titles of the publications. In addition, each study was examined to ensure that it used multivariate analysis. Purely psychological studies were excluded. A manual search was also performed to include additional papers of potential interest.

RESULTS

A total of 451 citations were identified in this rapid and systematic review of the literature. Of these, 104 citations on the relationship between quality of life and survival were found to be relevant and were further examined. The findings are summarized under different headings: heterogeneous samples of cancer patients, lung cancer, breast cancer, gastro-oesophageal cancers, colorectal cancer, head and neck cancer, melanoma and other cancers. With few exceptions, the findings showed that quality of life data or some aspects of quality of life measures were significant independent predictors of survival duration. Global quality of life, functioning domains and symptom scores - such as appetite loss, fatigue and pain - were the most important indicators, individually or in combination, for predicting survival times in cancer patients after adjusting for one or more demographic and known clinical prognostic factors.

CONCLUSION

This review provides evidence for a positive relationship between quality of life data or some quality of life measures and the survival duration of cancer patients. Pre-treatment (baseline) quality of life data appeared to provide the most reliable information for helping clinicians to establish prognostic criteria for treating their cancer patients. It is recommended that future studies should use valid instruments, apply sound methodological approaches and adequate multivariate statistical analyses adjusted for socio-demographic characteristics and known clinical prognostic factors with a satisfactory validation strategy. This strategy is likely to yield more accurate and specific quality of life-related prognostic variables for specific cancers.

Cancer survivorship research: the challenge of recruiting adult long term cancer survivors from a cooperative clinical trials group

Introduction

With the growing number of adult cancer survivors, there is increasing need for information that links potential late and long term effects with specific treatment regimens. Few adult cancer patients are treated on clinical trials; however, patients previously enrolled in these trials are an important source of information about treatment-related late effects.

Methods

Focusing on colorectal cancer survivors, we used the database from five phase III randomized clinical trials from the National Surgical Adjuvant Breast & Bowel Project (NSABP) to recruit and enroll long term survivors in a study of late health outcomes and quality of life. We describe the challenges to recruitment of patients more than 5 –20 years after treatment.

Results

Sixty-five NSABP treatment sites were invited to enroll patients in the study. Sixty participated with the potential to recruit 2,408 patients. We received registration forms on only 976 patients (41%) of whom 744 (76%) expressed interest in participating and 708 completed interviews (95% of those expressing interest; 29% of total potential sample). There were multiple barriers to recruitment (difficulty locating patients, lack of institutional commitment, lack of patient interest).

Conclusions

Patients treated on clinical trials are an important potential source for examining the late effects of cancer treatments. Retrospective recruitment has substantial limitations. In the future, mechanisms should be established for prospective long-term follow-up to identify and understand the frequency and type of late effects associated with cancer treatments.

Implications for Cancer Survivors

As cancer patients are living longer, it will be important to learn from participants in clinical trials whether or not specific treatment regimens are associated with any serious late effects.

Health-related quality of life as a survival predictor for patients with localized head and neck cancer treated with radiation therapy

PURPOSE

To assess the added prognostic value for overall survival (OS) of baseline health-related quality of life (HRQOL) and of early changes in HRQOL among patients with localized head and neck cancer (HNC) treated with radiation therapy.

PATIENTS AND METHODS

All 540 patients with HNC who participated in a randomized trial completed two HRQOL instruments before radiation therapy: the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and the Head and Neck Radiotherapy Questionnaire. Six months after the end of radiation therapy, 497 trial participants again completed the two HRQOL instruments. During the follow-up, 179 deaths were observed. Multivariate Cox proportional hazards models were used to test whether HRQOL variables, baseline and change, provided additional prognostic value beyond recognized prognostic factors.

RESULTS

The baseline EORTC QLQ-C30 physical functioning (PF) score was an independent predictor of OS. The hazard ratio (HR) associated with a 10-point increment in baseline PF was 0.87 (95% CI, 0.81 to 0.94). In multivariate models, the change in HRQOL was significantly associated with OS for most HRQOL dimensions. Among these, PF change was the strongest predictor. The magnitude of the association between PF change and survival decreased over time. At 1 year, the HR associated with a positive PF change of 10 points was 0.75 (95% CI, 0.68 to 0.83). After PF is taken into account, no other HRQOL variable was associated with survival.

CONCLUSION

Our findings indicate that both baseline PF and PF change provide added prognostic value for OS beyond established predictors in patients with HNC. Assessing HRQOL could help better predict survival of cancer patients.

A biobehavioral model for the study of exercise interventions in cancer-related fatigue

Cancer-related fatigue (CRF) is a multifactorial, biobehavioral phenomenon experienced by the majority of persons with cancer. It has negative consequences on the individual's physical functioning and quality of life. An array of biological, psychobehavioral, and functional mechanisms contributes to its occurrence. A relatively large number of studies have examined the effect of physical exercise on CRF over the past few decades. Most of these studies did not specifically examine the effect of physical exercise on the biobehavioral mechanisms underlying CRF. For the most part, these studies have not been guided by a consistent theoretical model. Consequently, the mechanisms by which exercise may ameliorate CRF are not fully elucidated. A theoretical model incorporating fatigue-related biobehavioral variables that could be affected by physical exercise will allow for effective knowledge development in this area and could lead to the development and refinement of exercise protocols that specifically target these mechanisms. Thus, the purpose of this paper is to present a comprehensive theoretical model to guide future research on the effectiveness of exercise interventions in CRF. The proposed model incorporates the biological, psychobehavioral, and functional variables implicated in the induction of CRF.

Anxiolytic effects of a yoga program in early breast cancer patients undergoing conventional treatment: a randomized controlled trial

OBJECTIVES

This study compares the anxiolytic effects of a yoga program and supportive therapy in breast cancer outpatients undergoing conventional treatment at a cancer centre.

METHODS

Ninety-eight stage II and III breast cancer outpatients were randomly assigned to receive yoga (n=45) or brief supportive therapy (n=53) prior to their primary treatment i.e., surgery. Only those subjects who received surgery followed by adjuvant radiotherapy and six cycles of chemotherapy were chosen for analysis following intervention (yoga, n=18, control, n=20). Intervention consisted of yoga sessions lasting 60min daily while the control group was imparted supportive therapy during their hospital visits as a part of routine care. Assessments included Speilberger's State Trait Anxiety Inventory and symptom checklist. Assessments were done at baseline, after surgery, before, during, and after radiotherapy and chemotherapy.

RESULTS

A GLM-repeated measures ANOVA showed overall decrease in both self-reported state anxiety (p<0.001) and trait anxiety (p=0.005) in yoga group as compared to controls. There was a positive correlation between anxiety states and traits with symptom severity and distress during conventional treatment intervals.

CONCLUSION

The results suggest that yoga can be used for managing treatment-related symptoms and anxiety in breast cancer outpatients.

Explaining inconsistent results in cancer quality of life studies: the role of the stress-response system

This study tests the hypothesis that avoidance and intrusion play different roles in health-related quality of life (QoL) in women who have undergone breast cancer surgery. We assessed QoL (RAND-36), avoidance, intrusion, and total cancer-related distress (Impact of Event Scale) in 83 women at 3, 6, 9, and 12 months after mastectomy. Social functioning and role limitations improved over time; physical functioning, general health, and mental health did not change; vitality initially improved followed by a decrease to a below initial level; physical pain initially improved followed by a decrease to an above initial level. Cancer-related distress remained high during follow-up. Individual variation in QoL as assessed across the four measurement times was associated with individual variation in intrusion but not with individual variation in avoidance. Baseline intrusion did not predict the subsequent course of QoL but high initial avoidance was associated with an unfavourable time course in physical functioning, social functioning, and general health. Hence, variation in intrusion over time explains variation in QoL while baseline avoidance predicts the subsequent course of QoL. The findings provide new insight into the relationship between the stress-response system in QoL and women with breast cancer.

The effect of psychosocial factors on breast cancer outcome: a systematic review

Introduction

We sought to review the available evidence regarding the effect of psychosocial factors on the survival of breast cancer patients.

Methods

We systematically searched the PubMed and PsycINFO databases to identify relevant studies.

Results

We identified 31 studies examining the association of various psychosocial parameters with overall breast cancer survival/disease free survival and 6 studies examining whether psychological intervention influences the disease outcome. Of the 31 studies summarized in this overview, 25 (80.6%) showed a statistically significant association between at least one psychosocial variable and disease outcome. Parameters associated with better breast cancer prognosis are social support, marriage, and minimizing and denial, while depression and constraint of emotions are associated with decreased breast cancer survival; however, the role of these factors has not been verified in all studies.

Conclusion

Most of the studies show a significant relationship between psychosocial factors and survival, but the actual psychosocial variables related to survival are not consistently measured across studies and the findings for many of the psychosocial variables with survival/recurrence are not consistent across studies. Thus, more research is warranted regarding the role of social support, marriage, minimizing and denial, depression and constraint of emotions on breast cancer survival.

The prognostic significance of patient-reported outcomes in cancer clinical trials

PURPOSE

Patient-reported outcomes (PROs), routinely collected as a part of cancer clinical trials, have been linked with survival in numerous clinical studies, but a comprehensive critical review has not been reported. This study systematically assessed the impact of PROs on patient survival after a cancer diagnosis within the context of clinical trials.

DESIGN

Cancer clinical trials that assessed baseline PROs and mortality were identified through MEDLINE (through December 2006) supplemented by the Cochrane database, American Society of Clinical Oncology/European Society for Medical Oncology abstracts and hand searches. Inclusion criteria were publication in English language and use of multivariate analyses of PROs that controlled for one or more clinical factors. Two raters reviewed each study, abstracted data, and assessed study quality; two additional raters verified abstractions.

RESULTS

In 36 of 39 studies (N = 13,874), at least one PRO was significantly associated with survival (P < .05) in multivariate analysis, with varying effect sizes. Studies of lung (n = 12) and breast cancer (n = 8) were most prevalent. The most commonly assessed PRO was quality of life, measured by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 in 56% of studies. Clinical variables adjusted for included performance status (PS), treatment arm, stage, weight loss, and serum markers. Results indicated that PROs provide distinct prognostic information beyond standard clinical measures in cancer clinical trials.

CONCLUSION

PROs might be considered for stratification purposes in future trials, as they were often better predictors of survival than PS. Studies are needed to determine whether interventions that improve PROs also increase survival and to identify explanatory mechanisms through which PROs relate to survival.

Close relationships and emotional processing predict decreased mortality in women with breast cancer: preliminary evidence

OBJECTIVE

To examine close relationships and emotional processing as predictors of breast cancer mortality.

METHODS

Ninety women were enrolled at 14 +/- 5 months after diagnosis of Stage II/III breast cancer. The Nottingham Prognostic Index (NPI) quantified disease severity. Cox proportional hazards analyses were used to predict mortality using standardized variables.

RESULTS

Twenty-one subjects developed recurrent disease and 16 died during an 8-year follow-up. NPI predicted increased mortality: risk ratio (RR) = 1.60 (CI = 1.05-2.41). Decreased mortality was predicted by confiding marriage (CONF): RR = 0.31 (CI = 0.10-0.99), and number of dependable, nonhousehold supports (SUPP): RR = 0.41 (CI = 0.21-0.80). A composite measure of close relationships (standardized CONF + SUPP = SUPPCONF) had a strong protective effect: RR = 0.30 (CI = 0.13-0.69). Two emotion processing variables, acceptance of emotion and emotional distress (POMS-TOT) were found to be negatively correlated (r = -.49). Acceptance of emotion predicted decreased mortality (RR = 0.46 (CI = 0.24-0.86)) when analyzed together with emotional distress, but not separately. There was a trend for a protective effect of emotional distress: RR = 0.37 (CI = 0.12-1.09) in the same analysis. RRs for mortality in a multivariable analysis were: SUPPCONF: RR = 0.55 (CI = 0.30-1.00); acceptance of emotion: RR = 0.48 (CI = 0.25-0.91); and emotional distress: RR = 0.40 (CI = 0.14-1.19).

CONCLUSIONS

Two aspects of close relationships--marital confiding and dependable, nonhousehold supports--were protective against breast cancer progression. Acceptance of emotion, after controlling for emotional distress, also predicted decreased mortality. Analysis of close relationships together with emotion processing variables suggested unique protective effects against mortality, but a larger study is necessary to determine whether this is the case.

Psychological distress and fatigue predicted recurrence and survival in primary breast cancer patients

This study examined whether psychological distress in newly diagnosed breast cancer patients was associated with their survival. We analyzed data from 1,588 breast cancer patients who filled in the EORTC QLQ-C30 questionnaire and the Hospital Anxiety and Depression Scale (HADS) 2 months after their primary operation. The median follow-up time was 12.9 years. Psychological distress (EORTC QLQ-C30 emotional function; HADS anxiety; HADS depression) and EORTC fatigue, physical function, and overall ratings were used to predict recurrence-free and overall survival, controlling for the known clinical and histopathological prognostic factors (biological model) using Cox multivariate regression analysis. Low levels of psychological distress (good EORTC emotional function) and low fatigue independently predicted longer recurrence-free and overall survival, controlling for biological factors. Lack of anxiety (HADS) also predicted longer recurrence-free survival. When added in combination to the biological model, fatigue remained a significant predictor of recurrence-free survival (P = 0.0004; risk ratio 1.32 (1.13-1.54)) and emotional function remained a significant predictor of overall survival (P = 0.0074; risk ratio 0.81 (0.70-0.95)). Low psychological distress and a low level of fatigue may cause a greater cancer resistance or may reflect underlying mental and physical robustness.

Temporal factors alter effects of social housing conditions on responses to chemotherapy and hormone levels in a Shionogi mammary tumor model

OBJECTIVE

To identify possible hormonal factors involved in the differential responses to chemotherapy observed in our tumor model, we investigated if the timing among tumor cell injection, rehousing, and chemotherapy administration differentially affects levels of corticosterone (CORT), growth hormone (GH), and testosterone and tumor and host responses to chemotherapy.

METHODS

Mice were reared either individually (I) or in groups (G). At 2 to 4 months, mice were injected with tumor cells and retained in their original housing conditions or rehoused into different experimental groups (GG, IG, II, GI) either immediately (experiment 1) or 14 days later (experiment 2); chemotherapy was administered when tumors weighed approximately 0.8 g.

RESULTS

In experiment 1, IG and GG mice had better responses to chemotherapy than GI mice. Chemotherapy increased CORT levels in II mice and decreased GH levels in GI mice compared with those of their drug vehicle-treated counterparts. Under the temporal conditions of experiment 2, IG and GG mice lost the advantage seen in experiment 1 in terms of tumor and host responses to chemotherapy. Before chemotherapy administration, CORT levels in IG mice and GH levels in GI mice were higher than those in mice in all other housing conditions. At 1 day after chemotherapy, CORT levels were higher for chemotherapy-treated than for drug vehicle-treated IG mice, and at 5 days post chemotherapy, GH levels were higher in GI than in IG mice.

CONCLUSIONS

Temporal relationships among tumor cell injection, rehousing, and chemotherapy administration critically influence responses to chemotherapy; these effects may be mediated, in part, by alterations in hormone levels.

The Diagnosis of Major Depression in Patients With Cancer: A Comparative Approach

Depressive symptoms not only impair quality of life in cancer patients but constitute an independent risk factor for increased mortality. In order to accurately and efficiently identify depression in cancer patients, the authors developed a biostatistical strategy to identify items of the 21-item, observer-rated Hamilton Rating Scale for Depression (Ham-D) that would optimize the diagnosis of depression among cancer patients. Exhibiting a relatively high sensitivity and specificity, our most optimal diagnostic tool contained six Ham-D items (late insomnia, agitation, psychic anxiety, diurnal mood variation, depressed mood, and genital symptoms). This study may serve as a prototype to generate valid instruments accurate for the diagnosis of major depression in other populations of cancer patients.

Effect of depression on all-cause mortality in adults with cancer and differential effects by cancer site

OBJECTIVE

The objective of this study was to compare the effect of depression on the risk of death in adults with and without cancer and by specific cancer site among those with cancer.

RESEARCH DESIGN AND METHODS

We analyzed data on 10,025 participants in the population-based National Health and Nutrition Examination Survey (NHANES) 1 Epidemiologic Follow-up Study. Four groups were created based on cancer and depression status in 1982: (a) no cancer, no depression (reference group; no CA, no DEP); (b) depression but no cancer (DEP, no CA); (c) cancer but no depression (CA, no DEP); and (d) cancer and depression (CA+DEP). Six CA sites were defined: lung, breast, gastrointestinal (GI), genitourinary (GU), skin and other. Cox proportional models were used to calculate adjusted hazard for death for each group compared with the reference group and by cancer site.

RESULTS

Over 8 years (78,433 person-years of follow-up), 1925 deaths were documented. The mortality rate per 1000 person-years of follow-up was highest in the CA+DEP group. Compared to the reference group, the hazard ratios (HRs) for all-cause mortality were as follows: CA, no DEP: 1.43 [95% confidence interval (95% CI)=1.23-1.67]; DEP, no CA: 1.44 (95% CI=1.28-1.63); CA+DEP: 1.87 (95% CI=1.49-2.34). HRs for depression by site were as follows: lung: 1.30 (95% CI=0.49-3.99); breast: 1.27 (95% CI=0.58-2.79); GI: 1.47 (95% CI=0.58-3.75); GU: 0.93 (95% CI=0.50-1.74); skin: 1.07 (95% CI=0.67-1.69); other: 2.13 (95% CI=0.55-8.25).

CONCLUSION

The coexistence of cancer and depression is associated with a significantly increased risk of death, and the effect of depression on the risk of death differs by cancer site.

Is baseline quality of life useful for predicting survival with hormone-refractory prostate cancer? A pooled analysis of three studies of the European Organisation for Research and Treatment of Cancer Genitourinary Group

PURPOSE

Patients with symptomatic metastatic hormone-resistant prostate cancer (HRPC) survive a median of 10 months and are often regarded as a homogeneous group. Few prognostic factors have been identified so far. We examined whether baseline health-related quality of life (HRQOL) parameters assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) were independent prognostic factors of survival and whether they bring extra precision to the predictions achievable with models based on clinical and biochemical factors only.

PATIENTS AND METHODS

Data of 391 symptomatic (bone) metastatic HRPC patients from three randomized EORTC trials were used in multivariate Cox proportional hazards models. The significance level was set at alpha =.05.

RESULTS

Of the 391 patients, 371 died, most of prostate cancer. Bone scan result, performance status, hemoglobin level, and insomnia and appetite loss as measured by the EORTC QLQ-C30 were independent predictors of survival. This model's area under the receiver operating curve was 0.65 compared with 0.63 without the two HRQOL factors.

CONCLUSION

Certain HRQOL sores, at baseline, seem to be predictors for duration of survival in HRPC. However, such measurements do not add to the predictive ability of models based only on clinical and biochemical factors.

Outcomes research in cancer clinical trial cooperative groups: the RTOG model

BACKGROUND

The Radiation Therapy Oncology Group (RTOG), a National Cancer Institute sponsored cancer clinical trials research cooperative, has recently formed an Outcomes Committee to assess a comprehensive array of clinical trial endpoints and factors impacting the net effect of therapy.

METHODS

To study outcomes in a consistent, comprehensive and coordinated manner, the RTOG Outcomes Committee developed a model to assess clinical, humanistic, and economic outcomes important in clinical trials.

RESULTS

This paper reviews how the RTOG incorporates outcomes research into cancer clinical trials, and demonstrates utilization of the RTOG Outcomes Model to test hypotheses related to non-small-cell lung cancer (NSCLC). In this example, the clinical component of the model indicates that the addition of chemotherapy to radiotherapy (RT) improves survival but increases the risk of toxicity. The humanistic component indicates that esophagitis is the symptom impacting quality of life the greatest and may outweigh the benefits in elderly (> or =70 years) patients. The economic component of the model indicates that accounting for quality-adjusted survival, concurrent chemoRT for the treatment of NSCLC is within the range of economically acceptable recommendations.

CONCLUSION

The RTOG Outcomes Model guides a comprehensive program of research that systematically measures a triad of endpoints considered important to clinical trials research.

Health-Related Quality of Life Parameters As Prognostic Factors in a Nonmetastatic Breast Cancer Population: An International Multicenter Study

Purpose

The purpose of this research was to evaluate whether baseline health-related quality of life (HRQOL) parameters are prognostic factors for survival in locally advanced breast cancer patients. Although the literature highlights the important role of HRQOL parameters in predicting survival in advanced metastatic disease, little evidence exists for earlier stages.

Patients and Methods

The overall sample consisted of 448 patients randomly assigned to receive cyclophosphamide, epirubicin, and fluorouracil versus epirubicin, cyclophosphamide, and granulocyte colony-stimulating factor. Patients were enrolled in 12 countries. HRQOL baseline scores were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. The Cox proportional hazards regression model was used for both univariate and multivariate analyses of survival. In addition, a bootstrap resampling technique was used to assess the stability of the outcomes. Bootstrap results were then applied for model averaging purposes as a means to account for the observed model selection uncertainty.

Results

The final multivariate model retained inflammatory breast cancer (T4d) as the only factor predicting overall survival (OS) with a hazard ratio of 1.375 (95% CI, 1.027 to 1.840; P = .03). The presence of inflammatory breast cancer lowers the median survival time from 6.6 to 4.2 years (36% reduction). None of the preselected HRQOL variables were prognostic for OS or disease-free survival, in either the univariate or multivariate analysis.

Conclusion

Our findings suggest that baseline HRQOL parameters have no prognostic value in a nonmetastatic breast cancer population.

Psychological factors and cancer development: Evidence after 30 years of research

The question whether psychological factors affect cancer development has intrigued both researchers and patients. This review critically summarizes the findings of studies that have tried to answer this question in the past 30 years. Earlier reviews, including meta-analyses, covered only a limited number of studies, and included studies with a questionable design (group-comparison, cross-sectional or semiprospective design). This review comprises only longitudinal, truly prospective studies (N=70). It was concluded that there is not any psychological factor for which an influence on cancer development has been convincingly demonstrated in a series of studies. Only in terms of 'an influence that cannot be totally dismissed,' some factors emerged as 'most promising': helplessness and repression seemed to contribute to an unfavorable prognosis, while denial/minimizing seemed to be associated with a favorable prognosis. Some, but even less convincing evidence, was found that having experienced loss events, a low level of social support, and chronic depression predict an unfavorable prognosis. The influences of life events (other than loss events), negative emotional states, fighting spirit, stoic acceptance/fatalism, active coping, personality factors, and locus of control are minor or absent. A methodological shortcoming is not to have investigated the interactive effect of psychological factors, demographic, and biomedical risk factors.

Immune function and adjustment style: do they predict survival in breast cancer?

The aim of this study was to investigate the role of immune status and psychosocial factors in survival from early breast cancer (N=61). Baseline assessments included lymphocyte number and function, natural killer cell activity (NKA), plasma cortisol and prolactin level. Psychosocial measures included anxiety, depression and mental adjustment to cancer and social support. Length of follow-up was 6.1-7.9 years with 14 (23%) breast cancer deaths. In Cox proportional hazards models adjusting for lymph node status two parameters predicted longer survival, low NKA (HR 29 per LLU, p=0.003) and minimizing the illness adjustment (HR 0.64 per scale point, p=0.012). These data provide little evidence for a psychoneuroimmunological mechanism in the survival from breast cancer. While this study is limited due to small sample size, and therefore the possibility of inflated estimates, longer survival in those minimizing the illness is a finding consistent with recent studies; however, the counter-intuitive finding that high NKA predicts shorter survival may be a marker for current disease or response to treatments.

Cancer supportive care, improving the quality of life for cancer patients. A program evaluation report

GOALS OF WORK

As medical care for cancer has become more specialized in diagnosis, treatment has become more technical and fragmented. In order to help cancer patients and their families, we developed a coordinated program called the Stanford Cancer Supportive Care Program (SCSCP) at the Center for Integrative Medicine at Stanford Hospital and Clinics. The Stanford Cancer Supportive Care Program was initiated in 1999 to provide support for cancer patients, addressing the need for improved physical and emotional well-being and quality of life. This paper is a program evaluation report.

PATIENTS AND METHODS

The number of patient visits grew from 421 in 1999 to 6319 in 2002. This paper describes the utilization of the SCSCP program as assessed by 398 patient visit evaluations during a 9-week period, January 2002 to March 2002. During this time we collected attendance records with demographic data and anonymous questionnaires evaluating each program. Patients were asked to evaluate how the program helped them regarding increase of energy, reduction in stress, restful sleep, pain reduction, sense of hopefulness, and empowerment.

MAIN RESULTS

Over 90% of the patients using the SCSCP felt there was benefit to the program. Programs were chosen based on a needs assessment by oncologists, nurse managers, social workers, and patients. Massage, yoga, and qigong classes had the highest number of participants. Qualitative data showed benefit for each program offered.

CONCLUSIONS

This evaluation of a free cancer supportive care program initiated in a hospital outpatient setting provides initial evidence of patient satisfaction and improvement in quality of life.

Prognostic significance of psychosocial factors in African-American and white breast cancer patients: a population-based study

BACKGROUND

It has been suggested that psychosocial factors, such as coping and emotional support, influence cancer survival, but results have been inconclusive. Given the scarce data from racially/ethnically diverse populations, the authors investigated the prognostic significance of selected psychosocial variables in a cohort of African-American women and white women with breast cancer.

METHODS

The authors examined the effects of coping styles, perceived emotional support, fatalism, and health locus of control on survival for a population-based cohort of 145 African-American women and 177 white women who were diagnosed with breast cancer in Connecticut between January 1987 and March 1989 and were followed for survival for approximately 10 years. Cox proportional hazards models were adjusted for sociodemographic factors, biomedical factors (American Joint Committee on Cancer stage at diagnosis, histologic grade, comorbidity, obesity, menopausal status, and treatment), and lifestyle factors.

RESULTS

Fully adjusted models showed that lower perceived emotional support (disagreeing with the statement, "cancer is a topic I can talk about freely with my friends/relatives") at diagnosis was associated with a higher risk of death from any cause (hazard ratio, 1.39; 95% confidence interval, 1.09-1.79). Adjustment for additional tumor characteristics (nuclear grade, estrogen and progesterone receptor status) and genetic alterations (p53, HER-2) did not alter the findings. No other psychosocial factors significantly predicted survival in patients with breast cancer.

CONCLUSIONS

Higher levels of perceived emotional support showed a moderate but significant association with increased survival in African-American and white women with breast cancer who were followed for 10 years after diagnosis when adjusting for known prognostic factors. Survival was not related to coping styles, fatalism, or health locus of control.

Depression and cancer: mechanisms and disease progression

Depression and cancer commonly co-occur. The prevalence of depression among cancer patients increases with disease severity and symptoms such as pain and fatigue. The literature on depression as a predictor of cancer incidence is mixed, although chronic and severe depression may be associated with elevated cancer risk. There is divided but stronger evidence that depression predicts cancer progression and mortality, although disentangling the deleterious effects of disease progression on mood complicates this research, as does the fact that some symptoms of cancer and its treatment mimic depression. There is evidence that providing psychosocial support reduces depression, anxiety, and pain, and may increase survival time with cancer, although studies in this latter area are also divided. Psychophysiological mechanisms linking depression and cancer progression include dysregulation of the hypothalamic-pituitary-adrenal axis, especially diurnal variation in cortisol and melatonin. Depression also affects components of immune function that may affect cancer surveillance. Thus, there is evidence of a bidirectional relationship between cancer and depression, offering new opportunities for therapeutic intervention.

Psychological distress and cancer survival: a follow-up 10 years after diagnosis

OBJECTIVE

This study tested the predictive role of psychological distress in cancer survival, while attempting to overcome several important methodological and statistical limitations that have clouded the issue.

METHODS

Measures collected on a range of emotional and cognitive factors in the early postdiagnostic period and at 4-month intervals up to 15 months after diagnosis were used to predict survival time up to 10 years among 205 cancer patients heterogeneous in disease site, status, and progression.

RESULTS

With the use of both baseline and repeated measures, depressive symptomology was the most consistent psychological predictor of shortened survival time, after controlling for several known demographic and medical risk factors.

CONCLUSIONS

Given the importance of depressive symptoms to cancer survival, discussion focuses on the possible mechanisms mediating this relationship, the importance of psychological screening of cancer patients, and need for further research.

Cancer survival in parents who lost a child: a nationwide study in Denmark

Psychological stress has been suggested to shorten cancer survival, but few studies have examined the effect of parental bereavement, and the results have been inconsistent. We identified all 21 062 parents who lost a child in Denmark from 1980 to 1996 and among them, 1630 parents with subsequent incident cancer formed the exposed cohort. We recruited 6237 incident cancer patients from a group of 293 745 randomly selected unexposed parents matched on family structure at the same time as the bereaved parents. All incident cancers in the two cohorts were followed to the end of 1997, or until they died. Cox proportional-hazards regression models were used to evaluate the hazard ratio (HR) of dying in exposed parents with cancer. The overall HR of dying from an incident cancer in exposed parents was 1.23 (95% confidence interval 1.03-1.47) compared to parents with cancer who did not lose a child. The HRs were nearly identical to those in the unexposed parents for site-specific cancers like lung cancer, breast cancer, and other groups of cancers like cancers in all digestive organs, smoking-related cancers, alcohol-related cancers, hormone-related cancers, virus/immune-related cancers, and lymphatic/haematopoietic cancers. Death of a child is not a strong prognostic factor for cancer survival among parents diagnosed with cancer after the bereavement. However, a small impairment in overall cancer survival cannot be ruled out.

Controversies in cancer and the mind: effects of psychosocial support

In the last decades of the twentieth century, interest in effects of consciousness on health and illness generated several lines of investigation into effects on cancer. Animal studies showed sensitivity of some cancers to hormonal and stressful influences. However, those findings did not translate into effects on humans, nor did they lead to advances in understanding of human cancer. The proposal that emotional state or stress, mediated through psycho-neuro-immunologic mechanisms would affect cancer generation or growth, resulted in conflicting information. Major surveys found no relationship. The proposal of a cancer personality (Type C) also was not confirmed. Initial observations that depression and stress affected human cancer seem to have best been explained by misinterpretations of cause and effect. By the mid 1990s, a remaining thesis--effect of psychosocial support on longevity and the course of cancer--was yet to be resolved. Initial positive results, especially findings in two popularly quoted studies, were not confirmed; they seem to have been due to inadequate numbers (chance) or to artifacts in study design or implementation. Psychosocial support may result in better adjustment and quality of life, but it does not directly affect the evolution of human cancer.

Comorbidity of depression with other medical diseases in the elderly

A major factor in the context of evaluating depression in the elderly is the role of medical problems. With aging there is a rapid increase in the prevalence of a number of medical disorders, including cancer, heart disease, Parkinson's disease, Alzheimer's disease, stroke, and arthritis. In this article, we hope to bring clarity to the definition of comorbidity and then discuss a number of medical disorders as they relate to depression. We evaluate medical comorbidity as a risk factor for depression as well as the converse, that is, depression as a risk factor for medical illness. Most of the disorders that we focus on occur in the elderly, with the exception of HIV infection. This review focuses exclusively on unipolar disorder. The review summarizes the current state of the art and also makes recommendations for future directions.

The changing face of cancer survivorship

OBJECTIVES

To provide a review of who is surviving cancer diagnosed within the last 20 years and key areas for research development related to cancer survivorship.

DATA SOURCES

Articles, studies, and Surveillance, Epidemiology and End Results statistics.

CONCLUSIONS

The information we have on today's survivors must be periodically revisited and revised to equip cancer patients with the knowledge and tools they need to master the new realities of their survivorship.

IMPLICATIONS FOR NURSING PRACTICE

With the increasing numbers of individuals being cured of or living long periods of time following a diagnosis of cancer, oncology nurses who work with cancer survivors must maintain their knowledge of the issues and practices critical to the well-being of the patient.

Effects of social housing condition on chemotherapeutic efficacy in a Shionogi carcinoma (SC115) mouse tumor model: influences of temporal factors, tumor size, and tumor growth rate

OBJECTIVE

The objective of this study was to investigate 1) whether social housing condition, tumor size, and tumor growth rate alter responses to chemotherapy and 2) whether the timing of tumor cell injection or chemotherapy initiation (relative to housing condition formation) influences tumor growth rate or the efficacy of chemotherapy.

METHODS

Mice were reared individually (I) or in groups (G). In experiment 1, mice were rehoused (IG or GI) or left in group housing (GG) immediately after tumor cell injection. In experiment 2, housing conditions (II, IG, GG, or GI) were formed when tumors weighed 1 g. Chemotherapy (adriamycin 4 mg/kg and cyclophosphamide 61.5 mg/kg IP) and exposure to acute novelty stress (15 min/d, 5 d/wk) were initiated 1 day after housing condition formation.

RESULTS

If chemotherapy was initiated when the tumor burden was undetectable (experiment 1), housing condition did not alter tumor response to chemotherapy, although IG mice lost the most weight and overall had the lowest probability of survival. If chemotherapy was initiated when tumors weighed 1 g (experiment 2), both tumor and host responses to chemotherapy were poorest for IG mice. Timing of tumor cell injection relative to housing condition formation also differentially influenced the rate of tumor growth in mice treated with the drug vehicle; in experiment 1, tumor growth rate was faster in GI and GG mice than in IG mice, whereas in experiment 2, the rate of tumor growth was faster in II mice than in GG and IG mice.

CONCLUSIONS

Altering the temporal relationships among social housing condition formation, tumor cell injection, and chemotherapy initiation differentially influences the rate of tumor growth and the efficacy of chemotherapy. Effects of housing condition are independent of tumor growth rate at chemotherapy initiation and, in terms of host responses, independent of tumor burden.